Anyone know why 8 TL072 Opamps in Triaxis?

[Mandarine]

Number IC1 - IC8 ? On the main Audio Board?

 

[msi]

They are part of the tone stack. The guitar signal never goes through them. They are used to ensure you get a constant and reliable setting on the tone controls. The Triaxis uses light dependent resistors instead of potentiometers. But LDRs can drift in value over time. The Opamps are there to ensure that the value one day will be the same the next. The patent number is 5,208,548 I believe.

 

[Mandarine]

Ah. Thank you very much for the insight. Learning more and more about this amp all the time. If one is to devote this much time and effort into such an instrument, it is nice to know that the instrument is worthy of such devotion. It has taken quite a bit of time to learn the intricacies of this device. Not so much a single mode on it's own, but all nine modes working together.

 

[Mandarine]

oops. 8 modes.

 

[disassembled]

The are 2 OPAMPs for audio signals. IC3 is the one that passes 100% of the signal no matter what. There's another OPAMP used for the recording outs but I forget which number.

FYI there's a thread about changing IC3 to a Burr Brown for a more dynamic preamp.

Greg

 

[msi]

yea, I kind of fudged the exact uses. One opamp is used for the dynamic voice, and another is used for the speaker sim outputs.