New, the Fet Valve 600R and 400R hybrid amplfiers

avahifi · « **Reply #40 on:** 19 Aug 2011, 11:14 am »

For what it is worth, the bandwidth of the Fet Valve R series amplifiers is 3 dB down at 4 Hz and 350,000 Hz. This is the natural bandwidth of the circuit design, no spec improving tweaks like feedforward compensation. We can use all of the bandwidth of the mos-fet output devices because all internal circuits have a Q of 0.5 or less, no underdamped resonances under any conditions. Thus we don't have to tie down the devices to keep the amp from turning into an oscillator. This also makes the amp very fault tolerant too.

Just for what it is worth. However, when you hear it, you will understand.

Regards,

Frank Van Alstine

I.Greyhound Fan · « **Reply #41 on:** 19 Aug 2011, 07:54 pm »

I picked up the 600R today and I will post a preliminary review tomorrow. It's going to be fun!

kc8apf · « **Reply #42 on:** 20 Aug 2011, 01:04 am »

Quote from: avahifi on 19 Aug 2011, 11:14 am

For what it is worth, the bandwidth of the Fet Valve R series amplifiers is 3 dB down at 4 Hz and 350,000 Hz. This is the natural bandwidth of the circuit design, no spec improving tweaks like feedforward compensation. We can use all of the bandwidth of the mos-fet output devices because all internal circuits have a Q of 0.5 or less, no underdamped resonances under any conditions. Thus we don't have to tie down the devices to keep the amp from turning into an oscillator. This also makes the amp very fault tolerant too.

Just for what it is worth. However, when you hear it, you will understand.

Regards,

Frank Van Alstine

My dad recently pointed out that his Denon SACD player has an option to output 50kHz or 100kHz bandwidth on the analog outputs when playing SACD. There is a warning that some amplifier could be damaged if they are not designed to handle such an input. Are you saying that the 400R would be fine with having a 100kHz bandwidth input?

avahifi · « **Reply #43 on:** 20 Aug 2011, 11:49 am »

Although out of band high frequency signals won't damage our amplifiers, they are not good for your speakers. We designed for wide bandwidth so that high freqency garbage from sources won't further mix and be further distorted by our amplifiers. However we suggest that deliberately introducing out of band high frequency content into the system is not a good idea.

Frank

I.Greyhound Fan · « **Reply #44 on:** 20 Aug 2011, 06:35 pm »

Just a preliminary note- The amp is spectacular! I will give an in depth review tomorrow or monday evening when I have more time. I am tube rolling my preamp and DAC to see how it responds to different combo's.

avahifi · « **Reply #45 on:** 20 Aug 2011, 08:12 pm »

Darn, I was afraid this was going to happen.

My clients are going to be unable to tear themselves away from listening to the new Fet Valve 400R or 600R long enough to have time to write a review here.

Frank

guest1632 · « **Reply #46 on:** 29 Aug 2011, 02:43 am »

Quote from: avahifi on 20 Aug 2011, 08:12 pm

Darn, I was afraid this was going to happen.

My clients are going to be unable to tear themselves away from listening to the new Fet Valve 400R or 600R long enough to have time to write a review here.

Frank

Oh well, sounds like you have finally the masterpieces. Now to work on your preamps some more.

By the way, I was kinda amused to see that on these units you included IEC connectors. So what power cord did you supply? And why did you go that route as opposed to the cord you use in your other units? Just curious.

Ray Bronk

srb · « **Reply #47 on:** 29 Aug 2011, 03:37 am »

From the AVA website:

"All NEW AVA equipment is now shipping with an IEC power jack and a removable 3 conductor power cord. No price increases for this new feature for now. Now you have the ability to try your own favorite power cord with AVA equipment."

I can't find the exact reference to quote, but it is a standard 16 gauge power cord that AVA has confirmed having a tight positive fit in the IEC jack.

The most recent topic about it can be found here: http://www.audiocircle.com/index.php?topic=95607.0

Steve

Charles Calkins · « **Reply #48 on:** 29 Aug 2011, 03:43 am »

Quote from: Ray Bronk on 29 Aug 2011, 02:43 am

Oh well, sounds like you have finally the masterpieces. Now to work on your preamps some more.

By the way, I was kinda amused to see that on these units you included IEC connectors. So what power cord did you supply? And why did you go that route as opposed to the cord you use in your other units? Just curious.

Ray Bronk

Bettcha that us common folks couldn't tell the audible difference between an IEC connector cable and the one Frank used for a whole bunch of years. K.I.S.S. OR!!! Keep it simply stupid! My fantastic sounding avastar preamp doesn't have a IEC connector and I sure as hell am not going to send it back to frank for an IEC connector.

Cheers
Charlie

avahifi · « **Reply #49 on:** 29 Aug 2011, 09:49 pm »

We switched all our chassis to use standard IEC power sockets and supply standard three conductor 16 gauge AC power cords simply because we decided that our "Custer's Last Stand" for rationality was costing us sales.

I can't hear any difference at all, we simpy ate the tooling costs to make the products more acceptable to those that absolutely must use their own better sounding power cable. It did not raise the cost, did nothing much bad, and so far has done not much good to improve sales. The IEC socket is definitely not available as a retrofit., circuit upgrades yes, dingleberry upgrades no

However, those that would never consider our equipment under any circumstances will now have to find a different excuse.

Regards,

Frank Van Alstine

rcag_ils · « **Reply #50 on:** 29 Aug 2011, 10:38 pm »

Quote

It did not raise the cost, did nothing much bad, and so far has done not much good to improve sales.

Give it time, Frank. I am sure word will spread out, it will just take a little time, that's all. Sale is a funny thing, I've done it as an hobby. Now that your product are on par with the audio industry's mechanical standard, I am sure it'll catch on.

JerryM · « **Reply #51 on:** 3 Sep 2011, 02:59 am »

Quote from: avahifi on 9 Aug 2011, 01:19 pm

New Fet Valve 400R/600R amp tour?

Lets see what Larry thinks about it when he gets to take it for the weekend. It can be this coming weekend if he has time.

Regards,

Frank Van Alstine

So now that Larry has had the time to post his cool 600R Review, what do you think about a quick amp tour?

It sure would be fun.

Jerry

guest1632 · « **Reply #52 on:** 11 Sep 2011, 04:04 am »

Quote from: avahifi on 29 Aug 2011, 09:49 pm

We switched all our chassis to use standard IEC power sockets and supply standard three conductor 16 gauge AC power cords simply because we decided that our "Custer's Last Stand" for rationality was costing us sales.

I can't hear any difference at all, we simpy ate the tooling costs to make the products more acceptable to those that absolutely must use their own better sounding power cable. It did not raise the cost, did nothing much bad, and so far has done not much good to improve sales. The IEC socket is definitely not available as a retrofit., circuit upgrades yes, dingleberry upgrades no

However, those that would never consider our equipment under any circumstances will now have to find a different excuse.

Regards,

Frank Van Alstine

hi Frank,

Ok, so if they still want the formerly standard two prong plugs, It's a simple fix. Put a plate over the ground lift switch, and a plate with a hole in it for the captive cable. leave the fuse on the outside. Charge $10 extra for the sideways move. . Actually what I would have liked to see is a Polarity switch. Sometimes the actual plugs are not always set up correctly. Just thought I'd mention it.

Ray

plaf26 · « **Reply #53 on:** 11 Sep 2011, 06:08 am »

One Fet Valve 400R--coming soon to a living room near me!

Listens2tubes · « **Reply #54 on:** 13 Sep 2011, 01:37 pm »

An IEC never stopped anyone from buying a piece of gear. They just don't tune with power cords.

Tone Depth · « **Reply #55 on:** 16 Sep 2011, 04:00 am »

Someone was asking me what an IEC was: "an Improvised Electronic Connection?"

Quote from: Listens2tubes on 13 Sep 2011, 01:37 pm

An IEC never stopped anyone from buying a piece of gear. They just don't tune with power cords.

dlparker · « **Reply #56 on:** 16 Sep 2011, 11:34 pm »

Quote from: Listens2tubes on 13 Sep 2011, 01:37 PM
An IEC never stopped anyone from buying a piece of gear. They just don't tune with power cords.

Quote from: Tone Depth on 16 Sep 2011, 04:00 am

Someone was asking me what an IEC was: "an Improvised Electronic Connection?"

Check out these links:

http://en.wikipedia.org/wiki/IEC_60320
http://en.wikipedia.org/wiki/IEC

And I always retune after power chords. But I'm always tuning, anyway...

Brett Buck · « **Reply #57 on:** 17 Sep 2011, 03:48 am »

Quote from: Listens2tubes on 13 Sep 2011, 01:37 pm

An IEC never stopped anyone from buying a piece of gear. They just don't tune with power cords.

What does "tune with power cords" mean? Power cords make *no difference* in the sound unless they are wired incorrectly, what is there to "tune" about them?

I would probably prefer not to have unnecessary connections, and I can bet that all those twits saying they wouldn't buy a Frank amp because it didn't have a IEC connector will now just find another excuse, like, "its not put together with cryo-treated sheet metal screws!" to not buy one.

Brett

dlparker · « **Reply #58 on:** 17 Sep 2011, 04:01 am »

Quote from: Brett Buck on 17 Sep 2011, 03:48 am

What does "tune with power cords" mean? Power cords make *no difference* in the sound unless they are wired incorrectly, what is there to "tune" about them?

I would probably prefer not to have unnecessary connections, and I can bet that all those twits saying they wouldn't buy a Frank amp because it didn't have a IEC connector will now just find another excuse, like, "its not put together with cryo-treated sheet metal screws!" to not buy one.

Brett

I readily admit my "..always retune after power chords. But I'm always tuning, anyway.." comment was a pretty sophomoric play on words. Play and tune - as on guitar.

I'm just in a funk 'cause it's Friday night and I'm sitting home with no gig.

But I AM listening to the Fish Fry ( http://www.kcur.org/fishfry.html and http://www.kcur.org/ListenLive.html - Fri & Sat nites - 8pm 12am US Central ) on my AVA/Hsu system! Sounds mighty fine.

JerryM · « **Reply #59 on:** 17 Sep 2011, 04:13 am »

Quote from: Brett Buck on 17 Sep 2011, 03:48 am

Power cords make *no difference* in the sound unless they are wired incorrectly, what is there to "tune" about them?

That's not my experience.

I once demo'd a fine pair of Vandersteen 5As being driven by some mighty fine CJ tubed gear. The bass modules had these huge cords. I commented, and he plugged in a pair of 12 ga. stock power cords. It sucked. The magic was gone. It was tolerable music, if you hadn't heard it moments before.

I know it mattered there. To me, now, cords matter everywhere.

JMHO,

Jerry

New, the Fet Valve 600R and 400R hybrid amplfiers

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