I believe if you check the forums, you might find some info on this. Its been discussed a few times.
Riley is correct about there being many forums about class d amplification, both positive and negative. I have been using class d for about five years. I have upgraded three time using the latest that Bel Canto offered. I can't tell you which brand to purchase. If you do put one in your system please give it a chance to break in. The Bel Canto REF500m I have now is still improving after eight months use.
Over the years I have owned many tube and solid state amps.
I took the plunge and glad I did.
Just purchased the Wyred 4 Sound STI500 after being very satisfied with their DAC1 and now DAC2. It hasn't fully broken in yet, but so far I am very impressed. I have Magnepan 1.7s and the STI500 has plenty of power with a very smooth sound. As it is breaking in, I am hearing more details.
Don't know about the Bel Canto. I purchased the Wyred 4 Sound STI500 based on quality materials in the construction, great reviews and terrific success with their DAC. It seemed to hit the sweetspot in price vs. performance.
The unit is very easy to use and very flexible. Highly recommended but give it PLENTY of time to break in - 200 hours, at least. When you do, you will love the sound with the Magnepan loudspeakers.
It's going to boil down to a lot of factors. I have owned a few class D amps, in fact currently own a pair of Ref 1000 by BC. In comparing the class D amps over the years, in evey comparison I have made to my class A amps (which have traditionally been Krell (4), Pass (2) or M. Levinson (3), but others as well), I have preferred the class A amps.
Across the board, my preference has been and continues to be class A. But, the class D amps have gotten gradually a bit better with each new generation - but still haven't proven to me to be top performers.
I'd look for a used Bel Canto over the W4S, but that is just me. I know W4S has a lot of proponents. I can't say from experience that you will notice much of a difference. The class D amps always made me feeling as though I was just missing something in the performance and that I couldn't always or immediately put my finger on it. My first experience with class D was pretty positive at first, but over time I came to realize that I wasn't as excited to sit down and listen to music or didn't listen as long.
I have heard this complaint about Class D amps before and it concerned me when I was making the final purchase decision on the W4S amp.
I did a quick scan of prices of the three amp brands you mentioned: Krell, Pass and M. Levinson and at anywhere near the output power of the W4S STI500 they are 3 to 15 times more expensive. This is really an unfair comparison.
Assuming quality audio reproduction of the equipment, Class D amps provide the following additional benefits:
They are very light,
Have very low power consumption, and
Give off little or no heat.
The pace at which the W4S is breaking in right now, my concerns about Class D lessen each day. I would possibly compare the "difference" in Class D amps with my previous Class A (up to 10 watts) /AB amp may be similar to how Magnepans sound different than other speakers. You either like it or not, but they do present the sound in a different manner. I don't hear any differences as big as Magnepans vs typical speakers in the W4S vs Class A or A/B amps, but possibly some slight differences.
Finally, the W4S STI500 does sound very very good with the Magnepans.
Ron, that is also an issue in my mind - the cost of the class A amps versus that of the class D amps. But to be fair, the Bel Canto is closer to half the price vs. a quarter or third.
But one of the claims of the class D amps is this performance per dollar and the many, many statements about the amps being better than amps costing many times as much. When somebody makes this claim, then I think it is more than fair to compare said amps with others costing twice as much.
Also, it should be noted that it costs considerably less to make a class D amp than a class A amp - that is just a matter of parts pricing, casework, etc. . .
I think the class D amps have improved dramatically, though my experience is that those that have shown the best performance and most promise are also the ones with the best power supplies and don't rely on just the switching amp. This, to a greater (vs. lesser) degree, can be seen in the weights of the better class D amps.
Ron, you are not the first to suggest the notion that the class D amps shine well on the Maggies, or e-statics/planars, etc. . . for that matter. I have owned Logans, but not currently and never at the same time as a class D amp - so I cannot comment at all in that regard. But based on what I have read, it seems your statements are well supported by owners of these types of speakers.
The Bel Canto is a Class D amp that goes for 1.5 to 2 times as much as the W4S. I understand it is also a great amp and makes sense for someone thinking of spending $2K to $3K on an amp or integrated amp.
I really like the simplicity of the W4S and how I can completely black out the lights on the amp and DAC when listening in a darkened room. It is incredibly easy to use.
Since my budget topped at $2K the W4S STI500 was an easy choice. There seems to be a lot of quality parts and good construction for its price range. I replaced a 55 lb Class A and A/B amp along with separate hybrid preamp with one simple box that puts out 2.5 times the power and has done amazing things with the bass response of the 1.7s.
Well Ron, it has been a while since I have been to this page. But over the weekend I picked up a couple pair of speakers. A pair of Thiel CS6 and a pair of Maggies (SMG-A, I think is the model). I'll give 'em a listen with the class D Bel Cantos
My experience so far with the Thiel's (very power hungry speakers) is that the Bel Cantos don't seem to have enough power for them (@ 1,000 watts at 4 ohms - which is what these speakers are). Instead I am using my Mark Levinson 125/250 @ 4 amp which seems to have a much, much better ability to power the Thiels.
But those little maggies don't need much power and I will hook the BC's up to them this coming weekend and give it a shot.
I would be curious to see if the W4S STI500 would make a difference on the Thiel's. I feel that the STI500 has an unlimited amount of power with my Magnepan 1.7s. At any listening levels that I am comfortable, the STI500 seems to be cruising along.
Reading some threads on both the Bel Canto and W4S integrated amps, the W4S seems to come out very well on build quality. Don't know if that is true or just opinion.
Just made a very simple change in my system - removed the Better Cables digital cable and replaced it with a Xindak digital cable. I am not sure that this can be the case but the music flows much more realistically and is much more involving than before. Very surprised at the results.
Working on upgrading my XLR cables connecting my W4S DAC2 and W4S STI500 from Morrow MA1.1's to either Morrow MA4/5, AudioQuest Colorado or MIT Shotgun 3.3. Looking forward to seeing if top dollar (for me) cables can bring out additional detail and musical realism.
As the W4S STI-500 has fully broken in, I would say that the characteristics are:
1. Incredibly smooth
2. Good detail, but not yet up to Class A amps - this has actually surprised me because of the STI500 reviews indicated that this unit has tremendous detail. I hope upgrading my cables will provide additional detail.
3. None of that Class A/B amp harshness
4. Unlimited feeling of power.
4. Decent feeling of space and depth - better than my previous amp.
5. I am just a frustrating step away from hearing three dimensional musicians playing in my room. Right now, I have clarity but it just misses that spooky three dimensional feel that I was beginning to get with my previous Class A up to 10 watt, Class A/B to 200 watt amp.
Limiting factors: I am still using a $100 APC UPS power supply providing surge and filtering for my audio equipment. Cables connecting DAC and Integrated are about $140 - good but not great. My music server is a $350 NETGEAR 9150 with 500gig hard drive. I burned my CDs to the NETGEAR using Microsoft Windows Media in a rather haphazard way. The files are lossless, but I have been reading on the net that Windows Media does not necessarily burn an "exact copy" of the CD.
Overall I would give the STI500 a Very Good rating.
I am using my ST-500 with Pure Note (TRS audio) Alluvion XLRs. These proved to be an excellent match between my w4s DAC2 and ST-500. Look for low capacitance XLRs with mostly air-spaced conductors. The Alluvions are cryo treated silver-palladium ribbons. Also later you can change the fuses on the ICE modules of the amp. I also changed my powercord on the DAC2 with a Neotech NEP-3003 cord (OCC copper based and cryo'd) with Furutech ends. This opened up the soundstage alot without being harsh at all. Had almost the same impact sonically to when I installed my pure notes.
I've tried several class D amps, historically I am class A all the way (to full rated power). My three most current/recent amps have been Krell FPB 300, Levinson 334 and a Pass Alpha (60@8/90@4), all fully class A amps. I have owned a few class A/AB amps but was always a bit disappointed in them in comparison to my class A amps. I found that when the higher power was needed, the A and A/B amps didn't perform as well.
The most interesting thing for me is with my speakers that enjoy more power, I have always felt that class D amps ran out of power, even when rated at 4 times as much, or more power than my class A amps. I think it is similar to how when people say in comparing tubes to SS amps; "how 60 tube watts is like a 100+ SS watts."
That has been my experience with the class D amps, so far. That and I have found that they have not grabbed my heart and sole in the same manner as the class A amps. But I have read several places that the Class D amps with certain speakers are a good match (it was suggested by many that the Bel Canto Ref. 1000 are great with the Wilson W/P's, that has not been my experience at all.) I have heard they are great with the maggies and I am looking forward to trying that combo this week.
I forgot to mention that I do have Xindak Power Cords for all of my equipment. They appear to be 10 guage (thicker than a garden hose!) These are very nicely constructed cables that would be comparable to $250-$400 power cables.
Ckoffend if you get a chance, try one of the W4S amps or integrated amps. I would be interested to hear if you have the same issues about them running out of steam. With the Maggies, the STI500 has the sense of unlimited clean and clear power. Really amazing.
By the way, looked up some of the amps you mentioned. Both the Krell and Mark Levenson looks like a battleships! I have seen Pass amplifiers and they were the biggest boxes I have ever seen in my life!
I do like the sound of Class A amps and believe they, like tubes, really provide more sound per watt than Class A/B. In addition, I think the W4S is very close to Class A sound (once I update some cables I think that they will take another step up - remember I am currently using a $140 cable and source is a $350 Netgear 9150). As of now, the W4S blows away the Class A/B amps I have listened to, especially at high volumn levels.
Here is my argument for Class D vs Class A:
Unlimited feel of power
Smooth, never harsh
Low power consumption (I leave my amps on ALL the time)
Small footprint (about the size of a preamp)
Better depth than my previous amp
Three dimensional but not yet up to my previous amp running in Class A mode where you feel the performer in the room
A fraction of the cost of a comparable Class A amp (less than 1/3 to 1/10 as much)
Truth be told, if inconvenience was not an issue, I would choose a Tube amp in the 100 watt range over a Class A or Class D amp but after all the issues you have to go through for tubes, I decided it was not worth the trouble.
Ron, I got around to hooking up my Bel Cantos to the little maggies. Initially I just did a quick hook up of the maggies to the HT Receiver (yeah I know, no comment necessary, it's a Pioneer Elite model???). I am not too much into HT, so this is just for my kids.
But the Bel Cantos Ref 1000 seem to sound quite nice with the maggies (which I have not hooked up in my main system yet). I am just running a pre-out from my HT Receive to the Bel Cantos into the maggies. The sound is a notable (unsurprising) improvement vs. the HT receiver driving the maggies. These were cheap speakers and it had been a while since I had run maggies in my house and I figured they would be nice to play around with, especially with the BC amps. I can understand why people like this combo. Though it certainly doesn't compare to the performance of my main system (again, unsurprisingly as none of the other components, cabling, room, etc. compare).
Outside of these notes, I can understand many of your comments on the class A, class A/B, class D and the tube amps. Not sure if I agree with all the comments as I have had a tough time finding anything outside of Class A that has performed as well "in my system". Though having had good tubed amps, I love the sound, hate my continuous concern about the tubes and maintenance insecurities. The sound can be great though.
I would have to agree with Magfan on his comments regarding similarity of class D amps having more in like, than major differences. I have owned and tested a few and found this to be the case - WITH WHAT I HAVE HEARD.
There are certainly other threads that make note of MAJOR differences; however, not to my ear!
I am surprised how content I am with the Maggie SMGa speakers, considering their price (I paid), their age and the lack of equipment support vs. my main rig. It makes me want to consider buying a more current and much larger pair.
As to the sound of Bel Canto and W4S, I can't say based on side by side comparisons, but again, I agree with Magfan that there is unlikely to be much of a difference. So many of these Class D amps seem to be comparing themselves to much more expensive Class A amps. I haven't experienced a level of performance that is anywhere close to matching the true class A amps that I am accustomed to in MY SYSTEM.
I don't think you can compare the two brands. Wyred amps are mostly similar save power ratings however BC designs vary more. THe better BCs have improved power supplies and are tube pre-amp friendly. Different BCs use different version ICEPOWER modlues. The Wyreds are tube pre-amp friendly but do nothing special with teh power supply TTBOMK and I think all Wyreds use the same version of the ICEPOWER module. So you have to compare specif models, not brands in general.
Resale prices tend to be good relative indicators of how specific models compare feature wise I think
The ASP module includes powersupply. So, they are pretty much plug /play.
The ASC module is meant to be powered from an ASP module OR from a stand-alone PS. At that point you can buy a transformer and a capacitor bank, or go SMPS.
The output sections are very similar...topology and device selection.
It would appear that W4S uses unmodified ASP modules with perhaps a few changes on the input end. My PSAudio, built in the same facility has what they call the 'GainCell' on the input. I have no detail on that, except it is a potted module.
Other 'd' implementations may have character of their own. Hypex, Spectron and the little known International Rectifier are all 'd' entries. Spectron is proprietary, Channel Islands uses Hypex and I have no idea about IR modules, except I've got one out in the garage needing a power supply.
The 2 major topologies of 'd' amps, what are called 'FullBridge' and 'HalfBridge' may account for differences in sound.
Would you or anyone consider such changes making the ASP moduled amps an Apples / Oranges proposition or maybe like a Fuji /Gala? (I'm a BIG fan of Apples!)
Changing (upgrade?) some caps? The only thing that would have a major effect, IMO, would be to change the feedback loop gain. I doubt even changing parts in the Zobel would have a major effect. The W4S integrated also has a different input impedance than the 'stock' ASP module OR my PSAudio which is a near-dead ringer. That supports your 'input buffer' remark.
I'd love to know what changes W4S makes. IF they are THAT major, why aren't they trumpeting it to the sky?
I'd LOVE it if someone organized a 'd' amp shootout. If it were local enough, I'd even bring my GCC250 over and put that in the rotation.
Wyred 4 sound amps are well worth the current asking price, they are very good sounding amps, but not great. My experience with the ST-250 impressed me to some degree and felt a need to play the highest quality recordings (audiophile music) to make it sound good, whereas other recordings didn't quite measure up. I am from the camp that a digital switching amp could benefit from an analog power supply but I have to give Cullen Circuits a thumbs up for implimenting a switching power supply that is acceptable. After inserting the older PS Audio HCA-2 the overall musicality regardless of the quality of the recording improved quite substantially. One would think that as time goes on that the sound quality of digital switching amps would improve but it is apparent that this is not the case here. The HCA-2 with its panoramic sound and analog power supply fleshes out velvety highs, bumped up midrange coupled with its ability to layer and texture the music in such a delicious way is superior in most all areas and found the overall involvement in the music was stepped up quite a bit. This is my opinion and I could still recommend the wyred 4 sound amps at their current going prices but I don't classify them as high-end but just very good midfi.