Pro Audio Design Forum

Cool to see BK on the case...

JR

I wouldn't expect too many feed-forward designs before decent VCAs with log control.

I have tricked up log control for OTAs but they were so noisy why bother?

Feedback comps can use any old gain law and the feedback keeps them OK.

JR

Without steering you toward a specific circuit it's pretty common in side chains to establish thresholds by adding a current to or subtracting a current from an opamp inverting input then comparing that current to a second varying one with the opposite polarity. A steering diode from the output of t...

Yes, as Wayne has already suggested it is pretty straightforward to add a diode break voltage clamp in the side chain to limit gain reduction at X amount.. I found this capability very useful in downward expanders as too much noise floor reduction starts to sound unnatural. One suggestion when opera...

Wow.. good work guys... 10-15 mV on a DC coupled 60dB gain stage could be real interesting.. Good useful data.

Knowing what to expect is really good to know.

Good progress.. when do we design our uber console?

JR

I believe I've shared this before but in my experience the noise contribution from leakage in the electrolytics are variable between brand/series of capacitors. I encountered one while at peavey that was so bad we had to black ball it for that application. My understanding from talking to the engine...

We have a smoking gun, for my concerns about DC coupling every mic in the world.

Problems reported with TLM 103

http://www.prodigy-pro.com/diy/index.ph ... #msg407094

JR

I agree with John that tricks are best performed elsewhere. ;) Alright then, I shall resist. LOL John, I remember you mentioned that bootstrapping trick once, and I stored it away in my noggin for possible later use. I'm more of a cookbook guy than a textbook guy, but examples of stuff like that ar...

Yup.. I once had to locate a mic trim pot about 18" away from a circuit in a console (back in the '70s) for ergonomic reasons. The C in the shielded cable was enough to destabilize the circuits. I ended up driving the shield of the cable with a CM output signal I derived to keep it happy.

JR.

Nah.. electrolytic capacitors don't do well at low impedances, and in that circuit node the cap is dealing with ohms or at best tens of ohms.. DC couple and HPF elsewhere...

Unfortunately you don't want to wrap anything like this variable HPF around a mic preamp due to input impedances...

JR