- This topic has 2 replies, 2 voices, and was last updated 6 years, 7 months ago by .
Viewing 3 posts - 1 through 3 (of 3 total)
Viewing 3 posts - 1 through 3 (of 3 total)
- You must be logged in to reply to this topic.
Home › Forums › Vintage EHX › Polychorus Service Manual, Notes, Schematics
Hi There!
I just recently bought an older Polychorus that needs calibration. I have an electronics workbench with test equipment such as an oscilloscope, isolated power supply, signal generators, etc. I also have many years experience building amplifiers. Do you guys keep service notes on these, or a verified schematic? The PCB is labeled TCI-A4H 94HB.
Any help is greatly appreciated
Thanks!
I take it that’s the model with the MN3008 & MN3009 from the PCB Code.
The schematic only gives the clock adjustment;
Sweep Filter – Off
Width – Full CCW
Rate – Full CCW
Tune/Delay – Full CW
Mode – Filter Matrix
Adjust Trim 8 for 100uS at 4013 pin 1.
Trim pots 1 & 4 are your BBD bias and Trim pots 2 & 5 are the BBD balance trims, setting those up will be similar to any other BBD set up procedure.
Nice, thank you!