[Doug_B]

Hi,

As I dig deeper into all the products represented on audiocircle, I get more interested in hybrid tube/SS amps. I'd appreciate some opinions on the current AVA Fet valves, and especially from those of you who have used either of them as well as an Odyssey Stratos. I currently have a "stock" Stereo Stratos (w cap upgrade) and was planning on upgrading it to a Dual Mono down the road (maybe w/in 6 months), but I am intrigued with what I've read so far on these AVA amps.

As a point of reference, I use planar Mains (Soundline Audio SL3s, which are based on a BG ribbon) and have my 2ch music listening integrated with my HT system. 2ch is still going through my HT controller (AVM20 w analog bypass), but I do plan on getting a pre with HT bypass so I can decouple my 2ch from it. A hybrid design like these Fet amps would allow me to mate a tube amp sound with my mains without getting into a more complicated bi-amp setup (at least to me it's more complicated, given the integration with my HT setup).

Thanks.

Doug

[jackman]

I compared my Fetvalve 550HC (the older model) to some Odyssey Xtreme mono-blocks a while back.  Here is a link:

http://www.audiocircle.com/index.php?topic=989&highlight=jackman

The Fetvalve has powerful bass, excellent detail and the sound can be slightly taylored to your system with proper tube rolling.  The model used in the listening evaluation used inexpensive Chinese tubes and has since been upgraded to EX status, a major improvement.   Tyson has also tried his Fetvalve versus some pretty nice amps and has written some excellent descriptions of the events.  

I have a suggestion, just order one and try it on your system.  Van Alstine has a 30 day demo policy (I think it's 30 days) and you can make up your own mind if you feel it sounds better.  AVA amps are very solidly made but the Fetvalve only weighs about 40 lbs. so return shipping won't be that bad if you decide to return it.    I don't know if you are in the Chicago area, but if you are, you are welcome to come to my house (as long as you bring your amp for a comparison).  

The Fetvalve is a very unique design that uses inexpensive/long-lasting tubes.  No other amp has sounded as good on my system.   Also, you may not want to limit your AVA choices to the Fetvalve.  The Omegastar amps sound mighty good.  I'm kicking myself for not buying a used one a local guy was selling at a good price.  It was sold before I could reply.   You just missed out on a used on on the AVA site (with one year warranty).  

Good luck,

Jack

[Tyson]

Do a search on 550ex with my username and you will see some pretty detailed comments/comparisons/reviews.  It's the only amp I've had that I didn't feel the need to upgrade after 6 months of ownership.

[Doug_B]

Jack,

Thanks for the feedback. Not near Chicago, but I do appreciate the offer (oops, didn't notice that I had left my location out of my profile). At this time, I am curious as to how tubes would sound in my system, either at the pre or amp level (FWIW, I do have an Ah! 4000 CDP). I sometimes perceive a bit of harshness with my ribbons at volumes a bit lower than the maximum I can stand.

Not having been exposed to tubes much and not being the type who buys and sells lots of equipment in search of audio nirvana, I must narrow down the contestants based on feedback from forums such as this before taking the purchasing step, even if a trial period is available.

Tyson,

Yes, I have seen a few posts of yours re the 550ex, and I'm well aware of your history with the Odyssey amps, so your opinions are particularly relevant to my situation. I haven't read the full thread associated with your 550ex review yet (but I will shortly), but I did read enough to get clarification on your interpretation of "lean", in that it really applies to just the mid and upper bass. Until that explanation, I thought you were referencing frequencies toward the high end. I wouldn't mind a further clarification of this leanness as it might apply to my speakers, though. Since you likely never heard them, they use a 50" BG ribbon that is crossed over at 250 Hz to an 8" woofer module. Any guesswork on your part would be appreciated. By the way, your repeated use of the "smoooothness" characteristic did not go unnoticed   .

BTW, what criteria should one use to determine whether to go with a 350ex or a 550ex?

In any event, I may end up purchasing a preamp prior to making my amp upgrade decision, so any thoughts on the Transcendence 7 would be useful (although I would need a HT bypass / unity gain input). Did you ever mate this with the Odyssey DM?

Edit: Looks like the EC version of the T7 has an External Processor Loop, which I assume can be used for HT bypass.

Thanks.

Doug

[avahifi]

Not that the existing Fet Valve 350Ex and 550Ex are not great amplifiers, but thought I might let you know that we are now starting to ship astonishingly improved Fet Valve 350EXR and 550EXR models (same price for the time being).  "R" stands for Regulated power supplies - - - an all new multi-stage, high voltage, low impedance, regulated power supply board with seperate wide band regulators for each section of each audio board (six separate regulator circuits in all).  The musical improvements are in the "drop dead" range.  More later after we get past the absolute chaos of relocating everything this weekend.  I believe we have raised the bar for high fidelity playback a whole bunch.  Frank Van Alstine

[dvb]

Now, as I await delivery of my "new" used 500ex, I can be immediately dissatisfied with it and start planning to send it back for an upgrade.

 

[Tyson]

Doug,
I can't comment on the new regulated versions of the amp (as I've not heard them, yet )  But I CAN say that the sound can be altered by changing tubes.  If you stay with the stock EH tubes, they sound like supersmooth, very dynamic solid state amps.  Switch in some Mullard tubes and they start sounding a LOT more tubey, with fatter bass, warmer mids, softer highs.  Amperex tubes have a nice sound that is midway between these 2 sounds.  I alternate between all 3 tubes depending on my mood this week or this month.

I can also say that with ribbon speakers (which are truly ruthless at revealing upstream equipment), getting a non-grainy, non-fatiguing amp is imparitive.  And, since ribbons are usually difficult to drive, you need a lot of grunt.  The 550ex has both of these qualies in spades.

I've heard the 350ex at a friends and it sounds just like the 550ex, but just won't play as loud or give you 500 watts in to a 4ohm speaker like the 550ex will.  But, within it's power range, it's control and drive are superb.

[jackman]

I totally agree with Tyson's statements.  I have a set of Mullards and find them to be more "tubey" than the stock EH (Tesla?) tubes.  I like the more solid state sounding EH tubes because my system doesn't need any additional warmth (I also use a T7 Preamp which is also an amazing pre).  Don't have the regulated power supply (yet!), but I'll keep everyone posted on the difference when I have my gear upgraded.  

One thing that really struck me regarding the AVA gear is the fact that all of my CD's are very listenable.  My system has all of the detail that I love, however it is never harsh.  If I hadn't seen it (or heard it!) first hand, I would have never believed a little 39lb. amp could be so powerful.  Even though I don't have ribbons, my Ellis are very resolving.  They can be brutal on less refined gear.  The AVA is a very nice match.

J

PS- Don't rule out the Omegastar series if your budget can't accomodate the Fetvalve.  I listened to an Omegastar 440HC and found it to be very close to the older model Fetvalve EX.  The Omegastar was not solid state sounding at all.  An Omegastar/T7R would make an excellent combo.

[Doug_B]

we are now starting to ship astonishingly improved Fet Valve 350EXR and 550EXR models (same price for the time being).

Just the kind of offer to make me shift my priorities . Thanks for the info ... I think.

Amperex tubes have a nice sound that is midway between these 2 sounds.
...
And, since ribbons are usually difficult to drive, you need a lot of grunt. The 550ex has both of these qualies in spades.

Hmm, I happen to have Amperex tubes in my Ah! player; informed that it would mate better with my ribbons than the more popular Seimens. Do tubes of a particular brand generally have the same characteristics across different tube types (I assume that the Fet Valves use a different type than my Ah!)?

As for my ribbons, the literature lists them at 88db sensitivity. My stereo Stratos drives them comfortably. I've also tried out an old 100W/ch Pioneer receiver and tested a HK 325 receiver for a friend, and both had no trouble driving them (at least there was no dynamics hit when pumping up the volume). I would think the 350ex (or exr) would have no problem based on its rating.

PS- Don't rule out the Omegastar series if your budget can't accomodate the Fetvalve.

As long as the increased expenditure is justified sonics-wise, I wouldn't have a problem going with one of the Fet Valves. May just be a timing issue, as I'd like to get a new modded universal player first.

Assuming I was in the market for both a T7 and a Fet Valve but needed to space out the purchases by a few months, which would provide the greater benefit first, given that I currently have the stereo Stratos and am using an AVM 20 for preamp duties (with no digital processing)?

Thanks.

Doug

[Tyson]

The T7, without question.  It's a hell of a preamp.  And the Stratos (while not in the class of the FetValves) is no slouch.

[avahifi]

The "R" power supplies (also done in all the Transcendence preamps and Transcendence DAC) bring up the musical listening experience way more than a tube swap.  The worst tube you can find will sound better in a "R" series unit than the best one did in the old series.  Of course the best tube will still sound best, but we are getting the best out of any tube.

We are talking explosive dynamic range and transcient response, no grain, no glare, rock solid three dimensional imaging from wall to wall and beyond, powerful deep clean bass control, highs that just float out with transparency and detail, I could go on and on.  Last night while I was working late, and already knowing how amazing the "R" series is, a man's voice on radio came on saying "hello how are you doing?" and that made me jump and turn around, cause I thought somebody was in the room with me!

A tube swap is not even in the same ballpark although you can still play with that if you like.

We will tell you about our pretty generous upgrade policies as soon as we move, running out of time here for the next few days.

[doug s.]

I totally agree with Tyson's statements.  I have a set of Mullards and find them to be more "tubey" than the stock EH (Tesla?) tubes

the jj toobs are the tesla tubes, dunno about the electroharmonics tubes.  i like the jj 6l6gc's in my mesa baron, a really nice replacement for the nos philips toobs i was using, but was having biasing problems with.  i got a good deal on the jj's from:

http://eurotubes.com/

supposedly, the jj's are a bit more neutral than the eh tubes, but i haven't tried them, so this is second-hand info...

doug s.

[John B]

we are now starting to ship astonishingly improved Fet Valve 350EXR and 550EXR models (same price for the time being). "R" stands for Regulated power supplies - - - an all new multi-stage, high voltage, low impedance, regulated power supply board with seperate wide band regulators for each section of each audio board (six separate regulator circuits in all).

Any chance these new models have detachable power cords?  You'd probably have an order coming your way if so

[avahifi]

Sorry, no detachable power cord, this is an upgrade to the existing chassis metal and circuits.

The power cord is simply the last 5 feet of several hundred feet of primary transformer winding wire, why you people are so obcessed with fiddly ass ding dong nonsense when that is simply not where the problems are is way beyond me.

We engineer a new power supply that lets our hybrid circuits simply knock you thru the back wall with dynamics and what you really want is a different power cord?  Geeze!

[John B]

why you people are so obcessed with fiddly ass ding dong nonsense when that is simply not where the problems are is way beyond me.

Sorry Frank, but you miss the point.  There is no problem with your amp as is, or any amp for that matter.  I've had your 350EX in my system, and it was wonderful.   What I have found though, is that the specific power cord that I own increases what is already good about an amp, pre-amp or source component.   It has a dramactic and universal effect on all equipment it's been used on, it makes electronic reproduction of music more "musical".   This power cord has done this transformation on every component I've tried it on.   So, for this customer, it's a plus, and one I would not give up simply because a manufacturer has determined from their limited experiments with power cords, that no improvement is possible.  I do respect your decision not to offer this flexibility with your gear, however, for this customer, it is a limitation I simply can not except.  If you ever decide to offer improved flexibilty for your amps, please let me know, I'd love to be return customer....and the point you missed you ask?.....it's that old adage don't you know..."the customer is always right"  

[doug s.]

john b, you can install an iec jack into almost any piece of gear that has a hard-wired power cord.  or ya can hard-wire yer power cord of choice directly into the component - this would likely give a better performance anyway, eliminating the connector...  if i *really* wanted someting, i wouldn't cut off my nose to spite my face...  

but, i understand the frustration w/that "customer is always right" thing.  yust yesterday, a cable mfr refused to even offer me the opportunity to buy a pair of 6m interconnects w/o added-cost sleeving, cuz that length requires "unsightly" poly-heatshrinking of the teflon insulation joints, which aren't required in their shorter runs, so they offer shorter runs unsleeved.  if i can live w/one or two visible heat-shrink joints in a 6m run of cable, for a better price, & possibly even better sonics, why does the mfr refuse to offer me this option?  

doug s.

[John B]

Doug,

I know I could have Frank's amp modified.   But why should I have to?Frank has already bit into the proverbrial apple.   His whole design philosophy centers around the fact that a well designed component should be perfect in and of itself.  Tweaks should not have an effect on such a well designed electronic instrument.   It's an attractive philosophy, especially at his prices.   Enough so that I bought his transcendence pre-amp and fet-valve amp.   I was very impressed with their musical nature.  But I'm an experimenter by nature and I just had to try some tweaks.  My wire experiments at the time proved Frank right, they didn't make much of a difference with his gear.   But then I tried a power conditioner by another talented designer, Mike VansEvers, and when I connected Frank's amp to this power condition there was a difference, a very positive musical difference.  So a chink in the purist design philosphic armor of was found.  

Then came a chink in the armor from the man himself  All of a sudden vaccum tubes made a difference, and he offered various types of the magical tubes to go with his gear.  Come on, vaccum tubes?  What is a vaccum tube?  It's a glass enclosure, a heated filament, a wire grid, a metal plate, and a number of leads.  Somehow one made in China, one in Russia and a bunch made 30 years ago all had sonic importance on a well designed component.  Where's the logic in that?  Well, I know from my own experiments with a tube CD player that different tubes in fact had a signficant effect on the sonics.  But taken from a purely logical, and design purist standpoint, it shouldn't have.  And for many years that's exactly what Frank espoused.

So, the vaccum tube fanatics are now being catered to by AVA.  So what about us wire heads  How far are we from glass enclosure, heated filiment, wire grid and a number of leads.   Heck I was in Frank's camp for many years, I couldn't get past the logic of how house wiring (certainly not audiophile grade) could interact with a $1000 power cord to produce better sound to the degree of the expense of said wire.    However, such that I am a diehard experimenter by nature, I took a challenge to try some expensive wire, with the provision if I didn't hear a difference commiserate with the expense of this wire I could return it for a full refund.   No chance of loss, so I took the challenge.   In the past when I'd tried moderately expensive wire I'd call the changes subtle.   That's what I was expecting with this power cord, and I was already thinking of ways to spend my refund  Suffice it to say the change was not at all subtle and I still have the power cords.  I did'nt blind test the changes, but I did a/b the cord more times than I care to remember, and with a number of components to the point where I understood the signficance and reality of the sound change produced by this power cord.  

So, I say my power cord version of glass enclosure, a heated filament, a wire grid, a metal plate, and a number of leads makes as much of a difference as Frank's offerings for the tube guys.   But since Franks heard a difference with the fiddly ass ding dong tubes, and not the fiddly ass ding dong power cord, the tube customers get what they want, and us power cord guys are simply delusional.  Me thinks a pot is calling the kettle black

[avahifi]

I have done listening tests over the years with various cables and wires, double blind tests, in which neither the listener or the tester know in advance what has changed and under these conditions the differences vanish.  If you know you just paid $1000 for a new cable, certainly it will sound better.

Regarding tubes, they are active devices, with different gain bandwidth products, and each brand is different, and even sample to sample within brands, most of which we can sort out with a square wave generator and dual trace scope.  As the equipment gets more sophisticated though, we can't make fine enough evaluations with test equipment, and have to resort to listening, oh dear! But active devices with different characteristics do make a difference.

Regarding removeable power cords, why should we retool the chassis and charge everybody extra for the higher cost when only a few are obsessed with power cord sound? Pray tell me what possible effect electrically that a different power cord will have (maybe a bit of RFI filtering - hey the power transformer is one hell of a RFI choke in and of itself) and I will pay attention.

If the customer was always right, our equipment would be need to be wired with Gonzo cable completely internally (customers choice as to which Gonzo cable), built completely with $50 each capacitors and resistors (again customer option), and cost $50,000 each instead of where it is and there would be no customers who were always right who could afford buying it, and we would be out of business like a lot of the "make it with an inch thick faceplate and weigh 200 pounds and charge you a fortune" companies.

Frank Van Alstine

[avahifi]

I have done listening tests over the years with various cables and wires, double blind tests, in which neither the listener or the tester know in advance what has changed and under these conditions the differences vanish.  If you know you just paid $1000 for a new cable, certainly it will sound better.

Regarding tubes, they are active devices, with different gain bandwidth products, and each brand is different, and even sample to sample within brands, most of which we can sort out with a square wave generator and dual trace scope.  As the equipment gets more sophisticated though, we can't make fine enough evaluations with test equipment, and have to resort to listening, oh dear! But active devices with different characteristics do make a difference.

Regarding removeable power cords, why should we retool the chassis and charge everybody extra for the higher cost when only a few are obsessed with power cord sound? Pray tell me what possible effect electrically that a different power cord will have (maybe a bit of RFI filtering - hey the power transformer is one hell of a RFI choke in and of itself) and I will pay attention.

If the customer was always right, our equipment would be need to be wired with Gonzo cable completely internally (customers choice as to which Gonzo cable), built completely with $50 each capacitors and resistors (again customer option), and cost $50,000 each instead of where it is and there would be no customers who were always right who could afford buying it, and we would be out of business like a lot of the "make it with an inch thick faceplate and weigh 200 pounds and charge you a fortune" companies.

Frank Van Alstine

[John B]

Pray tell me what possible effect electrically that a different power cord will have (maybe a bit of RFI filtering - hey the power transformer is one hell of a RFI choke in and of itself) and I will pay attention.

This is the white paper done by the inventor of thi s particular power cord design http://www.audiolon.com/photo/sahuarowhite.PDF   Not that I expect it to resolve your issue, as most engeener types who've read it, thought it was nonsense.   But for me, a simple deluded audio listener it makes alot of sense to keep this product in my audio chain, irregardless of it's price or the intellectual debate about it's design properties.  For me it comes down to what I've heard, not what you tell me I shouldn't be hearing.