Search found 3714 matches

by JR.
Sun Sep 16, 2012 3:39 pm
Forum: The Peabody Lounge
Topic: An Example of Good Level Control
Replies: 2
Views: 7852

Re: An Example of Good Level Control

I guess it's inevitable at some point for delivering dynamics to become a way to differentiate from the mainstream.

JR
by JR.
Thu Sep 13, 2012 3:36 pm
Forum: Document
Topic: Spectral Interleaving in the NTSC System
Replies: 2
Views: 7471

Re: Spectral Interleaving in the NTSC System

remember when 3.58 MHz seemed like a lot?

JR
by JR.
Tue Sep 11, 2012 1:53 pm
Forum: Document
Topic: Panasonic Discrete Transistors, JFETs and MOSFETs
Replies: 3
Views: 10003

Re: Panasonic Discrete Transistors, JFETs and MOSFETs

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? ...
by JR.
Tue Sep 11, 2012 11:56 am
Forum: Document
Topic: Panasonic Discrete Transistors, JFETs and MOSFETs
Replies: 3
Views: 10003

Re: Panasonic Discrete Transistors, JFETs and MOSFETs

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...
by JR.
Sat Sep 08, 2012 10:07 am
Forum: Pro Audio Design
Topic: CE certification
Replies: 6
Views: 14305

Re: CE certification

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...
by JR.
Tue Sep 04, 2012 12:30 pm
Forum: The Peabody Lounge
Topic: Entropy
Replies: 1312
Views: 1151698

Re: Entropy

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...
by JR.
Fri Aug 31, 2012 4:00 pm
Forum: Document
Topic: A new audio amplifier topology with push-pull transimpedance
Replies: 2
Views: 7626

Re: A new audio amplifier topology with push-pull transimped

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...
by JR.
Sun Aug 26, 2012 1:10 pm
Forum: Document
Topic: JFET Follower Amplifier Cancels Distortion
Replies: 15
Views: 31897

Re: JFET Follower Amplifier Cancels Distortion

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...
by JR.
Sun Aug 26, 2012 10:26 am
Forum: Document
Topic: JFET Follower Amplifier Cancels Distortion
Replies: 15
Views: 31897

Re: JFET Follower Amplifier Cancels Distortion

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
by JR.
Fri Aug 24, 2012 1:40 pm
Forum: Document
Topic: JFET Follower Amplifier Cancels Distortion
Replies: 15
Views: 31897

Re: JFET Follower Amplifier Cancels Distortion

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...