[S_Dedalus]

I recently put together both a cmoy and a meier bass enhanced crossfeed.
At high volumes and low frequencies, it seems like the cmoy loses control over the headphones, and the sound gets really grainy, and the bass seems boomy and bloated. Without the crossfeed filter it sounds fine. I know its not a problem with that, though, because it works great leading into the mint amp I have.
Is this problem just the cmoy not being able to provide enough current for Grado's?

 

[drewd]

Quote:

Originally Posted by S_Dedalus I recently put together both a cmoy and a meier bass enhanced crossfeed. At high volumes and low frequencies, it seems like the cmoy loses control over the headphones, and the sound gets really grainy, and the bass seems boomy and bloated. Without the crossfeed filter it sounds fine. I know its not a problem with that, though, because it works great leading into the mint amp I have. Is this problem just the cmoy not being able to provide enough current for Grado's?

That seems reasonable. Remember, the MINT has output buffers to provide extra current, and with low impedance cans like Grados, current is a precious commodity. If you're using a standard resistor divider for the virtual ground of the CMoy, the supply voltages may be drifting somewhat when the opamp is driving hard. Tangent's web site goes into some detail about that in his excellent article on virtual ground circuits.

I haven't used crossfeed on a CMoy amp, but I can definitely hear signs of struggling when I crank the volume up with a pair of SR125's plugged in. The CMoys that I've built with buffered outputs don't seem to have that problem - but at that point, they're really a MINT without the multiple feedback loops.

-Drew