Class D Amplification Announcement

@jjss49 Really appreciate the detailed response. If I didn't know any better, I would have said "too good to be true." :) But since I'm well aware of your experience and expertise, I have to say that this is a ringing endorsement of AGD. 

A few days ago, I opened a thread about the possibility of moving from integrated to separates, but I purposely requested an all-tube solution (amp and preamp). Based on your impressions, I'm very tempted to give AGD a shot. 

I have gone back and forth between tubes and SS, and each time I come to the same conclusion that for my taste and preferences, tubes appeal to me the most and pull me in emotionally better than SS amps. If I'm forced to pick only one or two attributes of tube amplification that appeal to me the most, it has to be the holographic/3D soundstage and the lit-from-within qualities that good tube amplification does it better than SS (of course, in my opinion only). How do you think AGD compares in this aspect? Are there any shortcomings (vis-a-vis tubes) that you can think of?

Sorry, I know I'm asking you a lot of questions but I'm very intrigued now :)

go listen to a purify before you type

I have to say I love technology debates because they have been ranging forever. I  have a Technics SU-R1000 that replaced a McIntosh Integrated (MA-6300). TAS also loved this integrated, but it was Stereophile's review wherein they compared it to the Technics SU-G700 which is the lower cost version in order to discuss the differentials as well as to S-Phile's review and Artkinson's extensive testing reveal an amazing array of new technology. The LAPC and JENO circuits are real tech. I think it took a company the size of Matshusita Electric (Panasonic) to produce a $10,000 digital (not D per se) integrated that is phenomenal against most A/B comers. It also weighs 54 pounds, built with superb capacitors, unlike lighter (see Marantz, NAD, et al) Class D amps that feel lighter and tinny and ones that did not advance the new tech properly.

I am not here to advocate any singular position--but there are always revolutionary changes in HiFi that shake industry standards every generation or so. Tubes gave way to stable solid state Class A and then Class A/B amplifiers. Tubes are making a rebound as millenials and genzers flex their economic muscle in seeking retro tech like fine turntables and tube amps (I recently purchased a McIntosh MA252 hybrid and put in Golden Lion Russian tubes--sweet for a 2nd office system). Tubes are warm, but not as reliable as well-built solid state--technology moves forward regardless of nostalgia.

The reason why I think more manufacturers will be using their resources in developing Digital and even lower cost Class D amps is in part due to the energy efficiency. With traditional energy sources so expensive, a class A amp that needs 600 watts to produce a 150 watts per channel at 8 ohms is the equivalent of a 1970's gas guzzling V8. Digital amps are the rough equivalent  of a Tesla that can go 0-60 in 4 seconds with efficient battery power. Sorry gang, market forces drive changes.

Is this new Borrenson designed Digital amp the epitome' or state of the art? Well, at $30,000 + it should be. The tell-tale will be at the sub-10,000 range. Oh wait, Technics is already there.

I think high-power Class A is environmentally irresponsible. 

Well I guess you can look at that both ways, I think a case can be made that very low inefficient speakers are environmentally irresponsible. Happy imaging!😎

Mike

@arafiq

@jjss49 Thanks for mentioning the AGD amps. How would you compare to an all-tube system in general? To be more specific, let’s say if someone like the tube sound and has not been satisfied with SS ... should this person consider AGD?

hard for me to answer specifically, as i am sure you can understand, all tube systems can vary alot in their degree of softness at the frequency extremes and their midrange ’bloom’

i still have alot of tube gear, mostly audio research tube amps (ref 110, 75, vt 100-2, v70, vt60) and still one a c-j linestage (et7-ii) and a don sachs pre - none of which i use hardly at all anymore... but my point in mentioning this is i clearly like a more extended, powerful and more transparent presentation, even from tubed gear

that said, i would summarize (as i did in an earlier post quite a while back when i first got the audions) what they do is rather like a beneficial cross-breed between the best of tubes and ss

-- treble is very clear, extended, fast and high resolution, but still exceptionally smooth and not at all harsh (think of a very very high resolution color photo or video picture, where the pixel count is so high that the texture is actually velvety, with absolutely zero perceptible grain or grit...)

-- mids are also very natural, detailed, fleshed out, but in proportion to the treble and bass, and not moved forward or accentuated relative to them (to many the forward and magnified midrange can be a defining aspect of tube-sonics... )

-- bass is airy but exceptionally tuneful deep and solid... here definitely this aspect is tip top solid state, which exceeds that of pretty much any tube amp -- short of truly mega ones with hundreds of watts of output power (think vtl wotan or arc ref600/610)

-- imaging is very open wide and deep, layered and highly specific... one can argue if image depth is 100% as good as my arc ref amps on their best day, but it is very close... i find that front end quality is very highly determinative of imaging/soundstaging quality

-- and of course, the behavior of the audions with low impedance loads is characteristic of a good ss amp, without the limitations of the classic output transformer based tube power amps

hope the above helps... i do believe that agd dealers (and alberto himself, if bought directly) will still extend a trial period with return privileges

several other agd owners are here, they can chime in to add to or differ from my observations above

@mglik please be specific on what you have compared the AGD amps to? Merrill? Atmasphere? Others? Thanks

+1 For AGD Audions

I used to be a die hard SET guy.

No more. And now no other amp but the AGD Class D.

Compared to any amp IME, AGD is in a class of its own.

A GaN based amp but the designer holds several patents from when he was a top exec at Infineon-major European chip company. One patent is for his proprietary, unique GaN module. He describes it as being dedicated to be used in Audio. Compared to other GaN chips designed for use in such things as radar,

The result are AGD amps that are superbly like real music.

All the best of SS and tubes… to put it mildly.

Coming from being familiar with pro amps, I had some adverse opinions regarding using them for Hi-Fi. Ok for HT, but not Hi-FI. Had class AB most of my life in my stereo setups. Then an opportunity came to test some lightly used MBL N15 Class D monoblock amps. There was a little glare, but they sounded so clean and powerful, with great bass of course, overall significantly better than my ARC Ref 160M (within my setup). Changed my cables from silver to copper and it got better.

I took the plunge and bought them. Several months have passed and they have just gotten better. Visiting audiophile friends confirm this, they cannot identify them as a Class D anymore just from listening. Perhaps they needed enough burn-in? I believe the original owner gave up on them too soon. MBL’s LASA technology has been around for a while but it does not seem to get all the merit it deserves.

This experience opened my eyes to the progress of class D amp technology.

@jjss49 Thanks for mentioning the AGD amps. How would you compare to an all-tube system in general? To be more specific, let's say if someone like the tube sound and has not been satisfied with SS ... should this person consider AGD?

P.S. I'm in no way implying that tubes are better than SS or vice versa. But for my personal taste in music, tubes offer something that SS does not. Of course, just the opposite can be true for someone else.

Ordinary audiophiles are not paid to write reviews. 

If the staff of critics at TAS deserve all this derision, how far down Hell's rings do the opinions of we ordinary audiophiles rank? Can we ride our horses under the door? 🙄

Well, this thread went in a direction different than what I had in mind.  I own class D amps, SET amps, and AB amps, but I didn't really want to get into the relative merits of each.  What I had in mind was to discuss the irresponsible ways that audio gurus 'infilict' their opinions and biases on us poor audiophiles.

I've been using a Pass X250.8 and then XA30.8 spread over the last 7 years and love the sound.

I recently purchased a pair of the Atmasphere Class D GaNFET monos to compare with my XA30.8 and so far have been very happy with them.   They may not be fully broken in yet and I have yet to switch back to the Pass so I'm still not done doing my listening comparisons.

But as a big Pass fan I can say I definitely like their general sound.  I find them to be very smooth and warm just like my Pass with nice natural tone.  I don't find them fatiguing at all.   I think they also image extremely well just like my XA30.8 which to me is one of the best imaging amps I've heard at home.  

If you like the sound of Pass and get the chance to hear the Atmasphere GaNFET monos, I would take it as you may just like them, even though they are Class D...

in all seriousness, alberto guerro’s agd audion mono’s are the best sounding gan/class d amps i have heard, and while they have their own sound character, they are - to my ear - as good as the very best class a or a/b amps i have had, of which i have had countless

vastly superior to any hypex purifi or other non-gan module based amps i have had or heard, which to me seem to 'grey out' the music some harmonically even if the tonal balance is good

I’m still playing with my Class A/B and it a good thing. This way they can have more time to prefect the tach.

“You can assume that he has.  The journalistic integrity of TAS is unquestionable.  Furthermore, I have never heard of Mr Valin being proven wrong.  His hearing and experience are so accurate that they are virtually objective.”

The sarcasm is strong in this one. 😁

It’s technology. It will change. I personally think we don’t much understand how our brain interprets reproduced sound, leading to a whole host of different personal preferences. I like Magnepan speakers. I can’t drive them with flea-watt amps. I think high-power Class A is environmentally irresponsible. Class D is a great choice. Give it a tube front end and find what you like.

Yea, right. AB still rules.

Ps,

To my rant, overwhelming ‘odds’ are Hi end revealing systems are not powered by Class D, And the reason is…. Sound !!

The first sign of class D arrival will be that people will stop talking about its arrival.

Love my Rogue Sphinx V3. Next go around I will audition the Cronus Magnum III.  We'll see...

Class AB and mostly tubes....845's are the best I've found for SQ.......BUT, I just got the Peachtree GAN 400 with the Gallium-Nitride ganfet transistors....WOW. My system ( approx $15,000) took a Big leap...It's a "Different" sound.....more detail. That means it really raised my Pendragons to a new higher level of enjoyment   ...the GAN technology is what raised the SQ in class D......Ice and Purfi are the old class D...if you want to try what This new buzz is....Peachtree...Orchard both under $3,000 for GAN....

Beauty is in the ear of the beholder when it comes to this hobby or obsession.

I have had a number of Class D come through my audio room and never has one stayed longer than 8 months. Ice, Purfi, GaN, none have made the cut. Just not my bag but I am not saying never. 
 

I welcome TAS to the end of the 20th Century.  May they continue to make great strides in keeping up with the rest of the world.

Once again, if I understand Class 'D' you will be put at the table of the designer's likes and dislikes with nothing to say for yourself. In other words, they are the ones that choose what and where in the audio spectrum things will get the emphasis with little ability of the end user to override THEIR likes and dislikes. This is exactly why I prefer pre-Amps and Receivers that let you bypass any tone control circuitry if you so choose. I want to hear how a particular song was meant to would like by the engineers and producers rather than some third party that has their own agenda in mind.

I have a couple of MBL monoblocks purchased used, model N15.

They clearly sounded better than my ARC Ref 160Ms, even after tube rolling, vibration treatment and good power chords.  It took some burn in time to get rid of the traces of class D sound signature but now they sound like a very good AB class amp.  They are efficient, powerful and never get hot.  Only adjust I had to make in my system was using good copper wire.

Sorry, but it arrived much earlier with Bruno Putzeys' NCore series at Hypex.

Class D arrived a while ago and at lower cost. I have a pair of Jeff Rowland Model 125s, a pair of AGD Audion monoblocks and a new Orchard Audio Starkrimson Ultra. All of them sound great. No glare, with plenty of power and headroom. Other than one Class AB integrated I still own, I have sold my class AB solid state monoblocks. 

There Might be a day when class D shines, and it will be over priced for the Minimalistic bits of junk inside their box that’s the normal gouge. There will always be a market for wire scam as there will always be stupid gullible gifted with ridiculous cash. That’s the facts jack ! 

@urbie   Aren't you forgetting that there are thousands on here dumb enough to pay up to $30,000 for a real piece of wire, namely a power cord when an upgraded stock item cannot cost more than $25.

Good news about Class D as I no longer have to suffer through endless sessions thinking my Pass XA-25 sounds so good while getting hot and all Class A...I can just get rid of what I thought were beautiful tubes and amps (including guitar amps) and just relax into some D. I already have a Class D bass amp so I'm on my way!

 My PASS LABS MOSFET amplifier smokes it. 

anyone that's dumb enough to pay $40,000 for a piece of wire has got more money than brains it's a piece of wire LOL.

JV is confusing Class D amps with poor digital playback (usual digital-like upper-mid/lower-treble glare). Overall, Class D amps don’t sound like that, to the contrary, they are flat and artificially smooth, and unresolving.

The recent PNW Audiofest Show was lightly attended. I took advantage

of the downtime and spoke with Michael Borresen at length. He was very proud

of his new 200wpc class A amp. No Heat. $70k. When I asked how this could be

he said it was all about the parts used and attention to detail in the build. He holds

a patent on the only speaker using no iron. At $30k they don't come cheap.

I heard the Aavik systems at the Long Beach audio show a couple months ago... It was fantastic, but the amp alone is $30k+, it better sound incredible ...

A little too "clean" and sterile maybe, but very powerful, tight, clear... Was it the most amazing thing I've heard, no.. my CI audio class D amps sound awesome, are these 10X better, no way, not even close

They made the speakers, cables, dac, streamer, preamp which were all super expensive and high end... It's amazing stuff with all kinds of crazy engineering, but not magical for the few tracks I heard

Jeff Rowland perfected Class D years ago. Amplification is just a technology, not bad or good. It’s what you do with it that counts.

iirc it was back in 2008 or 2009, someone talked me into getting a pair of the fairly recently (at the time) released pair of jeff rowland class d mono blocks... sure looked pretty with those 3/4 in thick milled faceplates ... but those amps were one of the most disappointing, grey and lifeless sounding pieces of gear i ever recall buying ...

i punted on them in less than two weeks

(Note for tomorrow:  Stock up on adult beverage and popcorn. Shows all the signs of a multi-page 'discussion' with the usual sturm und drang....)

Jeff Rowland perfected Class D years ago. Amplification is just a technology, not bad or good. It's what you do with it that counts.

Yes, Class D has arrived. It took some fellows with radar experience to do it. You can buy the PuriFi modules for about $1000 (a pair, with a front end & connectors) that are  used in NAD's well reviewed gear, LKV, and others. In their big amp, LKV adds their own front end and power supply and charges $10,000 for it. If you can DIY a  suitable power supply (it needs three different voltages) you can have a PuriFi stereo amp for about $1200. I built two of them. If you don't want to build it yourself, Starke  Sound offers a new version of their four channel amp, now called the Fiera4, for $1500. I have six of the earlier version in five different systemsand a  marvelously tolerant wife. Starke designs their own power amp modules. Those are slightly smoother than the PuriFi in the upper treble region, to my ears anyway. I drive Maggie LRS, Linkwitz LX mini, LX 521, some slim Wharfdales, and several sets of DIY speakers with them and am very happy with the Starkes. If you don[t like the amp, you can return it. Starke is a commercial sound outfit and makes gear for sound reinforcement in halls and auditoriums. No chrome, no flashy looks. They didn't pay some designer to make it look like a geaming relic from Tut's tomb, I've praised this amp before on this site, but many people don't realize you don't have to spend a fortune to get great sound. It's not like the candy bar business where you sell hundreds of thousands of units. How many people really buy power amps? So the manufacturer's markups are considerable since a thousand units is a dream come true, and you have to have a building,insurance, a work crew and sales manager.. You can have excellent sound at a reasonable price, and you can save even more if you DIY. Happy Listening!

I always knew the word "compare" was a dirty word, esp. in audio.

I never read a negative review either, I'm sure that would cause major turmoil, financially or otherwise🙄

Will it take another 60 years for them to be able to drive Magnepans correctly?  Ok, that's tongue and cheek...but since capacitance is king for making planars truly come into their own, how will D get this done?  

@russ69  What class D amp do you have?

Soix, my post was intended to be ironic. We are in agreement.

johnlnyc, let’s just focus on this particular journal (TAS), this reviewer, and this class D amplifier.  The reviewer has stated repeatedly over the years that he has no use for class D amplification.  Recently, he has decided that class D has progressed to the point that it meets his minimum level of acceptability.  Can we assume that he has listened critically and objectively to most of the recent  implementations of class D?  Since the answer is quite clearly “No”, does it not annoy you that he is able to claim the latest Borrenson amplifier to be a game changer?  If your answer is ‘no’, then I think you are missing something.

or am I missing something here? 

@johnlnyc You’re absolutely missing something here. 

Sorry. I am not sure I get this “comparison” issue. Firstly, anyone listening to any piece of equipment is comparing what they are hearing to everything they have listened to previously.

Experience counts.

I would love to know what benefit is derived from any comparison if the equipment reviewed is accurately described by someone with enough knowledge and experience to know what they are hearing and can provide enough information so others can have a good idea of what that equipment offers sound-wise and whether    
or not it might be worth auditioning themselves.

or am I missing something here? 

Soix: I completely agree. To be fair, Valin includes vague comparisons in his reviews from time to time, so he is not the worst offender in this regard. But his habit of generalizing and making sweeping judgements is probably the most irresponsible thing he does. I present the Borrenson amplifier assessment as an example among many.

and if a reviewer was to say anything negative about a piece of equipment they are reviewing, wouldnt that hurt the company that made it as well as the review company ?

@riley804 Having written professional reviews for 15 years or so, I was never instructed to not say anything negative about any review product.  The fact is that the only pieces that make it to the level of warranting a review are pieces that have very good customer feedback or pedigree, so crap products that probably deserve negative comments just never make it to being reviewed.  The way to read reviews is not to look for negative comments but to glean from the review where a product may fall short RELATIVELY to other gear.  That is why product comparisons are so critical in a truly thorough, credible, and useful review and why TAS reviews are Absolute Crap.