1

CP4500 Stereo Bus Compressor / Re: Bad power voltages and reversed THAT1246

« on: January 09, 2026, 06:51:03 PM »

All calibrated and working now, thanks JP

2

CP4500 Stereo Bus Compressor / Re: Bad power voltages and reversed THAT1246

« on: January 09, 2026, 04:03:17 PM »

Bingo. Thank you. Another mistake! 

3

CP4500 Stereo Bus Compressor / Re: Bad power voltages and reversed THAT1246

« on: January 08, 2026, 06:32:41 PM »

OK I'm up to step 8 on the setup guide. I have a reading of 0.5VAC on the DMM but the trimmer T4 isn't affecting the meter at all. Turned it a considerable amount in both directions. No movement at all. 

4

CP4500 Stereo Bus Compressor / Re: Bad power voltages and reversed THAT1246

« on: January 08, 2026, 06:15:01 PM »

78L12 AND 79L12 were in the wrong place! 

Thanks for your patience and help. (I may be back once I get past the first stage of setup!)

5

CP4500 Stereo Bus Compressor / Re: Bad power voltages and reversed THAT1246

« on: January 08, 2026, 01:23:11 PM »

Still getting the same readings when it's just PCB (A). 
R41 Doesn't seem to be getting hot. 
I've replaced all the 1N4004 diodes.
Still the same. 

6

CP4500 Stereo Bus Compressor / Re: Bad power voltages and reversed THAT1246

« on: January 07, 2026, 11:49:28 AM »

pictures:

7

CP4500 Stereo Bus Compressor / Re: Bad power voltages and reversed THAT1246

« on: January 07, 2026, 11:42:32 AM »

Yes, sorry V- = -16.40

I've triple checked all diodes, BRs and polar caps are correct. Not seeing any solder bridges or forgotten joints - reflowed all the joints too.
I have R52 as 5K1 in the parts list, do you mean R41 and R42?
R41 and R42 both read 1.2 ohm.
I've given it a good clean too with Isopropyl alcohol.

I'm still getting the same results.

Trying to add pictures but the spam filter won't allow me to embed them or post a link.

Thanks

8

CP4500 Stereo Bus Compressor / Re: Bad power voltages and reversed THAT1246

« on: January 06, 2026, 04:41:02 PM »

Thank you. Including the VCAs?

I'm now getting 

V+ 4.59
V- 16.40

+12: 3.55
-12: .682

with no IC's in their sockets.

9

CP4500 Stereo Bus Compressor / Bad power voltages and reversed THAT1246

« on: January 06, 2026, 02:12:11 PM »

Hi,
I was getting bad readings in the first stage of the setup guide:


V+: .890
V-: 15.67

-12: .711
+12: .174

I checked everything over and realised the THAT1246 was in upside down.

I've since replaced the 1246 but it's the same - so I'm guessing something else has blown.

Not sure where to look,
Any help much appreciated.

10

EQ573 Equaliser / Stereo Link

« on: June 05, 2025, 01:10:56 PM »

Is there any reasonable way to mod these in order to stereo link 2 of them?

11

EQ573 Equaliser / Re: Knob issue

« on: May 26, 2025, 06:56:23 PM »

That fixed it, thanks!

12

EQ573 Equaliser / Knob issue

« on: May 24, 2025, 11:13:38 AM »

Hi
I’m having an issue where the frequency dial often moves the gain knob with it, is there any way to avoid this? Is this normal behaviour? 
Thanks