225.00 $ USD MOTM 485 G1-X VCF

For sale is an MOTM 485 G1X Filter. This module was built, tested, and calibrated by me to MOTM specs (shielded cable for audio signals, etc…).

The MOTM-485 is a recreation of the Yamaha GX-1 LP/HP filter.

The GX-1 was a massive organ/synth hybrid, costing over $60,000 in the late ‘70s. The best example is the ELP song ‘Pirates’, but was also used by Stevie Wonder and Led Zepplin..

The actual GX-1 used a pair of these filters to form a bandpass response (the same method used in the MS-20 and the CS-80).
There is a HP filter set to “half tracking” followed by a LP at “full” tracking. However, you can still use a single MOTM-485 as yet another distinct tone in your setup.

  • Faithfully captures the unique GX-1 timbre

  • 2 audio inputs

  • Voltage-controlled resonance

  • Switchable HP/LP response

  • Switchable half/full tracking of the 1V/Oct input

  • Fully temperature compensated using TEMPCO resistor and matched pairs

  • Not a ‘clean’ filter: has higher distortion than other MOTM filters

$225 + Shipping to US; contact if interested. Proof of life video here.


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Published date: March 8, 2015
  • Location: Close In NE, Portland, NW, USA
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