Absolute top tier DAC for standard res Redbook CD

You know very well as I do that the output impedance on both are very similar with discrete transistor direct coupled outputs at 40ohms Bricasti and 32ohms Total, and clipping or drive is not the issue for either direct into 100kohm of the Gryphone, nor into the 10kohms of the Lightspeed Attenuator.

No, I don't know this.  It is really easy to get entirely different AC impedance by having different power delivery to the output stage, even if everything else is identical, which I'm certain it is not.  Even 40 versus 32 is a big difference.  These are static measurements, not dynamic.

The input DC resistance of the amps is not very relevant either.  The issue is the di/dt current required to achieve dynamics from the amps. Most amps have 50K-100K input resistance.  This is simply the resistor soldered at the inputs, not the same as the input impedance of the active devices.

Steve N.

Empirical Audio

The only situations where I see bypassing the preamp as possibly the same or better would be the using a DAC and amp of the same brand where the DAC is also specifically designed to output directly to the amps.

I agree.  Sometimes it can work out, but a good preamp, usually tubes will make the playing field much more fair for DAC shootouts.  DACs just don't have the low output impedance that a good preamp will have.

Steve N.

Empirical Audio

Sometimes it can work out, but a good preamp, usually tubes will make the playing field much more fair for DAC shootouts. 

DACs just don't have the low output impedance that a good preamp will have.