Rhodes Chroma Polaris group photo

Yahoo Groups archive

Rhodes Chroma Polaris

Index last updated: 2026-03-31 23:19 UTC

Message

Rre: [chromapolaris] failing Polaris autotune

2016-01-25 by Eric Frampton

Alas, that wasn’t it. Solid connections there, and when I measured the output of the ALT buffer I made sure to probe at the input pin of Z46 in the timer circuit, so I know the signal was making it that far.

Past that I’m not sure I understand the tuning routine enough to know what I’m looking for. Could it be something in that timing circuit?

e

The most likely culprit is a bad connection to the output board. When
tuning, the signal from each channel is routed to a different line (ALT
OUT) to the output board, where it is squared up and fed back to the main
board on the SYNTH ZCD line. It could even be a bad ground to the output
board, which could account for the audio noise, too.

--

Ciao, Paul D. DeRocco
Paul mailto:pderocco@...

Attachments