D-SONIC SOA Class-D Core Amps. The best Class-D ?


Owner/Designer Dean Deacon of D-Sonic in Houston in recent months dropped using the B&O ICE amps which he now only uses in the surround channels of his multi-channel home theater amps. He now uses a new Class-D amp in all of his Magnum2 mono and two channel amps which he states is the most technically advanced Class-D amp on the market, called the SOA Class-D core amps. The recent review in 6Moons of his new M2-1500M amp concludes its the closest that Class-D has ever come to tube amps in the upper mid-range and high frequencies.
Anyone bought or heard recently the D-Sonic M2-1500M or the M2-600M? What are your opinions?
audiozen
Audiozen,

I just noticed that you still haven't recognized that H2O is me, Henry. So yeah! It is me Henry of H2O AUDIO :-)
Well Henry..I tried connecting on Google, Yahoo, Babylon, Bing..ain't gettin nuttin!...
Audiozen/Tom,

you guys must have tried iceh2o. Iceh2oaudio is the website address. It is there. Thanks again for your interest Audiozen and Tom.
Henry, you may want to contact the friendly business people at Audiogon, because H2O Audio info page seems to be obsolete:

http://www.audiogon.com/cgi-bin/manu.pl?h2oaudio&1&showmanu&Ice+H2O+Audio

* Phone number has still Virginia area code;
* Link to web site is dead;
* Company is listed under "I"... Shouldn't it be listed under "H"?

Saluti, Guido
Hi henry:

http://www.iceh2oaudio.com

is invalid, or is offline. It would be a good idea for you to copy/paste the entire valid URL from your browser directly into your next post. G.
Still not able to connect. Either you or we are crazy!

This page can't be displayed !!!!!!!!!!!!!!!!!!!!!!!!!!!!!
I'm not sure what is going on but It works fine for me. What browser are you gents using? I use google chrome. However I just notice that some of the link is not working. Links to all the reviews next to pictures seem to work but not for the pictures to get the specifications. Guido when I click on your link you provided, it does take me to website's homepage fine. But like I said, some links just doesn't work. Looks like I need to talk to my web hosting provider. Thanks

Henry
Hi Henry, I am using IE8 on XP Pro 32 bits with SP.3 and all critical/optional patches. Guido
Guys,
This is actually not funny. Not one person has come forward regarding their "personal" experience with D-sonic. Then there is the talk how good a preamp "is". And now IT support for H2O.
A thread gone bad!
Henry, I have tried Guido's link using Chrome and it fails with the error: "Oops! Google Chrome could not connect to www.iceh2oaudio.com". I suspect that you may be accessing a page in your cache and that's why some of the other links don't work. I think you need to address this with your hosting provider as there is obviously something wrong!
Hi Deadlyvj, my personal apologies for the unwitting contributions to the temporary derailment of the thread. One of the problems is that, Abletec modules being only recently introduced in component design pipelines, not too many major designers of switch mode amplifiers have introduced products based on these power conversion modules. As the initial batch of Abletec-based amplifiers reach consumers, and more manufacturers adopt these power conversion modules, I am hopeful that we will start to see real findings, hopefully on this thread.
Deadlyvj..my intent starting this thread, was to engage those who may have experienced D-Sonic, with the emphasis as Guido points out, on the Abletec amp modules, which are just now being recognized as an alternative to B&O and Hypex. So far, it appears at the moment not very many have experienced D-Sonic and Abletec, since I was hoping to get a much greater response. Now that the holiday and CES is over, I hope this thread will increase reply activity on Abletec, and if this thread winds up becoming a "Class-D Cafe", thats a good thing to...
If they gain traction, I'm sure well hear about them in due time.

I suspect they should/will.
I haven't seen any one else respond to Henry's offer, but being a Pure Class A user for several years, I'd love to try a quality class d product in my system.... if a tour starts, please sign me up.
Tim
The last sales feedback to Henry/IceH2o on Gon was way back on October 20, 2010. It appears his business is in survival mode.
Audiozen, I find that to be an unreasonable and thoughtless statement. I have absolutely no connection with Henry or his company, but his business may be doing fine with sales from other sources than Audiogon. There are many major audio companies that do not do any business here, and that fact doesn't mean that they are struggling to survive.
derailing the original thread was certainly not my intention. Audiozen, I still used the B&O modules. Thanks again for who alert me on the H2O website problem.
Henry..last time on the subject..want to stay focused on D-Sonic/Abletec. Discovered that IceH2oaudio.com ISP is hosted by Covad Communications which was bought out by Megapath Communications. Called Megapath and they do not have IceH2oaudio in their system and informed me that its a domain name that is available to purchase. The current location for IceH2oaudio.com is in Lutherville Timonium, Maryland. Ring a bell?..
The Abletec amps in the D-Sonic products use a modulation technique called phase shift modulation rather than pulse width modulation...interesting..
I'm not a electronics expert. PWM leads to issues in the freq. domain.
I would presume phase modulation might have a similar effect on the phase domain.
Assessing different technical approaches for Class D seems to me like a technical assessment of ice cream, chocolate versus vanilla. You can read and analyze all you want but won't know what you have exactly until you try it. Often the case with home audio gear. Each company has its own design or marketing focus to help distinguish from the pack. Fun stuff!
Mapman,
Agree!!
Just thinking aloud, since no one has come forward with their experience.

Another thing that is possible- considering phase is manipulated, there is a fixed frequency window - band width limited (which may be the case in PWM as well). However as my understading goes, there might be an error correction factor needed, may not be the tradional negative feedback, but maybe along the phase wave. Negative feedback if institued properly is generally a nonissue. Probably that's why it's called SOA, where all parameters are optimized.
Bill-k...give me a break..Henry's website is currently offline for sometime and his phone number is disconnected which is a very strong buisness indication that his business is stressed. When a company fall's off the radar it becomes a ghost business, and the result is a much greater risk for the buyer to get reliable service from a business that has very weak stability. If Henry comes back online and things go back to normal, then more power to him.
AudioZen and all, ICEh2oaudio.com is back online at:
http://iceh2oaudio.com/
Henry's current phone number is listed as:
1 713 371 7591
which indicates that Henry has moved West, and now resides in my state of Texas.

may I now gently suggest that we return this thread to the discussion of technical merits of Abletec and other new generation class-D power conversion modules, to their application to actual amplifier components, and to the findings of those who have had an early chance of listening to such creatures.

Regards, G.
Henry..I thoroughly read through your site last night and all the reviews. I noticed you amps have an input impedance of only 8000 ohms. Wow thats low! Never seen an amp below 10K ohms. Curious as to why you don't adjust the input stage to raise the input impedance to make it easier for Preamps to drive your amps. Have you explored the recent developments of alternative current modulation from Abletec and Hypex, and do you have any plans to use their products in the near future, or do you think their approach to alternative modulation is nothing more than snake oil?
Hi Arthursmuck, I reside in the State Capital.... Just sent you a PM with more info. Guido
Audiozen,

Thanks for the interest. Yes 8k input impedance is low but not too terrible low. One has to be a bit judicious in choosing the preamp. Of course, most if not all solid state preamps will drive the amp fine. The only exception is those with open loop design and/or some tube units. Changing input impedance is certainly an option but I'm not equipped to work with surface mount components. But more importantly, Raising the impedance would introduce more noise, plus I like to keep the original designer's intent of how it should sound. I have not tried either Abletec or the Hypex, though I have customer who have listened to the Hypex Ncore so I have a very good idea of how they sound. I have intention of getting a couple the Hypex Ncore to try but discourage as the lead time is exceeding long, plus the fact that that the modules are extremely expensive so I have put it off so far. Someday I might try it. So currently I'm still using the Ice modules without the integrated switching mode power supply. I use traditional linear power supply for my design.
Interesting Henry..I noticed your Fire preamp has a very low output impedance of 20 ohms, which matches perfectly with your amps. Never seen a Preamp with an output impedance that low.
Since this thread is focused on Abletec/D-Sonic, as well as Hypex and other's, another newer Class-D switching technology just popped up. Phew!! hard to keep up with.
The Jeff Rowland Group had a private showing of their new Class-D integrated amp at CES, which is called the Continuum Series Two. No longer using B&O Ice Amps that where in the Continuum 500. The new integrated will be using the new Pasquale Class-D amps, exclusive only to Rowland. Rowland said at CES they are far superior to the B&O ICE technology. The integrated will be released in April and will put out 400 watts into 8 ohms.
Not all B&O icepower modules are the same. Some are newer, some are older. SOmetimes, different ones are used in teh same line at same time, like BC ref500m versus ref1000m.

Have not kept up on new Icepower development though. Have they stopped refining Icepoweer at this point? Certainly there is more and more competition all the time now it seems, which is to be expected. The landscape might be totally different in just a few years. Not uncommon for companies that forge new frontiers to fall by the wayside over time as others follow.
It appears that B&O has not moved beyond pulse width modulation, which is the area that amp enigineers have focused on in recent years claiming that PWM has hit its limit regarding the problems with PWM such as feedback and noise in the upper frequencies, as well as RFI/EMI problems. The only Class-D company that has fallen by the wayside and gone out of business was TriPath. Abletec, Hypex and the others are doing very well. Lets see whats in store for Pasquale. It appears based on my discussions with these company sources, that newer, alternative modulating techniques have resulted in zero feedback, much better linearity, and lower noise bringing Class-D much closer to the very best Class A and A/B SS and tube amps.
"It appears that B&O has not moved beyond pulse width modulation, which is the area that amp enigineers have focused on in recent years claiming that PWM has hit its limit regarding the problems with PWM such as feedback and noise in the upper frequencies, as well as RFI/EMI problems. "

I wonder if B&O or other engineers still dealing with it would agree that PWM has hit its limit? No surprise the competition would claim that.

I can vouch that Bel Canto ref1000m Icepower based amps do very well in regards to RFI/EMI. I have had those problems in the past. THe Class Ds would not be in my system if that had turned out to be a problem. There are many Class D amps out there, including ones that use stock Icepower, that have been reported to have that issue, but apparently it is not terminal for all Icepower amps.
True..but John Stronczer at Bel canto does extensive mods and upgrades to correct that problem. As a stock amp, the problem is their and can only be corrected with additional filters and shielding. The newer stock designs from Abletec and Hypex don't have that problem and the in house class D devices from Audio Research and Nuforce seem to overcome those issues as well. B&O ICE amps have been in production since 1999, and recently companies such as Jeff Rowland and D-Sonic have dropped B&O in favor of newer Class-D engineering that is more advanced with less technical problems.
I noticed on B&O's ICE power website that they are in need of engineers and are taking job applications. I found out this morning that the new Pasquale Class-D amps that Jeff Rowland will be using are designed by former B&O engineers.
I bought the demo M2-600M monoblocks from D-Sonic. I have been listening to them for 4 days now and they already far exceed my expectations. I am still juggling around power cords and screwing around with component placement now that these tiny boxes freed up a huge chunk of turf behind my speakers. I'm using these in a music only system that has recently suffered a catastrophic OTL amplifier failure. I can't afford to fix the amps and am hoping (like a QB throwing a Hail Mary at the last second) these new-fangled class D amps may offer at least some of the magic I used to have.

Due to all the setup issues I still need to plod through until I know I have done my best to hear them at their best, I can't honestly compare them meaningfully to a pair of amps I have had for nearly 25 years the cost then 4x as much as these. At this early stage, I will say that I already know there is a lot of magic in these things and I suspect that I haven't heard them at their best yet. I believe that they may be the most transparent and revealing amps I have ever heard and that they will be ruthless about reproducing everything good or bad in from of them in the chain. I suspect they may get me closer to the correct VTA & azimuth settings. Very musical, bass power and articulation that just don't quit, gorgeous reproduction of strings and horns, All are right up there, but they are not tube amps. After the first two nights with them, I realized that part of the "tubiness" I was missing had nothing to do with the sound of the amps or even with the sense of hearing at all. I Missed the heat and the orange glow - sight and touch senses. I rectified that with a couple of candles and turning up the room temp a couple of degrees. I think I will suggest to Dennis to throw a few lumps of charcoal and some candles in the box whenever he is shipping an amp to someone who whines about it not having tubes.

If you guys want, I can come back with more observations about the amps as they get settled in. I am really excited about these amps filling some really big shoes in my system.
AudioZen, by pure coincidence, I received today some additional specs for the class D Rowland Continuum Series 2 integrated amplifier.

CONTINUUM Series 2
Integrated Amplifier OUTPUT POWER: 400W @ 8 ohms/800W @ 4 ohms
FREQUENCY RESPONSE: 5 Hz - 70 kHz, -3 dB @ 8 ohms
THD + NOISE: 0.05%, 20 Hz - 20 kHz
INPUTS: 2 pair balanced (XLR) 2 pair unbalanced (RCA) 1 pair unbalanced bypass (RCA)
OUTPUTS: 1 pair balanced (XLR) 1 pair unbalanced (RCA)
WEIGHT: 35 lb / 15.9 kg
DIMENSIONS: 5.3" x 15.5" x 15.0" 135mm x 394mm x 380mm

The device will come in three configs: basic, or with additional DAC card, or with additional phono card.
Thanks Guido fot the info..very excited for the Series 2. Have a feeling that Jeff just may hit one out of the park on this one. Any clue on the MSRP?
Guys,
Since the original thread went off in a different direction, I wanted to keep off the path!
However the latest comment from AZ made me take the bait ;-)

Class D is very different from other classes, if it does not have a few zeros after the decimal point, one has to seriously consider the product. It's specs should be near perfect!! Since class D is doing everything else other than amplifying, spec are out most important. Not that it's not impossible, but knowledge is power! You don't want the manufacturer to just dump a product. In many cases such as tubes it's very easy to "create" a circuit and >50% of the time it will sound good. SS maybe <50%, but will sound acceptable. But with class D is a much smaller chance, and " we". want them to make the right choices. Class A is stuck for a few decades, only new tech in linear amplification recently I hear is from Siltech! Class D is progressing!! Tubes, of course is the golden standard.
Regards,
Mcbuddah..please keep us informed on your progress with the D-Sonic amps. Of course, only having them burned in for four days, you have a long way to go and are in for a real treat based on the 6Moons review last September. After extensive burn in, 6Moons described the amps as more organic and full, with much smoother, more laid back high frequencie's, then other class D amp's they have tested, and found them closer to tubes then previous Class D design's. I'm certain in two weeks the amps will settle down and fall into their true character and look forward to your on going impressions in the next several weeks.
There is no way for me to know how far along they are in the burn-in process because they were demos and not absolutely brand new. Mr. Deacon had loaned them out to someone for a short while. I would like to put at least 250 more hours on them before doing too much critical listening, but it's hard to resist the urges to pop up and fix something I know is wrong. Last night I listened to a Japanese reissue of Jon Faddis' 1976 "Youngblood" album where he works out with Dizzy's rhythm section. At the very end of Gershwin's Prelude # 2 there is a massive crescendo. While Jon is blowing away like the angel Gabriel, Micky Roker ends the piece with massive cymbal crashes whose transients sound all crumpled up in the in the mix with the horn. The last 5 seconds of the tune almost set me to packing up the amps for an airplane ride back to Texas. I went at it again today and figured out that my VTA was set imperfectly even though I thought I had nailed it months ago. I dialed it in again after a few hours of really hard work listening to more records and all is fine again. It seems to me that these amps are so revealing and play so cleanly at high volumes that very small changes in tonearm/cartridge geometry are easily heard. Obviously, these amps are not a drop-in replacement in my system and will require a lot of TLC to sound their best.
Hi McBuddah, yes please keep us posted on how the M2-600M amps break in.... Unless the Abletec modules behave tremendously different from old ICEpower, you may expect a 600 hours to 1200 hours of music making before they reach peak and yield their very best. G.
Hi AudioZen, as far as I know, Continuum S2 will be priced in mid $9K for its basic version, and will still shy below $10K for the versions that incorporate the optional DAC card or the optional Phonostage card.

I have since learned that the preamplification circuit of Continuum S2 is based on the new Capri S2 preamplifier... I Also heard that the Capri S2 circuit, as well as the DAC card, were developed in an engineering collaboration with Danish company Holm Acoustics.
Guido..Its mentioned on the Rowland website that the discontinued Continuum 500 also used the Capri circuit. I checked out many interior photo's of the Continuum 500 and was amazed how extensive the mods were. Two circuit boards stacked on top of each other. The ICE amps were upside down and accessed from the bottom. The top board has a dozen large power capacitors and two filter caps. The most extensive mods I've ever seen using ICE amps. Way beyond the mods in the Bel Canto's. If the mods are just as extensive with the Pasqualle Class-D amps, and the sound quality is superior as told by Rowland, it will more than likely turn out to be the best integrated on the market due to Jeff's perfectionism.
Hi AudioZen, I readily admit that am extremely fond of the creations of both Jeff Rowland and John Stronczer of Bel Canto.... Fact is that these people are true audio electronic engineers and audio circuit designers, rather than modders. Class D power conversion modules are components... With them you can derive a very basic amplifier implementation, or a sophisticated circuit that instantiates the sonic/musical philosophy of the designer.... Rowland, Stronczer, and ARC engineers, just to name a few, are definitely in the latter camp.

On the other hand, each product can only justify itself in the music it produces... hence, until I hear a well broken-in Continuum S2, I will not know if Mr. Rowland has scored yet another bull's eye.

By the way, do you happen to know which Pasquale power conversion module has been utilized inside the new Continuum S2?

G.