1

MU524 Vari-Mu Tube Compressor / Re: Initial AC voltage jump

« Last post by JPK on February 09, 2026, 03:55:00 PM »

Check the solder joints of the potentiometer P1, of the connectors J2a and J2b and of the transformer daughterboard to main PCB connector.

2

MU524 Vari-Mu Tube Compressor / Re: Initial AC voltage jump

« Last post by CGMix on February 07, 2026, 06:51:39 PM »

Yeah it looks like that may be it. The ohm load doesn’t change. It’s stuck at 100ohms

3

AB528 Microphone preamplifier / Re: AB528 DI not working

« Last post by JPK on February 06, 2026, 10:41:04 AM »

Can you report the DC voltages on each pin of U2 on the DI board?

4

AB528 Microphone preamplifier / AB528 DI not working

« Last post by Ritualknive on February 06, 2026, 02:17:46 AM »

Just put together one of these. Mic and line work well along with the phantom power. DI all I hear is hiss and the front LED doesn’t work either. Any ideas? Thanks! 

5

DI503J Triple DI and Re-Amp / Re: DI503J triple DI output buffer

« Last post by TheWoodman on February 04, 2026, 06:55:54 PM »

Thanks very much for your answer. Depending on levels/impedance this possibly thins out the instrument signal a little when another load (amp for example) is connected to the unbuffered TS output. Which can easilly be handled by placing my own buffer before the input. So thanks again, this is just good to know.

6

DI503J Triple DI and Re-Amp / Re: DI503J triple DI output buffer

« Last post by JPK on February 04, 2026, 06:49:49 PM »

It is just in parallel with the input, without buffering.

7

DI503J Triple DI and Re-Amp / DI503J triple DI output buffer

« Last post by TheWoodman on February 04, 2026, 06:30:55 PM »

Is the output TS jack of the Triple DI buffered (when not in reamp mode, so just paralleling the input signal).

8

MC624 Monitor Controller / Re: 12 year old manual recommendations outdated

« Last post by JPK on February 04, 2026, 08:57:06 AM »

Hi,
We use this one.
We couldn't find a TV model that worked 100% so we programmed the MC624 manually for this remote.

9

MU524 Vari-Mu Tube Compressor / Re: Initial AC voltage jump

« Last post by JPK on February 04, 2026, 08:46:32 AM »

Check that the input potentiometer is working by measuring the resistance between pins 7 & 10 of the input transformer. The value should vary from 0 to 200 ohms when rotating the input potentiometer.

10

MC624 Monitor Controller / 12 year old manual recommendations outdated

« Last post by Steveng on February 03, 2026, 02:33:10 AM »

JPK, 
as per a previous communication almost a year ago, you said you were going to update the section that spoke to the unit being controlled by TV remote and update suggestions, as to specific unit(s) that would work, I never got that info back from you. 
I've already gone thru a programmable remote that didn't work well, and I would like this advertised function to use.
Thanks, 
StG