Building my first super amp - questions

[krisbee]

This was posted on headwize also...

I am about to build my first cmoy amp. I will be adding an active bass/treble circuit, as well as the crossfeed filter.
My first question:

To power the bass/treble circuit, will the cmoy rail splitter be enough to power both amp and bass/treble? I assume I put it all to the same virtual ground.

Second, I will be adding a bypass so I can put a line out from the line in that will run to my computer in case I don't use my amp. Tying all these grounds to the vgnd is fine, corect?

I will also be adding a mono switch (for records), and a balance control as well.

The crossfeed will be a high-z version inserted in the line... where do you think, before or after the bass/treble? Should I wire in an bass/treble bypass? How would I do that, by putting a small resistor in line at the output of the circuit?

Thank you all for any suggestions.
Kris

 

[tangent]

Quote:

Originally Posted by krisbee To power the bass/treble circuit, will the cmoy rail splitter be enough to power both amp and bass/treble? I assume I put it all to the same virtual ground.

Put it this way: I don't think it will be any worse off than it already is. But I wonder, if you're going to put all this signal filtering in the way of the amp already, would you blanch at an AC-coupled ouitput? If not, there's a modification to the basic CMoy circuit that avoids the virtual ground imbalance problem. PRR posted it on Headwize, or you can find it in the single-supply circuit appendix of Op Amps for Everyone.

Quote:

Tying all these grounds to the vgnd is fine, corect?

Yes.

Quote:

The crossfeed will be a high-z version inserted in the line... where do you think, before or after the bass/treble?

Depends on what the tone control circuit looks like.

Quote:

Should I wire in an bass/treble bypass? How would I do that, by putting a small resistor in line at the output of the circuit?

Again, no one can guess without seeing the circuit.

 

[amb]

See the thread below for a Baxandall tone control circuit I posted. It can be used in a cmoy-style circuit. Since the tone control stuff is all in the feedback path, it doesn't interact with any crossfeed circuitry you add to either the input or the output.

http://www6.head-fi.org/forums/showthread.php?t=107568

 

[krisbee]

Quote:

But I wonder, if you're going to put all this signal filtering in the way of the amp already, would you blanch at an AC-coupled ouitput? If not, there's a modification to the basic CMoy circuit that avoids the virtual ground imbalance problem. PRR posted it on Headwize, or you can find it in the single-supply circuit appendix of Op Amps for Everyone.

Not at all... I have been looking at all the power supplies on your website, and still haven't figured out what would work best for me! I wish I could use the circuit with the noise reduction, but I think this will draw too much power.


Here is the circuit as posted on headwize

 

[krisbee]

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