Morgan Jones step attenuator in Valve Amplifiers 4th ed

[jwags81818]

That sounds like an analog volume control on the DAC reference? To attenuate a signal digitally the bits have to change. Or am I missing something?

I said the data didn't change.
https://forum.psaudio.com/t/directstream-dac-mk2-bit-perfect-testing/34622
I don't understand it. I just trust PS Audio

 

[jwags81818]

You realize how ironic this sounds in the context of a valve amplifier where each device burns up watts of power in its heater... A typical audio signal of 2Vrms into 10k load is only 0.4mW "wasted"...

Thats why I said I like the IDEA of none of the signal being wasted. Surely there is no practical implication. But damn! they sound better.

 

[Mark Tillotson]

That's exactly how to think with microwave amplifiers, where every bit of gain is hard-won, but audio is easy, devices with 140dB gain cost a few cents!