91

MP512 Microphone preamplifier / Re: LED activity reflected in sound

« Last post by Mar on April 02, 2025, 09:35:12 PM »

It has to be something on the DI side of things. When I am going DI on my other pre and coming out into the mic input of the 512 at the back problem goes away. I use DI a lot, this unit didn’t bring me a lot of joy. Not wasting any more time on it.

92

MU524 Vari-Mu Tube Compressor / Re: No AC volage from TP1 on

« Last post by coostor on April 02, 2025, 04:14:38 PM »

I measured it wrong, the resistance is 3.4 ohms.
I tried it with a telefunken ecc189 tube, there is no difference in the result.
It doesn't glow and VAC values are zeros.

93

MP512 Microphone preamplifier / Re: LED activity reflected in sound

« Last post by JPK on April 02, 2025, 03:18:19 PM »

Can you try to reproduce the effect with pulses of sine wave coming from a generator pluggin?
This is because I don't understand how it could be caused by the preamp.

94

MP512 Microphone preamplifier / Re: LED activity reflected in sound

« Last post by Mar on April 01, 2025, 07:43:07 PM »

Here it is. Dry guitar followed by a bass https://limewire.com/d/zfSxT#MU82BZAeTL

95

MU524 Vari-Mu Tube Compressor / Re: Tube PCBs

« Last post by AcdNrg on April 01, 2025, 04:23:53 PM »

Thank you!

96

MU524 Vari-Mu Tube Compressor / Re: Tube PCBs

« Last post by JPK on April 01, 2025, 04:10:56 PM »

The tube PCB's are the same except for the test pins added on the True Grit.
The tube socket is this one:
https://www.tubeampdoctor.com/en/9-pin/noval-socket-ceramic-white?c=58

97

CP4500 Stereo Bus Compressor / Re: CP4500 - No output and incorrect voltages

« Last post by JPK on April 01, 2025, 04:02:35 PM »

Do you confirm that TP11 is at 0VDC ?
If true there is something wrong arount U21 and R95 to R99. Check the resistors value.

98

MU524 Vari-Mu Tube Compressor / Tube PCBs

« Last post by AcdNrg on April 01, 2025, 11:37:55 AM »

Are the tube PCBs on True Grit and MU524 the same?
 
And is this the right socket:

Noval S9CPC-1
18mm diameter
UPC: 4251594908081

I messed up one of the two MU524 kits and need to replace the whole rube assembly. Since the TrueGrit has spare tube PCBs, I wonder if I can use these. 

99

CP4500 Stereo Bus Compressor / Re: CP4500 - No output and incorrect voltages

« Last post by SKa on April 01, 2025, 11:25:56 AM »

Yes, it goes between -11.8 and +11.8 V.

100

MU524 Vari-Mu Tube Compressor / Re: No AC volage from TP1 on

« Last post by JPK on April 01, 2025, 11:03:00 AM »

Dead tube. Contact us here for a replacement.