Anyone swap out a CA3080 for an LM13700 in a compressor?

[neandrewthal]

I was reading the Fuzzdog thread so I decided the check out their site and I see that they sell an adaptor board to use an LM13700 on a PCB that calls for a CA3080

http://shop.pedalparts.co.uk/CA3080_-_LM13700_Adapter_PCB/p847124_13121572.aspx

Has anyone tried this on a Dynacomp/Ross style compressor? If so, is it worth the hassle for any reason except that the 13700 is more readily available?

I just finished my Ross Compressor on a PCB from Aion Electronics last week and I find it a bit noisy. I did a google about compressor noise and I read that the 13700 is a more modern product with lower noise. Another source told me that the CA3080 is not inherently noisy and the noise is caused by the low signal levels  and the high gain required after. If that is the case then only a circuit designed (or at least tweaked) for the 13700 could take advantage of its lower noise capabilities.

I'm not looking to tweak the hell out of my compressor, just wondering whether a straight swap would or would not make a noticeable difference in noise.

[midwayfair]

It will be quieter. But a quieter OTA chip isn't saying that much.

The chip DOES idle at very high gain. Whether the inherent noise is greater than the line noise from your guitar (it isn't) isn't really the point -- the chip ALSO has its own noise that gets amplified a bunch. The 3080 IS inherently noisy. Noise specs aren't mojo or psychoacoustics, they're in the datasheets of ICs.

If you want something that uses an OTA chip and lower noise chips, that's this thing:
http://www.valvewizard.co.uk/engineersthumb.html

[neandrewthal]

Thanks for the reply.

I stumbled upon the Engineer's Thumb in my research and I kind of wished I had built that instead but I only need one compressor and I'm not ready to throw out my Ross yet. Only if I decide that I can't stand the noise in the long run.  I don't record or play live so it's completely up to my own hearing pleasure or displeasure.

I'm not expecting anything short of overhauling the whole circuit with a 13700 (but of course, why would you do that when you can start over with the ET like you said) to make it whisper quiet but do you think swapping it would make it even a little bit noticeably quiter? Just enough to make it worth paying postage for a little board and a few minutes of desoldering hell?