I have a number of Acoustic Reality amplifiers,they are absolutly wonderful.I have there stereos the monos and even the new 1000watt monos which cost me new w/o shipping 700$ each.Excellent sounding,light weight and no heat.I have some very highend amps in my systems and these compete well.You can see my system on audigon.I am in the office I do not remmember the model #s.
What's Your Experience with Digital Switching Amp?
The ICE class-D amplifier modules (with self-oscillating transistors) have started a new generation of digital switching amps (DSAs for short) for people interested in high-quality sound at affordable price. If you own one of these amps, I am very curious about how it performs in your home, how it compares to other solid-state and tube amps, and especially how it compares to other switching amps that are starting to appear out there. To start things off, I will go first with you my own—very positive—experience with the Velluto DSA (Analog Research-Technology; 500 wpc; $2800). I’d love to hear your experience with your own DSA in return.
A LITTLE BACKGROUND
I am not an electrical engineer so I hope you will forgive my errors in summarizing the inherent problems with the ICE modules. Out of the box, the frequency response of the ICE module is far from flat. Class-D modules are also very susceptible to RF that can make them sound awful. The ICE modules, like all class-D modules, emit EMI that can create havoc with the sound as well. Like many solid-state (ss) amplifiers, most DSAs have relatively low input impedance that makes them difficult to be driven by a tube preamp. How designers solved these problems affects the amp’s performance.
After a long search—there are quite a few suspicious DSAs in generic boxes out there!—I settled on the Velluto Digital Switching Amp from Analog Reseach-Technology, a firm located here in Dallas, for several reasons: 1) Living in Dallas, I can audition it exhaustively before purchasing; 2) I like previous products by Pat Digiacomo, the engineer who designs and builds these amps in-house with eyes toward great sound at a reasonable cost; 3) Unlike many DSAs that use off–the-shelf chassis and generic front panel, the Velluto comes in a custom chassis with a massive front panel finished in attractive brushed silver. I will skip the description of the amp’s looks, features, and circuitry—I can tell you about them later if you are interested—and go directly to the most important thing about this DSA: its sounds.
THE SOUND OF MY VELLUTO DIGITAL SWITCHING AMP
I have listened to the Analog Research Velluto for a few months now and the sound of this amp is quite unlike that of any other amp that I’ve ever owned, solid-state or tube. The Velluto’s sound is wonderful: silky, dynamic, and expansive. As I just recently RE-discovered Audiogon and read interesting threads about the H2O amps, which I believe uses the same ICE modules as the Velluto, I realize that I am not alone in my enthusiasm for the sound of a DSA. One thing I noticed immediately about the Velluto’s sound was the bass: tight, deep, dynamic, and abundant! Compared to the Velluto, my Rowland Model 7 monoblocks sounded anemic in the bass, which is hard to believe with 300 wpc of class AB power. The bass on my BAT VK-60 monoblocks was as dynamic as the Velluto’s, but with clearly less depth, tightness, and volume. Another thing that captivates me is the Velluto’s midrange. It is very smooth, but not liquid like my BAT’s midrange or neutral like my Rowland’s, or analytical like many SS amps I dislike. Rather, it is silky smooth. I have never heard such midrange before from any amp, tube or solid-state. It is quite an alluring sound, worthy of the amp’s name— I think Velluto means velvety in Italian. The highs are extended and detailed—that was expected from a frequency response that’s down less than 0.3dB at 20 KHz—but surprisingly without the dryness, or edginess of many ss amps.
But the one thing I love most about this amp is its soundstage: it is positively gargantuan. It extends so deep and so wide beyond the speakers that you feel like the walls of your room have dematerialized. The sound just seems to expand for ever beyond the speakers to fade away at a far distance. It is quite an uncanny effect. By comparison, the sound of my BATs is more intimate but bunched up in the middle with far less information around. It becomes obvious that the BATs, like many tube amps, is missing quite a bit of high-frequency information which, by subtraction, gives the illusion of a very focused and dynamic midrange. I now much prefer the panoramic sound of the Velluto, especially for orchestral music though the BATs still have their moment with intimate music.
THE FUTURE OF DIGITAL SWITCHING AMPS IN HIGH-END AUDIO
Without trying to be controversial, I feel that many manufacturers with great reputation based their own successful designs will not readily adopt these ICE modules in their new amps. The poor sound of traditional class-D amps will not help promote these new DSAs either. On the other hand, some well-known high-end manufacturers like Jeff Rowland have already started to offer many models based on the ICE modules. When designed right, these new DSAs can remove many limitations of older ss designs: excessive heat, large heatsink fins, cumbersome size, heavy chassis that strain backs and cost a fortune to ship, insufficient power and bass, analytical sound, edgy highs, or constricted soundstage. This is assuming that all the kinks in the DSAs are worked out properly. For example, these amps may have to be rolled off (!) a little more for tube lovers who just can’t get used to the additional information in the highs and the panoramic soundstage—I’m not one of them but some of my friends are. You also have to be extremely mindful of nasty RF and EMI gremlins still sneaking into the sound. The Velluto overcomes these hurdles successfully but I doubt that all DSAs out there have identical sounds.
I am keenly interested in hearing the impressions of other (I hope very happy) owners of DSA amps.
Justin_Time
My Audio System:
Speakers: Watts/Puppies 5
Amps (Balanced): Rowland Model 7s, BAT VK-60s
Preamps (Balanced); BAT VK5, Rowland Consumate w/ phono stage
Analog source (Balanced): SOTA Cosmos, Graham 2.2, Sumiko Geneis, Benz, Koetsu
Digital source: Sony DVP 9000ES (for SACD only)
Power cords: TaraLabs Prism AC Special and RSC; homemade hospital-grade PC
Speaker cables: OCOS Triple runs, MIT CVT, Straightwire Maestro
Interconnects: Onix GMR XLR, homemade XLR (Nutric connectors/microphone cables)
Miscellaneous cables: Audioquest phono cable; TaraLabs digital cable/special termination
A LITTLE BACKGROUND
I am not an electrical engineer so I hope you will forgive my errors in summarizing the inherent problems with the ICE modules. Out of the box, the frequency response of the ICE module is far from flat. Class-D modules are also very susceptible to RF that can make them sound awful. The ICE modules, like all class-D modules, emit EMI that can create havoc with the sound as well. Like many solid-state (ss) amplifiers, most DSAs have relatively low input impedance that makes them difficult to be driven by a tube preamp. How designers solved these problems affects the amp’s performance.
After a long search—there are quite a few suspicious DSAs in generic boxes out there!—I settled on the Velluto Digital Switching Amp from Analog Reseach-Technology, a firm located here in Dallas, for several reasons: 1) Living in Dallas, I can audition it exhaustively before purchasing; 2) I like previous products by Pat Digiacomo, the engineer who designs and builds these amps in-house with eyes toward great sound at a reasonable cost; 3) Unlike many DSAs that use off–the-shelf chassis and generic front panel, the Velluto comes in a custom chassis with a massive front panel finished in attractive brushed silver. I will skip the description of the amp’s looks, features, and circuitry—I can tell you about them later if you are interested—and go directly to the most important thing about this DSA: its sounds.
THE SOUND OF MY VELLUTO DIGITAL SWITCHING AMP
I have listened to the Analog Research Velluto for a few months now and the sound of this amp is quite unlike that of any other amp that I’ve ever owned, solid-state or tube. The Velluto’s sound is wonderful: silky, dynamic, and expansive. As I just recently RE-discovered Audiogon and read interesting threads about the H2O amps, which I believe uses the same ICE modules as the Velluto, I realize that I am not alone in my enthusiasm for the sound of a DSA. One thing I noticed immediately about the Velluto’s sound was the bass: tight, deep, dynamic, and abundant! Compared to the Velluto, my Rowland Model 7 monoblocks sounded anemic in the bass, which is hard to believe with 300 wpc of class AB power. The bass on my BAT VK-60 monoblocks was as dynamic as the Velluto’s, but with clearly less depth, tightness, and volume. Another thing that captivates me is the Velluto’s midrange. It is very smooth, but not liquid like my BAT’s midrange or neutral like my Rowland’s, or analytical like many SS amps I dislike. Rather, it is silky smooth. I have never heard such midrange before from any amp, tube or solid-state. It is quite an alluring sound, worthy of the amp’s name— I think Velluto means velvety in Italian. The highs are extended and detailed—that was expected from a frequency response that’s down less than 0.3dB at 20 KHz—but surprisingly without the dryness, or edginess of many ss amps.
But the one thing I love most about this amp is its soundstage: it is positively gargantuan. It extends so deep and so wide beyond the speakers that you feel like the walls of your room have dematerialized. The sound just seems to expand for ever beyond the speakers to fade away at a far distance. It is quite an uncanny effect. By comparison, the sound of my BATs is more intimate but bunched up in the middle with far less information around. It becomes obvious that the BATs, like many tube amps, is missing quite a bit of high-frequency information which, by subtraction, gives the illusion of a very focused and dynamic midrange. I now much prefer the panoramic sound of the Velluto, especially for orchestral music though the BATs still have their moment with intimate music.
THE FUTURE OF DIGITAL SWITCHING AMPS IN HIGH-END AUDIO
Without trying to be controversial, I feel that many manufacturers with great reputation based their own successful designs will not readily adopt these ICE modules in their new amps. The poor sound of traditional class-D amps will not help promote these new DSAs either. On the other hand, some well-known high-end manufacturers like Jeff Rowland have already started to offer many models based on the ICE modules. When designed right, these new DSAs can remove many limitations of older ss designs: excessive heat, large heatsink fins, cumbersome size, heavy chassis that strain backs and cost a fortune to ship, insufficient power and bass, analytical sound, edgy highs, or constricted soundstage. This is assuming that all the kinks in the DSAs are worked out properly. For example, these amps may have to be rolled off (!) a little more for tube lovers who just can’t get used to the additional information in the highs and the panoramic soundstage—I’m not one of them but some of my friends are. You also have to be extremely mindful of nasty RF and EMI gremlins still sneaking into the sound. The Velluto overcomes these hurdles successfully but I doubt that all DSAs out there have identical sounds.
I am keenly interested in hearing the impressions of other (I hope very happy) owners of DSA amps.
Justin_Time
My Audio System:
Speakers: Watts/Puppies 5
Amps (Balanced): Rowland Model 7s, BAT VK-60s
Preamps (Balanced); BAT VK5, Rowland Consumate w/ phono stage
Analog source (Balanced): SOTA Cosmos, Graham 2.2, Sumiko Geneis, Benz, Koetsu
Digital source: Sony DVP 9000ES (for SACD only)
Power cords: TaraLabs Prism AC Special and RSC; homemade hospital-grade PC
Speaker cables: OCOS Triple runs, MIT CVT, Straightwire Maestro
Interconnects: Onix GMR XLR, homemade XLR (Nutric connectors/microphone cables)
Miscellaneous cables: Audioquest phono cable; TaraLabs digital cable/special termination
57 responses Add your response
QUOTE: "I really enjoyed my Spectron 1, driving a pair of Maggie 1.6's...plenty of power to bring out the bass [the 1.6's need oodles of power]. Drove everything with a tube preamp." Hello again Fatparrot, I am very curious about your set up with the DSA. Do you know what the input impedance of your Spectron 1 is? (I assume it is a digital amp based on the ICE module). Normally, the input impedance of most DSA is below 10k, which tends to drive tube preamps nuts--poor choice of word; it's the preamp that goes nuts in the process of driving a low-impedance DSA amp. Do you know why you are having such a good success with your tube preamp? The input impedance of my amp was 10k, which OK, but I am in the process of having it increased to 50k like in the newer Velluto to give my BAT VK5 a better performance. If you have any secret on how to use a tube preamp with a low-impedance amp, I would love to steal it from you. Cheers |
QUOTE: "I have the Bel Canto eVo 4 amp, which is also a DSA, but based on a Tripath technology. It also sounds wonderfully smooth, and has a purity of tone rarely found in SS amps. When run in bridged mode, it has one of the best, most dynamic and articulate bass I have heard. In short - wonderful amp." Hi Elberoth2, My experience is very similar to yours, i.e., a very good one. I much prefer your choice of word to mine: "purity of tone" was what I was looking for but couldn't find. It describes the sound of a DSA much better than "silky." I also agree about the bass. There is also a different sense of rythm with my digital amp that's I haven't heard from other amps. It's hard to explain. Have you noticed that? Could you tell me more about the Tripath technology? I am afraid I haven't heard of it before. How is it different from the ICE? Does it have to be transformer-coupled at the input to keep the RF (and ground loop) out? Does is radiate EMI like the ICE module? And if yes, how did the designer keep the EMI contained? The fact that the Bel Canto sounds wonderful clearly suggests that there are no RF or EMI problems. Thank you for sharing your experience. |
Hey Justin time, I like the name. I was an early convert to ICE magic. I owned the eAR, loved it over any solid state amp I had owned. I sold it to Ramy, and later bought H2O signature monoblocks. The improvement was significant. The H2O has a robust power supply. I know people who have crossed to H2O from great tube amps, and solid states, as well as class D amps suggested here, including Tripath's best. |
I'm in the process of audtioning the following DSAs: JJAZ ICEpower stereo Audio Zone AMP-2 monos NuForce Reference 8 monos Channel Islands D-100 monos These technologies have come a long way in the past few years. Each of these amps would be right at home in any medium to high-end system. They all exhibit very low noise floors, great detail retrieval, excellent soundstaging, great macrodynamics, and good to great microdynamics. In some cases, these amps even hint at the kind of tube" magic I would never expect from a solid state design. Based on what I've heard so far, my preference is for DSAs that incorporate traditional power supplies. Input impedance matching should be carefully considered. In some cases, DSAs may not "mate" well with other tube components in your signal chain due to EMI or RFI. That said, when your signal chain is properly matched, DSAs offer a very valid alternative to tube amplification. I'm planning to post my impressions next week after comparing each amp to my Antique Sound Labs 1009 DT tube monos. I have a desire to move away from tube amplifiers and I think I've found a suitable replacement among the DSAs mentioned above. These are interesting times... |
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QUOTE: "Hey Justin time, I like the name. I was an early convert to ICE magic. I owned the eAR, loved it over any solid state amp I had owned. I sold it to Ramy, and later bought H2O signature monoblocks. The improvement was significant. The H2O has a robust power supply. I know people who have crossed to H2O from great tube amps, and solid states, as well as class D amps suggested here, including Tripath's best." Hello Muralman1, I got the nickname from friends because I am a watch collector as well (Swiss automatics). I also have a penchant for arriving at meeting "just in time," not too late or too early. Anyway, I am glad to hear that there is a difference in sound between digital switching amps based on the same ICE modules. Could you tell me more about the design of the H2O? As you implied, a good power supply is important and a dual mono design like the H2O is best. Strictly speaking the Velluto DSA is not a true dual mono amp but, in actual operation, it is. Each channel has its own toroidal transformer for the low-voltage power supply. Though the output stage voltage is supplied by a common (oversize) toroidal transformer, each channel has its own winding. The designer, Pat Digiacomo, said that he did this to cut cost without cutting performance. His measurements showed that during normal operation, the channels did not modulate each other because the current to each module was actually supplied by the filter caps. For all practical purpose, the Velluto has a dual mono operation. In addition to a robust, dual power supply, RF and EMI eliminations are very important to making a digital switching amp sound good. I would love to compare the solutions in H2O monoblocks with those in the Velluto. |
The H2O Sig monos have been reviewed by 6Moons http://www.6moons.com/audioreviews/h2o/m250.html You can see what they are made of there. I am not conversant in amp technology. I do know the power supply would do well for a class A solid state. All H2O amp components are chosen to bring out the best of the new technology. I know the stereo H2O Signature has dual toroidals. I did a search, and couldn't find the Velluto. You are correct in your understanding of RF, and EMI problems. They are easily controlled if you use shielded power cords on not just the amps, but all components. I made my own using Belden wire, and Marinko plugs. Now, here is a tip for you, Justin time. Ditch the MIT CVT. Frankly, for speaker cables, I have found nothing better than the absurdly cheap Speltz Anti-Cables. |
Hey Muralman1, Gee, I wished you hadn't said anything about the MIT CVT cables until I've sold them :-). I bought them because they were recommended for the Watts/Puppies (!). The Velluto revealed their flaws pretty ruthlessly. Surprise: the OCOS triple runs work well with my DSA amp & the Watts/Puppies perhaps because they are transmission lines but I have no technical understanding of that. I have no trouble at all with RF and EMI with the Velluto. Each ICE module in the Velluto is encased inside a metal box and all leads in and out are treated with ferrite material to completely eliminate EMI. To stop RF, the Velluto uses coupling transformers at the inputs which also eliminate ground loops. This solution allows the use of either RCA or XLR inputs without adaptors. Coincidence: my homemade cables are also shielde Belden! Where can I get the Marinko plugs? Thanks for the review of the H2O. Sorry I forget to provide more background info about my amp in my thread. You can find out more about the Velluto at the following site: http://home.att.net/~analog.research/main.html |
I have one of the original DSA designs from the now defunct California Audio Labs. The MCA 2500 uses the switching power supply in a 5 channel by 500 watt configuration. I can verify the EMI issue as I was getting feedback from the amp because it was too close to my speakers. I am sure the technology has improved since this beast was made but it sure packs a punch! My woofers love it! |
Hello Fedreams, I believe that it's the way of using the ICE mudules that has evolved. In my Velluto, each ICE module is FULLY ENCASED in a metal box and all leads in and out are treated with ferrite material to eliminate the EMI problems: it works. I have no problem whatsoever with EMI. I have the manufacturer of the Velluto (Analog research-Technoly) built me a five-channel video amp as well, but with just 100 watts per channel as a test: this amp blew away the Parasound 2250A (250 wpc class AB) and the Cinepro 3k6. Those excellent video amps are now sold! The bass and dynamic impact of the DSA with just 100 wpc are so powerful they rattle the walls the way the bigger amps never did. Half of the time, I turned off the subwoofer. I can also hear the benefit of the low noise floor and the clean sound. The soundstage is of course a mute point in 5.1 These digital switching amps are doing something right in a very different way: it's not just the power. |
QUOTE: "06-16-05: Wrp I'm in the process of audtioning the following DSAs: JJAZ ICEpower stereo Audio Zone AMP-2 monos NuForce Reference 8 monos Channel Islands D-100 monos" Hi wrp, You owe it to yourself to audition the Velluto as well. http://home.att.net/~analog.research/velluto1.html Pat Digiacomo (972) 495-3762 I am quite impressed with this amp, not just by the sound, but the meticulous design approach, the high-quality construction--no off-the-shelf chassis here--and the reasonable price. It is not just a great amp; it's a great value as well. |
"Now, here is a tip for you, Justin time. Ditch the MIT CVT. Frankly, for speaker cables, I have found nothing better than the absurdly cheap Speltz Anti-Cables." Muralman1- Please enlighten us, what other hiend speaker cables you've recently tried. "All components chosen to bring out the best of the new technology." Do you have a degree in electronics or are you just passing along Henry's marketing hype? |
As an aside- I too love the Speltz Anti-Cable. Replace my Audience AU-24 at a fraction of the price. The Audience is a great cable- but the Speltz holds it's own- no problem. I've also owned Cardas Hexlink Gold, Harmonic Tech Pro-9, Various Analysis Plus, all the Goertz speaker cables, and numerous others I don't remember. Speltz tops 'em all. If I wereyou guys, I'd try them. |
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Tvad, I appreciate the criticism. I am the most vocal supporter of the H2O. Im sure being a good friend of the H2O builder has something to do with my overenthusiasm. Increasingly, as you can see, I am not alone. H2O does not have a marketing scheme. There is no advertising. Sales had been generated solely by word of mouth. Now there has been a show, and a publicized review. Eventually, I will slip back into audio oblivion, much to the satisfaction of many. Maybe I should take up evangelizing. Seems their preaching earns praise. :) BTW - The word "hype" denotes dishonesty, which there never has been a case for. Read the reviews. |
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Response to Tracer: "How much is the Velluto?" They cost $2200 with the 250 wpc modules and $2800 with the 500 wpc modules. You can find out more by looking up: http://home.att.net/~analog.research/velluto1.html You can also buy small 100 wpc mono modules for $500 each from the company if you are on a budget and not worried about getting the best possible performance. I hesitated to mentioned the price and omitted the company's other products as well as its website in my original thread not to withold information but because my primary goal was to share my enthusiasm for the amp and to elicit the experience of other owners of these digital switching amps in return without sounding like a salesman. That is a difficult path to negotiate. I can only hope that I have partially succeded. If I have failed, it is only through my ineptitude, and not because of any dishonorable intention. |
Hi Justin_time, I sent an e-mail to Analog Research several days ago on how to obtain the Velluto for an audtion, but thus far no one has not responded. So I figure that they are either too busy or they are not that eager to get new customers. Any suggestions? Thanks. Also, has anyone compared the H20 with the Velutto? |
The recurring issue of "Ditch the MIT" in these ICE amps threads without clarifications as to why this should be done gets kinda old. In a response to a similar thread last week, I put a lot of effort to explain some problems I had with an MIT 350 EVO single-ended cable between the Aesthetix Callisto Signature line stage and the H20. Blaming network boxes for a huge midrange suckout is a bit of a stretch. I would normally expect such a problem at the frequency extremes and this was not the case. Ultimately it sounded like the problem I had was more likely due to an incompatibility issue with the Callisto line stage running the single-ended low input-impedance of the H20. The jury is still out as to whether or not the same MIT cable in an XLR configuration would cause the same problem or perhaps work incredibly well with the H20. Even though I prefer the sound of the NBS Statement over the MIT 350 EVO or Ref Proline, it's just by a hair due to the NBS bringing on a little more dimensionality. The MIT cable has a more extended top end than the NBS. The fact that both of these cables drive the CAT JL-3 amps from the Callisto with neither having any tonality coherency problems nor dynamic limitations speaks for itself. Both cables in this setup had far more low-level resolution and dimensionality than I could get with the NBS into the H20. The ONLY component I have had problems while using the MIT IC cable is the H20. The ARC VT130 and CL150 monos, Counterpoint NPS400, Wolcott P220, CAT JL-3 amps, and the ARC LS5, BAT 31SE and Callisto Sig line stages .... all have worked incredibly well with MIT 350 Proline Ref and EVO cables. This is quite a list of tube based products for a cable that is claimed to only work for a few solid state products. Rather than echo second-hand news here, hopefully people with direct experiences using MIT cables will share their experiences here. Telling us the associated gear and cable model they used will add value to what has worked and not worked for them with the H20 and other digital switching amps. Compatibility is definitely a factor to assemble any audio system. But throwing blanket statements out there based on heresy serves no purpose. And keep in mind, there is a huge sonic difference within the MIT product line. "Frankly, for speaker cables, I have found nothing better than the absurdly cheap Speltz Anti-Cables." What else did you try to come to this conclusion? If you are going to make indirect comparisons here, please share with us the other products you tried. Without comparative product models mentioned, such a statement brings on no value. The lack of differences or improvements between speaker cables may have more to do with weaknesses elsewhere in a system. John |
Tvad- mahalo for explaining "hype" to Muralman1. Muralman1- I see nothing on the H20 website supporting your statement: "All H2O amp components are chosen to bring out the best of the new technology." So once again, what qualifies you to make this statement or are you just "evangelizing." As to the fellow you know, who sold his recently bought TacT amps, that his choice, but I fail to see how it relates to your statement about the H20 components. |
Jfox, this is a thread topic that covers the new breed of amps that don't do as well with MITs and like. I didn't make a "blank statement." I said, as you quoted, "You should....," meaning Justin-time. Cable designers molded their creations to suit their use. The choices at MIT's inception were solid state, and tube. They work well for some solid state. But, we're not talking solid state here. |
I've used MIT 750 Shotgun speaker cable and interconnects with the Bel Canto eVo 2 and the JRDG 201's and all that happened was I heard a more transparent sound. I did hear more depth and a lower noise floor, but I attribute that to the amps and overall resolution of my system. Maybe some perceive added depth/distance and lower noise floor as a midrange suckout? I haven't tried the H2o but I'd like too. bill |
Kana, I made that statement based on conversations with Henry, where he talked of his amp evolution. I know some of the ingredients that go into his amps, and I trust him on all others. You have to know something about Henry. He is trying to make the best amp he can. That is more important to him than sales. |
I assume problem with MIT and ICEPower is that the network cables are of a high capacitance design with capacitors in the signal path. Best results are had with low cap desings like Nordost, Empirical, VH, and from what I hear the Anti-Cable may be a low cap desgin. The H2O SS250 is my reference. Carlton |
Well........since I am being talked about, maybe I should clear up some things. I see some errors, technical and otherwise, that should be addressed. First, we do have a proper domain: http://www.analogresearch-technology.com Yes, there is an older version on ATT. We are still writing the html for the new one, and some pages do not work. The "news" page will be fixed soon, and I suppose it would be a good idea to get the contact one right. Speaking of not working......I am trying to use Google Mail. It is not working. Some mail is stuck on there somewhere. I may have to ditch using it. 2 GB of free storage is appealing, but if you can't access it................ Second, anyone can tell that it is not more than one person trying to drum up sales as I would never spell my name wrong. I am grateful for a loyal customer telling everyone about our product(s), and how he is pleased. But as he said, he is not an EE. OK.........I do not call these "digital switching amplifiers". The input is analog. There are no logic gates on the module. The guys who designed the module don't like the "digital" moniker, either. Self-oscillating Class D amplifiers. In some ways, they are no different from a typical amp. The self-osciilating part comes from fact that unlike a conventional amp, we actually want there to be enough feedback for it to oscillate. In the past, Class D amps had a clock that drove the comparator. In a sense, the amps drives the comparator itself. It still has an input stage. The difference is that it then goes through some strange modulator thingie that makes the outputs switch on and off. Usually somewhere around 400 kHz or. Obviously, this creates EMI. If it is really bad, you will not be able to watch TV channels 2-5. But if some is floating around.........like say.......on your interconnects......and it gets back inside (it will get back inside if it is on it!)........it very well muck up the sound. So, I go to great lengths to get rid of it. Frequency response: I can give 2 guys the same amp. One will say "Too bright!, the other "Too dark!" To make matters worse, it will also depend on your load impedance which way you are likely to come down on that subject. Additionally, the frequency response (out of the box) between the 250 modules and the 500 modules are not close. I have been working hard to make them sound as close to each other as possible, and negate all the "too dark"/"too bright" kvetching.(Kvetching is best left to professionals at it. Like me.) It is possible that we will provide a rear panel switch that will allow you guys to make up your own mind. This is America, after all, and we all value our right to chose. So, we plan to give it to you in your own listening room. I am about out of time right now......someone has to do the cooking at home, and that is me. I will be glad to answer your questions either here, or via e-mail, in the future. Thanks for taking the time read this. Regards, Pat Di Giacomo Analog Research-Technology Garland, TX |
QUOTE: "I ... noticed Pat's phone number was listed..." Hi Grk: No trouble at all about you emails. I am sorry I did not provide all the info you needed in the thread. I was mainly interested in discussing my enthusiasm for the sound of the Velluto and other DSAs and I did not want to sound like a "salesman" for any particular product. That's a difficult balance and I can only hope I was partially successful. |
Guys -- what about the Red Dragon ICE based amp? "Intro" price of only $1650., with a 45 day audition period, and prepaid freight (in BOTH directions. At 1000 watts per channel, I am personally taking them up on their offer. What do I have to lose? The guy I emailed at Red Dragon seems pretty confident that it will more than hold it's own against just about anything available. I've owned and/or auditioned Spectron Musician II, Bel Canto Eve200.2 and the H20 stereo amp, and have owned more solid state & tube amps than I care to mention, so the Red Dragon will be interesting, if nothing else. Hope to post my impressions in a month or so... |
Mr_Bill: Your response, "Maybe some perceive added depth/distance and lower noise floor as a midrange suckout?", was not at all what I addressed here. I did not imply such a correlation. If the guitar player and the piano are so very far back from the band, when in fact they should be with the band, it is not depth - it is a severe component incompatibility or component malfunction. In the context of the MIT 350 EVO running into the H20's single-ended inputs, there was a huge drop in level in the middle 4-5 octaves. A change to either CAT JL-3 amps or a Counterpoint NPS400 amp and and the midrange suckout problem was gone. I am not attacking MIT cables here. I was simply stating my experience with a severe problem between this cable and the H20. If you read all that I wrote above, you will realize ONLY the H20 had this problem. I find the MIT cables to be exceptional which is why I also use them. |
Jafox, My comment wasn't directed at you, it was just a comment, just sharing my experiences. You seemed to make good sense with your explanation. I just find it hard to believe that a networked cable wouldn't work with a transparent amp such as the H2o - seems strange to me. But I've never tried it, so I may never know. |
Thanks Justin for the kind words. Since the thread is not intended to be a marketing pitch for our amps, let's kick around what I suspect he really has under his hat: "Does anyone else think that the midrange of these amps is.........uh........different?" Not just mine, or ICEpower based: any of them. A lot of anecdotal evidence to suggest that there is. I don't have a firm opinion on the subject yet, but it bears attention. OK, guys........let's hear from you. Pat |
"Kana, I made that statement based on conversations with Henry." Muralman1- Mahalo for the source of your statement. As I suspected, it is not based on any proven facts or electronics knowledge. I'm sure you think Henry is trying to build the best amp he can, but based on the pictures in the sixmoon review, I'll bet there are much better components/ingredients than the ones Henry's limited time as an amp builder has discovered. "He is trying to make the best amp he can. That is more important to him than sales." You just can't stop hyping/evangelizing this product can you? Maybe you should teach a course at your local community college- "Internet forum marketing hype, the modern form of evangelizing." - 101 ;-) |
I think we should appreciate the different thoughts and opinions here - like Kana's too. Looks like Kana is just challenging some of the comments made on the topic of Class D amps and one in particular - he's offering an opinion, like Muralman does and you just did. Let's all hold hands now and join in on a verse or two of Kumbaya. |
Owners of Bel Canto, H2O, JJaz and other switching amps, do you think that switching amps share a family sound? I suspect so. I’ve listened to just a few of these amps with modules from different manufacturers and with some design differences. But they definitely share a family sound which is distinct from that of tube- and other solid-state amps. This family sound is best described in the midrange. This midrange is clean and smooth. Each voice or instrument is well defined and surrounded by its own air giving the overall impression of open sound within three-dimensional space. Different modules and designs seem to alter only the degree to which these characteristics are presented but not their inherent (?) nature. Do the sounds of other switching amps out there share these same characteristics? How do different features in the design affect them? Owners of Bel Canto, H2O, JJaz and other switching amps out there, I’d like to hear your opinion. Please chime in. |
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I have listened extensively to the eAR, TacT (heavily modified), eVO, and the H2O. The two ICE based amps do share some tonality characteristics, but their presentation diverge remarkably. The eVO is a second cousin to those two, at best. The Tact is similar in it's detail retrieval, while being drier. I feel there are wider differences between "switching" amps than there is between solid state amps. |