Pearl 3 Burning Amp 2023

[6L6]

Perhaps U3 or U4?

U3 and U4 are the halves of the dual opamp.

This would be very simple to check, swap the opamp left to right.

 

[cubicincher]

I would say, that it was a not so lazy sunday...
PEARL 3 - single OPAmp in the cases.
Greets
Dirk

 

[PierreQuiRoule]

Very nice. I like the big caps 👍. What is the second DIP switch for?

 

[bpr]

Verify that the TTA004 and TTC004 are in the proper positions on the bad board.

U3 and U4 are the halves of the dual opamp.

This would be very simple to check, swap the opamp left to right.

A004 and C004 are in the correct positions, and I've swapped the opamps between the boards to no effect. I've also re-checked all of the cabling and channel connections and it does indeed seem to be a problem with that board and not anything pre- or post- the Pearl 3.

 

[cubicincher]

Very nice. I like the big caps 👍. What is the second DIP switch for?

Hello PierreQuiRoule,
the left DIP-switch is for resistor loading (MC), the right DIP-Switch is for capacitance loading (MM).
Greets
Dirk

 

[6L6]

@bpr

On the inoperative PCB, are both the LED lit?

What is the voltage from opamp pin 4 to gnd? From pin 8 to gnd?

How tall are your standoffs? Perhaps someting is shorting out underneath?

 

[PierreQuiRoule]

A004 and C004 are in the correct positions, and I've swapped the opamps between the boards to no effect. I've also re-checked all of the cabling and channel connections and it does indeed seem to be a problem with that board and not anything pre- or post- the Pearl 3.

Troubleshooting can be frustrating. If you have not done so already, flip the board and carefully inspect for solder bridges. It happens...

Next, set your Voltmeter to DC, ground the black lead, then probe and compare bias voltages between your known-good and faulty boards to verify that they are the same. Check supply rails, output, and both sides of R1 as a start.

 

[PierreQuiRoule]

and follow 6L6's tips