2024-04-22: We interrupt this Devil Fish program to bring you an important update: 

Most people, without substantial (0.125mg 5000IU/day for 70kg bodyweight) vitamin D3 supplementation, have far too little circulating 25-hydroxyvitamin D for their immune systems to work properly.

Most doctors think that 20 ng/ml (50 nmol/L) or perhaps 30 ng/mL (75 nmol/L) is sufficient for general health - but these levels are based on the needs of the kidney for regulating calcium/bone metabolism, not on the needs of the immune system.  The immune system needs at least  50 ng/ml (125 nmol/L) to function properly.

For the most pertinent research on vitamin D and the immune system, please see:

This begins with recommendations from New Jersey based Professor of Medicine, Sunil Wimalawansa on how much vitamin D3 to supplement, on average, per day, to attain this without the need for blood tests or medical monitoring.  His recommendations are as ratios of body weight, with higher ratios for those suffering from obesity.

For 70 kg (154 lb) adults, 0.125 mg (5000 IU) a day is a good amount.   Governments only recommend 0.015 to 0.02 mg (600 to 800 IU) a day.

See also my Substack:

Returning you now to normal Devil Fish programming:

Real World Interfaces logo

Devil Fish modifications for the Roland TB-303 - and in the future, the TT-303 (Mk 1) and RE-303
Photos, pricing and shipping information, links to other sites etc.

Devil Fish User Manual.  Versions 5.0 and 5.1 include a 3.5mm headphone socket and a low voltage dropout system to protect the C-cell batteries from being completely discharged if the machine is accidentally left running from these batteries for several days.  The three toggle switches of 5.0 / 5.1 Devil Fishes look the same as those of earlier versions, but are of a different type with a more definite 3 position feel.  They should retain this feel for decades, whereas the three positions of the previous switches tended to become less definite with a few years use.
Battery arrangements for retaining memory data in the Devil Fish. 
Instead of the cylindrical, soldered-in, non-rechargeable lithium battery we used until late 2016, TB-303 Devil Fish memory data is now retained with a  user-changeable 2032 non-rechargeable lithium coin cell.  These should last for at least ten years and can be easily replaced by removing the back panel.  The system also includes a large capacitor to keep memory data alive for several days in the absence of power, C-cell batteries or the lithium battery.
Manual for the MIDI In System V1.0.4.
Manual for the MIDI In and Out System with Dynamic Bank and/or Channel Switching.
The MIDI In and Out system has numerous capabilities, including the ability to operate as a CV to MIDI converter.  Dynamic Channel Switching involves switching the Devil Fish synthesizer and MIDI Out between the notes received on four contiguous MIDI In channels, according to MIDI commands, toggle switch movements and two Audio or CV inputs.
Manual for the MIDI In System V1.0.0 to V1.0.3.  This includes descriptions of and workarounds for two bugs: MIDI In notes are played 1 semitone higher than they should be and invalid data may be written to the non-volatile memory which stores the settings for the MIDI In system.
Manual for the 32 Bank Memory System.
Manual for the 32 Bank Memory System with Dynamic Bank Switching (DBS) or Dynamic Bank/Channel Switching (DBCS, with the MIDI In and Out system). 
midi-options/ This covers the Devil Fish MIDI In system and the Devil Fish MIDI In and Out system.  The Sonic Potions MIDI In and Out CPU replacement system is another possibility. 
sounds/ Sound samples. 
Photos of Devil Fishes.
videos/ Videos of Devil Fishes in action.
ECO/ Engineering Change Orders - technician-installable hardware changes to solve problems with Devil Fishes which we discovered after shipping the machines to their owners.  Also, in some cases, workarounds to get around these problems without hardware changes. 
TT-303/ Information on the Cyclone Analogic TT-303 Bass Bot.
Please do not press down on the six small knobs of the Bass Bot while turning them! 
This can cause the pot's rotor to cut through the conductive tracks.  The same is true of the TB-303's original pots.
prices-au/  prices-int/
Prices for customers in Australia and overseas.
../tr-606/  ../tr-808/  ../tr-909/
TR-606, TR-808 and TR-909 modifications. 
32 Megabyte memory boards for Akai samplers.

© Robin and Tina Whittle, Real World Interfaces, Daylesford, Victoria, Australia  22nd April 2024
ABN 29 836 876 922 rw@firstpr.com.au  

The TB-303 is a product of the Roland Corporation, from the early 1980s.  The first Devil Fish mods were in
1993.  The first V2.0 versions, on which the current modifications are based, were in 1996.

To the Real World Interfaces page. To the main First Principles site.

Devil Fishes are extremely valuable - too valuable to send via Australia Post.  Please see: ../freight-insurance

Latest news

22nd April 2024

We are catching up with electronic work, after I spent so much time raising awareness of the need for proper vitamin D3 supplementation, since March 2020.

I recently worked on a TB-303 which will be offered for sale by Melbourne Music Centre.  This would be well suited to the Devil Fish mods.  Please see:

SoundToParts.com in France, which is closely associated with Cyclone Analogic, has a small number of new old stock Bass Bot TT-303 version 1 machines for sale.   We will be able to modify these for the basic Devil Fish mods, but not for 32 banks of memory, and probably not for the Devil Fish MIDI In or MIDI In and Out systems.  

I am completing Devil Fish mods for an RE-303: https://shop.re-303.com which is in a TR-606 case.  Electronically, this is the same as working on a Roland TB-303.   However:
  • The widely used aluminium cases cannot be used with the Devil Fish mods. 

    At present the only option, apart from a Roland TB-303 case,  is a TR-606 with a newly manufactured aluminium switch plate, which are available from Michigan Synth Works and perhaps one other company. 

    In the longer term future - ideally in 2025 - we should be able to fabricate suitable cases from ABS sheet.  There is a lot of work to do, mainly regarding CNC milling, but also spray painting and screen printing, to achieve this.   Such fabricated cases could also be used for TB-303s, but not for  TT-303s, which have surface mount three colour LEDs, rather then 3mm LEDs which fit holes in the switch plate.

  • The Sync socket needs a dual pole, normally closed, switch.   Based on other people's work, I have developed a 3D printed solution for this.  At some stage I will make the design and STL files freely available and offer switched socket sub-assemblies for sale.

  • There are three options for the CPU in an RE-303 (actually, it is a microcontroller):

    • A TB-303 CPU, in which case the Devil Fish memory and MIDI mods are also applicable.

    • A Sonic Potions CPU.  This has no MIDI In control of Filter Frequency, while the Devil Fish MIDI In and MIDI In and Out systems do.  It may be possible to install these Devil Fish systems with the Sonic Potions CPU.   It is not possible to install the 32 bank memory system, since the Sonic Potions CPU uses is own internal storage rather than the three 1k x 4 bit static RAM chips the original TB-303 CPU uses.

    • A Pixie based emulation of the original CPU.  This is a remarkable system in which a 32 bit ARM CPU emulates the 4 bit NEC microcontroller and runs a modified version of the original CPU's firmware.   This firmware has been modified not to use the three memory chips and to provide MIDI In and Out facilities, also without MIDI In control of Filter frequency. 

      If I were able to obtain the original firmware, it should be possible to install the 32 bank memory system with a Pixie CPU.  This would not have MIDI.  With this or with the modified firmware it should be possible to install the Devil Fish MIDI In or MIDI In and Out systems.

31th May 2022

We were considering modifying the Behringer TD-3 but decided against it. 

The Devil Fish mods are applicable to the RE-303  http://re-303.com . There should be no electronic problems modifying them since the circuit board design is based directly on that of the TB-303.  The 32 Bank Memory system and the Devil Fish MIDI In and MIDI In and Out systems are only applicable to machines with an original TB-303 CPU.  We have not yet had an RE-303 in the workshop.

Unfortunately the aluminium cases for the RE-303 seem to be unsuitable for the Devil Fish mods.  We plan to fabricate our own cases, from ABS sheet. but this is a project for the future, once we are up to speed working on TT-303s.

When doing the Devil Fish mods for the two MIDI enabled machines mentioned above: the TT-303 V1 and the RE-303 with its Sonic Potions CPU replacement we will include a microcontroller to receive a MIDI In control change to drive the Filter frequency.  The default controller will be Mod Wheel.  It may be difficult to provide controls to alter this.  Can anyone imagine a situation in which they really need the Filter frequency control to be on some other controller number?

5 February 2020:

A customer sent us a screenshot from Behringer's Facebook page with a CAD-generated image (not a photo of an actual object) of a "TD-3-DF"  which resembles a TD-3 with all the Devil Fish controls, inputs and outputs, in a brooding, dark colour scheme.  Sure enough, we found this on the abovementioned page.  The screenshot is here.

You can read our response to this posting, and the background to it, in a separate page behringer-unauthorised/ .  We updated this when Behringer went into production with the TD-3-MO.  Apart from the sub-oscillator, this is a direct unauthorised copy of the Devil Fish circuitry - though I have not seen one, so they may not have included the ECO updates.  They mis-attribute the design to "third party mods" as if these were floating around, as many instructions for modifications are.  They were too dim to provide MIDI control of filter frequency.

Our dispute is with Behringer management, not those who purchase these machines.

18 December 2018: The Quicksilver 303 CPU replacement system, with MIDI In and Out, is no longer available.  I will try a Sonic Potions CPU replacement system ( https://www.sonic-potions.com/re303 ) which also has MIDI In and Out.  This can't provide Filter Frequency control (as is done by the Devil Fish MIDI In and MIDI In and Out systems, and which the Quicksilver 303 system also provided) and there is little prospect of it doing so in the future since there are no pins available for the requisite PWM signal.

Roland's TB-03 does not use analogue circuitry.  Instead of the transistors and integrated circuits which produce voltages for audio and control, with the filter being done by transistors (operating as diodes) as the vertical segments of a ladder, with capacitors as the rungs, all the sound generation and control is done with digital calculations.  This is no-doubt a good, reliable, compact and cost-effective way of producing sound, but it is not at all amenable to modifications such as the Devil Fish.

7 February 2016: I have added an ECO directory, as mentioned above, for technician-installable hardware changes to correct problems in Devil Fishes which we discovered after sending the machines to customers.  Devil Fish owners: please take a look at this page to see which of these problems may apply to your machine.

15th September 2014: I have completed the MIDI In and Out system, with its Dynamic Bank and Channel Switching capabilities.  See the Devil Fish MIDI In and Out Manual (the link is above) for the full documentation of these.

One of three modes of MIDI Out operation is automatically selected:
Int Seq mode  Note pitches result from the Internal Sequencer when it is playing a pattern, in Pattern Write, Pattern Play, Track Write or Track Play modes.
Ext CV mode  Note pitches result from measuring the voltage of an externally applied Pitch CV, plugged into the CV In socket – or, if no lead is plugged into this socket, by measuring the internally generated CV (from the TB-303’s 6 bit DAC) which results from the Internal Sequencer playing notes during Pattern Write mode when it is not playing the pattern.  This is when the user is entering and altering pitch, timing, Accent and Slide information.
MIDI In Follow mode  When the MIDI In system has reception of Notes and Control Changes ON (hold TAP and press and release BACK), the MIDI Out system replicates via MIDI Out Note On and Off messages the notes the MIDI In system is playing on the Devil Fish.  This includes the way notes are generated with Dynamic Channel Switching.

For full functional details of these modes, please see the MIDI Out further explanation section of the user manual.

Here is a description of the the 32 Bank Memory system and how it can work with the MIDI In and Out system and two signal inputs which detect in an on/off fashion CV voltages or an audio signals.

For the TB-303 Devil Fish (with or without the MIDI In and Out system or the MIDI In system), for the TR-606 and for the TR-808, Dynamic Bank Switching (DBS) enables two external Audio/CV signals (or potentially four for the TR-808) to alter the currently selected memory bank, instantaneously.  This is done by detecting the signal exceeds about +1.15 volts, and using this to invert one of the five address bits which select which of the 32 memory banks is currently accessible to the Internal Sequencer.

You can hear DBS in action with both the Devil Fish TB-303 and a TR-606 in Lincoln Webber's late 2015 video: https://youtu.be/FV9g7xBsPYA .  An earlier video, mentioned below, https://youtu.be/grjqTnyf8Ss shows how it works with the Devil Fish.

The following description concerns memory bank switching, but the same two inputs, detector circuits and switches can also be part of Dynamic (MIDI In) Channel Switching, in Devil Fishes with the MIDI In and Out system.

The primary purpose of this is to enable switching between patterns, moment-by-moment, in response to manipulation of the toggle-switches and pushbutton and in response to external audio or CV signals.  Since the Internal Sequencer reads from memory every time it plays a note, this means that notes from patterns in various memory banks can be played in the middle of patterns.

The manual for this is above: #MEMDBSMAN .  The only visible parts of this are two 3.5mm sockets on the left of the machine, and two LEDs, which, when on, indicate that the detector circuit has been activated and that the address bit from the corresponding toggle-switch will be inverted before it is used to select one of the 32 memory banks.

Devil Fish mods for the TB-303: 32 Bank Memory address bit inversion with Audio or CV input

Here is a description of Dynamic Bank Switching (DBS) for the TB-303 Devil Fish, which involves just the switches, input sockets and LEDs - not the MIDI functions.  The same capabilities will be possible for the TR-606 and in 2 and 4 channel versions for the TR-808. 

The DBS hardware for consists of two 3.5mm audio or CV input sockets on the left of the machine.  Whenever the audio or CV input signal becomes more positive than +1.15 volts (which high level audio signals will exceed in the positive part of their waveforms), the circuit turns on.  The circuit remains on for about 33 milliseconds after the input signal goes below the +1.15 volt threshold.  So  audio signals of 30Hz and higher (and somewhat lower, depending on the waveform) will produce a continual On state as long as part of their waveform exceeds about +1.15 volts.  The inputs can handle -15 to +15 volts.

When the detector circuit is On, its Red LED is On and the address bit which is generated by the associated toggle-switch is inverted.   If the detector circuit is Off, everything is as per normal:  The low and high positions of the toggle-switch produce 0 and 1 respectively for the address bit.  This is one of the 5 bits which selects one of 32 (2 x 2 x 2 x 2 x 2 = 25) memory banks, numbered 0 to 31.  When the detector circuit (and so the LED) is On, the low and high switch positions produce 1 and 0 respectively, thereby selecting a different memory bank than when the circuit is Off.

Each of these sockets, detector circuits and LEDs is like an audio or CV controlled version of the Red pushbutton switch of the 32 Bank Memory system.  That pushbutton inverts the address bit produced by toggle-switch 4.  The two new inputs invert the address bit produced by toggle-switches 3 and 2.

This means audio or CV signals can switch the Internal Sequencer from playing a pattern in a particular bank of memory to playing the same pattern number in some other bank of memory whose 5 bit address differs in one bit.  Since the Internal Sequencer looks into memory for each note it plays, this means that the notes it plays, with Accent and Slide, can chop and change between those from patterns in multiple banks of memory, in the middle of a pattern.  The Devil Fish synthesizer and, if it is installed, the Devil Fish MIDI In and Out system and its one more slave devices, will play this set of notes.

Lincoln Webber has has posted an annotated demo of using this Dynamic Bank Switching (DBS) system:

In this demo he is using as inputs a CV from an LFO and the Accent CV out of the Devil Fish itself.  He is not using audio signals as inputs or driving a slave device from MIDI Out.  In this configuration, the Accent signal is coming from him pressing the Accent Button or from any Accents which may be programmed into the pattern. 

A simple and elegant approach is to alternate between two patterns with an LFO which is running with a cycle just a little slower or faster than the pattern time itself.  Lincoln is doing this with one of the signals.

Since there are two channels, there are four patterns which can be selected by the four combinations of the two input signal states.  One or both input channels could be MIDI controlled by driving any MIDI synthesizer with Note On and Off events and using its audio signal, perhaps through an amplifier if its positive peaks do not already exceed about +1.15 volts.   With the MIDI In and Out system, if nothing is plugged into an input socket, the output of the socket (the input to the detector circuit) can be driven by a signal derived from MIDI In: Note and/or Control Change messages received on Channel 15 or 16.

Other sources of signal to drive these inputs include: CV or audio from modular gear; talking into a microphone, the signal of which is amplified to a suitable level, and: using some audio, including from the Devil Fish or a slave instrument and delaying it.   Also, using a brief audio signal into one input and a delayed version it into the other.  Then a pulse of audio will take the memory system through four memory banks:

Pulse -   invert A2:  0000001111110000000000000001111111100000
Delayed - invert A3:  000

Bank number: 0 0
0000 ------         ------------           --
0 0100       ---                  ---
0 1000             ---                    ---
            12 0 1100          ---                  -----
   Address bit 4 3210
                      Time ------------>

The above timing chart is for all switches being down, with the pushbutton not activated.  At any time these can be activated, and in the case of switches 2 and 3, this would invert the bits shown above, thereby selecting different banks.

I was prompted to devise this modification by discussions with Ricardo Velarde and Lincoln Webber.  Lincoln has some other Devil Fish videos here.

Here is some more information about the MIDI Out functions of the  MIDI In and Out system.

In MIDI In Follow mode the Accent Button and/or the Accent CV In socket adds Accent to MIDI Out notes where these are generated from MIDI In notes without Accent.  This replicates the behavior of the Devil Fish synthesizer by ignoring the Accent state of the Internal Sequencer, which might be on due to the sequencer having stopped on an accented note.  I have also added:
  • Automatic turnoff of Run/Stop drive to the TB-303 due to MIDI In Sync reception, if while this Run/Stop being on, there are no MIDI In Clock bytes for 1.5 seconds.  This can be disabled.

  • The ability to turn on and off the reception of MIDI notes and most Control Changes, as with previous versions of the MIDI In system (but without halting the reception of MIDI In Sync), with the ability to allow the reception of Filter Frequency Control Changes at all times.  This enables turning MIDI In note and Control Change reception on and off (with two differently timed combinations of pressing the Back and Tap buttons) while the Internal Sequencer is running, so alternating between external (MIDI In) and Internal Sequencer control, while patterns are playing while still allowing external control of the Filter Frequency.

  • Stronger drive from the Accent CV Out so it can drive the Slide In CV socket sufficiently to turn on both Slide and Gate.

  • Suppression of capacitive coupling in 5 conductor MIDI cables from the MIDI signal wires to the DIN Sync Run/Stop and Clock wires.

  • Hardware reset of the Internal Sequencer's Accent flip-flop at power on to prevent the occasional problem of notes being played with Accent on when CV and Gate inputs are used.

Devil Fish modification for the Roland TB-303

From Frankfurt am Main:
Today I passed it over to the band.  They went mad.  Immediately they 
locked the studio and started to build sounds. Nobody can stop them now.
They are very happy and they say thank you thousand times!

to Moscow:
I want to let you know I am successfully exploring what the Devil Fish
has to offer. And it IS overwhelming... I've owned plenty of
synthesizers before but... I've never imagined a "relatively simple"
synth such as my Teebee will transmute into such a miracle.

Also, I've noted that the Devil Fish is very capable of creating clicky
sounds with low decay values. They can be very useful for percussion
and other things. What's more, the resonance and muffler settings can
get relatively thin sounds, this feature can be utilized to fit more of
the Devil Fish "juice" into the mix. More tracks, more layers, more

I begin realize that it's, in fact, possible to create a lot of
layeristic stuff - create entire soundscapes using only the Devil Fish
and outboard effects.

at a gardener's residence on a Queensland resort island:
Oh by the way you probably know this....  You can change MIDI modes and 
reset while machine is running so you can turn off/on MIDI reception
during a track, its really neat I use it a lot, as well as running the
Accent Out to an attenuator(Moogerfooger CV processor) and out back into
the Devil Fish Slide In and I can Turn the Att. up and down to turn on
Slide/Gate etc...thats fun also the CV processor has a Square/Triangle
L.F.O which I often use for the CV filter in for rhythmic filter sweeps
and other crazy fast bell like effects when turned up full and I love
using the mod wheel to filter it means I do real dramatic filter stuff
without killing the D.F.'s Cutoff knob and also be able to freak it out
and return to the exact same sound setting.....Endless...........
Sound samples are at: sounds/linxstar/ .  Seven years later (2013), from and undisclosed location in the Dandenong Ranges, with
occasional transmissions via YouTube, and soundcloud.com/linxstar/ Linx writes:
I have at the moment (even as I'm writing this) a convoluted modular 
patching arrangement between the Devil Fish and three Moogerfoogers -
CP251 control processor (receiving and sending CV to/from-the Devil
Fish, MF-101 lowpass filter, MF104z delay (which is receiving the audio
out of the Devil Fish and is in a feedback loop, using the delay signal
only to the lowpass which in turn is sent to the DF audio in to filter.
The CP251 is also sending noise to the FM in (there is only the slide
in and accent in not being used). The DF CV out is controlling the
feedback on the Delay. The Accent out is used to trigger the sample &
hold unit in the CP251 and the Gate out is modulating the env amount on
the lowpass. Its creating a percussive acidy snarey rhythmically
changing delay with a twist. I'll record this tomorrow, I probably
should have today as at one point when I stopped the sequencer the CP's
LFO and S&H kept triggering the DF and MF's and it was quite
interesting how it all evolved.
and in many other countries, musicians have placed themselves in the care of the Devil Fish.

Devil Fish modified TB-303


The Devil Fish is a modification to the TB-303 - a synthesizer/sequencer produced by Roland in 1981/82, which has played a crucial role in the development of electronic dance music. A detailed description of the Devil Fish can be found in the User Manual Devil-Fish-Manual.pdf .  Features include:
  • CV and Gate inputs.
  • CV input to turn on Slide.  (2.3 volts turns on the Slide circuit and > 4 volts turns on Gate to tie notes together.)
  • CV input for Accent.
  • CV input for Filter Frequency.
  • Output for Accent.
  • Audio In to Filter. *
  • Audio In to frequency modulate the filter. *
  • Audio Out from filter (pre-VCA). *
  • Overdrive pot to control the level of oscillator going to the filter: zero to 66.6 times normal level.
  • Separate control of Main Envelope Generator times in accented and non-accented notes.
  • Volume envelope is no longer fixed, and can be varied from 16 msec through 3 seconds and to no decay at all, i.e. for notes which last indefinitely.
  • Soft Attack control gives attack times between 0.3 and 30 msec. (TB-303 attack was ~3 msec.)
  • Slide time is variable to five times longer than normal.
  • Variable Filter Tracking causes the oscillator CV to control the filter frequency.
  • Internal Filter FM: a unique approach of AC coupled Filter FM from the audio output of the VCA.
  • The Muffler is a unique post-VCA soft-clip distortion circuit which retains bass response.
  • Push-button to manually activate Accent.
  • Filter can be switched to self resonance.
  • Accent Sweep has three modes and can be disabled.
  • Filter Cut Off pot range doubled to 5 kHz max, and widened to include much lower frequencies.
  • Env Mod pot range extended to include zero and go as high as three times the normal maximum.
  • Bass response is improved.
  • There are new battery arrangements in 2015 for retaining memory data, which do not involve us sending Devil Fishes containing lithium batteries by air-freight.  See the DF-Memory-Backup.pdf manual for further details: #DFMB.  The C-cell batteries provide backup power to the memory system, and a new under-voltage protection circuit ensures that these will not be flattened if the machine is accidentally left running from these batteries for a long time.  A large capacitor enables the machine to retain memory contents for a longer period than usual without these C-cell batteries and without being run from an external power supply.  There is an internal holder for a 2032 20mm x 3.2mm coin/button cell lithium battery, which can be accessed by removing the bottom part of the case  (photo). Overseas customers can install a 2032 battery in this, after which there is no need for C-cell batteries other than for operating the machine.  When we ship Devil Fishes to Australian customers, by road, we install the 2032 battery.  The 2032 battery should last for ten or more years.
  • The six TB-303 knobs Tuning to Accent are mounted 1.5mm higher, making them easier to turn.  More details: knob-heights/ .
  • The Devil Fish can still sound like a TB-303.  See page 7 of:  Devil-Fish-Manual.pdf .

  • The original Headphone signal is now available on a 3.5mm socket mounted between and above the Power and Audio Output sockets.
*  These three audio signals are connected in the following manner:

The Audio In to Filter signal is plugged into the old 6.5mm mono Mix In socket, on the left of the rear panel.  There is an option (see below) for a three position toggle-switch to control this signal.

The Audio In to Frequency Modulate the Filter signal is plugged into the old Headphone socket, with the tip of the socket accepting this signal.  This means a mono 6.5mm plug can be used for this function.

The Audio Out from Filter signal is driven to the ring of the old Headphone socket.  There it can be accessed with a suitable stereo plug, or by partially inserting a 6.5mm mono plug.

To make it easy to use the Audio In to Frequency Modulate the Filter and the Audio Out from Filter, the Devil Fish is supplied with a special lead with a 6.5mm stereo socket and two 6.5mm mono plugs on a Y-lead.

Devil Fish photo by Ken Knezick www.islandream.com
"Devil Fish", Lembeh Strait, Bunaken, Indonesia. © Ken Knezick.
Great photos: 


Dynamic Bank Switching or Dynamic Bank / Channel Switching

The optional 32 bank memory system enables switching between banks while a pattern is playing. So the sequencer reads the next note from the same pattern number in the new bank.  This enables much more interesting and unexpected results than are obtainable by having the sequence change from one pattern to another, which it only does at the end of each pattern. 

Full details: DF-32-Bank-Mem-Manual.pdf .

There is a second version of the 32 Bank Memory System manual which covers Dynamic Bank Switching (DBS if there is no MIDI In and Out system) or Dynamic Bank and  MIDI In Channel Switching (DBCS), if the MIDI In and Out system is installed:  DF-32-Bank-Mem-DBS-Manual.pdf .   The DBS/DBCS versions of the 32 Bank Memory System can be fitted with an optional Disable Switch, which enables or disables the detectors of the two approximately +1.15 volt Audio/CV input sockets.  This switch is normally mounted to the right of the Tempo knob.
Detector circuits and their LEDs and address bit inversion circuits are enabled.
They are disabled.
They are enabled, but this is a momentary position, with spring return to Mid position

Sync lead for Devil Fish with MIDI In

The optional MIDI In and MIDI In and Out systems use the existing Sync socket, and receive Sync, Notes, Accent (depending on the note's velocity), Slide (from MIDI controllers or tied notes) and Filter Frequency (from a selectable MIDI controller number, defaulting to Mod Wheel).  Full details: Devil-Fish-MIDI-Manual.pdf 

There is also a special Sync Lead which accepts MIDI In, and provides a daisy-chain of three Sync out connectors to drive, for instance, devices such as other TB-303s or Devil Fishes, TR-808s or TR-606s.  See the sync-lead/ page. 
New LEDs of various colours for the Devil Fish modified TB-303 New LEDs in Red, Orange, Yellow, Green, Blue and White: leds/

We suggest all Blue LEDs, except for the Run/Stop LED, in which we install a new Red LED.  These are a broader blue spectrum than most blue LEDs, with more violet a somewhat different colour than the slightly aqua color of most blue LEDs. They are also a good brightness, whereas the ordinary blue LEDs are too bright unless the drive circuits are adjusted.

Parts for TB-303 Devil fish - Pots from Technology Transplant and Omron sealed tact switches
Replacing pots and switches.  The tact switches underneath the 24 buttons almost always need replacing.  We install Omron B3W-4050 sealed tact switches.  These are sealed against dust and liquids and we expect they will last for many decades.  More information about the Omron switches and why we chose them over the alternatives: tact-switches/  (We sell these specially modified Omron switches for people who want to replace the switches themselves:  #tact_switch_kits .)

The six small pots along the top of the TB-303 sometimes fail.  Between about 2004 and 2012 we replaced them with newly manufactured pots from Technology Transplant (this company ceased operations in 2015/16) and since 2013 we have been using pots identical to those in the Cyclone Analogic TT-303 Bass Bot.  I dismantle these pots and replace the original friction grease with a lighter grade silicone grease, so the 6 small knobs are very easy to turn.  I also modify them to reduce side-to-side and up-down movement, which should also prevent the edge of the rotor cutting the conductive tracks if the knob is turned while downwards pressure is applied.  This was the main failure mode of the original ALPS pots.  Nonetheless, please try not to apply downwards pressure on any TB-303 or TR-606 small pots while turning them.

The Tempo and Volume pots rarely fail, but I can replace them.  I usually fix a noisy volume pot by dismantling and cleaning it. The two rotary switches have never failed, in my experience.

I now have a technique for spray painting the parts of the case which are worn around the 6 small pots.  Where the markings and silver paint are worn away, I can spray some silver and by hand colour in new markings. Please see the refurb/ page for more on this.

There is also an option for:

Switch for Audio In to Filter.  In the Devil Fish, the old Mix In socket is used for feeding an external audio signal into the filter, in addition to whatever amount of the Oscillator is selected by the Overdrive pot.  Since this pot can be turned down to zero, it is possible to run the machine without its internal oscillator and have the Filter processing purely an external signal.

With this option, a three position toggle-switch is mounted between the Tempo and Track-Pattern Group knobs.  It has three positions:

Audio In enabled.
Audio In disabled.
Audio In enabled, but spring return to Mid position.

This enables convenient switching of the external signal, including dropping in short bursts of it by pressing the switch to the down position, with the toggle returning to the mid position as soon as the finger pressure is released.

MIDI options; AluCases no longer available


Martin Rothlisberger in Switzerland http://acid.chused to make magnificent Anodized Aluminium cases for the Devil Fish, replacing the ABS silver plastic cases which are now at least 30 years old.  The email address link at that site is incorrect.  Here is the proper email address: 303@acid.ch .   Please see the photos/ directory for images of some AluCase Devil Fishes.

Martin is a DJ and Devil Fish musician himself.  Please see the videos/ directory for him and the Liquid Trolls in action. 

Please see midi-options/  for further information on these MIDI In/Out systems:

The Devil Fish MIDI In and Out system.

The SonicPotions CPU replacement system.

xCover of Our Boys' Tip Top and Our Boys' Gift Book, Renwick of Otley London ~1930s

Click for larger version.

The Devil Fish is the most dynamic, pulsating, wailing musical instrument I know of.  If you and your TB-303 have a sense of adventure, the Devil Fish modifications will propel you into musical territories dark, destructive, delicate, languid, undulating, exquisitely detailed, throbbing, luscious and lurid . . . . .    Best of all, the spaces between these extremes can usually be traversed by judiciously turning a few knobs.
Tina's illustration on the Devil Fish job progress book.

Some of the sound samples

Artist Robin Whittle Uniform Bass Code Charles James Linxstar
Track Melodic pulsations & knobulations acidtrax2-edit cj03 Devil Fish with Mooger- Fooger
Time 1.44 1:06 1:00 2:40
MP3: rw12.mp3 cw-acidtrax2-edit.mp3 cj03.mp3 Linxstar- Devil-Fish- Mooger-Fooger- edit-excerpt.mp3

24 minutes of sound samples are in the sounds/ directory.

Peter in the Netherlands has some MP3s of music he made with his Devil Fish: tek.tekmac.nl  

Common Black Devil Anglerfish Yellow from bioinfo.kordic.re.kr - now gone.
Click for larger version.

Emma Chisit?

(Translation from Strine: "How much is it?"  "Strine" is Strine for "Australian". )

prices-au/  Prices for customers in Australia.

prices-int/  Prices for customers outside Australia.

The basic modification cost includes cleaning the machine and a moderate level of repair work. 

There is no extra charge for removing the Kenton CV socket kit. (The Devil Fish performs all the functions of that kit, except that the Kenton kit automatically deactivates the internal sequencer's accent state, and the Devil Fish Version 2.1D and beyond enable a high Slide input voltage to drive the gate, in order to "tie together" notes which have separate Gate pulses.)

Upgrading to MIDI In or to MIDI In and Out

If you have a Devil Fish version 1.x (1993) 2.x (2006 onwards) or 3.x then I can upgrade the machine to a 4.2 version with MIDI.  It is not possible to install the MIDI In system with these older Devil Fish circuit boards.  This replaces the existing Devil Fish circuit boards, so your machine will have 7 new small black pots with silver lines and three new toggle-switches in the Devil Fish panel, with new CV, Gate etc. sockets at the rear. 

If your machine is one of the few version 4.x machines without MIDI, the upgrade can be done with the existing circuit boards, to MIDI In or to MIDI In and Out.

If you have a 4.x Devil Fish with MIDI In, I will be able to extend this to provide MIDI Out as well.  If it is an earlier version than this, then the Devil Fish boards need to be replaced with current version 5.x boards in order to provide either MIDI In or MIDI In and Out.

Set of tact switches for TB-303 or TR-606

In general, we don't sell spare parts.  Please see the eBay store of Sound-to-Parts in France for many specially manufactured parts for electronic musical instruments, including new battery contacts and battery compartment doors for the TB-303 and TR-606.  Many or perhaps all of these parts were originally made by Technology Transplant.

Before mid-2010, I replaced the tact switches with the original type, ALPS SKHCAA (now known as SKHCBEA010).  These were not sealed against dust.  Dust (mainly flakes of skin . . .) gets into the switch and builds up on the contacts, making the switches operate erratically.  I installed them with a flexible plastic dust guard, which greatly prolonged their life.  Still, after 10 years, some heavily used machines needed their switches replaced again.  There are sealed tact switches from ALPS (SKQEAAA010), but I don't like them since they have a higher activation force, a much lower lower "click force" and a much lower "click displacement".   Please see tact-switches/ for details.

The only alternative is to use Omron B3W-4050 sealed tact switches.  These are pictured above: #pots_switches.  These are slightly firmer than the SKHCAAs, and have about the same initial and click displacements so they have a very good "click" action.  The Omron switches have stems which are a little too wide for the TB-303 / TR-606 buttons, so I modify the stems to make them fit the buttons.  This is done with a 0.6mm Dremel cutting wheel, with two cuts at right-angle through the top part of the stem. 

While we can't guarantee these switches for any particular period, they are very well made and well sealed against dust and liquids.  They are specified to have a life of 3,000,000 operations. Dust seems to be the only thing which makes tact switches erratic, and there's no way dust can get into these Omron switches.

The page 303-mods/ discusses how to obtain the Omron switches and how to to modify them so they fit the TB-303 buttons.  To support people with the task of replacing these switches, but who do not want to modify the switches themselves, we are now selling Omron switches, with their stems modified to suit TB-303 TR-606 buttons.  Each pack contains 25 switches.  The TB-303 needs 24 and the TR-606 needs 21.  Australian customers please email us.  Overseas customers, please use PayPal to send Australian AUD$90 for one pack, or AUD$160 for two, to rw@firstpr.com.au .  We will airmail them to you within a few days, so you should have them within two weeks at most. 

Western Blue Devilfish Paraplesiops meleagris


Shipping and turnaround time

Tina and I aim for a three week turnaround time between you, the customer, sending your TB-303 and receiving it back as a Devil Fish.  However it is best to allow four to six  weeks.   (Note 2022 - have a large backlog of work and have not been taking on new jobs for the last two years.)

Please email us with your requirements and we will reply with the full pricing information, shipping address etc.  I suggest copying and pasting from one of the Prices pages linked to from above: #emma, retaining only those lines in your email which are relevant to your desires.

Please send the TB-303 with a reputable courier company, rather than by the post.  TNT,   DHL, Federal Express and your Post Office's EMS service are all good choices. 

The German Postpak service and a similar service from the Belgian Post Office is not a courier service and should not be used.  Despite assurances about tracking numbers and someone having to sign for delivery, it will be delivered in Australia as an ordinary parcel.  This means it may be left on our doorstep.  Ordinary airmail with the recipient having to sign for the package is not secure enough for an item such as a TB-303.  Post Offices in many countries deliver their packages not through the Post Office of the destination country, but by various transport companies.  Australian truck drivers won't understand instructions in French regarding the recipient signing for the package. 

Please send just the TB-303 no batteries, vinyl carry case, or original styrofoam/cardboard box.  Batteries should only be included if you do not want the 32 banks of memory and you wish to retain the existing memory contents.  Memory contents cannot be retained if the 32 bank system is installed, and I can't absolutely guarantee that patterns will be retained if the memory is not installed, so please write down all important patterns before sending the machine for modification.  The  patch-sheet/ directory has some PDFs to help with this.

The modifications are very reliable and are guaranteed for two years.   The value of a Devil Fish exceeds Australia Post's AUD$5000 limit, so we now ship the machines overseas, and potentially within Australia, using UPS.  See: ../freight-insurance .

Contact details

It is generally best to enquire via email:  rw@firstpr.com.au.  We are located in Daylesford, about 120km north-west of Melbourne: Wikipedia, Google-Maps.

Other information at this site
Sound Samples  These are in the sounds/ directory.  Videos There are an increasing number of YouTube videos depicting Devil Fishes, including some live acideee action by Martin Rothlisberger (Liquid Trolls) who makes the AluCases.  See the videos/ directory.

Patch sheets in PDF, GIF and other formats can be found in the patch-sheet/ directory.  Also in this directory you will find a single page PDF file for conveniently writing down every aspect of a TB-303 pattern.  

Some modifications you can do to the TB-303, including replacement of the push-button switches and some notes on the late-2009 and later Technology Transplant 6 small pots: 303-mods/ .  This file also contains a few maintenance tips of interest to technicians.

I am now able to refurbish the case to a limited degree regarding the silver paint and markings wearing away around the knobs, especially the Resonance and Cutoff knobs.  Please see the refurb/ page for more details.

Comparison of 3 types of tact switches and why we use the Omron sealed tact switches: tact-switches/ .

In December 2010, Ulf Kaiser wrote an article for Keys Magazine: www.keys.de .  Thanks very much to Ine Gundersveen for this translation: Devil-Fish-article-Keys-Magazine-Dec-2010-English-tr.pdf .

The main images from the cheatsheet card which accompanied the TB-303.
  tb-303-card/  This is a mini guide for the TB-303 sequencer's Pattern and Track writing operations.

A short treatise on the exact timing of the Gate, CV and Slide in the TB-303 sequencer: 303-slide.html.

Another treatise looking at the TB-303's Accent Sweep circuit and how humans respond to its pattern of pitch variations in the filter when multiple accented notes follow each other in quick succession: 303-unique.html.

A picture of the excellent 9 volt regulated, 200 mA (milliamp) Boss power adaptor which is (or was - they are no longer produced, see the next paragraph) best for the TB-303, Devil Fish, TR-606 etc.  In Australia, this is called a PSA-240P.  "Regulated" means that its output voltage is always very close to 9 volts irrespective of load current, up to its maximum of 200 mA.   Most ordinary (mains power supply, diodes and capacitor - no regulator - but these are becoming replaced by switch-mode adaptors) power adaptors have unregulated outputs, such that with a light load, they may produce 11 volts or more.   There's no way of telling just by looking at an adaptor what voltage it will actually put out when loaded relatively lightly by a TB-303 / Devil Fish.  If it puts out too high a voltage, then this will cause a power transistor in the TB-303 / Devil Fish to overheat, and perhaps to fail.  This over-voltage problem is more likely to occur with an adaptor which is rated at 9 volts at a high current such as 500 mA.   Since TB-303s are precious devices, the best approach is to buy a 200 mA 9 volt Boss adaptor!  

In 2012, the situation with these adaptors has changed somewhat.  The Boss PSA-240, PSA-120 etc. models, with mains transformers, diodes, capacitors and an internal linear regulator are no longer produced.  In their place are Boss PSA-240S, PSA-120S etc, models.  These are totally different, but which also work well.  They have a compact switch-mode power supply (Wikipedia article) in the adaptor, which produces a well-regulated 9 volts DC.  Switch-mode power supplies can introduce high frequency (such as 40kHz to 100kHz or more) interference into audio systems, and these Boss adaptors have an elaborate double toroid filter in the output cable in an effort to reduce this.

Also pictured is the Boss Metal Zone MT-2 a popular distortion and three band EQ distortion pedal which sounds great with the Devil Fish.   This is Chad and Lincoln's, and we had fun in the usual configuration (passing the Devil Fish signal through the Metal Zone), and by sending the Devil Fish's output into the Metal Zone, with the Metal Zone's output going into the Audio In to Filter of the Devil Fish with the output of the system being the Devil Fish's output, not the Metal Zone's.  This caused filter oscillation right down to low frequencies, irrespective of the setting of the Resonance pot, and we got some great effects where the system would oscillate at both high and low frequencies, and subtle changes in the Devil Fish's pattern (its volume envelope, filter frequency and the pitch of the oscillator) would sometimes perturb the overall system from its normal high frequency mode of oscillation into a totally different low frequency mode.   Feedback, distortion and especially a little delay can give rise to fascinating, complex and sometimes chaotic results.  Lincoln says that Metal Zone aficionados / maniacs sometimes run three of them in series . . . 

A large picture of the TB-303 circuit boards.  The background is a painting by Adriana Hardy, whose paintings are drawings are at the ../../gallery/ section of this web site.

You may be interested in my 1993/94 material on Music Marketing via the Internet, especially with electronic delivery: ../../musicmar/

Links to the sites of kindred spirits

Martin Röthlisberber in Switzerland http://acid.ch custom-makes AluCases for TB-303s and Devil Fishes.  These are machined from solid billets of aluminium.  They are anodized and the engraved lettering hand-painted with epoxy paint.  See #alucase above for more information.

AluCase Devil Fish TB-303s

Photos of some of his AluCases are in the photos/ directory.

A remarkable blog site which lists TB-303s for sale with separate pages for many other synthesizers: http://www.synthfind.com/category/roland/tb-303/ .   eBay is probably the best place to find them for sale.  It is possible to save the search and have eBay send an email every day when one or more new items match.  In Melbourne, Australia, these two second-hand musical instrument sellers would be worth checking too:  http://www.foundsound.com.au and   http://www.musicswopshop.com.au  (They have an RSS feed and web page for new arrivals FS & MSS, and apparently there is some way of subscribing to emails about particular items which may become available.)

Check out the BugBrand BoardWeevil 2012 (link) from Tom Bugs in Bristol, England. 

Salute the BugBrand BoardWeevil - a denizen of the Idiosyncracy City

This creature is a denizen of the catacombs of Idiosyncrasy City.  When the time comes to cast off the constraints of 16 beats to the bar, 12 pitches per octave, synchronization, tuning and the entire boxy concept of notes, this creature would be an excellent traveling companion.  Note the 18 body contact pads and the two light-dependent resistors (LDRs).  3 square wave oscillators (audio and low frequency switchable), two ring modulators and a filter.  There's a pot and LDR for power-supply starving, so the whole machine self-modulates itself according to its instantaneous current drain.  This would make an excellent source of signals for the Audio In to Filter of the Devil Fish.  Tom Bugs also has other devices and a complete modular synthesizer system.

From New Zealand, extraordinary upgrade kits for the Korg PolySix, and Roland Juno 108 and JX-8PJhttp://kiwitechnics.com.  NiCad battery corrodes the PolySix controller board to the point where it cannot be repaired?  No problem: create a whole new controller board with a modern CPU, flash memory (no need for batteries) and a host of new MIDI capabilities!  Projects like this require a huge investment in developing the hardware, firmware and documentation.

Salute Brian and Leon Dewan who make extraordinary electronic musical instruments:  http://www.dewanatron.com , not least the Hymnotron (http://www.youtube.com/watch?v=EgakrRWs0r8) which can play sacred or profane, dirty and demonic . . . "Your wish is its command or maybe its wish is your command."  This is a just-intonation chord organ with an extraordinary pedal-steel-guitar-like slide function.  Check out the Swarmatron http://www.dewanatron.com/instruments.php?page=swarmatron "The span control expands the sound of a swarm of eight notes spread just a few cents apart into a wide chord of equidistant pitches spread over the entire spectrum. The player can taffy pull the resulting chord by using the span control and pitch ribbon in tandem. ".    Sound on Sound have a detailed review .  There's a Wikipedia page.   Some sounds are at: http://soundcloud.com/keyboardmag/sets/12-2011-dewanatron-swarmatron/    An article about the Dewan cousins is: http://www.newyorker.com/talk/2011/01/24/110124ta_talk_paumgarten  From  the Dewanatron manifesto:

While inherently musical in their impulses, the machines have no discipline and require governing by judicious overseers.  (...)

The operators begin a process which develops into a shape beyond their authorship; the operators become gardeners, watering and pruning, mulching and composting sound. The music becomes a contrapuntal morass, twining and climbing, chirping, buzzing, blinking, snapping. The operators guide the instruments, and the instruments carry the operators and others through an ever metamorphosing landscape.

Google reports that the word "MIDI" does not appear at the Dewanatron site.  These are extraordinarily physical sounding electronic instruments, with a 1950s science-fiction sensibility about their mechanical embodiment: all wood, baked enamel paint, chicken-head knobs, the the odd telephone dial and a keyswitch to power up the Swarmatron.  The Devil Fish is keen to become acquainted with these beautiful, exotic instruments!  Add some reverb - ideally in a real room, auditorium or underground vault - roll tape (or whatever it is these days) and play.

A customer in London sent his TB-303 in a beautiful plastic box, which makes a great Road Case for  any TB-303 or Devil Fish:  http://www.reallyusefulproducts.co.uk/uk/html/onlineshop/rub/b04_0litre.php

Excellent 4 litre storage box makes a good road-case for the Devil Fish, TB-303 and TR-606. 

They have online shops for several countries, including Australia, with relatively low shipping costs.  Another customer sent their machine in a 9 litre box, which is better still (see the image on the right), since we can ship the Devil Fish back in it, with the manuals inside the box.  The link to the Australian shopping page for this 9 litre Really Useful Box is: http://www.reallyusefulproducts.co.uk/australia/html/onlineshop/rub/b09_0litre.php  

Nothing to do with the TB-303, but there are some "video documentaries" on the making of some great tracks: http://www.youtube.com/user/TheAudioMystic Heart of Glass (Blondie) and I'm not in Love (10cc)  There's also a minimal version of Riders on the Storm I had never heard and a great instrumental version of Paint it Black.  These two "video documentaries" were put together by someone using excerpts of a series of radio documentaries, called The Record Producers by Richard Allinson and Steve Levine: http://stevelevine.co.uk/therecordproducers.html .   In this message (2011-09-06) on the Analogue Heaven mailing list I discuss more about this series

WikiPedia has a good page: en.wikipedia.org/wiki/TB-303 .

There are a bunch of mailing lists, including Analogue Heaven, at Hyperrealwww.hyperreal.org/music/lists/Hyperreal is an excellent site with many resources of interest to electronic music and rave culture.  In particular, the section on musical instruments is of interest: machines.hyperreal.org.  The TB-303 section is at: machines.hyperreal.org/manufacturers/Roland/TB-303/ . This page includes scans of the TB-303 schematics.

SonicCouture www.soniccouture.com/en/products/p42-devilfish/ in London have DVD with a bunch of samples of a Devil Fish, which are playable in the Native Instruments Kontakt 4 player.  

A second outfit to sample the Devil Fish for use in digital audio software is Sonic Faction .  Their "Evil Fish 303" functions as a plug-in instrument within Ableton Live, with on-screen controls and interfaces to hardware devices such as the Novation Launchpad .  The promo video, from late 2011: http://www.youtube.com/watch?v=5hcZI5toStQ  This no-doubt does some things a physical Devil Fish can't do, but generally it wouldn't compare with the hands-on use of the real Devil Fish.  Still, it costs $20 and comes with a free Whoosh Machine white-noise-based plug-in instrument.

The Propellerheads www.propellerheads.se are legendary for ReBirth, the excellent software emulation of two TB-303s, a TR-808 and a TR-909.  

CustomSynth.co.uk www.customsynth.co.uk  . Please see the photos/  directory for an image of Jeff Toman's radical restoration of a badly worn TB-303 plastic case, for a machine which I had just converted into a Devil Fish.

The main Roland site is  www.roland.com. From there you can reach the various subsidiaries and distributors in other countries.

Nothing to do with the TB-303 or Devil Fish, but a fascinating site for musical instrument history:  www.obsolete.com/120_years/  However the site is now defunct . . . .  The history can be found at: https://web.archive.org/web/20070202032312/http://www.obsolete.com/120_years/ .

Check out the two oscillator Future Retro 777 sequencer-synthesiser: www.future-retro.com/.  While you can easily plug a synthesiser into the Audio In of the Devil Fish to give you more "oscillators" the main spirit of the Devil Fish is a relatively straightforward oscillator feeding an intense and convoluted process of filtering, distortion, gain control, more distortion and then perhaps some Filter FM.

A MixMag interview with Hardfloor, the quintessential 303 maniacs: www.techno.de/mixmag/interviews/Hardfloor1.html

A vast array of information about synthesizers, including the TB-303, is at www.vintagesynth.com/  .

This page contains an extremely finely detailed optical (not electron microscope) photomicrograph of the TB-303 CPU chip:  http://siliconpr0n.org/archive/doku.php?id=digshadow:nec:upd650c_133  The 4806 x 4689 image itself is:
http://siliconpr0n.org/map/nec/d650c_133/single/nec_d650c_133_mz_mit5x.jpg .  Here is a smaller version, with enhanced contrast:

NEC upD650C-133 TB-303 CPU image from http://siliconpr0n.org/archive/doku.php?id=digshadow:nec:upd650c_133, smaller version with enhanced colour and contrast.

The 2000 x 8 bit mask programmed (the bits are built into the chip as a final stage of manufacture) program ROM is in the lower right corner.  Above this is the 96 x 4 bit RAM (local registers in a microcontroller).  In the TB-303, three 1024 x 4 bit battery-backed-up static RAM chips are used for storing patterns and tracks.  The TR-606 and TR-808 use the same type of chip, but the mask programmed ROM would be built with different data.

Some other links of potential interest regarding this series of microcontrollers:

The image below is an illustration of from Volume 2 of the three volume set The Science of Life by H. G. Wells, Julian Huxley and G. P. Wells from 1929-39 (I think). Click the image to see the full page and some more devilish deep-sea creatures.


Deep sea cuttlefish from The Science of Life by H. G. Wells et. al.


Q1: "Can the Devil Fish still make the sounds of the TB-303?"

Yes.  See page 7 of:  Devil-Fish-Manual.pdf for how to restrict the Devil Fish to the TB-303 subset. 

It was always my intention that the Devil Fish sound-space be a super-set of the TB-303s, but with repeated fast accented notes, the Version 1.x Devil Fishes did not sound identical to the TB-303.  This lead to the development of the Sweep Speed switch, with the "Fast" mode being that of the version 1.x machines, the "Normal" being that of the TB-303 and the "Slow" being a super wide and sloppy version of the TB-303 response.  This switch was retrofitted to several of the 18 Version 1.x machines, so there remain about 15 or so which cannot do everything a TB-303 can do. 

The TB-303 has a weedy bass response due to the low value of capacitors C20 and C21.  These are replaced with larger capacitors in the Devil Fish, so if you want to replicate the TB-303's thinner bass sound, you should use external filtering such as the bass EQ control of a mixer.

Q2: "Does the Devil Fish have MIDI?"

Yes MIDI In.  MIDI Out will soon be available.  Please see the midi-options/ page for more information on this and an two other approaches to providing MIDI In and Out.

Q3: "Do you have any TB-303s for sale, or do I know of any?"

Sometimes.  Please contact me if you wish to buy or sell a TB-303 and I may be able to put you in touch with someone.  See above: #tb303sforsale .

Q4: "Are you going to make a standalone Devil Fish?"

One day.  It is a very big project to do it as well as I believe it should be done.

Q5: "Is it OK if a TB-303 has the Kenton CV/Gate/Slide/Accent/Filter input sockets?"

Yes.  Before doing the modifications, I remove the sockets, fill the holes with epoxy, paint them silver and then carefully drill the Devil Fish holes with my template. 

Q6: "My TB-303s pots are stiff. Can you replace them?"

The 6 small pots (potentiometers Tuning to Accent) typically are rather stiff.  This friction may be reduced if the pots have been used a lot and/or if the pots are warm.  The friction in the pot is not caused by the wiper on the carbon track, but by a special part of the shaft rubbing on the case in the presence of high-viscosity silicone grease.  By dismantling the pot, it is possible to remove that grease and replace it with less viscose silicone grease, which makes them move relatively freely. 

As noted above, I can install a new set of 6 small pots, identical to those used in the Cyclone Analogic Bass Bot (though in 2016 it seems they started using a different type of pot).  I have replacement Tempo and Volume pots from Technology Transplant, but the original pots are typically highly reliable.  Crackling noise in the Volume pot is common, now these are a few decades old.  I fix this by dismantling and cleaning the original pot with isopropyl alcohol.

I normally install low-viscosity grease in the 6 small replacement pots. 

Some people think that stiff pots are a sign that the pots themselves are substantial and likely to last a long time.  There is no such relationship.  I think the original stiffness of the pots, at least in cold conditions, is too stiff.  Making them significantly less stiff enables them to be turned faster and with greater ease.

Q7: "The TB-303's memory contains precious patterns.  Will they still be there after the Devil Fish modification?"

I don't absolutely guarantee this, but I have procedures for retaining Lithium battery power to the RAM chips at all times, so your data should remain intact.  Be sure to have four good C cells in the machine when you ship it.  Take extra care with the packaging, especially to use tape, packaging or whatever to make sure that nothing can turn the Volume knob to the On condition.  That would flatten the batteries.  The patterns cannot be retained if the 32 bank memory system is installed.  It is best to write your patterns down anyway.  See the pattern sheets mentioned in the Other Information section above.\

Q8: "Do you install Ultra Violet LEDs?"

No.  UV LEDs produce very little visible light and plenty of UV, which may be damaging to the eyes especially up close with the iris wide open in dark conditions. 

Q9: "What about spare parts, repairs to Devil Fishes and TB-303s"

It used to be the case that certain parts are vital for the TB-303 and cannot be obtained from any source other than another TB-303.  The problem parts are:
  • CPU chip an early 1980s NEC 4 bit device with mask-programmed (i.e. the pattern built into the chip at the manufacturing stage) software.  See the D650-133 photo above. This family of CPUs has not been manufactured since 1984, so even if it was possible to extract the software from a TB-303 CPU, there is no available chip which will run it.  However . . . from 2012 until around 2017 there was a CPU Replacement system (Quicksilver 303) and since around 2017 there has been another one: https://www.sonic-potions.com/re303 .  This could be used directly.  There should be some original TB-303 CPUs available as the result of installation of these systems into TB-303s.

  • The six synthesiser control pots. This style of potentiometer has not been manufactured by Alps since the early 1980s.  Sound-to-Parts (eBay store) sell sets of six small pots.  See 303-mods/  for more information.

  • The TB-303 case, battery holder cover etc.  The cases can be obtained from a scrapped TR-606, as can the knobs and buttons.  The metal panel part of the case is no longer obtainable. Sound-to-Parts (eBay store) sell excellent kit with a newly manufactured battery compartment cover, and two battery contacts – the positive metal contact and the negative spring contact.  They may also sell chrome-plated reproduction buttons and knobs.  As far as I know, these buttons are made for the Cyclone Analogic Bass Bot, and the holes for the tact switch stems are a little bigger than is ideal for the TB-303's original tact switches.  The solution to this is to install Omron sealed tact switches, as mentioned above, which have the slightly larger switch stems to suit the Bass Bot buttons. 

  • The DIN Sync socket with switch.  (Roland part number 13429706.) The socket is reasonably standard, but its integral dual pole switch is unique and unobtainable.  A workaround is to install a toggleswitch instead.
Fortunately a number of hard- or impossible-to-obtain parts never seem to fail.  These include the Tempo (actually, I have a report of one failing) and Volume pots, the miniature transformer in the power-supply and the dual-transistors in the VCO and filter.  The Volume pot can become noisy.  The solution is to dismantle it and clean it with isopropyl alcohol.

The rotary switches never seem to fail.  ALPS still makes them, but getting one could be tricky.  The 6.5mm Output, Headphone and Input sockets (Roland part number 13449218, or is it 13449217?) are no longer available from the original manufacturer, Hosiden, but they are extraordinarily reliable and I have never had to replace one.  Considering the use these sockets have had over the last 35 years, the fact that they always (in my experience) work reliably is a testament to Hosiden's design and manufacturing expertise.

I do not do general service work.  However, I do maintain machines I have modified, and of course repair machines prior to modification.  I also do repair work on TB-303s, TR-606s and TR-808s.

See the page on modifications 303-mods/ for more details of maintenance, spare parts and alternatives for replacing pots.  See above: #tact_switch_kits regarding purchasing modified Omron tact switch replacement kits.

See 303-mods/ regarding the 1K x 4 bit memory chips, which sometimes fail.

Q10: Other maintenance questions regarding knobs, pots, switches, contamination etc.

Never let anyone spray anything inside any equipment you care for!!!  (With the possible exception of isopropyl alcohol if you really know what you are doing.)  Many TB-303s have been damaged by people spraying oily and/or corrosive liquids inside them.  It is possible to remove the oil – but only be removing some components and soaking the whole PCB in a hydrocarbon resembling petrol.

Please see 303-mods/  for more information.


Loose ends

Apart from the images of aquatic Devil Fishes, and the sound samples by other people, all material in this /rwi/dfish/ section of the web site is copyright 1996-2016 Robin and Tina Whittle.  If you would like to use some of this material for your own purposes, please ask: rw@firstpr.com.au .

The photo at the top of this page is different for each day of the week.  The photos are Devil-Fish-TB-303-front-panel-00.jpg to Devil-Fish-TB-303-front-panel-06.jpg .

If you wish to link to this site, please link to: http://www.firstpr.com.au/rwi/dfish/ and let me know.  I will add your site to the links section.