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CP4500 Stereo Bus Compressor / Unbalanced channels + + +
« on: December 07, 2023, 09:49:24 PM »
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So, this is a continuation of thread: https://www.soundskulptor.com/forum/index.php?topic=419.msg2349#msg2349
Just to politely not weddingcrash the other users questions.
So:
I have unbalanced output after a couple of years.
My issue is that whn i start calibrating the unit from start, i can not get T1 on channel one to match the 3.0 VAC signal that is present when i standby. T1 only manages to increase the voltage to 2.595 VAC.
Edit: and on channel two board i can't get T2 og T3 down to 2.595.
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@JPK
3.0 VAC source signal gives me 1,492 VAC on TP1.
With T1 turn on max, it gives me 2.709 VAC on the unit output.
My VCAs are in sockets
EDIT:
I realized now, that when testing with only board 1 powered, i get the above results. As soon as i power both boards, board/channel 1 suddenly gets a bump and is suddenly outputting 2.95 VAC
When removing board 2, it goes down to 2.7 VAC.
EDIt 2:
I had a bunch of OPA2134PAs laying around, so startet switching them. When replacing U21, i finally was able to match the bypass and active signal. But i have no chance of getting T4 to trimm the meter to 12 dB attenuation (worked yesterday).
Also noen of the trimmers on board 2 is reacting. And i feel the threshold is very sensitiv.
So, this is a continuation of thread: https://www.soundskulptor.com/forum/index.php?topic=419.msg2349#msg2349
Just to politely not weddingcrash the other users questions.
So:
I have unbalanced output after a couple of years.
My issue is that whn i start calibrating the unit from start, i can not get T1 on channel one to match the 3.0 VAC signal that is present when i standby. T1 only manages to increase the voltage to 2.595 VAC.
Edit: and on channel two board i can't get T2 og T3 down to 2.595.
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@Dolbah
Do you get TP1=1.5VAC with 3VAC at the input?
Are the VCA's socketed or SMC?
@JPK
3.0 VAC source signal gives me 1,492 VAC on TP1.
With T1 turn on max, it gives me 2.709 VAC on the unit output.
My VCAs are in sockets
EDIT:
I realized now, that when testing with only board 1 powered, i get the above results. As soon as i power both boards, board/channel 1 suddenly gets a bump and is suddenly outputting 2.95 VAC
When removing board 2, it goes down to 2.7 VAC.
EDIt 2:
I had a bunch of OPA2134PAs laying around, so startet switching them. When replacing U21, i finally was able to match the bypass and active signal. But i have no chance of getting T4 to trimm the meter to 12 dB attenuation (worked yesterday).
Also noen of the trimmers on board 2 is reacting. And i feel the threshold is very sensitiv.