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Sequential Circuits Pro One Modded J-Wire Rare Vintage Analog Synthesizer Mono
Sequential Circuits Pro One Modded J-Wire Top
Sequential Circuits Pro One Modded J-Wire Rear
Sequential Circuits Pro One Modded J-Wire Top Left
Sequential Circuits Pro One Modded J-Wire Bottom Right
Sequential Circuits Pro One Modded J-Wire Rear

Sequential Circuits Pro One J-Wire Modded

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Sequential Circuits Pro One #0197

This SCI Pro One is in good condition. It came out of climate controlled storage from a client of ours. They told us it was put away in storage many years ago and working when put it but not tested since then. Our techs are too backed up on other projects to service this. It has some mods but it appears none of the mods are connected to circuitry on the internals. The good part is it is serial number 0197, so it's an earlier J-wire model. Due to condition it is sold as-is, no warranties or functional guarantees. It will likely need some servicing. Could be a great DIY project for someone looking to get this classic synth as a discounted price.

We powered it up and did some brief testing. It powers up and makes sound. Pots are scratchy and could use a cleaning. J-wire keyboard likely needs some new bushings, reworking of the J-wires to trigger better and track properly. The oscillator waveshapes all work, although the pitch seems to waiver as if there is some modulation happening. The noise source, filter section, envelopes, glide, LFO, modulation sections seem to all be operating although will need calibration and possible further repairs as it's hard to tell exactly if all functions to specs with oscillator sections not up to full functionality. Have not tested any in/outputs on the rear except for audio out. From internal photos, it appears the mods on the left side have been completely disconnected and not attached to anything. Typically for early serial number J-wire keyboards, the power transformer is attached to the circuit board, which is a hazard due to it's weight/size and not secure and can cause damage to the circuit board or should it come loose. This one looks to have been modified where the power transformer has been safely attached to the chassis. The internals look clean. We did not have time to take the top panel circuit board off to inspect further. The rear jacks appear in the original photo to not be lined up properly, but upon disassembly and reassembly the rear jacks fit fine into their proper alignment. Mod wheel and Pitch wheel are working.

Sequential Circuits Pro One Modded J-Wire Rear
Sequential Circuits Pro One Modded J-Wire Top Left
Sequential Circuits Pro One Modded J-Wire Bottom Right