Power Amp..opinions please

Hi All,
I am looking for a power amp (mono or stereo) to go with my Promitheus Reference C-Core TVC. Till some time back I was leaning towards the Wyred 4 Sound's SX-1000 monos. But as I read the net, I found people mentioning that the initial impressions of class D are detailed sound, neutrality, "true to original" etc. 10audio also has a great review about the wyred4Sound amp. At one point I was considering the RWA Sig 30.2 amps, as 6moons had a glowing review for these. Later I decided that they will not be enough for my average efficiency speakers.
Now I also read from others threads that as time goes by Class D becomes boring, no tone, etc, etc. I am a bit confused now and cannot decide which way to go. There is no dealer nearby that I can go to and listen to a Class D. So I also started to look at used Bryston, Parasound, Pass, McIntosh, Ayre, etc.
Can you please provide your experiences with Class D VS Class AB amps? Please do not suggest tubes. I would be using the amps with a Marantz SA-8260 CD player, Promitheus TVC and Quad 21L speakers. The cabling is Signal Cable through out. Currently using the NAD C352 integrated amp as power amp, but want to explore and experience a bit more high-end sound. A constructive thread with opinions (rather than mine is better than yours) will be highly appreciated and valuable to the forum.
Thanks much in advance.
Your post sounds llike you got plenty of opinion to put it mildy already.
"Istarted to look at ...." did you hear them as well? Class D is something you will have to hear to understand the meaning of the comments.
It may not seem constructive for people to tell you a negative criticism you say. Like class D sounds sterile and you run with it. At least you have certainly worried about it.
What kind of money are you throwing into these oversized minimonitors on a box. Mono Pass and McIntosh you have thought of Wyred4sound amps cost 3 times the cost of your 35 lb floorstanding 6.5 inch mid/woofer Quads. If you can afford big Pass or even the lighter weight Macs then you should get speakers that they were intended to play with. I had 400wpc mono I never considered using my smaller speakers with them .
I have driven my VR2s about twice that size with 2X 6.5 mid and woofer and two tweeters one a 2" mid tweeter facing backward and a 1.0 +" dome forward with a 40 watt amp. I used the amp for years with good results. Now I upgraded a whopping 20 watts to a 60 watt amp. The VR2s are 88 Db just like the 21Ls.
Yes the current amp is tubed and is more massive than both your speakers together (a DA-60) but honest it is rated at 60 watts.
Are you planning using this Quad and "could be stereo or mono block amplifier" for endless hours at earsplitting volumes or use it as reinforcement in a concert hall, arena??? A disco, PA system. If I can impart some wisdom think system not numbers. It's synergy between the elements of your acoustisphere (Copyrights retained neologism) that really is, the most critical objective, in order to make any set up sound good. These speakers aren't behemoth power hungry monster electrostats or planars. I bet your NAD sounds good but can't know from this computer.
As is oft repeated you will really only what amp sounds good to you with your stuff in your space playing your kind of music.
So you got what you asked for.
If the moderators allowed the poster to insinuate stupid responses I hope they are fair and post my stupid answer.
The only way to know is to jump in and try one.
I did and don't find class D amps the least bit boring. In my system they do exactly what I want an amplifier to do. Have to say I am susceptible to harsh or grainy sounding amps and experience none of this with the class D amps I've used.
I lived with a Bel Canto eVo2i integrated for two years before going the separate route. Current setup is the Bel Canto Pre-3 driving a pair of PS Audio Trio C-100 amps in bi-amp configuration.
BTW I have a pair of Quad 21L2s in the closet and was thinking about putting them in the system this weekend. I love the Quads. I did find setting the Quads on 2 inch thick plinths improves them a bit.
I guess you are right. That is what I may have to ultimately do. And if I don't like the amps, then why do we have audiogon for? :-) I want to get some maple wood plinths for my Quads, but that is not the priority right now

You have provided your opinion about speaker sensitivity and power ratings which is perfectly valid. But it does not answer my question. And I did not mean to insinuate stupid response. I do not understand why you felt the urge to make a stupid reply - if you say so.
About power ratings - I have heard a pair of high end Krells drive a PSB Silver-i and the same Silver-i driven by a NAD integrated. The dynamics of the sound and the ease that I felt when listening to this speaker when driven by the Krells was something I always yearned. But the Krells or some other high end amps were never affordable - even now. So my search for a high power amp.
Krell is one of the options. I do not have many dealers nearby that I can go and look at. I believe more in forum members rather than editorial reviews and paid publications to make a decision when I don't have much options. That is how I ended up with the wonderful Promitheus.
I am sorry but I could not understand some of the sentences in your post - like - "Mono Pass and McIntosh you have thought of Wyred4sound amps cost 3 times the cost of your 35 lb floorstanding 6.5 inch mid/woofer Quads". The Quads are good enough for me and I intend to buy the amps from audiogon - "used". So I really am looking for a good deal and am willing to wait for one. I am also considering the Monarchy Audio's SE-100 MK2 Class A monos. The reviews are good on this amp and they have a good deal going on. Have you compared Class D to the regular A/AB amps? If so please post your opinion. And believe me, however much stupid you feel your response was - I don't think so. I am eagerly waiting for opinions. If not I would not have been sitting watching this thread - instead of playing some music this Friday night :-)

"Now I also read from others threads that as time goes by Class D becomes boring, no tone, etc, etc. I am a bit confused now and cannot decide which way. . ."

Fear not, class D amps are just like amps of any other class. . . some are great and some are not. I use a spectacularly good Rowland 312 stereo amp, which is coincidentally class D. I chose it because I preferred it over all other amps I listened to, regardless of class of operation. W4S are good amps. . . in class D you can also look at the excellent Bel canto Ref 1000 Mk.2. See my Positive Feedback article at:
Class "D"; so much has been said. I have tried a Tripath based class d and now have a Hypex UcD based power amp. I like them both but for me, the hypex is preferred. Channel Island, Bel Canto, Rowland, many good names.
I believe there is a 30 day trial period with the Wyreds. Also not all class d's sound the same.

FWIW i traded a pair of nuforce ref 8v2's for a cary rocket 88r and i much prefer the sound. i also have it paired to a promitheus rev4 tvc.
I have read that review before. You have done a very nice and in-depth review there. But the price tag is a marriage-breaker than deal-breaker. I can't think of spending that kind of money right now. I am sure the Bel Cantos are great..but sorry, not with that price tag. Yep I know, all good things come with a price tag. But good to know that Class D is not a bad option.

I have decided to go ICE rather than Hypex, if at all I am going Class D.

Thanks for your opinions gentlemen.
How do the NuForce go with the Promitheus? What is the sensitivity of the NuForce? Is having a sensitivity of > 1V good or bad for Promitheus TVC?

i did not audition the tvc with the nuforce. the nuforces were gone before i received the tvc, which is now being used with the Cary and a very nice combo. fwiw Nicholas at Promitheus said the nuforce would pair fine with his tvc.
I have been listening to the Wyred4Sound ST-1000 stereo power amp for about 300 hours and they are fabulous sounding: ultraclean, dead quiet, sweet top end with complete elimination of phase distortion, zero audible distortion, and power reserves that are the thing of legend (~600W into 8 ohms; ~1200W into 4 Ohms). The ST-1000 are hands down better than any AB SS amp I've ever owned. As for the supposed rolled off top end - I can't detect it at all. But, I'm 52 years old and can't hear a whit above 14 KHz. Cymbal crashes and high strings and bells sound just so right - never grainy or offensive. The ICE amp will deliver whatever your CD transport/DAC can scrape off the little silvery disc.
sweet review mamboni. what's cool is wyred is right up hwy 101 from me, neighboring town of paso robles.

Milpai i didn't answer your question in full. sensitivity can be an issue if your amp/speaker combo needs the juice. with lower sensitivity speakers and the passive pre you could find the volume doesn't go high enough. impedance, however, is also an issue, the higher input on the amp side the better, which was my concern with the nuforce at 47k ohm. Nicholas at Promitheus assured me through email that his product would work well with my Nuforce.
Hi Milpai, I was not suggesting a new Bel Canto Ref 1000 Mk.2 at $6K. . . rather, there are a couple of Mk.1s on Audiogon for approximately $2K. Given the times, you might be able to negotiate the final price down a few $$s. The original Mk.1 has most of the sonic characteristics of the Mk.2. . . and some people prefer Mk.1 over Mk.2.. Guido
I am glad that the Wyred 4Sound delivers the sound that you want. What other Class AB did you use earlier before you settled with Wyred? In my system I have never heard a stand alone power amp. So I can only "imagine" the "ultraclean, dead quiet phase distortion, zero audible distortion" when compared to my NAD. One thing that got me looking for a separate power amp was I need to set the volume control on TVC to position 12 (from 1-24 available) for a decent sound in my 12X14 listening room. Though I love the sound I think a more powerful amp can eleveate the sound to a higher level - I believe.

My Quads have sensitivity of 88dB and a nominal impedance of 6Ohms. So this seems to be a speaker with low sensitivity and I would need more power than what I currently have for better dynamics at lower volumes. I almost decided to buy the Marantz SM-11S1 on Audiogon that is available. But found that it's low sensitivity (2V) would not match my TVC and the input impedance was alo on lower side (22kOhms). I see the spec on Wyred site that the SX-1000 has an even lower sensitivity (> 2.5V) but the input impedance is high at >64kOhms. So I am looking for other amps as well - like the Parasound A21. The sensitivity of this amp is 1V and it has a high input impedance. Besides, it has a high power ratings and that would mean very good dynamics at lower volume. I also want to check on other SS amps with higher sensitivity and input impedance. I will have to rely on the published specs and experience of users on the forum.

I've owned several Rotel amps, B&K and Classe amps of mid 1990s mintage, and SUMO Polaris and Andromeda II. Of these, I thought the Andromeda II (240W into 8 ohms; 400W into 4 ohms; 80 Amps peak)best, having a warmish sound for SS and a sweet top though the bottom end was a bit soft and ill-defined. The Wyred4Sound amp sounds very similar to the Sumo, but the bottom end is now completely fleshed out and solid and defined. I hear subsonic info that was barely discernable before. The top end is sweet like the Sumo but is more pure and detailed. I am driving Ohm Walsh 5 (Mk III) which have a moderate 87 SPL and like a lot of current. The Wyred4Sound ST-1000 is the first amp to truly push the Walshs to their full measure of output, and then some!
Thanks for your inputs. I like the warm sound of the NADs and I am looking for amps which will retain that character. To give you an example - when I was auditioning integrated amps 4 years back, I found the NAD to be warm while the Rotels were cold (not in a offensive way) and too forward for my taste. The Rotels had an "in the face" presentation while the NADs had a laid back presentation.
I was initially drawn to the power ratings of the Wyred4sound SX-1000, as the Quads like some more power than what they get now. But looks like it's input sensitivity is a bit high - greater than 2.5V which might prove to be a mismatch for my (passive preamp) TVC. What preamp do you have in your system?
My preamp is a vintage Pioneer Elite SP-99D preamp/processor. It is an active unit which I believe puts out more than 5V at max. I never have the volume dial past 11 o'clock and that is for low-level classical CDs. I believe the sensitivity of 2.5V on the W4S is for maximum power output - you'll never need anything close to this under normal use I think.
Your last statement is interesting. Do you mean the sensitivity of the amp shows how much volts a amp should get to output the full power? Or is it what is required to drive the amp comfortably? My CDP outputs 2V. So what does a TVC do with that and how many volts gets passed on to the power amp? I thought the TVC "gains" and passes on. Do you have any info on this?

Yes, sensitivitity is defined as voltage input to drive power amp to maximum output. A passive preamp and CD source outputtind standard 2V should drive the W4S amp to very satisfying levels.
Reread your original post. I should have mentioned that between the Classe and Bel Canto amps I briefly used the NAD C-352 integrated. I concur with your assessment on its sonic character. In fact I actually preferred it to the much more expensive Classe.
Yes Milpai -
I have listened extensively to Channel Islands 100 and 200 watt amplifiers which are class D. I have auditioned Bel Canto. I am unsure they are a simple class D and not a modular digital amp using ICE or similar modules for output power. I own a number of class A/B amps of relevance here. That woud be McIntosh and an ARC non class D SS Amp.
Most of my other gear is older or tubed. My speakers are JM lab Electra 936s in my main rig. Power is Opera Consonance 800 Mono blocks with 4 PP parralel 6CA7s two pairs on each side 8 total. I roll all of my tubes except in these I prefered the stock EH. I have as many as 12 pairs of speakers.
The 60 watt amp is a Jadis DA-60 hooked up to the VR2s a good one esp for a WAF rig. Which she doesnt give a ---- about.
The class D does in fact do for me what you hear has done for them. It's sonic is stunningly strong,clean, very clear, quick and transparent... for a while it amazed me . Then something happens to many class D (not ICE) owners, they get a sense that there is a critical richness of tone missing . The amps start to sound more and more lke empty, dry, shell like with no soul. As you said sterile.
They seem perfect for things like home theater where dialogue is too often muted and lost.
The A/B amp in terms of rocking your soul or tapping your toes or internalized symphonic music is highly and truly amp dependent. Some amps just smear everything into each other creating mud from a spectral. While Others maintain clear dimensional air and spaces between the elements in the music you're listening to. The tone in all cases, I find IMHO is richer and the timbre decay more pleasing in A/B or A class amps. (lets leave SET amps out for now)
The consideration of Class A is good one but almost diametrically opposed to class D. It is the heaviest richest biggest sound of all. Although sluggish vs. class D- if you want a real punchy but toneful bass you should try it. The only other issue is that the iron fisted bass can dominate the whole presentation and soundstage can be obliterated.
Since you are a devout tube hater I will only mention in passing that my 60 watt amp runs in pure class A and preserves the holographic soundstage. A good SS Class A amp with a good pre is always a delight to hear but I never had both simultaneously.
That is my honest thinking.
Just to clarify, Bel Canto class D Ref series contain analog ICEpower modules. Ref 500 is based on the 500ASP module; Ref 1000 Mk.1 and Mk.2 have been designed around the 1000ASP module.
I have most experience with Ref 1000 Mk.2. . . Ran it for 4 months before completeing my PFO review. there is nothing sterile nor congested about this amp. Rumour has it that Ref 500 may be even sweeter. Regretably, these devices -- even used -- tend to exceed the target budget for this thread. G.
Thanks guys. I was out for the long weekend and did not get time to go through the updates.

Good to know that the W4S may sound good in my system. I found from the user manual that the Marantz outputs 2.2V.

I am a bit worried that if the new amp is does not have the good characteristics of the NAD sound, then I will really have some (many) sleepless nights despite spending some $$$$. I see that you have updated your system pics with Quad 21L2. I really love the dynamic Quads. You will not believe it, but I have heard some Dynaudio, Triangles, Totems, Dalis, Paradigms, etc in their price range (and couple thousand $ more) and the Quads come out on tops for me.

That character of Class D is what is keeping me away from finalizing on a good Class D amp. I can get a demo Spectron Musician MK II - albeit at a bit higher budget - but I am still not decided.

Yes the Bel Cantos exceed my budget by quite some $$$$.

At this point I am seriously looking at the Parasound A21. Does any one know if this amp has been upgraded (internally)? I believe that this amp was meant for home theater rather than 2-channel. Any cmparisons of this amp against other highly regarded amp?

I have repeated this in other threads - I am not a "devout tube hater". It is just that I don't want the problems of tunes like biasing, heating, matching, etc. Don't have too much time on hand for those issues. If I go tubes, I will loose whatsoever little time I am able to devote to this great hobby.