GSSL HELP THREAD!!!

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chilidawg

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Nov 27, 2013
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So I measured FI for +15V at NE5534 Pin 7 and I'v got -.013V at pin 4 I've got -14.99V Checking TL072 at pin 8 I've got 12.14V and at pin 4 I've got -12.03V
Please confirm this, you got -0.013v at pin 7?
For all NE5534, or just one?
If only one, with the GSSL switched off, set your meter to continuity mode. Put one probe at pin 7.
Do this:
1. put the other probe to ground (any solder point labeled "0" on the PCB)
2. if no beep, move the probe to pin 3 of the 7815 regulator.
3. report back here
 
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Harpo

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So I measured FI for +15V at NE5534 Pin 7 and I'v got -.013V at pin 4 I've got -14.99V Checking TL072 at pin 8 I've got 12.14V and at pin 4 I've got -12.03V
Double check, you measured the line receiver single op-amp NE5534 pin 7 for +15VDC, not the dual op-amp NE5532 (that would have pin 8 connected to +15VDC instead).
 

atticus1872

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Aug 12, 2021
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Double check, you measured the line receiver single op-amp NE5534 pin 7 for +15VDC, not the dual op-amp NE5532 (that would have pin 8 connected to +15VDC instead).
Yup totally checked the wrong one there. Now that ive checked the correct one I've got the following.
Left Side Right Side
Pin4 -14.98V Pin4 -14.99V
Pin7-1.343V Pin7 -0.683V
 

Harpo

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atticus1872, are the pics from post #8660 from your build? (you never confirmed)
If so, temporary disconnect the supersidechainboard in order to get a standard GSSL working.
Double check, the 10 ohm resistors located in between the 1000uF caps are still resistors (one looks blown).
Install the missing jumper at the on-board HPF provision, so signal could reach the sidechain.
Pull all +/-15V supplied op-amps and audio-VCAs and check if the +15VDC rail now comes back alive.
Nada, exchange the blown 7815 voltage regulator or remove the short on pcb from a FI solder blob.
If the +15VDC rail is operating again, power down and refit the pulled opamps and VCAs with correct orientation back in in a one by one cycle with a voltage check after each refit in order to catch the maybe blown part.
After replacement of the blown part, a standard GSSL should be operating.
 

atticus1872

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atticus1872, are the pics from post #8660 from your build? (you never confirmed)
If so, temporary disconnect the supersidechainboard in order to get a standard GSSL working.
Double check, the 10 ohm resistors located in between the 1000uF caps are still resistors (one looks blown).
Install the missing jumper at the on-board HPF provision, so signal could reach the sidechain.
Pull all +/-15V supplied op-amps and audio-VCAs and check if the +15VDC rail now comes back alive.
Nada, exchange the blown 7815 voltage regulator or remove the short on pcb from a FI solder blob.
If the +15VDC rail is operating again, power down and refit the pulled opamps and VCAs with correct orientation back in in a one by one cycle with a voltage check after each refit in order to catch the maybe blown part.
After replacement of the blown part, a standard GSSL should be operating.
I apologize for that! The only pic I posted on here was how I have the bypass switch wired up to verify I had done so correctly. I currently don't have pics posted of my build but I can add them if need be, but I think the build your referring to isn't mine as I don't have a super side chain board.
 

atticus1872

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Aug 12, 2021
Messages
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Location
USA
Please confirm this, you got -0.013v at pin 7?
For all NE5534, or just one?
If only one, with the GSSL switched off, set your meter to continuity mode. Put one probe at pin 7.
Do this:
1. put the other probe to ground (any solder point labeled "0" on the PCB)
2. if no beep, move the probe to pin 3 of the 7815 regulator.
3. report back here
Sorry that took me so long to get back to you I was away from the build and studio space for awhile.
Yes thats correct I've got -0.013V at Pin 7
For both NE5534 at the input.
Tried it out of curiosity no beep at pin 7 to 0
I Have continuity from pin 6 of both 5534 Input IC's to Pin 3 of the 7815 Regulator.
 

Gustav

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I wish I knew, I honestly don't know.
Are you getting +15 on the output pin of the 7815 regulator?

This might help

 

Ricardus

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No longer in NY and below the Mason Dixon line.
I apologize for that! The only pic I posted on here was how I have the bypass switch wired up to verify I had done so correctly. I currently don't have pics posted of my build but I can add them if need be, but I think the build your referring to isn't mine as I don't have a super side chain board.
Why don't you post some hi-res pics of the top and bottom of your board?

Also, I'm finding this thread hard to follow, but are you missing the +15 at some opamps but you have it at others? Check to see that you didn't miss installing this jumper, which I didn't notice at first when I built mine.
 

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atticus1872

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Why don't you post some hi-res pics of the top and bottom of your board?

Also, I'm finding this thread hard to follow, but are you missing the +15 at some opamps but you have it at others? Check to see that you didn't miss installing this jumper, which I didn't notice at first when I built mine.
Again sorry for the delay in reply reply I’ve been away for traning at my new job I’ll post some pics of the board later tonight, but I checked and I do in fact have that jumper wire installed!
 

atticus1872

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Location
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Are you getting +15 on the output pin of the 7815 regulator?

This might help

Sorry for the delayed replay I was off at traning for work. I checked the output pin of the 7815 regulator and the trafo secondary as a ground reference and I’ve only got .3 mV
 

chilidawg

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Nov 27, 2013
Messages
153
Sorry for the delay in reply. I don’t have continuity between either 0 and pin 6 as well as 0 and pin 7 either.
I didn't ask you to test continuity between pin 6 and ground.
I asked you to test continuity between the V+ supply pin and ground to make sure there's no short to ground.


For NE5534, the V+ supply is at pin 7.
NE5534-Pinout-537x303.jpg
For NE5532, is at pin 8.
5-x-NE5532-Dual-Low-Noise-Audio-Op-Amps-DIP8-NE5532p-Amplifiers-361917135130-3.jpg

Anyway, if there's no short, the next move is to check the 7815 regulator itself.

Sorry for the delayed replay I was off at traning for work. I checked the output pin of the 7815 regulator and the trafo secondary as a ground reference and I’ve only got .3 mV
To check the 7815 regulator, set your multimeter to DC voltage mode, put the black probe at pin 2.
First, check for input voltage. Put the red probe at pin 1.
Then check for output voltage. Put the red probe at pin 3.
LM7815-Pinout-525x360.jpg
 

Gustav

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Sorry for the delayed replay I was off at traning for work. I checked the output pin of the 7815 regulator and the trafo secondary as a ground reference and I’ve only got .3 mV

"Trafo secondary" as reference is vague. Do you mean the center tap?

Did you check the transaformer AC output voltages?
Did you check the voltage on the input pin of the 7815.

As I read your post, I do not know if you are seeing nothing on the ouput of 7815, because your reference is incorrect.

As I read your post, I have no idea if the voltage is "lost" on the regulator, before rectification, or on the output of the transformer.

This may help


Start at the start, let us know what works, and what/when it doesnt, and then, we may be able to help!


Gustav
 

Juanaca

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Dec 8, 2019
Messages
141
Hello everyone, I recently purchased 2 dbx202c (gold), I would like to know what parts I have to change apart from cleaning the entire VCA area. I have to change some resistance values in the nearby zones? Do I have to make a bridge in resistors taken from the VCA area? thank you
 

Juanaca

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Dec 8, 2019
Messages
141
I have been reading on the subject, I have found that you have to adapt the output impedance by changing the 2 15k resistors that are on the top of the 5532 oamps, also putting a 50k trim on the input pin of the 202 goal can. is this correct?
Thanks a lot
 
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