Omegastar line

hertz · « **on:** 6 Mar 2007, 01:35 pm »

Been seeing a lot of talk only about the fet-valve amps on this thread. Makes me wonder a lot about the Solidstate omegastar line.
Will combining a 260EX solid-state amp with a good used valve preamp from Audio research or Hovland give me the results that most Fet valve owners are talking about on this forum ?

Zheeeem · « **Reply #1 on:** 6 Mar 2007, 04:34 pm »

Quote from: hertz on 6 Mar 2007, 01:35 pm

Will combining a 260EX solid-state amp with a good used valve preamp from Audio research or Hovland give me the results that most Fet valve owners are talking about on this forum ?

No. But the 260EX is an outstanding solid state amp.

rustneversleeps · « **Reply #2 on:** 6 Mar 2007, 05:59 pm »

I too, have been wondering what is "fet-valve" all about technically? How does it differ from the other hybrid designs, what makes it stand out from the others? How does it sound comparing to other SS or tube designs, if it's really better than the others, is it because of "fet-valve"? Or is it a "buzz word" for AVA?

mfsoa · « **Reply #3 on:** 6 Mar 2007, 06:39 pm »

And is it really the "poor man's Moscode?"
(Since poor men buy $1800 amps!)

carusoracer · « **Reply #4 on:** 6 Mar 2007, 06:46 pm »

Hard to say what I was hearing that could differentiate the Amp(Fet Valve 550) or the gorgeous Salk HT3's but they sound really good together

I will hopefully get a chance to hear the Moscode in a couple weeks paired with the Salks' but in a different environment, not side by side.

Have not heard the SS versions but the Fet Valve is nice

avahifi · « **Reply #5 on:** 6 Mar 2007, 06:59 pm »

Well, Foxfire crashed out from under me while trying to respond to this thread, so I will start over.

The "Fet Valve" name is just our verbage in describing our patented circuit topography of a valve (Brit name for a vacuum tube) and a power mos-fet in a clever loop that provides the high input voltage overload capability of the tube, and the low output impedance and high drive current of the mos-fet, and blazingly fast bandwidth and absolute stability to boot.

No it is not a "poor mans Moscode" inasmuch as we are not attempting to drive the high gate input capacitance of a power mos-fet output circuit with the poor current drive and high output impedance of a tube. In the Fet Valve designs, the tube looks only at "air" and the linearity is at least 10 dB better than when driving a load. It works pretty darn well.

Our solid state OmegaStar amplifiers are reasonable unique too, inasmuch as they have active feedback loops, so that the outputs are not taxed with having to drive large low impedance voltage dividers. The amp also features thermal feedback everywhere in the driver stage so that DC stability is so good no DC balance adjust control is needed. The bandwidth is half power at about 500,000 Hz without feedforward compensation or other tricks - - - we can simply use all the bandwidth of the output devices without slowdown or stabilization compensation and still retain absolute stability.

The techniques used in both the Fet Valve and OmegaStar designs (designing for a Q of 0.5 both at high and low frequencies, and power supply and ground lines too) makes the units unusually fault tolerant as a bonus. Nasty transients in general do not generate enough excess heat to melt things or cause catastrophic burn ups.

Good listening.

Frank Van Alstine

George Kaye · « **Reply #6 on:** 6 Mar 2007, 11:27 pm »

We are very flattered that Moscode has been referred to in this thread in the way that it has.
I would like to say I admire Frank's work.
I would also like to point out that in our research we have tried using a variety of solid state drivers in the effort to eliminate one tube from the circuit but the results have always been less satisfactory than using our cathode follower circuit.
The output Mosfets just aren't that difficult a load to drive and 2 triodes in parallel in our constant current cathode follower just add so much dimension to the music we can't think of doing this any other way.
I hope this helps this discussion.

Remember: It's all about the fun!

Thanks,
George Kaye
President
Moscode, Inc.

St_PatGuy · « **Reply #7 on:** 7 Mar 2007, 01:10 am »

Quote

Remember: It's all about the fun!

Very nice response, George. There are many different ways of accomplishing one goal, and that is to enjoy the music. Your last line sums it all up. I like that, especially coming from the president of Moscode.

rustneversleeps · « **Reply #8 on:** 7 Mar 2007, 04:05 am »

>>>>The techniques used in both the Fet Valve and OmegaStar designs (designing for a Q of 0.5 both at high and low frequencies, and power supply and ground lines too) makes the units unusually fault tolerant as a bonus.....<<<<

Frank, the Q in RF term means quality of a coil, the higher the Q the better the coil, the better the selectivity. So what does the Q of .5 mean in audio term?

hertz · « **Reply #9 on:** 7 Mar 2007, 05:36 am »

If one already owns a good valve preamp, what would be the better option if one is a neutral sound lover? Omegastar 260 EX or fetvalve ? I love the sound of tubes. Actually I am on the “warm side of neutral” camp rather than the “clinical” side. But I am a bit worried about the tubed power adding too much of a good thing.

martyo · « **Reply #10 on:** 7 Mar 2007, 12:00 pm »

I ordered a 550 and T8 last week. Frank designs his equipment in a way that doesn't require circuitry to compensate for problems that develope from having components do things they don't excell in. I'm not a real technical guy. His tube equipment does not sound "tubey", but open, extended, fast, dynamic, you know, musical! Far from clinical and only warm in the sense of real music has a warmth. I'm not poor, but in no way rich. His equipment is affordable. Happy listening!

BrianM · « **Reply #11 on:** 7 Mar 2007, 12:29 pm »

Quote from: hertz on 7 Mar 2007, 05:36 am

If one already owns a good valve preamp, what would be the better option if one is a neutral sound lover? Omegastar 260 EX or fetvalve ? I love the sound of tubes. Actually I am on the “warm side of neutral” camp rather than the “clinical” side. But I am a bit worried about the tubed power adding too much of a good thing.

When I first switched from SS amp to an AVA FetValve if anything the sound became more "solid state" -- why? my guess is that the FetValve was just faithfully exposing some harshness in my SS preamp, that my prior amp had only complemented. So while I had made obvious gains in imaging, power, range and lack of compression, I'd also added a touch of clinical fatigue (nothing extreme, but noticeable)...So nothing tubey about a FetValve amp, IMO. Seems entirely neutral to me, so I wouldn't worry about too much of a good thing. When you think FetValve you shouldn't think "tubes," you should think "wide open" -- that's the best way I know how to describe it. Soundstage is huge and frequency seems to extend to infinity in either direction without emphasizing either high or low. No matter how loud I play the image stays the same -- which can get almost scary!

Switching to the AVA T8 preamp did make things tubier, but not in an extreme sense. And of course, the fatigue totally vanished. So, T8 + FetValve amp is a very good combo, IMO.

BrianM · « **Reply #12 on:** 7 Mar 2007, 12:50 pm »

I used the term "wide open" to describe a FetValve amp, but the other obvious characteristic is FAST.

If you want to know what your amp/speakers are capable of, there are numerous recordings of avant-garde classical/experimental music which will throw everything including the kitchen sink at your speakers.

The other day I put on composer Luciano Berio conducting his own "Laborintus 2"

http://www.amazon.com/Luciano-Berio-Laborintus-2/dp/B00004TVH4/ref=sr_1_1/102-9689072-4437709?ie=UTF8&s=music&qid=1173271318&sr=1-1

which makes huge demands from one end of the dynamic/frequency range to the other, with everything from the sounds of human breathing to full percussion battery to extreme HF and LF electronic noise and everything in between, all at light speed. Particularly challenging is the way volume continually fluctuates from extremely loud to extremely soft in a split second.

Play it with a FetValve amp and prepare to be impressed!

avahifi · « **Reply #13 on:** 7 Mar 2007, 01:59 pm »

I want to apologize to George Kaye for some less than complimentary and inaccurate remarks I made about the Moscode amplifiers. i was having an overall pretty bad day here, more things going wrong than right, and managed to put my foot in my mouth big time as i really don't have any useful info about the driver - output stage interface in the highly regarded Moscode amps at all.

George your response was more than gracious, thank you.

I will try to keep my comments regarding competitors to things I know about (not all that much evidently).

Regards,

Frank Van Alstine

mfsoa · « **Reply #14 on:** 7 Mar 2007, 02:15 pm »

Frank,
Maybe I need to offer you an apology for my comment that seemed to hit you in a way I did not intend. I'm sorry.
I truly meant it as a compliment that your gear has been compared favorably to gear that is far more expensive and that is also held in high regard.

No slight intended, OK?

-Mike

BrianM · « **Reply #15 on:** 7 Mar 2007, 02:23 pm »

Competitor? Last I checked a Moscode 401 costs around 5 grand. Always worth pointing out I think...you could bi-amp two Ultra 550s for less than that.

George Kaye · « **Reply #16 on:** 7 Mar 2007, 06:41 pm »

Frank,
I know what you mean about "those days". No apology needed but thanks anyway.
Keep up the great work.
George

tonyptony · « **Reply #17 on:** 8 Mar 2007, 12:29 am »

Well, as one who has heard both the original NYAL Moscode and the FetValve (which I own) in my own system I can say hats off to both George and Frank. While the original 'code was not the best match for my system, it was musical and very nice to listen to. I can only suspect the latest version is better still. For me, after years of great SS amplification, I went to the FetValve and have no plans to change anytime soon.

Wayner · « **Reply #18 on:** 8 Mar 2007, 12:57 am »

Gentlemen, we are in Franks thread and I am amazed that everyone is truely a "gentleman"! I have to say that both Frank and George are people that have pioneered the art and science of music and I tip my hats off to the both of them. aa

dB Cooper · « **Reply #19 on:** 8 Mar 2007, 01:50 am »

I second wayner... Compared to a different thread that's getting a lot of posts right now, where you'd think the topic under discussion was not audio but the reasons for genocide in Darfur (judging by the level of the emotions expressed), this is nice and civil (as you'd think any discussion of audio should be.)