[Wicked Ace]

I have an Audio research SP-6 now that I have been using in an all tube rig. My question is: would this mate with a fet valve 400r?

[avahifi]

The Fet Valve 400R and 600R hybrid amplifiers have triode vacuum tube input stages and thus both have very high input impedances, in the range of 1 meg ohm.

Thus either is a very easy load for any preamplifier to drive, either vacuum tube or solid state preamplifiers.

Both have a voltage gain of 25 (28 dB) so both have normal gain for most any preamplifier or speakers.  The 400R swings 60V peak output, the 600R 70V peak output.  Thus 2.4 volts in drives the 400R to full power, 2.8 volts in drives the 600R to full power.

Frank Van Alstine

[Wicked Ace]

Thank you Frank, for both responses.