1

MU524 Vari-Mu Tube Compressor / Re: AudioPath Test Question

« on: July 02, 2024, 08:13:28 PM »

Found the problem.
I had R8 and R18 in the wrong spots..  Switched them and everything is working good now!
Rookie mistake..

Thank you for helping me figure it out!

2

MU524 Vari-Mu Tube Compressor / Re: AudioPath Test Question

« on: July 01, 2024, 04:40:16 PM »

Ok so tested 0v to both sides of R8.

Lower side of R8 (toward the TP pins) reads 46.6
Upper side of R8 reads .607

3

MU524 Vari-Mu Tube Compressor / Re: AudioPath Test Question

« on: June 22, 2024, 07:14:09 PM »

So I checked R8.  Looked good, re-soldered it to be safe..  All the solder joints on the unit look to be good.
Still no signal once unit is switched on

4

MU524 Vari-Mu Tube Compressor / Re: AudioPath Test Question

« on: June 17, 2024, 09:07:35 PM »

B+ to 0V = 46.5
V+ to 0V = 15.3
V- to 0V = 15.3

5

MU524 Vari-Mu Tube Compressor / Re: AudioPath Test Question

« on: June 15, 2024, 06:11:02 PM »

Ok so it was a issue with my chassis.  Got the unit up and running now with no problems!

I do have another issue with the 2nd stereo R unit i built...

I run the signal bypassed and get the 1 VAC.  But when I turn the unit on it kills the signal, 0.000 vac.
When I turn the out pot to 10 still 0.000 vac.

Ran through the tests and got this

TP1 290 mV VDC
TP2 203 mV VDC
TP1 to TP2 .215 VAC
TP3 to TP4 0 VAC
Output 0 VAC

with Jumper and out pot at 10
TP3 0 VAC
TP4 0 VAC
TP5 0 VAC
TP6 0 VDC
Output 0 VAC
Meter 0

The tube slow start test was good

Power voltage meter test was good
V+ 15.36
V- 15.31
B+ 46.3

6

MU524 Vari-Mu Tube Compressor / Re: AudioPath Test Question

« on: June 12, 2024, 10:13:22 PM »

When I bump the 1KHz to 0.0dB my multimeter reads 0.039 when bypassed.
0.309 when In
10.99 when In and out turned to 10

7

MU524 Vari-Mu Tube Compressor / Re: AudioPath Test Question

« on: June 12, 2024, 10:11:16 PM »

Yes when bypassed.

From my DAW I send a 1KHz at -11db
Unit is set at
In 10
Out 0
Rec. 10
JMP1 removed

My multimeter reads
when bypassed = .010
when in = .085
when in and out set to 10 = 3.655

I checked the solder joints on the relay and they look good
I hear it click when flipping the switch

8

MU524 Vari-Mu Tube Compressor / AudioPath Test Question

« on: June 10, 2024, 01:10:37 AM »

I'm new to building these kits.  I'm on step 6 to test the audio path and when I send the signal I'm getting 0.003 vac on my multimeter.  No matter what I change in my daw I can't get it close to 1.0 vac.
Not sure what I'm doing wrong here

Everything checked out good in the steps before.

Austin