What is the Sound of Impedence Mismatch?

Lack of dynamics, recessed sound, and different interconnects making big differences to the tonality - are what you would expect if the ratio is too low. But you can also have problems when the ratio is too high. For example I has a ss preamp using BUF03s as an output device, and these things have vanishingly low output impedence, driving a tube amp with high input impedence and the sound was overly hyped and hard-edged. Padding down the input impedence of the tube amp improved the neutrality and overall naturalness, and fleshed the images out.

Dull, lifeless musical rendering, massed strings undifferentiated, often somewhat harsh, grainy sound, no bloom, lack of dynamics . Redkiwi is right to these here ears.

Thank you, gentlemen.

I am playing with a First Sound Presence Deluxe tubed line stage, which has an output impedence of 1700 ohms. It's very happy with my CJ 11a at 100K ohms input impedence. But with the Pass X-150 (spec sheet says 22K balanced, not sure what it is unbalanced, which is the way I am running it), the sound is, if anything, a bit bright and over-etched. No problems with bass or dynamics, definitely not lifeless, just tilted up a little. From your descriptions, it doesn't sound like this is a technical mismatch, however. Could be a listener mismatch :)

dan

Sounds like the Presence has too much "presence". Which tubes is it using? Sometimes a simple tube swap is all that's required to restore a more pleasant tonal balance...
Of course if you are just borrowing the piece and can't change the tubes, that's another matter.

No, I own the piece. To tell the truth, I don't know what tubes are in it. I'll have to open it up and check.