First of all if you think all amps sound the same then please ignore this post and forgive my audacity for posting a review based on personal opinion with very little if any scientific facts. My only wish is that perhaps someone out there would find it useful. My knowledge is obviously infinitely inferior compared to the masters of audio in this forum so I will go ahead and disappear quietly.
Why the comparo? Each of these represents the current Class D best of specific amp modules or brand. The ultimate goal is to note the perceived differences of the different designs and whether it is necessary to spend upwards of $500 to get not just a different sound but “a better sound”. There is a public interest to check whether today’s technology is able to provide similar or better sound quality to expensive amps of old while being very efficient and small in space AND packed with features. Is there a need to spend any more if the specs look similar on paper? Even compared with highly regarded Class D amps such as the new ICE or an ultimate power DAC from NAD the C390DD?
Supporting Equipments: Onkyo C-S5VL SACD Player + Ascend Acoustics Sierra Tower RAAL toed in. And Blue Jeans 75 ohm coax & 10 gauge speaker cables ultrasonic welded bananas (if they even matter). Bliss Quiet Letter CD, Pharos CD, Usher demo music CD. Room size is 16.5 x 19.5.
Setup: All amps are reviewed as complete products and that includes the internal DAC. Only SPDIF digital coax connection to the internal DAC is used for this comparison as the whole point of having these amps is to have a 1 box solution. Two of these amps have USB input but I will stick with SPDIF coax. All amps were run in direct mode with no EQ or any other signal altering option enabled. All amps volumes are level matched as best I can using the good old ratshack SPL meter. Unfortunately I’ve disposed of my old Tripath and other proprietary Class D amps of gone era so they won’t make it here but you can’t buy them anyway so won’t matter. The Onkyo CD player is the cleanest sounding one I got at the moment, better than the sweetened NAD C545BEE. Sierra Towers because obviously it’s one of the most popular accurate ribbon based speakers that’s also highly efficient.
Here we go…
NAD C390DD: 150W @ 8 ohm, Zetex chip, 2012 version, $2000 (street net price). http://nadelectronics.com/products/hifi-amplifiers/C-390DD-Direct-Digital-Powered-DAC-Amplifier
This “power DAC” (direct digital amp) is the smaller brother of the M2 and uses Zetex chip instead of the typical TI chips. More expensive the others in the bunch even at the discounted price I got it for (the first and only unit to enter this country from the local NAD distro). Highly touted as the next generation in amplifiers that beats old school Class A integrateds, loaded with whatever input you can think of short of firewire, upgradable module slots, etc etc… it resembles a small PC rather than an amp which is a good thing. This amp is as big as a typical NAD receiver which is a minus in placement flexibility but who cares about that right? Impressions below are made only 3 hours after installing so if you believe sound may change after “break-in” then too bad. The USB port also requires the NAD drivers installed to be able to play bit perfect.
Highs: 5 stars. With the black silent background the highs are clear, very clear. Total absent of noise and distortion. When I put my ears 1” from the tweeter I hear zero hiss, totally nothing! That’s what separates this amp from everything else… What is also remarkable is the total lack of fatigue even after half a day of cranking with whatever kinds of music thrown at it. Usually at that high end resolution and volume my ears would be bleeding after 15 mins. Nothing else I’ve heard in decades of experimenting with different Class A and AB amps exhibits this character. Realism and accuracy without distortion. That in IMO is the real game changer with this latest generation of power DAC.
Midrange: 4 stars. Vocals are a bit forward and drier than usual but that’s probably the way it’s supposed to sound if it’s to be accurate to the recording. Sounds transparent as any clearest amp I’ve heard. True as is, no sugar, no catering to old school audiophiles looking for the sweet.
Bass: 4 stars. Not super deep but tight, very fast, controlled. Probably the way it’s supposed to sound as is the recording. Not sure yet as I don’t have time to play with the built in room correction feature or I’m just used to the mINT’s overpowering bass.
QLS QA100: 60W @ 8 ohm, 2 x TI TAS5162 chip, 2012 version, $300. http://qlshifi.com/en/wzcapi/qa100.htm
Represents the last true direct digital amp chip from Texas Instruments before they added closed loop analog feedback. This is in spirit the successor of the infamous Panasonic SA-XR and TACT Millennium of the past. A true PCM – PWM conversion without the addition of anything analog in between = absolute ultimate purity if not accuracy ala power DAC. So this amp has no additional DAC, no analog input, no headphone out, no feedback. Of course that comes with all the issues associated with that design (high distortion, low impedance…) but in theory nothing else can be more transparent sounding than this. In fact I still prefer the sound of the old Panny compared to everything else I’ve got since 2003 when I can stand the distortion. The QA100 uses one TAS5162 for each channel so it sounds powerful. Even when driving an inefficient speaker such as the Usher Be-718, the average volume range I use is 11-16 out of 80 which is the max with these TI chips. The chassis is small and ultra light. Remote quality is good. Makes a neat looking inexpensive office room amp.
Highs: 3 stars. The overall image of the sound is very clear, crisp, and transparent. When you want all the background ambiance music in a song this has it.
Midrange: 1 stars. Vocals are the clearest of the bunch and effortless but slightly edgy which makes them less natural and fatiguing to my ears.
Bass: 2 stars. Not deep but tight. Surprisingly acceptable (which is the opposite of the old SA-XR57) even when used with an inefficient Usher Be-718.
Sinewave “Genius” G33D: 75W @ 8 ohm, 1 x TI TAS5630 chip, ADI DSP, 2012 version, $295. http://www.csinewave.com/product.asp?pid=162
Represents the current most powerful TI chip with closed loop topology. Alas, I found out about the new $380 G36D which uses 2 x TAS5630 a minute too late after placing my order for the G33D. The G36D is twice more powerful, has 2.0 24/196 USB input, and comes with remote. But then Sinewave most likely is going to release an amp based on the even newer TAS5624A which was released by TI on May 2012. The new TAS5624A chip has 0.025% THD compared to the 5 year old TAS5630’s 0.03%.
Compared to the TAS5162 in the QLS, the TAS5630 has flat freq response but with much lower dynamic range rating although to me the bass is more than acceptable. This amp is designed to be a 2.1 with stereo + sub speaker posts. In fact, it uses a fully user programmable ADI DSP chip instead of a standard DAC and myriad options for stereo main + sub integration options. Aside from the insane amount of options in a slim small box, added features are headphone out and USB input that doesn’t need the PC to be rebooted if the amp is ever turned off like the W4S mINT. Better yet playback resumes right away after I change the input from anything else back to USB. Plus I didn’t have to install a driver as Win7 automatically loads an external DAC driver.
Downside? Only 16 bit USB input accepted. No remote but the G36D will come with one. Now the major downside: Visually the built quality is lower than the other amps in this shootout and alas it only reaffirms the fact that it kept breaking down. The first one was blown the moment I first pressed the power button. I had it shipped back to China and they resend it back with 3 unplugged cables inside including power cables. Once I took care of that myself, I noticed the main board is bent. Now the amp would only run for about 15 mins until it heats up before the right channel shuts off. Sinewave customer support is top notch though. They respond to emails within 1 hour and they shipped a new replacement the same day we corresponded. The replacement is working good for 2 months then start exhibiting slight distortion and the input button takes 10 secs to switch. Also it seems I’m not the only one that’s having problems with Sinewave products.
Having said the above, watch for the newer $380 G36D as it may very well be the ultimate plug and play integrated amp / soundcard replacement to get under $1000 that’s futureproof. And by that I mean, you can even program the DSP as a 3 way digital crossover to run a single 3 way speaker or a 2 way single speaker with a sub. You just need to get 2 amps to get stereo if you’re gonna go that route. The possibility is infinitely more than other amps in the market. Sinewave releases a newer amp every year with features and specs that are quite impressive for the price as long as they last.
Highs: 4 stars. Still has all the ambiance details of the QLS without the tiring edge. I can crank this up at my loudest limit for a few hours and my ears would still feel ok.
Midrange: 3 stars. Like QLS but without the edge but with a slight veil. Certainly not as transparent as the QLS but pretty damn good.
Bass: 1 star. Lacking authority and lean compared to even the QLS.
Wyred4Sound mINT: 102W @ 8 ohm, 2 x ICEpower 125ASX2 modules, ESS Sabre ES1023 DAC, 2012 version, $1500. http://www.wyred4sound.com/webapps/p/74030/117839/612512
4x more expensive than the other amps here except the obviously large NAD. Lots of big names in one hell of a micro box. Hyped Sabre DAC + ICE’s newest amp module that’s supposedly fixes the treble cutoff that most people complained about = ultimate single box solution? With damping factor >500 I expect the usual powerful bass I’ve heard from the past ICE products I’ve owned. Has USB, Toslink, Coax SPDIF, analog RCA inputs along with RCA stereo output and headphone out. The chassis is smaller but taller compared to the QLS and Sinewave. That much power and features but as light as a cheap Samsung DVD player. Driver needs to be installed on PC prior to using it through USB.
Highs: 1 star. More extended high than old school ICE but dark and lacks spark which makes it great for jazz and solos but definitely not for complex musics. However, this sounds like a characteristic of the Sabre DAC and not the ICE amp or is it? They should’ve fixed the rolled off treble issue with the ASX2 series. Listening to Bliss Kissing’s last half is like
listening in a new song, that is with the ambiance part omitted. Very disappointing coming from a brand that touted accuracy in their slogan.
Midrange: 2 stars. Vocals are natural and believable top to bottom but the singer seemed farther from the listener than the other amps. I prefer a forward presentation of vocals so could be just my preference. Tonally the vocals sound just right. Guitars sound like being played in an anechoic room. Strong and impactful but with very dark background which some people attributed to the Sabre DAC’s character. Where’s the timbre?
Bass: 5 stars. The best of the bunch. As expected from the high damping factor of ICE, the bass is controlled, tight, and deep. Has the proper realism as in you’re in the club.
Onkyo A-5VL: 40W @ 8 ohm, Onkyo’s proprietary Class D module, Burr Brown 1796 DAC, 2009 version, $350. http://www.intl.onkyo.com/products/hi-fi_components/amplifiers/a-5vl/index.html
Heaviest of the bunch, 10kg, built like a brick just like true high end audio products, solid quality all around that makes the mINT looks like an amateur DIY. Most people are expecting Onkyo’s newer Class D to sound similar to the “warm” A-9555 or A-9755 which I owned and were excellent in some regards. I believe most are disappointed to hear this cold sounding but more accurate amp. This amp represents the last Class D amp ever released from Onkyo since 2009 as they’ve gone back to huge traditional linear separates. This amp has a bunch of inputs including phono, toslink, and SPDIF coax in but no USB. The most interesting thing is when paired with the matching C-S5VL player, it would play SACD and stream through digital coax. Probably downgraded to PCM first…
Highs: 2 stars. Detailed but without the fatiguing edge like the QLS. Not sure if it’s the effect of their vector linear technology or something else but it tries to present everything as
transparent as possible without forgetting to make it smooth, too smooth...
Midrange: 5 stars. Vocals sounded forward and full bodied. Female to male vocals are smooth and believable. I guess I prefer this over the C390DD simply due to the lack of slight dryness which makes vocals more believable. Acoustics though sound more realistic on the C390DD.
Bass: 3 star. Uncontrolled, not tight and fast enough = not musical. However the presence is balanced to the rest of the sound unlike older class d amps. Acceptable.
I didn’t have time to set up the speakers in the optimal position, do measurements, etc etc. But the difference between a $300 integrated and another that cost 5 times as much is just a matter of taste. Well except for the NAD which sounds like on another level of goodness and has more virtues than flaws (which could be found by nitpicking beyond accuracy). Which means like any other electronics, technology has caught up and there’s no excuse not to get these cheap fully loaded integrated class d amps as long as they are durable. The amp chips are designed by big names in Europe or US anyway. All of these amps sure sound a lot better than the Krell, Bryston, Sim Audio and other top branded amps I had in the 90’s. Yes you get some plastic cheap knobs but none fell off yet unlike the one on a Yilong DAC. As long as you don’t need more power these cheap amps sound just as good as the established names in the market. Of course as long as the speakers used are easy enough to drive. I’ve also heard that tube and linear chinese amps are excellent as well.
Those who love the old Panny would want to give the QLS a try. It uses the newer (and last) direct digital (power DAC) TI chip than the Panny’s, sounds similar but more powerful. The fact that someone is still selling a pure integrated amp dedicated to this chip at a bargain price is a boon to those in the Panny cult. The QLS goes well with the Newforms just like how John Meyer keeps recommending the Panny to go with his speakers. But it is currently paired with some KEF Q500 at the office that replaced the Usher Be-718. The pairing lacks bass so I wonder if a similar direct digital design that uses a different chip such as the Infineon chip in the $550 Nu Force DDA-100 (direct digital / power DAC) would be more balanced.
The Sinewave is basically less dynamic, less distortion, and more accurate frequency response than the QLS. Yes it’s not a pure digital amp anymore but is the improvement more than makes up for giving away some transparency? YES! The G33D doesn’t have the bass control of the mINT or the smooth high end of the A-5VL, but it is the most balanced in the group. Even throwing sound quality out, the features alone would make the choice amp for anyone looking for a highend soundcard or an all purpose amp not only suitable for poor college kids but anything outside a true reference system. It’s also the only 2.1 Class D integrated amp that I know of. Having said that, a broken amp is nothing but a piece of sh__ brick and should be treated as such.
Those who like to listen to live music, tubeheads, old timer audiophiles, solos, or those only interested in SPL and bass would most likely prefer the mINT. Heck, actually the mINT is powerful enough to be used for a frat house party (until Sinewave G36D comes out). It’s the audiophile choice but certainly not for those interested in ultimate transparency or accuracy as hacking a piece of high end information means the signal has been severely altered. Could be because I hate dark sounding equipment as it takes out the realism of the overall presentation. This is especially true when pairing with the Newform R630 ribbon arrays. I admit prior to ordering I was highly concerned about the potential of missing high end details with a dark DAC mated with an ICE. Having said that, I know many people shy away from anything bright and welcome products like this. An alternative is the $370 TEAC A-H01 which also has 2 x 50ASX2 ICE module but with a more balanced sounding Burr Brown PCM5102 DAC and vastly superior chassis quality to the mINT (just check out the pics). Sure it only has 40% of the mINT’s power but it sure sounded balanced top to bottom to my ears when I demoed at the store. I can see that only in a really large room the mINT would be the preferred choice over the 60% cheaper TEAC. But the TEAC has an ultra cool high quality casing that’s probably the best one out of any amps listed here so that’s a plus.
The Onkyo A-5VL got lots of bad rap when people expected it to sound sweet like the high end A9755 which I was fortunate enough to own once. I didn’t expect it to do well as it seemed a great deal of the budget goes into the chassis and build quality. But compared to these newer generation class d amps it held its own and sounded more natural. Would’ve been perfect if the bass is as tight and powerful as typical linear or ICE amps. Also the problem with it being the older generation (3 year old design) is the lack of USB input but that can be fixed by getting one of those USB to coax converter. In any case, for $350 it’s a lot of amp especially considering the superb built quality which is similar to the TEAC A-H01.
So which one do I actually prefer to pair with the Sierra Towers? Truth of the matter is I can live with any one of them except for the mINT, so that’s out for sale. The Onkyo is limited in connectivity so it will eventually be replaced with something else (most likely the TEAC). Broken amps are good for USB headphone amp from the PC. The QLS is decent for the office or baby’s bedroom playing Twinkle2 Little Star. So that leaves the obviously most expensive NAD with the Ascends. This is also the wife’s favorite pairing. Keep in mind that the Ascends are quite efficient and less efficient speakers may result in the something else being more suitable. In the next shootout the comparison would be strictly for amps with USB input as it would be the standard connectivity given that media servers are replacing CD players.