Power Supply Question +/-15V with 1176

[dryman]

After building an 2x1176 with Stereo-Link, i try out a to integrate an internal crush'n'blend. For CnB i am using NE5532 and NE5534. I wonder, if i can use the +30V from the PSU as Power for the Opamp. I want to get the signal after input-transformer, and before output-transformer, to get the signal through the irons. Do i need an extra PSU or is there a trick to get +-15V and GND?

 

[gswan]

You can use +30V, but will need to create an artificial ground point halfway between the two with a resistor divider and a voltage follower. Since there will be a 15V DC offset at the output you will need to make sure you use capacitors to decouple the input and output.

 

[dryman]

thanks for your answer. In the meantime, i saw on the gyraf-schematics, that the opamp is doing it in the same way. It uses two 100kOhm resistors to create the artifical ground point. Because i am not shure, if the Alternate PSU of my 2x1176 give enough power, i build a seperate PSU for +-15V with 7815.