Class D Amplification Announcement

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

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

@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

@arafiq

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?

not sure how to answer... i would say that most low powered sweetie-pie tube amps provide a level of 2nd order harmonics that give voices and instruments a certain glow and lusciousness... i do not feel that the agd’s really do that nearly as much, its midrange is more neutral (if well detailed, very dimensional and ’human’ to my ear) but i don’t think anyone would mistake the agd female vocal reproduction to sound like that of a 300b 10 watt single ended amp .... then again, the agd’s speed, control and its own sense of very high purity in driving a much much wider range of normal and even hard to drive speakers needs to be factored in

imaging wise, i think the agd’s are really excellent - and as @twoleftears says one can always go tube linestage into agd power amp for an infusion of tubey goodness with very few of the downsides

relative to what may be your current, traditional tube amp, i really don’t think there are any downsides... or rather, maybe there are simply 7500 of them 🤣

@arafiq

if you reach out to alberto i think you will find him responsive and very knowledgeable... obviously he will champion his (excellent) product and he will clearly explain how the audion monos differ from the one chassis stereo model in technical and practical terms

you are experienced at this hobby now, so i am sure that if/when you get an agd amp, you will listen to it on its own first, before coupling with tubed gear in the chain... you may well be surprised you may not want/need add’l ’tubey goodness’, (which certainly comes at a price monetarily, and usually, also sonically, to some degree, while bringing its gains)

i think i have mentioned this in an earlier post... i have been a hard-n-fast die-hard tube gear guy since the 90’s, i have much tube gear and boxes and boxes of so many tubes, but as my streaming journey has progressed since 2020, as the front end has gotten purer and purer, i now am ecstatic about the quality of sound i am getting without a single vacuum tube in the chain - i've come to realize how much of my perceived need for tubes in the chain was palliative in nature, solving for digititis and/or solid state artifacts introduced in the source and amp stages... in this crazy, unpredictable journey i have been on, i would never, never have thought i would be here... 

i agree very much with ralph/@atmasphere

class d is a class of technology, even within it, there are substantial technological variants, not to mention myriad of ways to implement

but folks keep at the old saw... class d is like this, class d is like that

it is all in the details folks!  would we say, well moving coil cartridges have this sound?  it's silly, in reality they run high and low, all over the spectra, it is a technological means to do something, how it is designed specifically, how it is implemented, drives the sonic result

regarding reviews, and in particular, doing apt comparisons of competing gear in reviews, i am 100% with @soix

of course a review can be a piece with just well crafted prose about the subject piece, and on its own it is of some help, but to me, as a consumer of such reviews, it is NOWHERE as helpful as when a reviewer carefully states his/her perceived sonic differences, pros and cons, versus what most would consider to be head on competitors/alternatives to the review piece

comparative info, even if subjective, is VERY USEFUL to a reader gathering info, for a whole host of reasons (hardly worth enumerating, it is common sense) -- that said, for a publication that needs to please many, multiple stakeholders (i.e. advertisers, retailers, and so on), one can understand why sharp comparisons indicating ’a may be better than b’ is unwise and undersirable from the reviewer/publication perspective

still, it doesn’t change the fact that comparisons are useful, indeed very useful for the reader, as much as many commercial reviewers try to avoid them

at the low cost end of the spectrum there is the excellent little mini gan5 - $700

it doesn’t have the uber silky refinement and tonal density of the agd’s but for the money it is very very nice amp, small in form factor only

slightly leaner midbass, slightly drier bass, very refined treble, very few classic solid state nasties, and does not have the bleached out lifeless sound of typical ice or purifi module based units

@twoleftears

you dummy, you just needed to use some audiophile fuses in that emotiva, and then a shakti stone on top, then it would be a world beater!!!

now, for cheap-ass chinese class d... one needs synergistic fuses, shakti stone, AND cable lifters!