User reviews of our new Fet Valve 600R & 400R amplifiers

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avahifi

For your convenience, I have compiled all the user reviews of our new Fet Valve 600R and 400R posted at AC so far all into this thread.  Check back from time to time as more information is posted here.

Thanks,

Frank Van Alstine

Tom Alverson

I have the Fet Valve 600R now and put it in my living room setup on my TV/computer system on some B&W 630i speakers I picked up used for about $400.  My "good" speakers are downstairs in my listening room which is not set up at the moment.  When I got these B&W 630i speakers I hooked them up to an old Transcendence amp and fed right from the sound card output of the PC.  It sounded pretty decent but the speakers sounded muddy in the bass (and compared to the current setup had much less clarity at all frequencies).  I now have the Fet Valve 600R hooked up to them being driven by the Vision combo preamp/dac fed from the SPDIF output of the PC.  The clarity at all frequencies is much better now and the bass better than I ever expected from these speakers.  They are spec'ed flat to 53HZ (2dB down).  I would much rather listen to this bass (even though it might lack a little reproducing movie explosions) that what I had before, even if I were to add a sub-woofer to the old setup.

If I had heard a subwoofer that gave me more power, weight  and visceral impact than I am getting now (which is pretty good) I might be interested.  My "good" speakers in my listening room go lower than this.

plaf26

Oh.  My.  Goodness! 

Have only had a few minutes to listen, but already, what a difference!  I say this every time I upgrade at AVA, but it's another layer of fog between the listener and the music removed.  Again am hearing more stuff I don't remember hearing before, even on a 55 year old mono LP! 

Frank asked me to start out without my subwoof on as I might never need it again.  I need more time to decide on that, but I'll say this: I'm hearing a lot more bass right now from my Maggie MMG's than I have a right to expect.

As always, Frank and his staff were most kind and helpful.  Homerun, AVA, thank you so much!!

NIGHTFALL1970


Anyone who is considering upgrading an AVA 350 to the 400R and is wondering if it is worth doing, it certainly is.  I notice that bass is tighter,  vocals are fuller and sound more life-like, and guitar sounds more "real".  I compared "stairway to heaven" from LED ZEPPELIN IV (Definitive Collection) on both versions of the amp.  Robert Plant sounded like he was in the room.  The solo at the end by Page sounded brite and shrill on the old version.  After the upgrade, the solo was smooth but not TOO smooth.  It sounded more like you would expect a guitar to sound like.

Next I wanted to try a good but poorly recorded album BLACK SABBATH "Born Again" (2011 Sanctuary Records Remaster).  The bass is muddy and the album is very "Noisy".  Iommi's guitar solo at the end of "Trashed" can kill a chicken!  After the upgrade the bass is tighter and more defined.  Iommi's solo is still brite,  but nowhere near as bad.  Ian Gillan's vocals sound MUCH better and life-like.  If this upgrade will make this album sound better than it ever has,  then imagine how nice STEELY DAN's "AJA" will sound.  If you are undecided about the upgrade, I highly recommend it.

aln

Several weeks ago, when I read about the new FET-Valve upgrade in this circle, I made a decision.  I would get another credit card, and upgrade my 550 EXR.  Once I received the credit card, I also purchased an Ultra 350 to tide me over while my amplifier was in at Frank's.

The Ultra was certainly cleaner than the EXR.  Transient attack and overall definition was superior as well as imaging information.  Yes things were better, and I enjoyed going through my music collection hearing parts of the mix that were subtly buried under the grundge that were a part of the EXR's performance. 

Yesterday, my upgraded Fet Valve 600R returned from Frank's.   I left work early so that I could retrive the amplfier from my back porch.  Downstairs it went and quickly it was hooked up, replacing the Ultra that I had been using.  I put on a Genesis SACD that was fresh in my mind as I had seen the concert only a few days before.  And I was stunned.  A complete layer of "haze" that was there with the Ultra no longer was there.  The music exhibited a "stark transparency" that was hard to believe.  After living with FET-Valve amps for 15 years this presentation was not just better it was completely better.  The distortion factor is so low that elements in the mix, the pans, the movements of the faders became immediately apparent.  Simply miked material such as Janis Ian had a voice that floated in its own space, with wonderful coherence and articulation.  Material with bass such as Steely Dan "Two Against Nature" was a revelation, as the mix's for the bass, drum and various synths was completely revealed.  Extension at both ends of the spectrum was well enhanced, more air, more low bass, and more spacial information for the material. 

I went upstairs and called Frank.  In the 30 plus years of sending him equipment I have never heard such an upgrade.  Whatever I sent him was ALWAYS better and well worth the money, but this upgrade was in another league.  I told him he hit a home run with this design and he hit it out of the park.  The best money I ever spent in audio.Ok,

I.Greyhound Fan

First let me take this opportunity to thank Mr. Frank Van Alstine for being so gracious and allowing me the privilege to do an in home audition of this wonderful amp.  And for all the other times he let me take home equipment.

Now for the review-

Equipment used-

AVA 600R power amp
AVA Ultra II preamp and Ultra II DAC
Modified Music Hall 25.2 CDP as a transport
Magnepan QR 1.6 speakers
Cables by Blue Jeans

I will list the music played at the end.

This amp is nothing short of spectacular.  When we first hooked it up, my 20yr old budding audiophile son and I noticed that it was a huge improvement over my Parasound A21(which strengths are dynamics,detail, bass, sound stage and transparency) and the FET Valve 550 that we auditioned a couple of years ago.  It was quite apparent that this is a special amp.  First off, the sound stage seemed to extend well past the walls of my 17'x17'x10' room.  The transparency of the sound seemed to have an almost holographic feel to it.  The spacing of the instruments was phenomenal.  I had to keep reminding myself that I was not listening to SACD's.  Even compressed older recordings like Fleetwood Mac opened up and became uncompressed with air and transparency.  Vocals and instruments were so life like that if you closed your eyes you got the feeling that Eva Cassady, Hope Sanduval of Mazzy Star or Johnny Hartman and John Coltrane were singing or playing in front of you.

The amp really showed its colors with classical music.  The quiet passages just sounded better and were more involving and the amp handled dynamic passages effortlessly.  The amp has great pace and rhythm.  The sound was grain free and the clarity, resolution and detail were on par with the $10,000 Ayres amp that I heard a couple of years ago and was better than my friend's $5,000 Nuforce Model 9se monoblocks.  Bass is powerful, smooth, deep crisp and well controlled.  It was the first time that I have heard my Magnepans produce that nice bass thump that you get with cone drivers.  Treble was natural and life like.  In fact, my son who plays the Sax in band commented that the amp produced the most life like cymbals that he has ever heard and I have to agree.  People who have heard my system have always commented on how life like the sound was but with this amp the music was eerily life like.  You get the feeling that you are sitting in the front row of an orchestra.

My only criticism if you want to call it that was that I had to do some tube rolling in my DAC and Preamp.  I use 6CG7 amprex in my Preamp and Tong Sols in my DAC which produce a slightly warmer sound with my Parasound, but with the 600R the sound leaned just a hint on the bright side with slight sibilance.  But once I switched to RCA clear tops in the Pre and DAC the amp was completely neutral with no real sound of its own.  But thats the beauty of tubes.  They sound different with different equipment and you can roll them to get the sound that you want.

So would I buy this amp?  Absolutely, it performs well above its price point just as all AVA gear does.  It is certainly on par or better than all of the amps that I have heard ( Ayres, Bryston, Theta, Luxman, Belle's, Nuforce, Parasound, Adcom, Jolida, Plinnius, Classe and MacIntosh ).





 



plaf26

Re: User reviews of our new Fet Valve 600R & 400R amplifiers
« Reply #1 on: 23 Nov 2011, 05:47 am »
Ditto what others have said. All I can add is this: I've now had time to try all my sources.  My 400R dug music out of an old pre-recorded CrO2 cassette it never knew it had.  Same for a 40+ year old quarter track open reel prerecorded tape.  The quick clarity (aka transient response) of this amp enhances the perception of the music's timing, pace and rhythm.  For example, some modern classical pieces have some odd timing that up until now I dismissed as performance error.  Not with the 400R/600R.  There's no mistake, it's in the music on purpose.  Frank is right--this thing is "simply astonishing!" :o

kc8apf

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  • Are you sure what side of the glass you're on?
Re: User reviews of our new Fet Valve 600R & 400R amplifiers
« Reply #2 on: 29 Nov 2011, 03:19 am »
I've had my 400R for almost a week but doing a review with my current speakers (Definitive Technology Mythos ST) seems a bit pointless.  The amp is a precursor to upgrading speakers to a set of Salk SongTower RTs in a few months.

avahifi

Re: User reviews of our new Fet Valve 600R & 400R amplifiers
« Reply #3 on: 7 Dec 2011, 10:53 pm »
Lets get this thread back to owner's comments about the new 400R and 600R amplifiers.  There are a few of you I was hoping to hear from by now

Frank
« Last Edit: 8 Dec 2011, 01:26 am by avahifi »

Hydro

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Re: User reviews of our new Fet Valve 600R & 400R amplifiers
« Reply #4 on: 17 Dec 2011, 04:49 pm »
I bought the 600R that Frank built over Thanksgiving. Been listening to it for over a week now and feel I have a pretty good handle on the sound. I replaced an Ultra 350 double in my main system that uses Soundlab A-1's. I tried it on my studio system that uses Elsinore diy speakers with an efficiency of about 90db. On both systems the first thing I noticed was the bass. Much more control, punch and extension. I can see why Frank suggests trying this amp before buying a sub. I have found that I like the way Gold Lion Genalex cryo reissue tubes sound in these amps. I used the supplied JJ's in my Ultra DAC and really like them there. Didn't like the Gold Lions in the dac. The Gold Lion's give the sound a very lifelike feel and really get the phasing of guitar pedals right. They might be a little etched sounding for some tastes. Back to the 600R, after getting used to the bass of the new amp I was able to concentrate on mids and highs. In my efficient studio system I didn't notice that much difference from the Ultra 350 dd, but on the very complex and inefficient load of the Soundlab electrostats there was a big change. Everything has the immediancy of live. Image is rock solid and there are layers of sound I had never heard before. I will not be sending this amp back on the 30 day trial. Thanks Frank for another great product.

avahifi

Re: User reviews of our new Fet Valve 600R & 400R amplifiers
« Reply #5 on: 19 Dec 2011, 08:21 pm »
Thank you Hydro, for your kind comments about your new Fet Valve 400R amplifier.

I notice other threads here at AC regarding the efforts of users to get better bass from their systems, often wondering what subwoofer to graft onto the bottom end or whether a tuned port would work better than a infinate baffle or so on.

Hardly ever do they wonder if their electronics ahead of their speakers might be the issue.  I have often suggested that your system won't play bass if the electronics ahead of the speakers don't reproduce bass properly.

Those of you with a Fet Valve 400R or 600R amplifier know what I mean.

Merry Christmas!

Frank Van Alstine

tonyptony

Re: User reviews of our new Fet Valve 600R & 400R amplifiers
« Reply #6 on: 20 Dec 2011, 10:10 pm »
Okay. I guess I'm next. This is my review of the 600R, which is the current version of my amp. I went from a FetValve EXR5 to an Ultra to an Ultra Double+ and now to the 600R, all via upgrades. In all cases for my listening rig I've used TFK ECC801S tubes.

Compared to the previous versions of the amp, the 600R is transparent transparent transparent. More so than I would have expected given how well I thought previous version of this amp portrayed the musical space. The very sense of the actual recording space is so clear now. The clarity extends into the deepest parts of the soundstage. No grunge at all coming from the speakers. In this, I'm not diminishing the previous versions of the hybrid, but the 600R does provide a cleaner, larger, more clearly defined 3 dimensional space. Very subtle musical cues which I had a hard time picking up on before are now more easily picked out of complex pieces when a lot of instruments are going.

The music also seems "faster" (improved transient performance - is this because of the improved regulation?). The sudden shifts that occur in some pieces of music (especially small ensemble acoustic jazz) grab my attention more than with the earlier versions. But the amp doesn't do this by being hard or edgy. It’s neither hard nor soft; double bass and bass drums have that proper organic “meaty” quality without being blurred. Trumpets and violins have the proper screech when called for. If you’ve heard either one live when the musician is really setting fire to them you’ll know what I mean. In the past I’m not sure I got as clear a sense of that – especially on trumpets with that neat combination of burnished brass but metallic bite.

The clarity goes from top to bottom. It's better in the top but gets progressivley more better :icon_lol: as you go to the lowest octaves. Yes, the bass is way better than it used to be - more spacious, more articulate, more powerful. But take that with a grain of salt. If your speakers are capable of reproducing the lower octaves you will get much better sound out of them. If not, well, it's better but there's no substitute for a larger enclosure and larger drivers. Let's say you'll get probably the best bass you've ever heard from whatever speaker you've got. :green:

What else is there to say? The front to back position relative to the speakers seems about the same. I first wondered if the 600R was setting the image a bit further back because of what I was hearing with the improvement in depth, but that was an error in my judgement.

Are there any negatives? I don't think so. I wondered briefly if the heroic amounts of regulation might cause the amp to "overdamp" the music, but I'm not convinced of this. What had me wondering about this was when I was listening to the Ondine recording of the Philadelphia Orchestra playing Saint-Saëns Symphony Number 3. I was actually at this performance when it was recorded, and heard it again a couple of weeks ago with Philly, but this time conducted by Marin Alsop. I sit in orchestra center about 10-12 rows back. In this piece there are a couple of points where the triangle is struck. When you hear it live the sound almost "shimmers". It just floats along in space for a while, until it gives up it's energy and disappears. When I played the recording at home the same triangle moments were clear, but seemed more matter of fact. There wasn't the same kind of "hang time" as when I heard these live. Is it because of the way the mics were placed? The way the recording was mixed or processed? Could be. Over-regulation in the amp? Not as sure about that but I don't think so. Too many variables.

Don't misunderstand me, my feeling about the 600R is nothing but positive. I haven't heard better in my system - ever. Look at what I'm doing: I'm sitting here talking about comparing a live event to a recording coming out of my home system! Before the 600R I'm not sure that kind of crazy talk would have been possible. Is the 600R better than any previous version I've heard of Frank's hybrid design? Yes. Should anyone looking for a better amp consider it? Yes.
« Last Edit: 21 Dec 2011, 12:54 pm by tonyptony »

martyo

Re: User reviews of our new Fet Valve 600R & 400R amplifiers
« Reply #7 on: 21 Dec 2011, 10:43 am »
Sounds pretty amazing Tony. Interesting comment about over-damped. Sometimes class D amps are praised for their bass response. The ones I've listened to all sounded over-damped (in all the frequencies) and there was no "proper organic “meaty” quality" to the bass. I'm very envious dude!
Thanks for the excellent write-up, ENJOY!! 8)   

mark funk

Re: User reviews of our new Fet Valve 600R & 400R amplifiers
« Reply #8 on: 21 Dec 2011, 11:04 am »
Ya, sounds like you like it.  :thumb:




                                                                                        :smoke:

tonyptony

Re: User reviews of our new Fet Valve 600R & 400R amplifiers
« Reply #9 on: 21 Dec 2011, 12:50 pm »
Sounds pretty amazing Tony. Interesting comment about over-damped. Sometimes class D amps are praised for their bass response. The ones I've listened to all sounded over-damped (in all the frequencies) and there was no "proper organic “meaty” quality" to the bass. I'm very envious dude!
Thanks for the excellent write-up, ENJOY!! 8)

Yes, I've heard Class D amps a number of times (but not driving my speakers) and I've heard that real overdamped quality. Takes some of the life out of the music. The 600R is not like that at all (no fear of that).

As I said, in my case I very well could have heard exactly what was on the recording. The last time I'd heard it through my system was too far back for me to remember this bit of subtlety.

pelliott321

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Re: User reviews of our new Fet Valve 600R & 400R amplifiers
« Reply #10 on: 21 Dec 2011, 03:38 pm »
Received my 400R yesterday and put into my Rebuilt Maggy IIIa system, cold out of the box the sound is quite good.  Bass is amazingly full, mids are round and sweet. Highs seem lacking a bit.
I can easily hear some of the magic, the enveloping of the music around me, but I am worried about the highs.
My test recording for is the Women of the World celtic cut called "Raindance"  The first few seconds is simulated Rain that is clearly heard from my seat with other amps, but was missing with the 400R. I had to put my ear to the ribbons to hear it.  To double check I put back another amp (250w/ch classD audio, cheapy) and the rain sounds were there clear as day.
So I put the 400R on the bench to burn in for the next 100hrs with pink noise (my cat hates this, I do need to get some big R's for this) to see what happens.
I will post again after the burn in....

avahifi

Re: User reviews of our new Fet Valve 600R & 400R amplifiers
« Reply #11 on: 21 Dec 2011, 03:43 pm »
Thanks for the thoughful and favorable review, Tony.

Regarding the concept "overdamped," this just is not possible with our power supply designs.  Since they always are available to supply instant current, instantly fast, with way more capacity and no interaction between devices that the audio circuits could ever possibly demand, they drastically improve transient response and overall clarity and bass response than possible with any other configuration.  Go back and listen to any old DMP CD to hear the highs just float out into mid-air.

For most users, the amazing clarity and imaging and just awesome bass depth and tonality and impact will be the best improvement they ever did to their audio system.  For many, a Fet Valve 400R or 600R will also eliminate their yearning for a subwoofer too.

Even Stereophile, which normally never gives us the time of day, reported that at this summer's California Audio Show, that the Salk room had the best bass at the show.  Of course they never reported that is was all AVA Fet Valve equipment driving the Soundscape 10s at that show.  Evidently the astonishing bass just appeared out of thin air.  Secret tip, it was us there driving the Soundscapes,  really!

Best regards,

Frank Van Alstine

tonyptony

Re: User reviews of our new Fet Valve 600R & 400R amplifiers
« Reply #12 on: 21 Dec 2011, 04:07 pm »
Thanks for the thoughful and favorable review, Tony.

You're welcome, Frank. I try to be as objective as possible, which some may misunderstand since the audio rags tend to portray things with an extremist mentality. The 600R is a big step up in amplification.

Regarding the concept "overdamped," this just is not possible with our power supply designs.  Since they always are available to supply instant current, instantly fast, with way more capacity and no interaction between devices that the audio circuits could ever possibly demand, they drastically improve transient response and overall clarity and bass response than possible with any other configuration.  Go back and listen to any old DMP CD to hear the highs just float out into mid-air.

I suspected you had a solid explanation. :)

Interesting what pelliott321 said.

festuss

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Re: User reviews of our new Fet Valve 600R & 400R amplifiers
« Reply #13 on: 21 Dec 2011, 05:09 pm »
 :scratch: No highs?  gonna "burn it in", double huh?  What do you think Frank does when they test and before shipping.  What "burns in"?  Perhaps you have a defective unit?  Another very rare first?   Ya gotta explain how playing it for 100 hours will somehow bring something, that ain't there now?  If it's a defective ckt, nothing.  Why Pink, isn't White noise even better? 

AVnerdguy

Re: User reviews of our new Fet Valve 600R & 400R amplifiers
« Reply #14 on: 21 Dec 2011, 05:33 pm »
I was evaluating the 600R and speaker combo for a few weeks before commenting.

I had a FET Valve 550 w/double die option which I had for just more than a year. When I purchased that model I was pleased at how much more detail I was hearing with materials I was very familiar with. The amp was very precise (only way I can describe it) with tight bass and very clean highs. Cymbals and brass instruments were reproduced with amazing clarity and the depth of the soundstage was outstanding. I was running it into a set of Maggie 1.7s which was a great combination.

Decided I wanted to try the Maggie 3.7s which had just been introduced. At almost the same time AVA announced the 600R mod for my current amp. After a long hard investigative process I decided that was too hard to pass up. However, I was wondering just how much better could it be over the FET 550 and was I just throwing around cash and getting into the next best thing that comes along cycle.

I am delighted to say that the 600R is better. The bottom end is tighter with more definition on bass notes.  It seems to have more drive down low. The high end is silky smooth and I’m not sure if it’s the amp or the speakers but where there used to be slight bit of harsh edging on brass instruments at high volumes is now gone. The soundstage is wide and deep. The individual instruments that used to get lost are all now independently recognizable and I find myself picking out a single instrument to follow through a song. Amazing to find out how much was going on in the background. Backup singers are individual voices easily distinguished whereas before they were grouped together. It is easy to place the location of instruments or vocalists within the soundstage.

Again, new speakers and a new amp at the same time make it difficult to point to which was the greater improvement. However, I believe the amp was a definite improvement and drives the 3.7s effortlessly. I find that I am listening at higher volumes with less fatigue. I don’t realize how loud it is until I turn it down and I attribute that to how clean it is. The amp is absolutely noiseless and can go from whispers to crazy loud volumes with astonishing speed and detail (has caught me off guard a few times). Never a hint of harshness or breakup.

On a side note – I think it dissipates heat a little better than the 550. I might be imagining that but the cabinet is not as warm as it previously was.

A solid upgrade to an already great amp. I am very satisfied with the improvements and highly recommend it to anyone thinking of upgrading a previous version.

rcag_ils

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Re: User reviews of our new Fet Valve 600R & 400R amplifiers
« Reply #15 on: 21 Dec 2011, 05:51 pm »
Quote
Even Stereophile, which normally never gives us the time of day, reported that at this summer's California Audio Show, that the Salk room had the best bass at the show.  Of course they never reported that is was all AVA Fet Valve equipment driving the Soundscape 10s at that show.  Evidently the astonishing bass just appeared out of thin air.  Secret tip, it was us there driving the Soundscapes,  really!

Best regards,

Frank Van Alstine

Maybe my comment is totally unrelated to this thread, but it's just plain poor journalism, not to mention unethical.

pelliott321

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Re: User reviews of our new Fet Valve 600R & 400R amplifiers
« Reply #16 on: 21 Dec 2011, 07:00 pm »
festuss:
I am just reporting what I hear, which is what this thread is for.  It was a pretty positive report for a new unit out of the box.
Is this a place for AVA zealots or for real information? Turn your flame down and you will live longer.

avahifi

Re: User reviews of our new Fet Valve 600R & 400R amplifiers
« Reply #17 on: 21 Dec 2011, 09:51 pm »
Festuss, I don't think it is really appropriate to subjectively discuss what someone else claims to hear, or not hear, in this thread.

I welcome all inputs here sticking to the topic of their own thoughts about new Fet Valve amplifiers.

I do note that pelliot's comments seem somewhat non-typical, especially since the 3 dB down points are 4 Hz and 350,000 Hz.  I suspect that there is a real difference beween his previous amp and ours and that he is simply used to the high end performance of the old one, even if it actually has more extreme high end output than it should have.  Time will tell,  but I agree that we don't think break in time is of much value.

Just stay back and enjoy the comments.  Maybe they will convince you to try a Fet Valve 600R or two yourself.

Merry Christmas.

tonyptony

Re: User reviews of our new Fet Valve 600R & 400R amplifiers
« Reply #18 on: 21 Dec 2011, 10:30 pm »
I do note that pelliot's comments seem somewhat non-typical, especially since the 3 dB down points are 4 Hz and 350,000 Hz.  I suspect that there is a real difference beween his previous amp and ours and that he is simply used to the high end performance of the old one, even if it actually has more extreme high end output than it should have.

I've spent a bit of time over the years listing to Maggies (yes even back to the IIIa). As I recall they are a bit of a difficult load to drive. I say this with some confusion, as the FetValve has always been known as something that could drive the most difficult sorts of loads. pelliott, which amp were you using previously?

In reviewing the reviews so far, I think only pelliott and I made any sort of specific elaboration on the high end. I'm approaching this question with caution as I think in my case I can explain it, but I'd like to ask the other reviewers if they could chime in with some additional thoughts on this end of the spectrum.

rockadanny

Re: User reviews of our new Fet Valve 600R & 400R amplifiers
« Reply #19 on: 21 Dec 2011, 10:55 pm »
In reference to the HFs ... Do cymbal strikes sound like plastic-tipped wood stick striking brass? Or is it more of a generic metallic sound?