[tonyptony]

High Frank. I just bought a pair of Von Schweikert Endeavor Special Edition speakers. They're rated at 4 Ohms nominal but I've been told they drop to 2 Ohms at a high negative phase angle somewhere above 1 KHz. Would that make either a mono pair of DVA 850 or SET 600 a better match?

[avahifi]

The DVA 850 mono amps would be your best choice if the speakers are very inefficient (83dB or less).

If a bit more efficient then a Fet Valve 600R would work great.

Remember if you increase the efficiency of a speaker by 3dB, this cuts the needed amplifier power in half.

[tonyptony]

Thanks Frank. They're rated at 89dB - figure probably closer to 88dB in real life. So you're thinking that in general the hybrid line would be a better option over the SET in this case?

[avahifi]

Given the very low impedance of your speakers, I think a Fet Valve 600R would be your best choice.

Note that this great amplifier has had several unannounced upgrades over recent years. You would not recognize its insides compared to a unit produced a few years ago.  Better in every respect.

Frank

[Tone Depth]

Frank,

Will there be an FET valve amplifier upgrade offered in the near future?

[tonyptony]

Given the very low impedance of your speakers, I think a Fet Valve 600R would be your best choice.

Note that this great amplifier has had several unannounced upgrades over recent years. You would not recognize its insides compared to a unit produced a few years ago.  Better in every respect.

Frank

Sigh. Not possible or cost effective to update an older 600R?

And is only the DVA 850 Mono available (in the hybrid line) with the switchable RCA / XLR input?

[tonyptony]

Hi Frank. Hope to hear back on my previous, above.

Also, is the 600R your recommendation in part because it is better at dumping current into a low impedance load than even the DVA 850 Monos?

[richter250]

I would also be interested in upgrading my older FET Valve 600R with the latest changes if it is possible and offers increased performance!

[avahifi]

Tony, since your speakers are 88-89 dB efficient, the big mono amps would be overkill.  Of course we would be happy to build you a pair.

It is not cost effective to upgrade an older 600R.  Every singe circuit board inside is different along with most of the wiring. The audio performance is real but not nearly the jump from the older “pre-R” versions. 

[tonyptony]

I appreciate the honesty, Frank, as always. Is the latest 600R available with an IEC socket and / or XLR in?

[avahifi]

IEC sockets have been standard on all new AVA equipment for several years now.

Optional switchable RCA/XLR inputs are a $200 option on our big power amplifiers. These require extra hardware and two more internal circuit boards, one to provide an active phase translator, the other the power supply for this.

[tonyptony]

Frank, this is just a curiosity question. How much current can the 600R supply into a nominal 8 Ohm load? Also for 2 Ohms? Thanks.