Aphex CX-1 Troubleshooting

Help Support GroupDIY:


Feb 19, 2015
Hey folks. I have an old Aphex CX-1 compressor that I got from an old studio neighbor.  He told me he never tried plugging it into an API lunchbox due to the Pin 15 external meter issue with phantom power. I figured I would try to get it up and running again, so I had a go at it.

(See https://groupdiy.com/index.php?topic=34050.0 for more info on the CX-1s and such. I've been following it thoroughly  throughout this process)

I've also attached the service manual, but the link for it is also here: http://www.eserviceinfo.com/downloadsm/54429/Aphex_CX-1.html

I used the dremel across the trace at pin 15 since it's not needed. Then plugged it into my extension jig from my lunchbox. It powered up fine. Ran a triangle wave into it and checked out the output on my scope, too. The only functions that weren't working properly were the C and X meter buttons. When engaged, the whole meter just lights up. I was trying to trace where the problem might be on the PCB, and I feel like I accidentally short-circuited the thing somewhere in the process (I probably got a little carried away with the multimeter...)

I also found that there's supposed to be a ferrite bead in place of a resistor on the non-transformer versions like the one I have, but when I looked on the PCB, I found a 120 ohm resistor in place of it, even though the component list makes no mention of one in either the transformer or non-transformer versions. It also looks cooked! Probably why I wasn't receiving signal anymore.

So, I'm wondering if anyone has experience fixing these. I'm debating whether I should just recap the big capacitors for the hell of it and place a ferrite bead (150ohm) in place of that random 120 ohm resistor to get things up and running again. Everything else looks and measures fine.

P.S. I'm also interested in fitting a Jensen output transformer into it! Anyone done that with these?


  • Aphex CX-1 Docs.pdf
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