Search found 23 matches

by Script
Thu Sep 11, 2025 11:02 am
Forum: Open Source PCB Design
Topic: Transformerless Feedforward Vari-Mu
Replies: 22
Views: 430075

Re: Transformerless Feedforward Vari-Mu

R22 1/4 W, got it. Thank you.
by Script
Wed Sep 10, 2025 4:37 am
Forum: Open Source PCB Design
Topic: Transformerless Feedforward Vari-Mu
Replies: 22
Views: 430075

Re: Transformerless Feedforward Vari-Mu

Resistors in the sidechain better be 1/2 watt or is 1/4 watt ok?
by Script
Tue Sep 09, 2025 6:04 pm
Forum: Open Source PCB Design
Topic: Transformerless Feedforward Vari-Mu
Replies: 22
Views: 430075

Re: Transformerless Feedforward Vari-Mu

Can't find the AM6T-1215D anywhere. Is there an alternative?

I can get hold of a 1218D by same maker, but gives only 166mA and would need to be pulled down to +/-15V. Is that still enough for hooking up two boards for stereo? If not, I might have to think of something entirely different.

Got it ...
by Script
Tue Sep 09, 2025 3:00 pm
Forum: Open Source PCB Design
Topic: Transformerless Feedforward Vari-Mu
Replies: 22
Views: 430075

Re: Transformerless Feedforward Vari-Mu

What is diode D1 on the dcdc board? Same as D9 on main board (170V/5W)? Or just a 400x?

And on the layout picture, D9 is not installed. Not really needed there?
by Script
Thu Jun 19, 2025 1:39 pm
Forum: Pro Audio
Topic: OPTO compressor design
Replies: 3
Views: 247153

Re: OPTO compressor design

Found this the other day. Have you ever test-built this?

How does the Auto Attack interact with the variable attack setting?
by Script
Tue Apr 29, 2025 12:46 am
Forum: Open Source PCB Design
Topic: Transformerless Feedforward Vari-Mu
Replies: 22
Views: 430075

Re: Transformerless Feedforward Vari-Mu

I like that idea. Did something like that on analag's DAOC with LED in antiparallel to optocell . But ended up also adding meter slowed down with a cap to show an approximation of average.
by Script
Sat Apr 26, 2025 10:30 pm
Forum: Open Source PCB Design
Topic: Transformerless Feedforward Vari-Mu
Replies: 22
Views: 430075

Re: Transformerless Feedforward Vari-Mu

What meter is good on this? 200mA? 1mA?
by Script
Sat Apr 26, 2025 4:11 am
Forum: Open Source PCB Design
Topic: Transformerless Feedforward Vari-Mu
Replies: 22
Views: 430075

Re: Transformerless Feedforward Vari-Mu

The Recom R12-150B is mighty in price. Is there a cheaper alternative you can recommend?

Or a power toroidal backwards also could work, no?
by Script
Sat Apr 12, 2025 8:34 am
Forum: Open Source PCB Design
Topic: Transformerless Feedforward Vari-Mu
Replies: 22
Views: 430075

Re: Transformerless Feedforward Vari-Mu

That makes sense.
by Script
Sat Apr 12, 2025 1:49 am
Forum: Open Source PCB Design
Topic: Transformerless Feedforward Vari-Mu
Replies: 22
Views: 430075

Re: Transformerless Feedforward Vari-Mu

I read the description of the U73b, document on groupdiy.

In that text they talk about 'solid release times' of 0.3 - 0.6 - 1.2 seconds. These are easy to derive by putting resistors or caps on a rotary.

But they also talk about 2.5 - 6 -1.2s as being ' influenced by their respective program ...