Class D amps,bang for your buck ones


Hello

First off,

I don't know much about class D amps, I did buy a Sonic Impact T-amp from Parts Express once to play with, I returned it because I don't have the speakers for it.

I did manage to hook it up to a pair of BIC Venturi horn speakers, and was floored with the clarity of the amp.

Those speakers had so many problems that I just didn't want to monkey with them, bad x-overs with busted pots,only sometimes could I get them to work right.

So, this leads me to my question.

Whats a high value class D amp with some hp/balls to drive normal speakers?

I'm looking for the Forte 4 of class D's, assuming (class D)is a tripath based/type amp.

Any suggestions or comments welcome.

I have an Accuphase pre and a minimax pre to use.

Thanks
mcgarick
The PS Audio trio A-100 in balanced mode is an excellent amp for the money. I say in balanced mode as I haven't used them through the RCA inputs. I use two of them to bi-amp my speakers. They are extremely easy to bi-amp with a back panel switch.
What is your budget for a class D amp? Like all other amp types, class D amps range from less than $1000 to over $40,000. . . quite a range. Guido
Love my Gilmore Raptor monoblocks. Extremely powerful, clean and neutral. Not cheap, though at $5K per pair.
I used to have Rotel RMB-1085 and it was very good. It employs Rotel proprietary class D chipset, not the more common and more expensive ICEpower chips. Excellent value at around $1000 for five channels of clean 100W. They also have cheaper two channel model.
PS Audio GCC series uses ASP ICE modules. Available in 3 ratings and use the PS 'Gain Cell' input. These are integrates.
PS also made basic amps without pre section.

My Maggies seem to be enjoying themselves with the GCC250, which doubles up at 4ohms.

ICE is not a 'chip'.
I 2nd PS Audio GCC-250. I am using it with Gallos Reference 3.1 speakers. These are pretty inexpensive now on the used market. I am very pleased with it.
I have the Audiosource 7t 200 wpc Tripath chip base amp also used in Bel Canto Evo 200.2, Audio Research 150.2 and the Carver Pro ZR1000. Someone was selling these new on Ebay several years ago with about 40 available. After buying one and enjoying the sound, I bought another one because of the price/performance ratio. My Bryston 4B-ST has been sitting lonely on the sideline eversince, best $250 I've ever spent on audio. It's killer with a tube pre. Excellent sound mating with Gallo 3.1.
Keep an eye on Virtue Audio amps. Stereomojo says more goods are coming soon.

Clarity, yes.
"Excellent sound mating with Gallo 3.1."

This is probably because Anthony Gallo develop his speakers AND , as a rule, display his speakers (CES 2009, I am not sure about RMAF 2009) with class D amplifier - Musician III by Spectorn Audio.

As a matter of fact many other speaker designers like late John Danlavy, Albert von Schweikert use Spectron amplifiers as well in their speaker developments

All The Best
Rafael
Mcgarick im going to mention Nuforce amps to you as the best bang for your hard earned buck. I ve owned my original ref 9 amps for nearly 4 years in that time Nuforce has offered upgrades to bring my amps to the newest available offered by Nuforce. For me its been first SE then V2 and now Nuforce has introduced V3. The money saved for upgrading instead of unloading and re buying is substantial. How can a better bang for your buck be found. When you take in effect the ability of these amps to drive your system to musical delight along with low cost upgrading. A business practice like this is unheard of in this hobby we love so much. Good luck in your quest.
Mike
I am considering upgrading from Nuforce Reference 9SE to Nuforce Reference 9 V3 SE. Anyone heard the Nuforce Reference 9 V3 SE? The upgrade path seems reasonable to me.

Mark
Spectrons are not bang for the buck, they are one of the expense D Class amps. Check out the older Bel Cantos or wyred 4 sound.
You may want to look into the new Rotel RB1572, 500W per channel at 4ohm class D. I believe it is based on the latest generation of ICE power but with a Rotel designed power supply. Retail is $1299, the reviews are limited however.
Onkyo has a stereo integrated amp that is class D - Model A-9555. It has been pretty well reviewed.

Mark
THat PS Audio HCA-2 was PS audio's first foray into Class D amplification. Although it had garnered some reviews in its early life, it was nothing to write home about as it was summarily dumped into the second hand market once its hype had passed. They must have released it in the early 2000s.

Their GCC/GCA line with the gaincell technology seems to have completed the maturation of their Class D designs and are hitting their used market as we speak. It seems as if the GCC line had more of the power and neutrality that is commonly associated with what you read about Class D amps that are "bulletproof" in reliability.

Their newer line, with the 1/2 size chassis do not seem to impress as you see them dumped into the second hand market without really much time in people's systems. For the choice of words that people use to describe the smaller digitals, they do not elicit much praise.

Of course, your miles might vary.

PS: I own a Henry Ho H20 amp, the S250 and these amps are bloody incredible even their non signature versions.
I now have had an opportunity to upgrade to the NuForce Reference 9V3SE and allow them to burn in. Burning in was critical. What incredible amps. I doubt you will be seeing any of these on the used market. I am a NuForce fan for life.

Mark
Markalarsen
I now have had an opportunity to upgrade to the NuForce Reference 9V3SE and allow them to burn in. Burning in was critical. What incredible amps. I doubt you will be seeing any of these on the used market.

Let me be the first to take that bet please. This is Audiogon after all. :)
FWIW.
I have a pair of the Wyred SX1000 monos and a Mcintosh MC352 which I've been listening to back and forth with different speakers.
Both driven by a Lavry DA10 DAC.
The wyreds sound great with my B&W 801 Matrix2, but I preferred the MC352 on my Dunlavys SCIV4a's. The Wyred are a bit more forward with better LF control to my ears and the MC352 is smoother. Both in the same league, just different flavors.
The Wyred are a bit more forward with better LF control to my ears and the MC352 is smoother.

Trinculo,
Does it mean that the W4S sound loser to the Rotel amplifiers when it comes to Trebal/mid-range? Are they more analytical?
I haven't compared the W4S to any Rotels so I can't comment to that.
Compared to the Mcintosh MC352, particularly on the Dun's the W4S sounded more aggressive in the hi mids. I would in no way call them "loser". My impression is that they are very fast accurate amps. Tight would be the adjective I would be more inclined to use. They sound great on the B&W 801's in my studio.

The Mac on the other sounds great on the Dun's, but is a bit wooly on the 801's.
Another vote for the Onkyo A-9555. I've had mine for 1-1/2 years. It is very fast and clean, yet not etched or irritating. The speed and low noise floor enable me to hear much more continuity to the music and bloom and fade in the individual notes. It's very dynamic, both for slam and for nuance. At its list price of $799 it's a good value; at its typical <$550 street price it's ridiculously good.

Only caveats:
1) It doesn't have pre-outs. You have to use it as an integrated unit. Fortunately it makes about 85/170 watts into 8/4 ohms and sounds more powerful than that with lots of slam and bass extension.
2) The built-in phono preamp is decent, but eventually you'll want at least a Cambridge 640P to add some slam and dynamics to LPs
3) The speaker terminals are those wimpy ones that accept only bare wire or bananas. The amp sounds so good this is a minor inconvenience. I'm using locking bananas and they're just as secure as spades and a lot easier to use.
4) You'll get a jump in sound quality with an aftermarket cord. Switching amps are pickier about the AC quality.
5) Must give it 100 hour break in or you'll think the A-9555 enthusiasts are deaf or masochistic.

Its low level resolution is very nice; it even warmed up my CDs.

Both TAS and Stereophile gave it positive reviews. S'phile gave it a class C recommended rating; based on the other class C selections, I'd say the A-9555 is borderline class B.
I just ordered the class D audio amp (600w version):

http://classdaudio.com/index.php
Jtwrace, the ClassD amps look very interesting as they utilize some fairly novel technologies from TI. What will you be using for power supply. .. unless I'm wrong, they seem to require an external PS. Guido
No external power supply required if you buy one of the kits. Just an power cable. I keep telling myself to try the 125 watt version.
Kkm, I did the same thing (audiosource/ebay/tube pre). I had a mint Son of Ampzilla I thought sounded pretty good, but what clear,superior, balanced, muscular sound for $250. I am still amazed. Music, just music. I do believe a Class "D" should be matched with a tube pre.
Yes, I got one of the kits. This one: http://classdaudio.com/index.php/class-d-amplifier-kits/home-kits/600w-class-d-power-amplifier-and-power-supply.html

add a power cord and you're off. The board is already built you just have to attach the toridal.
01-18-10: Jtwrace
Yes, I got one of the kits. This one: classdaudio.com/index.php/clas...

add a power cord and you're off. The board is already built you just have to attach the toridal.
What are the challenges to mounting one of these on a chassis and adding a housing? Will it fit into an over-the-counter chassis or does one have to be fabricated to size?
if u want to try buy the Morrows on agon they are cheap and u can find out if u like or not
Johnnyb53

Yes, they will fit into many different chassis. Par Metal, Hammond just to name a couple all make something that will work and look nice. It will all depend on what you're after.
I bought a Virtue Audio ONE.2 and now I am upgrading the input caps to Sonicaps, I will report my findings here later.
I will be using a couple different PS.
I haven't read EVERY word in this thread, but has anyone mentioned the DIY aspect of the question?

Hypex 'd' amps and power supply parts are available and can turn into quite the nice amp.

International Rectifier makes a 'd' amp....which also needs a PS. I think the are an OEM supplier to a few manufs.

B&O doesn't make modules available to the DIY crowd. I suppose if you were willing to buy hundreds...if not a couple thousand, arrangements could be made.
Regarding Magfan's 12-10-10 post

Definitely check out the Hypex Class D modules and power supply parts. If you are a DIYer you can build yourself a pretty sweet sounding amp. I'm not a DIYer but I purchased a someone elses DIY effort using the Hypex UCD-100 module with beefy power supply and transformer and the amp sounds great. LF is excellent with my KEF 104/2 speakers and the mid-range and treble are just right. Before this I was using a pair of Outlaw Audio M2200 monoblocks and the music seemed kind of lacking all around.
The Virtue Audio ONE.2 with the input caps upgraded to Sonicaps, sounds wonderful.

It's smooth, dynamic and musical, very transparent. I would say it is one of the best amps I've had so far.

It's been breaking in for 10 days or so and I expect it to get even better with more time on the unit.

I would like to try some other Class D amps just for fun. like the Nuforce power amps.

The real upgrade with this amp (beside the Sonicaps) was the power supply I'm using.

It's an Astron LS-10A power supply and it maxes out the voltage the Virtue can handle, and makes it sound very powerful. It's funny how this little amp puts out a huge sound,but I guess the power supply is also part of the amp, just separated by a power cord. But, you can hide the power supply and just have the little Virtue exposed and blow peoples minds with it.....
fun amp.
For anyone investigating the Virtue amps, I recommend getting the TWO.2 amp instead of the ONE.2, because the TWO.2 will already have the better caps in it.

I personally thought the
Virtucaps that come with the ONE.2 and holds the amp way back.

The TWO.2 comes with Auricaps, which are superior.

But, I'm glad I got the Sonicaps, the sound is totally open with them.
Has anyone but me noticed that the W4S looks nearly identical to the PSAudio GCC series? I just looked at a backpanel photo from W4S and the differences are tough to spot.
Do (did) these amps come off the same line? Same sub? Did the PSAudio guys sell the 'rights' to the design to Wyred?

I'd like to compare the Wyred to my PSAudio in my system. Wouldn't surprise me to learn the differences could be covered by a single finger.....
There is a review of the W4S STI-1000 on 6moons. The pictures provided by the reviewers there are always a highlight. If you've ever looked under the hood of your PS Audio amp you could take a look at the pics and compare. It doesn't look to me that they are using the Gain Cell packs like the PS Audio gear. As you said though, the rear panel looks nearly identical.
Yes, Tim, I believe you are right. the GainCell is proprietary.

As a result, methinks, the input impedance of the PSAudio gear differs from that advertised for the ASP modules.

I'll check out the review, but am reluctant to crack a case at this time. It'd be a lot of hassle freeing it up.
I've heard it and repeated it.....that the 'd' amps using the B&O modules have more in common than differences (sound-wise), but is that TRUE?

Has anyone simply lined a bunch of 'em up and gave a reasonable listen?

The case and front panel...not to mention the backpanel layout is so similar to the PSAudio it makes me wonder.
i think a well designed class a amp is more pleasant to the ear than any class d amp, with the possible expection of the virtue audio, which has a tube front end.

ice power sounds icy (LOL)
I have acquired a W4S ST-250 amp, and LOVE it!!
I'm going back and forth between that and the Virtue right now and it's driving me crazy.

They're both soo good...

What to do?

I'll enjoy both.