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CP5176 FET compressor / Re: CP5176 only compresses in 20:1 / SLAM mode

« Last post by Ptb on December 04, 2025, 03:56:20 PM »

Measurements: U1 pin 1 = 1.10 VAC, U1 pin 5 = 0.55 VAC.

I inspected the solder joints around U1 and the checked resistors; solder joints look OK and the resistor values (R25, R27, R33, R34, R35) match the values.

82

CP5176 FET compressor / Re: CP5176 only compresses in 20:1 / SLAM mode

« Last post by JPK on December 01, 2025, 04:04:12 PM »

With the same conditions as in 4. Check the side chain
What AC voltage do you get on U1 pin1 (1.4VAC) and U1 pin5 (0.7VAC) ?

Check the solder joints and value of resistors R25, R27, R33, R34, R35.

83

SK49 Multi-patern Tube Microphone / Re: How long is the 7-pin XLR cable that comes with the SK49 kit?

« Last post by JPK on November 27, 2025, 11:34:32 AM »

84

EQ573 Equaliser / Re: Signal going through the unit but it doesn’t effect the sound

« Last post by JPK on November 27, 2025, 11:34:15 AM »

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CP5176 FET compressor / Re: CP5176 only compresses in 20:1 / SLAM mode

« Last post by Ptb on November 26, 2025, 09:29:48 PM »

Thanks, here are the measurements

AC level on TP3:

• Ratio 2 : 0.65 VAC = 3,3
• Ratio 4 : 1.3 VAC = 6,58
• Ratio 8 : 2.1 VAC =  9,04
• Ratio 12 : 3.4 VAC = 11,02
• Ratio 20 : 5.9  VAC = 11,69
• Ratio SLAM : 6.6 VAC = 9,56

DC level on TP4:

• Ratio 2 : 0 VDC = 0
• Ratio 4 : -0.5 VDC = -0,5
• Ratio 8 : -1.3 VDC = -1,3
• Ratio 12 : -2.5 VDC = -2,5
• Ratio 20 : -5.5 VDC = -5,5
• Ratio SLAM : -0.6 VDC = -0,6

DC level on JMP1 pin 1:

• Ratio 2 : 0.6 VDC = 0,7
• Ratio 4 : 0.9 VDC = 14,42
• Ratio 8 : 1.2 VDC = 12,3
• Ratio 12 : 1.9 VDC = 11,78
• Ratio 20 : 2.3 VDC = 9,17
• Ratio SLAM : 7.9 VDC = 13,8

DC level on TP6:
      -4.5 to -1.2 VDC depending on P6 = -13,2

DC level on TP5 with jumpers JMP1 on 2-3 and 4-5 [o o-o o-o]:
      0.32 VDC =  0,32 

A 12,7
B -0,6
C 13,3
D -0,2
E 15
F -0,8
G -15,1

86

EQ573 Equaliser / Re: Signal going through the unit but it doesn’t effect the sound

« Last post by Colindsv on November 25, 2025, 10:57:48 PM »

Fixing the relay worked!


Thanks for your help!

87

SK49 Multi-patern Tube Microphone / Re: How long is the 7-pin XLR cable that comes with the SK49 kit?

« Last post by Alex Harmer on November 25, 2025, 10:57:37 PM »

Thanks very much for an amazing microphone design!

I've just finished building my pair in New Zealand. They are working perfectly, no issues. 

88

CP5176 FET compressor / Re: CP5176 only compresses in 20:1 / SLAM mode

« Last post by JPK on November 25, 2025, 09:52:57 AM »

Can you do the measurements shown in 4. Check the side chain in this page?

89

CP5176 FET compressor / CP5176 only compresses in 20:1 / SLAM mode

« Last post by Ptb on November 25, 2025, 07:07:08 AM »

I have a problem with my CP5176: it only compresses in the 20:1 (SLAM) mode. In all other ratio settings (4:1, 8:1, 12:1) there is no audible compression and the gain reduction meter does not move, even with high input level.

All calibrations have been done according to the manual and the values are correct. The unit passes audio fine and sounds good in 20:1, but the other ratios seem inactive.

90

MP566 Tube microphone preamplifier / Re: MP566 no DI sound

« Last post by TomT on November 21, 2025, 02:58:13 PM »

Thank you very much!

The voltage is 21,37V in both situations, no drop.
I will replace the Q1.

I will send an email for an order (need some other things as well  ).

Kindest regards,
Tom