TB-303 for sale
2024-06-04 Robin Whittle rw@firstpr.com.au../ To the Devil Fish page.
I recently repaired a TB-303 for Melbourne Music Centre, who will be offering it for sale:
+61 3 5348 4794 info@melbournemusiccentre.com.au
This machine has Omron sealed tact
switches, which should last for many decades. The original
ALPS unsealed tact switches, one for each button, fail after years or
decades of use due to dust ingress.
I replaced the wires between the main board and the switch board.
The three filled in holes in the front panel would not be visible with the Devil Fish mods. I filled them with epoxy and then used a silver felt tip marker. These epoxy pieces are not as flat as would be ideal, but I would make them so before affixing the Devil Fish polycarbonate faceplate.
The battery compartment door and positive battery contact are new. I installed a cleaned up, used, spring for the negative contact since I had run out of replacement springs from https://SoundToParts.com.
The volume pot has been dismantled and cleaned, so it should be free of crackles for the next decade or two.
I dismantled the six small pots, cleaned them, checked they are all in good shape, applied new, lighter, silicone grease so they are easier to turn - but not too free - and re-installed them.
Some of the silver paint and legends are worn off around the Cut Off Freq and Env Mod pots. As is usually the case for a 43 year old machine, silver paint is worn from the corners of the case. However, no corners of the case are broken off.
There is discolouration near the battery compartment door due to battery leakage. The original battery spring and positive contact were missing, so they were surely corroded in the past. The three NEC memory chips had suffered from corrosion of their pins 8, 10 and 18 (those with +5 volts on them when batteries are installed), which is a common problem with or without battery leakage. I saw no other signs of problems due to battery leakage. I have installed used Toshiba memory chips, which I don't recall seeing with their pins corroded. NEC chips seem to be the most prone to this. The corrosion occurs within the (not plated through) hole in the phenolic circuit board, over very long periods of time (years or decades).
The case is sound with no problems with the pillars of the top part of the case, into which the 7 rear panel screws are attached. The buttons and knobs are in good shape. (These are chrome-plated ABS and it is remarkable how well they last, even with extensive use.)
Please contact Melbourne Music Centre if you are interested in purchasing this TB-303. I have it here in Daylesford, so if you wanted it for Devil Fish modifications, there would be no shipping costs to get it here.
I replaced the wires between the main board and the switch board.
The three filled in holes in the front panel would not be visible with the Devil Fish mods. I filled them with epoxy and then used a silver felt tip marker. These epoxy pieces are not as flat as would be ideal, but I would make them so before affixing the Devil Fish polycarbonate faceplate.
The battery compartment door and positive battery contact are new. I installed a cleaned up, used, spring for the negative contact since I had run out of replacement springs from https://SoundToParts.com.
The volume pot has been dismantled and cleaned, so it should be free of crackles for the next decade or two.
I dismantled the six small pots, cleaned them, checked they are all in good shape, applied new, lighter, silicone grease so they are easier to turn - but not too free - and re-installed them.
Some of the silver paint and legends are worn off around the Cut Off Freq and Env Mod pots. As is usually the case for a 43 year old machine, silver paint is worn from the corners of the case. However, no corners of the case are broken off.
There is discolouration near the battery compartment door due to battery leakage. The original battery spring and positive contact were missing, so they were surely corroded in the past. The three NEC memory chips had suffered from corrosion of their pins 8, 10 and 18 (those with +5 volts on them when batteries are installed), which is a common problem with or without battery leakage. I saw no other signs of problems due to battery leakage. I have installed used Toshiba memory chips, which I don't recall seeing with their pins corroded. NEC chips seem to be the most prone to this. The corrosion occurs within the (not plated through) hole in the phenolic circuit board, over very long periods of time (years or decades).
The case is sound with no problems with the pillars of the top part of the case, into which the 7 rear panel screws are attached. The buttons and knobs are in good shape. (These are chrome-plated ABS and it is remarkable how well they last, even with extensive use.)
Please contact Melbourne Music Centre if you are interested in purchasing this TB-303. I have it here in Daylesford, so if you wanted it for Devil Fish modifications, there would be no shipping costs to get it here.