CA-810 "measurments and adjustments"

David57

Active Member

• Feb 17, 2011

• #1

My CA-810 service manual just arrived and I am trying to dial this amp in after doing some work on it.

There is no mention in my manual of the adjustment of VR801, physically located at the back of the amp, off center to the right, and in front of the pre-out connectors.(as viewed from the front of the amp)

The two meter and two "idling current" adjustment points are accounted for.

Could this be a voltage adjustment for the protection circuit? does anybody know the purpose, spec and test points of this VR?

Thanks,
David

 

ecluser

Super Member

• Feb 17, 2011

• #2

It seems to me an adjustment for the + and - regulated supplies. Nothing in the power supply section about adjustments?

Are you entomologist?

 

David57

Active Member

• Feb 18, 2011

• #3

I suspect that my service manual is lacking. There is nothing in mine about adjustments for the power supply.
With your advice I have found a direct link between this VR and the +- voltage going to the tone control board, this value (+and-25V) is printed on the pcb so I will set it for that.

No, not an entomologist. It was a mistake I made in my photo editing software that seemed to fit. A break from the linear. Maybe I could use it as a highlighter?

Thanks for your help.

 

brutal

YamaHoarder

Subscriber

• Feb 18, 2011

• #4

There's a bug in the design.

 

avionic

" Black Knights " F-15 back shop EW avionics

Subscriber

• Feb 18, 2011

• #5

1-800 -Call-Orkin

 

EastPoint

Recycler

Subscriber

• Feb 3, 2020

• #6

David57 said:

I suspect that my service manual is lacking. There is nothing in mine about adjustments for the power supply.
With your advice I have found a direct link between this VR and the +- voltage going to the tone control board, this value (+and-25V) is printed on the pcb so I will set it for that.

Click to expand...

Thanks for posting this. I had some issues on a Ca-810 and accidentally adjusted the Vr801 trying to change the idle. Thanks to this post I was able to readjust it correctly.