Seventh Circle Audio

Im using the AD797 opamp, and the instructions only pertain to the 990.

What do the voltages need to be for the 797? The sticky on this forum just says to install them, but it doesnt say what voltages they need. right now i have it at the lowest setting about +/- 14.6 volts.

SecondQ:
When Biasing i dont notice adifference in voltages on th e797 when SW2 is fully clockwise or Counter clockwise. Im not sure if im effectively shorting Conn1 pins 2 and 3, i kinda just stuck a wire in there.

and lastly when i switch the jumper on J6 and J8 from ADJ to the normal position the voltages at pins 4 and 6 dont drop to zero like the sticky says it should.

Any help would be lovely. Thanks

anyone out there?

The voltage should be set to +18 http://seventhcirclestudios.com/SCA/php ... ight=volts

I think i had the same problem you did with SW2. It turned i had the diode at D6 installed backwards. I flipped it around and it did the trick.
http://seventhcirclestudios.com/SCA/php ... .php?t=917

Well I successully set the voltages to +/- 18.

All my diodes are correct.

and I succesfully biased the U1 voltages, but i cant seem to bias u2 R50 seems like it has no effect on the voltage.

I have just finished two J99 with AD797, ans I have some troubles too.

- I cannot bias U2 with R50, same problem than hopelessennui.
- There's a lot of noise with the gain knob higher than 6.
- The output of the preamps are quite hot (more than A12 and N72), I cannot set the gain knob higher than 1 on drums overheads !

The voltages are +/-18.
The two units have the same comportment.

I have also succesfully finished four A12 and two N72 and they sounds absolutely fine !

Ok, i've switched the line output (j4) of my two J99 on power ground and the noise is gone.