[alex231343]

Having read the circuit of Jan's Corda amp, I found that no matter which crossfeed is switched (even the fourth switch), crossfeed signal still present because of the 2200Ohm resistor connection to both left and right channel.

My question is:
How to eliminate crossfeed signal totally?

Thanks for your attention

 

[Braver]

hmm, I'm not so good at reading circuits, but you seem to be right.

 

[slindeman]

There's more to it than that, though I don't know the math behind it. Basically it has to do with impedances or something. See http://headwize.powerpill.org/ubb/sh...fnum=3&tid=405 where Jan discusses the methods to bypass the crossfeed, and its here that he briefly mentions why with method 1 (which is the method used in the Corda HA-1) there must be a buffer before the crossfeed in order to prevent there being crossfeed when the side branches (the cap and resistor pair) are bypassed with the switch.

 

[Jan Meier]

"Having read the circuit of Jan's Corda amp, I found that no matter which crossfeed is switched (even the fourth switch), crossfeed signal still present because of the 2200Ohm resistor connection to both left and right channel. "

With the crossfeed switch in position 1 the side branch of the crossfeed filter has (nearly) zero Ohm resistance. The signals at each site of the 2200 Ohm resistor therefore simply are the output signals of the input buffers and there will be no crossfeed.

Cheers,

Jan

 

[alex231343]

ic

thanks Jan