Problems with 2 X DBX 165 compressors

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nycstudio1

Member
Joined
Jun 17, 2013
Messages
6
Hi there,

I am new here and thought of sharing some of the issues I am having with two DBX 165 compressors:

Unit #1

All functions work and it is compressing, however if I set threshold to -30 I can't get passed -10. These units usually compress  very hard but this particular unit does not.

Another issue, which I am not sure if is related is that the meter only works in gain reduction. Although signal is passing and output is working, meter won't work in in our out mode. If I hold the gain reduction switch half way I can get the meter working in output mode.

All caps and ic's are new, except for LM308 which I don't have in stock.

I slaved this unit to a working 165 and it compresses fine if controlled by another unit.

Unit # 2

The problem with this unit is that although it compresses fine, if I switch to gain reduction the meter will stop moving and will stay fixed at whatever ratio selected in the compression knob. This only happens if the switch is in gain reduction mode. If I move to output or input the meter works just fine.

Like the first unit, this one is also recapped and has new ic's except for LM308.

I swapped QA 1, 2 and 3 on both units to see if anything changed but so far nothing.

I appreciate if anyone could point me in the right direction.

Best!!

Louis
 
Hi,
it looks to me that you have problems with the dirty and corroded switches. Try to clean the master-slave, meter-input and meter-output switches by injecting some cleaning fluid (isopropyl alcohol etc..) into the switches, and switch them several times.
Regards,
Milan
 
Hi, thanks for the reply. Unfortunately the problem is not with switches. I found that both units have low input at some section of the circuit since I can't get passed -10 threshold, this is also causing the meter not to register output or input levels. I replaced all ic's including lm308 but so far I can't figure out where the signal gain drops. I am trying to get a clearer schematic so I can continue following with the scope. Meantime, if there's any other suggestions or someone out there who had to deal with similar problems and found the solution, I appreciate any tips/help. Thanks again.
 
Thanks for the reply.

Yes I went through the calibration procedure but unfortunately it didn't solve the problem. :(
 
Just to add to the description of the identical problem I am having with two units, Meter registers Gain Reduction.

Signal must be pushed for the Input meter to register. Output meter is not registering.

Thanks again.
 
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