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Class D amplification?

Discussion in 'Audio Hardware' started by Khorn, Dec 3, 2020.

  1. KT88

    KT88 Forum Resident

    It'll keep the cat off...
    -Bill
     
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  2. Noel Patterson

    Noel Patterson Six pack of stout, and a stick of sensi

    Location:
    Ontario, Canada
    Yep you're exactly right. I'm glad I experimented as I thought the Brio was driving them just fine. No slight against the Brio, just not what it was designed to do. I'll put it on the little system upstairs with some small PSB speakers and let it shine there!
     
    Khorn likes this.
  3. rbbert

    rbbert Forum Resident

    Location:
    Reno, NV, USA
    I have a W4S ST -250 with the upgraded connectors that I have been using for the past 3 yrs driving a pair of Acoustic Zen Crescendos (89 dB, 6 ohms) very nicely indeed. I’m selling the speakers, and so possibly the amp too, but it’s so nice I may just hang on to it as a spare. If anyone wants, though, I’d be willing to part with it for $750 inc shipping
     
    Khorn likes this.
  4. Mike-48

    Mike-48 A shadow of my former self

    Location:
    Portland, Oregon
    On December 24, I received two Class-D monoblocks with PuriFi modules from Apollon Audio. I'm posting here to give preliminary listening impressions in my main system. (The rest of my gear is in my profile.)

    Note: When the amps arrived, I swapped them for my usual amp (a Bryston 4B3) and adjusted gains per spec to match my subs the same way. The goal was to get an immediate impression, with the existing amp in recent memory. However, that was foiled by tonal imbalance, requiring a new gain calibration. I'll post more after I swap the Bryston back in, in a few weeks.

    Current impressions:
    • The amps are in the same league as my usual.
    • They are the most transparent and uncolored amps I've heard in my system. Like clear alpine water.
    • As part of the above, they offer tremendous clarity. I'm not good at hearing lyrics in general, but I'm understanding some I never got before. The word "opaque" in a Beatles song, for example.
    • Very natural overall timbre and tonality. No grain or edge.
    • With my usual amp, the system had a measured peak of 2-3 dB centered around 9 kHz. That gave sparkle but also excess sibilance and could be annoying, so I often EQed it out. It is now gone, which I chalk up to less interaction of the amp/cable/(electrostatic) speaker system.
    • Excellent bass
    • No change in clarity or timbre as volume and complexity increase. This is reminiscent of the Classé CA-2300 that I auditioned a few years ago but ruled out because of fan noise.
    • Slightly less "sheen" on strings than the usual amp. Maybe because of the flatter frequency response?
    I want to emphasize, these are first impressions, in a particular room, particular system, and with my specific taste in sound. I can say, I'm enjoying the amps quite a bit.
     
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  5. fish

    fish Forum Resident

    Location:
    USA
    Hypex Based Class D is what the newer Marantz References are using too.

    I find your impressions of the Apollon similar. Marantz PM-KI. Makes a pair of vintage KEF Model Fours I have dance with nuance, tight sharp bass and vocals. Great soundstage and layering. I know its mostly coming from the amp! Other amps dont bring out these qualities in the KEFs.
     
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  6. Khorn

    Khorn Senior Member Thread Starter

    Great that you’re getting a chance to do this. I’m sure there are many here who will be extremely interested in the outcome specially since you’re able to plug in your Bryston after listening to the new amps for a while. Not many who purchase equipment go back to actually compare new with old. From the preliminary info that you have provided it seems very promising. Have fun checking it all out.
     
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  7. Mike-48

    Mike-48 A shadow of my former self

    Location:
    Portland, Oregon
    I am going to crib something I posted to Audiogon forums and edit it for this thread, about the two amp models I'm trying to compare.

    I put the Bryston back in the other day and tried to compare the two setups (Bryston 4B3 or Apollon PuriFi monoblocks). I find both models to be really nice-sounding amps, so it's not simple to say one is better, or even that I like one better. They are a little different, but the comparison is tricky.

    One big issue is that their gains are different, and since I have subs in the system, it's not trivial to swap one in and the other out while keeping levels constant. Indeed, it's proven to be more fiddling and fussing than I'm up for. Related to that, the Bryston tends to interact more with the capacitive load of my speakers (I think), leading to different treble response. I can adjust for that, but it takes time, and it makes comparison difficult and unreliable. The experience gives me appreciation of what audio reviewers deal with.

    That said, after a week more, the things I (still) notice about the Apollon amps are
    • Extremely quiet and neutral
    • More detail, with none of the etch or glare that can accompany that; for example, I'm separating instruments in ensembles better and hearing lyrics more clearly
    • As noted, the Apollons seem to control the treble better, possibly because of less interaction with my electrostatic speakers
    • Both the Bryston and the Apollons have great imaging and soundstaging; both have great bass
    • I have a tendency to listen louder with the Apollons. Why? Is that good or bad? I don't know!
    So, it's proven more difficult than I expected to form a definite preference. Maybe that itself says something useful -- I hope so. If you see me selling one or the other, you'll know I made up my mind.
     
  8. RockAddict

    RockAddict Forum Resident

    Location:
    UK
    Just some idle thoughts for conversation...

    Based on personal subjective experiences over many years, my "gut" is that the first 3 observations listed above the one about listening louder with the Appollons go a long way to explaining it. If "control the treble better" means slightly less forward, that would potentially suggest "less 'tsss' and, in turn, less room for fatigue". Also, would it be fair to suggest that the soundstaging with the Appollons is slightly different (not "better" or "worse") insofar as there is a small but perceptible increase in space around the instruments which, in turn, would make listening "closer" easier allowing the volume to move up a notch or two before it becomes a wall of sound?

    Main thing: is this experiment helping to make listening to music more enjoyable? If so, job done. :)
     
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  9. Mike-48

    Mike-48 A shadow of my former self

    Location:
    Portland, Oregon
    I'll respond in the same vein--

    Regarding "less forward," that is a tricky issue. I use a system with DSP and can set the treble response to anything I like -- and I'm perpetually experimenting with how to translate "what I like" (which I equate with "realistic" ;)) into a graph. But yes, I think the apparent ability of the Apollon amps to control the treble of the electrostatic speakers more evenly could loosely be translated to "less forward" or "less fatiguing." It's hardly a controlled experiment, even in the loosest sense, because the new amps have prompted me to try different options when adjusting the upper-end DSP. In the end, my path isn't about evaluating amps, it's about tweaking the system to get more pleasure from it on a wider variety of recordings -- pretty close to what you said. And I think that for me, in my room, with my tastes and the rest of my system, the Apollons are doing it.

    Yes, the soundstaging is a bit different. Maybe it's more space around instruments. All I can say is, I was listening to a string quartet last night, and I thought "Oh, that's the first violin . . . that's the second violin . . . that's the viola (a distinctive timbre) with more certainty than usual.

    Sometimes, I think the Bryston might be more beautiful in some way. A realistic way? I don't know.

    Based on my experience, I'd recommend anyone with electrostatic speakers who's looking for a new amp try one of the modern class D options. That said, I don't think either approach is bad or lacking. In my system, and with the right recording, either can produce startlingly beautiful sound.
     
    Last edited: Jan 10, 2021
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  10. David Sonnier

    David Sonnier Forum Resident

    Location:
    Broussard LA
    My friend has Emotiva’s new Class D monoblocks. They are very small and basically use B&O class D modules (kinda rebadged I guess).

    Anyway he says he was blown away by how good they sounded. I’d love to listen to a class D amp at some point.
     
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  11. Khorn

    Khorn Senior Member Thread Starter

    I’m starting to see the benefits of class D amplification in relation to far more compact systems like the increasing the popularity of integration such as integrated amplifiers and active speaker systems. These could be modular based for easy upgradability. Class D could open up the market for a higher performing and more cost effective range of audio products for many more music lovers.
     
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  12. timind

    timind phorum rezident

    Location:
    Westfield, IN USA
    That's become my gauge for whether or not what I'm hearing is better than what I'm comparing it to. If I find myself turning, it up it means it's more engaging, and I'm enjoying it more. If I'm enjoying it more, it's gotta be better.
     
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  13. RockAddict

    RockAddict Forum Resident

    Location:
    UK
    The Stealth PA-1s? During a journey of, ahem, "discovery", I bought a NAD C 658 pre/DAC/streamer but didn't have much budget left for the power section. Enter the Stealth PA-1s. For me, they did a job of getting me under way but after a few months they were replaced by a PS Audio Stellar S300 (dual mono) which uses a variation of the ICE modules but, importantly, also has what PS Audio call an "Analog Cell". There was a noticeable difference with the S300 being warmer sounding than the PA-1s and the lower frequencies more controlled. I think the PA-1s are great as an entry into separate pre / power boxes but perhaps are likely to work best with a system that is on the warm side of neutral.

    As stated elsewhere on the SHFs (more than once), my current (main) setup really has helped to bring the focus back to music rather than hi-fi. Happy as I am with the main setup, that isn't going to stop me experimenting with my second system. Entry level valve / tube amps here we come... (and, quite probably, another thread) :).

    Happy listening all.
     
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  14. Saint Johnny

    Saint Johnny Forum Resident

    Location:
    Asbury Park
  15. David Sonnier

    David Sonnier Forum Resident

    Location:
    Broussard LA
    Good to hear. Class D has come a long way. Yeah I think the Emotiva Class D amps are PA1 monoblocks
     
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  16. macster

    macster Forum Resident

    Location:
    San Diego, Ca. USA
    I have a Wyred 4 Sound STI-1000V1, and am loving it. IMHO, it has a wonderful tube like texture without the tube fickleness (IMHO) and doesn't have to go through a warm up period before it sounds great. I really like it.

    M~
     
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  17. SoCalUser

    SoCalUser Forum Resident

    Location:
    91006
    Just getting my first taste of class "D" via a tiny desktop amp sold on Amazon for 100 USD! With Bluetooth, a 192/24 bit DAC and sub out. I normally wouldn't look twice at this stuff, but I'm glad I did. Rated at 50W/Channel into 4 ohms, I'm driving old 3-way bookshelf speakers from my computer, streaming with an m-audio AP 192 PCI card via coax to DAC.

    The sound is amazing! Crystal clear, detailed and spacious, with enough volume for nearfield. I feel this could be my only system, streaming music, movies, and You Tube vids. This is proof, at least to me, it doesn't take much money to get something that sounds great. If I would have known this earlier, I might have done things differently, but we will see if I feel the same next week.
     
  18. Andy Saunders

    Andy Saunders Forum Resident

    Location:
    England
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  19. SoCalUser

    SoCalUser Forum Resident

    Location:
    91006
  20. Andy Saunders

    Andy Saunders Forum Resident

    Location:
    England
  21. Silverwolf

    Silverwolf Occasional Esoteric Freak

    Glad that works for you... I’ve been looking at class D since the ‘giant killing’ tripath days 15 years ago (I was never convinced they were quite that though...).My Temple Audio amp is my second, the first was a tripath, my current one is not but improved in all areas (including a now massive 25 watt output, which drives my fairly difficult Dynaudios loud enough for a party (a small one admittedly, in my small space.)
    Everything is improving in these amps, from budget to high end - far more time seems to be spent on the analogue side of these amps, power supplies etc. The Temple Audio story reflects this with their Bantam One amp - dual mono, in built linear power supplies for each amp which seem similar in description to Teddy Pardo power supplies, more analogue inputs. Higher output at 100 watts, able to drive comfortably down to 2 Ohms etc...
    They still make the tiny budget amps with one input which in a small to medium space will power speakers that are ‘proper’ hifi speakers - like my lower end Dynaudios, and similar offerings from Monitor Audio, Kef, B&W and the like and sound great. But they’ve also expanded into the midrange and possibly lower high end based just on reviews rather than price.. I guess it’s a similar story to the huge increase in DAC quality over the last 10 years, and an also huge increase in ‘bang for buck’ as the technology has been developed and made more widely available and accessible. It’s an amazing time for audiophiles on a strict budget like myself to explore a higher end sound than previously available at these lower price points. Sure, I’m sure there’s kit out there that’s not class D which will blow them away, but at what cost? It’s a shame these types of amps from the cheapest offerings upwards aren’t getting noticed or at least tried by audiophiles some of whom seem to dismiss them simply because they’re newish tech and relatively a bit cheaper, or haven’t looked into them for a while.

    Oh I’ve no connection to Temple Audio by the way! I’ve just been following them and have been very impressed with what this small, passionate company has been doing for a long time. I really hope they branch out into DAC’s one day...
     
  22. Andy Saunders

    Andy Saunders Forum Resident

    Location:
    England
    Would like to hear the Bantam One!
     
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  23. Silverwolf

    Silverwolf Occasional Esoteric Freak

    Yeah me too. I looked on their site after my last post as I haven’t for a while - they’re not making it at the moment, but I think it was only ‘made to order’ anyway. So I guess Covid has shut them down for now and they’re just selling other stock already made. I hope they survive ok, they’re a small business. Did you check out the Bantam One website? It’s got it’s own site, linked from their main site..
     
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  24. Ralph Karsten

    Ralph Karsten Forum Resident

    Location:
    St. Paul MN
    Both of these are because the Purify is lower distortion and is making less higher ordered harmonics. The ear interprets all forms of distortion as some sort of tonality; the higher orders add that sheen. Because the ear uses the higher orders to sense sound pressure it is very sensitive to their presence! So if you can reduce that kind of distortion not only will the sheen be gone but you're far more likely to turn the volume up higher because the amp will be lacking the artificial loudness cues that were stopping you before. If you use a sound pressure meter this will be easily seen.
     
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  25. Andy Saunders

    Andy Saunders Forum Resident

    Location:
    England
    Yes l did- bit confused on the power rating, some say it is 100WPC then you read elsewhere that it is 40WPC, does look a brilliant product.:)
     

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