Pro Audio Design Forum

While I wouldn't expect huge terminal voltages in the mic pre gain leg (same voltages pretty much as the inputs), I have run these down to single digit ohms so surely low impedance, and perhaps several mA of peak current. These are often polarized and 6.3V. They can see amps of fault current and du...

I don't know if you've followed Sam Groner's work in this area. I think his current preference is to parallel two electrolytic caps, back to back, with one by definition reverse polarity. On his bench, he reports a first order cancellation of some distortions. JR It's been awhile since I followed S...

JR. You might want to go back and re-read my post. Not because you missed anything but it may have changed due to editing. (There's some combination of keystrokes that will completely nuke a post and I've done that a lot lately. So I edit/re-edit/submit out of fear of losing it.) The best solution i...

I think I want to make a capacitor null tester. As JR and I have both discussed elsewhere, the terminal voltage developed across a coupling capacitor is usually very small until low frequency cut off is reached. At low frequencies, the reactance begins to become significant relative to the load resi...

Roland - For set and forget you might just want to use the auto non-linear capacitor if you want an RMS compressor. To emulate an SSL feedback peak limiter you could use a pair of untrimmed 2181C or 2180C VCAs for the sidechain along with the 4301s for the main path. Wayne

I finally got around to scanning some of the material JR sent me.

This is the 1981 Signetics Compander Product Guide with applications.

https://www.ka-electronics.com/Images/p ... _Guide.pdf

Thanks, John.

1/(2 x pi x R x C) What JR said. Javascript calculator: http://www.muzique.com/schem/filter.htm With that dramatic of an audible difference I would be tempted to do some null tests between cap A and cap B to better quantify and qualify the actual differences. That's how I would go about looking for...

This thread is a copy of the Loftech TS-1 Schematic document thread. JR is in the process of considering a modern replacement for the ubiquitous Loftec TS-1 using modern DSP-based electronics. I could do that entire puppy today, even better using only a few digital chips... (somebody stop me...) :l...

Loftech TS-1 Test Set Schematic https://www.ka-electronics.com/images/jpg/Loftec_TS1.jpg Loftech TS-1 Schematic Loftech TS-1 Schematic Large Format jpg : https://www.ka-electronics.com/images/jpg/Loftec_TS1_Large.jpg (2MB) Loftech TS-1 Schematic pdf : https://www.ka-electronics.com/images/pdf/Lofte...

It seemed as a generalization, physically larger resistors performed better and, as previously mentioned, the Susumu and RCD resistors performed best. Glad I saved that e-mail. Bigger is better seemed to be particularly true with the Panasonics he tested. As I previously mentioned there are some sp...