[Orson Garnsey]

Given that the output of the Chime at the DAC chip is 50mV, is it possible to use a pair of output transformers to step up the voltage instead of using an output stage?

I realize that there is an opamp buffered output, but am thinking that a pair of 30:1 ouput trannies tied directly to the DAC would sound good.

Any thoughts? Anyone tried this yet?

[hagtech]

I don't think it will work, not enough output power.  We only get 1.2mA output full scale from the converter chip.  At a 30:1 output tranny, you'd get an output impedance of 45,000 ohms (from HAGDAC).  That won't drive anything.

jh

[Orson Garnsey]

I don't think it will work, not enough output power.  We only get 1.2mA output full scale from the converter chip.  At a 30:1 output tranny, you'd get an output impedance of 45,000 ohms (from HAGDAC).  That won't drive anything.

jh

Right, that pesky Ohm's Law.

I am also curious about the opamp choice for the HagDAC. Why the bi-polar 2604 instead of something like an AD8620? Are there technical concerns?

Thanks.

[hagtech]

Why the bi-polar 2604

The 2604 is a fet input.  Very good sounding opamp with plenty of drive.  I think maybe a little more slam than the 2134 I like in the Bugle.

Who knows why I pick certain chips.  Sometimes it is just kharma.  In fact, I rarely use AD parts because they screwed me royally back in '93 or so.  That may not be kharma, but at least unserendipity.

jh