Pro Audio Design Forum

the gain stage has to drive the total Rf+Rg to ground in parallel with input impedance of following circuits Obvious enough, I hadn't thought about that part. These are mostly 75 ohm output rated op amps, and the following circuits are 600 ohm at minimum, mostly 10K. So not a problem. Back to the d...

When attempting to get best s/n at high gain you want low total impedance in feedback network (Rf and Rg in parallel). The pot varying the leg to ground give you lowest impedance at highest gain. The above hits the nail on the head. Amazing how I can dig through a stack of books, and browse the web...

Safari is cutting off the right side of the image here, but Firefox is showing everything.

When attempting to get best s/n at high gain you want low total impedance in feedback network (Rf and Rg in parallel). The pot varying the leg to ground give you lowest impedance at highest gain. That's finally in layman's terms. Perhaps it makes more sense to fix a constant Rf value, and use S3 fo...

Yep, these use Grayhill MBB switches, and I have 5 channels that have survived to this late date; 35+ years.

I was working on some early '70's RCA preamps with transformer input (15K sec), which use a discrete op amp in non-inverting mode. I note RCA chose to have Rg be a set value, and varied Rf via a stepped control, along with tailored Cf's. In almost every other similar preamp I've encountered, Rf is f...

We did these tracks as extras when we made the ZOMBIE BOOGIE Halloween record earlier this year. We cut these songs live in their living room over a weekend. Guitarist is also playing the drums at the same time. Generous abuse of Pico mono and stereo comps on this one, though maybe hard to tell, as ...

MikoKensington wrote: throw it between two mono Picos to make a M/S compressor.

That's what I'm planning for one set! Dual mono, or M/S stereo.

I'll report back, smoke or no.....

So, looks like the TDK/Lambda CC6-2412DF-E DC/DC converter can be wired with floating input, and is fine with either side of the output grounded, to achieve SE PSU voltage, either plus or minus. Looks useful, if I'm interpreting correctly. Not an idea I've delved into before. The addition of turn-on...