[marvda1]

what else are you getting for the $350 difference besides power ?
to re-word the question:
are there any other differences in the two amps beside power?

thanks

[avahifi_lj]

Hi:

The power output is the only difference between the two amps.  That said, however, the 550EXR has a bigger transformer to provide the additional ouput.

If you don't need the extra power go with the cheaper model and spend the savings on some good music!


Thanks for your interest in AVA products.

Larry

[Toka]

Sorry to bring this thread up again, but I'm trying to find the best match for my Polk SDA speakers...I was settled on the 550EXR, but then noticed this last sentence on the 350EXR page:

This is amplifier is recommended as the best Fet Valve amplifier for very low-impedance loads and electrostatic speakers.

Since my Polks are rated at 4 ohm (and typically dip below), would the 350 be the better choice? Or does the above statement apply equally to the 550?

[avahifi]

Since the 350 is lower powered, but uses the same array of output devices, obviously it cannot drive the outputs as hard, and thus has even more tolerance for very low impedance loads.

However, the "this amp is recommended as the best for very low impedance loads" actually goes back to the days when we were using Hitachi power mos-fets.  The new Exicon devices have greater current, voltage, power limits yet, so both the 350 and 550 are even more rugged than originally (and we have never had an output device failure with any production 350 or 550 series amplifier).  Either will work just fine with anything down to a nominal two ohm load.

Frank Van Alstine

[Toka]

Sounds perfect...and such a fast reply! Thank you sir. 

[rustneversleeps]

So under what condition would we need the extra power? I know you said something about 2 ohm load, how many 2 ohm load speakers are out there. I have the MMG, but they are not 2 ohm load, and I can drive them with 50 to 75 watts, wouldn't even need the 150 watts.

How many of you bought the 550 just for the sake of having the extra power? My question is will the 550 sounds better than the 350 if I don't use it's extra power?

Now if the 350 and 550 are only for high power application, will the lower power Delta (not being made anymore), or the Omaga have the same sound as the 350 and the 550, and just lower in power?

[Zheeeem]

I also have MMGs and am running a 350 EXR.  Works fine.

Maggies are pretty easy loads to drive.

I opted for the 350 because in the coin toss with my wife, I ended up with the smaller room.  She is running some older AVA electronics with some Tympani 1(U)s.

The Omegas will have similar sonic characteristics.  And it is indeed fine solid state equipment.  I had Omega stuff for years.  But, in a word, the Fet-Valve stuff is better. 

What to buy is always a challenge unless you simply have the cash to buy whatever you like.  I would venture that the 350 is one of the better, if not the best, hybrid amps out there.  But make sure you save enough money for an Ultra DAC.

[avahifi]

Really the only reason to get the Fet Valve Ultra 550 instead of the Fet Valve Ultra 350 is if you really need the additional power (nearly 300 watts per channel vs: nearly 200 watts per channel).

Note that the smaller amplifier can be upgraded to the larger one for the difference in price within the first 30 days of purchase (plus shipping) if you get the smaller amp, love it, but wish you had gone for the higher powered unit.

The sonic quality is identical.

Frank Van Alstine

[Toka]

One last question on this topic...are these amps 'common ground' amplifiers? I realize this may be a stupid question but I gotta be sure.  Thanks!

[avahifi]

Yes all Audio by Van Alstine amplifiers are common ground designs.  Of course the common ground point is selected to minimize internal ground currents and thus the amplifiers are very very quiet and have excellent separation.

Frank Van Alstine

[Toka]

Superb once again!  Absolutely cannot wait to make my first AVA purchase...strongly considering eating nothing by Ramen Noodles to make it happen. Such prompt and helpful replies mean more to me than all the hyperbole in the world.