Pro Audio Design Forum

remember when 3.58 MHz seemed like a lot?

JR

I've use a pair of BS170s N-ch MOSFETS back-to-back as an audio switch and they work very well. Above about +15 dBu they need a little bootstrapping. Having two of them in a package is really cool. Was it ROhm that coined the term "digital transistor" for those having internal resistors? ...

Thanx,,, I didn't see complete noise data on the few JFET data sheets I checked. One said 1 uV but can't tell is that is audio band or dominated by 1/F The FC4A2205 dual MOSFET is cute... With two of them in series back to back, that is a helpful trick for switching battery powered products, to prev...

I believe the FCC is the local authority on RF emissions for the US. While the CE regulation is not just for interference generated, but behavior in the presence of interference, without much clear definition of how much and what kind... Enjoy... FWIW you can get a sense for how much of a EMI source...

Apparently I spoke too soon about my mower repair... it is back to squirrely spark when restarting hot.. I have disconnected the safety switches and that is definitely the problem. arghhhh. more work involved. I am tempted to blow off the brake/clutch switch, and just connect the seat switch in seri...

Kool, Looks nice and symmetrical. Also front end can be run from low voltage rails-process. So only level shifter and power stage needs high voltage technology. Sam needs to be working on new opamps, while I've seen some odd stuff already in new school opamps, and they don't publish schemos like the...

The transistor with resistor base emitter does look mostly like a current source "at it's base", because most of the current there is constant with only a small variable fraction from the base current. Phantom power interfaces are always a bit of neither-nor, for the emitter side to look l...

I missed the 1G resistor value so agreed, not injecting corrective AC voltage into gate to linearize.

I had to google AOT, I used to see SAT (select at test) on schematics and miss the good old days where schematics didn't always show values, until after we finished the design.

JR

I don't know... One very low distortion "linearized" JFET shunt example is in the gain leg of the AGC for the low distortion sine wave generator published by Robert Cordell in his Audio Magazine distortion analyzer article. He did some clever stuff in how he extracted a buffered source vol...

Thanks for posting this... Interesting, but as far as I can see this IS NOT the same mechanism as the phase splitter schemo also posted. The latter example uses the well known JFET mechanism where a fraction of the source voltage (usually 1/2 or -6dB) is introduced back into the gate voltage to crea...