Custom Modded Oberheim TVS-1 with one SEM Replaced with Patch Points

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"Custom-modified Oberheim TVS-1 two-voice synthesizer, with one SEM replaced by a custom patch panel providing access to all SEM, Sequencer, and Keyboard patch points. Modifications done in the early 90's by the late great Andy Topeka, keyboard tech for the Rolling Stones, David Bowie, myself, and many others. Modification highlights include a switch to convert the sequencer from 8x2 to 16x1 with blue LED indicator. A full list of mods follows below.

Patch Panel #1
• (2) 1 in/1 out attenuators
• (2) 4-point mults
• (2) attenuators to the filter's inputs, one from the KCV, the other connecting the VCF EG to the exponential response input to the VCF
• (2) KCV outputs
• (2) Quantized AND Analog outputs, one from each row of the Sequencer
• Clock (Step) and Reset inputs for the Sequencer
• Keyboard Gate
• Sequencer Gate

Patch Panel #2
(2) VCO CV inputs (one for each VCO)
VCF CV inputs
Individual VCF outputs: LP, HP, BP, Notch
VCA CV inputs
LFO reset
(2) EG gate and outputs

Additional Modifications:
• Noise from S/H hardwired to the #1 input of the EXT. pot on the filter
• Line Output switch with red LED on/off indicator, extremely useful for private programming via headphones without sending audio to line out
• Kill Switch for VCO #2 (to prevent any possibility of bleed when using only VCO#1)
• Decay Switch, sets EG#1's decay to 0 (short to ground). This was originally intended to switch in a fixed-value resistor so that the decay time could be toggled between a specific (short) value and the pot, but this modification was never completed.
• Sequencer: switch provides either normal 2x8 operation or custom 1x16 operation, seamlessly scanning between Row 1 and Row 2. Blue LED indicator illuminates when Row #2 is being scanned.
• Original red LED's indicating EG trigger replaced by blue LED's"