Final Testing Question

[leo]

I just assembled two T15s. In performing the final check, I am getting some different voltages. On both I get approximately -18v at pin 4 of U1 on both units and I get +18v at pin 7 of U1.

I checked the THAT 1512 datasheet and it appears that the V+ should be at pin 7. The instructions indicate that the V+ is at pin 8 so I guess that is just a typo.

I was wondering if the +/- 18V is an issue. The instructions indicate I should be getting +/- 20V.

Both units have almost identical voltages.

I do not want to send a signal through if it is going to cause an issue.

Thanks for the help
Joe

[tpryan]

Your measurements are correct, it doesn't sound like you have any problems. If you install 1K8 resistors at R31 and R34, you'll get +/-20V for a bit more headroom.

[redstudio]

where would you get 1K8's to replace those? Just curious?

Thanks,
C

[tpryan]

http://www.mouser.com/search/ProductDet ... 71-1.8K-RC