Calibra DIGI 1600

[Perry Babin]

Which terminals of the regulators have DC (look with scope)?

Measure from those terminals to the secondary ground.

 

[chrisg4]

I got 108v

 

[Perry Babin]

#81 should have been rectifiers, not regulators.

Are you saying that you have ±108v from the secondary ground to the rectifiers?

Which terminals of the rectifiers has the DC voltage (center or outside)?

 

[chrisg4]

No sorry, I got 108v to the voltage regulator... from secondary ground

the outside legs of the rectifiers have 35v dc

on the source pads of high and low sides I measured 71vdc and -71vdc from secondary ground.

 

[Perry Babin]

What DC voltage do you have on the center legs of the rectifiers?

 

[chrisg4]

Hi Perry,

please advise what ic is OU2 in below circuit?

 

[Perry Babin]

I don't know. For the remaining markings, do you see any other ICs in the amp with the same markings?

Post a photo of the bottom of the board for those components.

 

[chrisg4]

Hi Perry,

Don't have a clearer pic right now.

OU1 is the MC14060

could it be a TL072?

 

[Perry Babin]

Some (all?) of the TL072s have a CP suffix, not a CN. In the datasheet for the TL-07x ICs, the 074 typically has the CN suffix.

Look at the attached diagram to see if you can find the IC that has the same circuit connections.