rca inputs to aleph-x

[jrsun]

2 questions:

1. ground xlr "-" or leave it open or no difference ?
2. change 10k input resistor to 1k to raise the gain ?

Thanks!

[Nelson Pass]

1) Ground the - input

2) No. That will give you a 1K input impedance and use up
all the gain the amp has.

[vdi_nenna]

Does the - input need to go through any resistance to ground? If so, any recommended value?

[jrsun]

Nelson,
Thanks!
How much bias current you would recommend for 12 x 240s per channel configuration if heat dissipation can be resolved ? 6 amps ? or higher ?

[Nelson Pass]

Originally posted by vdi_nenna
Does the - input need to go through any resistance to ground? If so, any recommended value?

A short is just fine.

Originally posted by jrsun
Nelson,
Thanks!
How much bias current you would recommend for 12 x 240s per channel configuration if heat dissipation can be resolved ? 6 amps ? or higher ?

Take the supply voltage, subtract 3 volts, double it, and divide
by 8. This would be the minimum total bias for that channel
(1/2 to each side) if the current sources are set at 50%. Of
course you can go higher or lower, but figure that 12X240's
is a max of 600 watts, and that practically means about 200+
watts of output, in other words, an XA200, although an XA200
uses 32 devices per channel, at about 25 watts or so each.