Atmasphere Class D amplifiers - great choice!
Please let us know what you think of your new combo.
Looking to Develop A Short List of Amplifier Candidates For A Pair Of JBL 4367 Speakers
Over a number of years I have owned JBL 4365 and eventually moved on from them. I tried a pair of Martin Longan CLX ART, but my room was not well suited for them. A failed experiment with a lot of lost hours in it. I ended up coming home to JBL and acquiring a pair of 4367.
They are a lovely speaker and are well suited for my 15' by 19' by 8' room. Controlled directivity from the horn augmented by minimal room acoustic panels and a light touch with the Trinov DSP system works for me.
The amplifiers I have been using are a pair of Classe Omega monoblocks. But the reality is they are massive, are way too much power for a pair of 94 db efficient speakers, cannot be moved by me alone, and are just wasted in this application. So they have been sold and are pending pick up when the new owner gets back from vacation.
So I am developing a short list of amplifiers. Going through the whole gamut, tube, solid state, and Class D. On the 4365 I once tried a pair of Audio Mirror Reflections since in my past I was a user of Single Ended Triode amps. But even with "larger" SET power, the woofers on the 4365 were not well controlled at all. Another failed experiment. With the 4365 I had used a PS Audio BHK250 with decent results, a pair of AVM Audio Amp Essential monoblocks with excellent results, and a H20 Audio 250 Signature Class D amp with interesting results. The AVM and Classe have provided the best results so far.
So the question is, are there Class D amplifiers that meet the sound quality requirements these days. I have seen some amps using a Hypex or Purfi module with a tube front end. Also have heard the latest generation Orchard monoblocks are worth looking at. Anyone have any other candidates, or thoughts?
In the past JBL was known to mate well with tube amplification. But I imagine this is going to have to be push/pull. In the past I have owned Dynaco and then Quicksilver before I went to explore the world of SET amplfiers. When I bought the 4365 I had thought they were going to be agood match with my Electraprint amplifier, but I was completely wrong on that one. What power level would I have to reach with tube amplification?
Finally in terms of solid state, the choices are huge. I know McIntosh was often a favored pairing, but I have never been a fan of the brand. I wonder about some of the solid state Conrad Johnson offerings, but I think they may be getting long in the tooth these days. I have thought about BAT. I actually have a First Watt F7 here that is my back up amp and it runs them better than a person would have imagined. The latest generation of AVM is now a hybrid, and ownership by Burmester might be a good thing, I would like to think I could get service in the US for them.
Any thoughts or experiences you want to pass along would be greatly appreciated.
Should you want to save a few dollars and have a world class amplifier please look at Odyssey’s Kismet. But don’t have high expectations of the website ... perfunctory at best.
https://odysseyaudio.com/kismet-reference-amplifiers/#
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So I ordered a set of amplifiers today. Decided to give a pair of the Atmasphere Class D amplifiers a go. I heard them a year or two ago at the Pacific Audiofest. Granted it was under show conditions and with unfamiliar gear. But the potential was there. I then have followed owners experiences over time and it kept my curiosity alive. Finally I had a phone conversation with Ralph at Atmasphere and my impression is that he is a straight shooter, polite, and patient person. Not a bunch of bullshit, just no nonsense engineering based answers. So I am going to give it a go.
i have read all the posts here and many are intriguing. The MC2 amps piqued my interest. JBL has often been paired with commercial/professional amplifiers and it is probably an option worth exploring. I just don’t know if these amps can be found in the US market. Finally I have a First Watt F7 in my garage. In many ways it has similar voicing to the Classe. It’s a great safety net for me while I explore a few different avenues. It has been awhile since I listened to Class D amplifiers. In the past I found them too smooth and lacking in harmonic texture and expression. I am hoping Ralph’s design has overcome those limitation! | |||||||||||||||||||||||||||
This really has been a fascinating thread - besides knowledge gained from the OP's original question on speaker matching I was exposed a bit more to what AI possibly can/or shouldn't do and how we as purchasers should always to consider the sources and do our own fact checking. All the feedback and comments were civil and never contentious. My thanks go out to @rhg3 for his thoughtful comments. Cant wait to hear what amplifier the OP chooses! | |||||||||||||||||||||||||||
We have used the Hypex Nilai 500 Monoblocks extensively the JBL 4349s and JBL L65s We have compared them with: Hegel, Mark Levonson, and Classe, all in this world class category. We never get bored with or irritated with the Nilai 500s, smooth and Incredibly accurate. Amazing control due to the super high damping factor Please note, Deer Creek Audio is an authorized Hypex dealer.
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@neonknight wrote: Out of curiosity: why did you get rid of the JBL 4365’s - i.e.: what did the 4367’s to your ears bring to the table by comparison?
The first question that pops into my head here, looking past your rationale to let them loose, is how the Classé amps actually mated with the JBL’s from a sound perspective? With regard to power and its speculated excess, practically speaking I don’t believe you can have too much power with more modern JBL’s with larger voice coil woofers - despite their moderately high efficiency; on the contrary more power to such woofers can turn out to be a benefit. Indeed, it’s about how those JBL’s react to more powerful amps/PSU’s, even at lower volumes.
I believe Greg Timbers had a notable fondness for Quicksilver amps over the horn-loaded mids/high compression drivers of his JBL designs and pairing them with solid state amps for the woofer section, albeit he seemed to find running them actively, initially with analogue, electronic crossovers was the preferred scenario, and so naturally gain matching between the driver sections had to take place anyway. This can be more tricky with passive bi-amping using different amps with different gain horizontally, a configuration that may otherwise have been a shoe-in in your case and trying to take advantage of different virtues of different amps topologies, while largely avoiding their weaknesses selectively. From my chair though using different amp topologies when bi-, tri- or quad-amping (or more), while tempting at first with the incentive behind it, invites potential new issues that can impact overall coherency, and so my choice would be to look for a same amp solution covering the entire frequency spectrum of the JBL’s. Leading me to this paragraph of yours:
A friend of mine who’s a pro audio dealer while being a true nerd (and gear collector) of an audiophile incorporating pro segment speakers and amps into his private, home audio setups with high-end analogue and digital sources, initially used McIntosh MC2300 amps in numbers over his then large and actively configured JBL 5670-series cinema speakers among others, in addition to Crown Studio Reference I amps later on. Eventually though these all had to go (finding buyers wasn’t a problem, and they willingly paid large sums for these older amps), and instead he set his sights on the british MC² Audio amps from the individuals behind Klark Teknik and Turbosound to take over, and which they have done since. As it so happens, with his influence I’ve been using MC² Audio in own setup for a few years now, and they are downright excellent amps - both professionally, I’m told, and in a home stereo environment, functionally as well and not least sonically. The catch to audiophiles? Mainly non-fancy pro looks and their built-in fans, which can be replaced with quiet versions. Another catch: low price (we should know what that’s about) and going below radar to most, coming from the pro audio segment not least. Summing up: using MC² Audio amp myself I have solid experience with them, less so with the JBL 4367 speakers (haven’t owned the 4367’s, although I’ve heard them several times), and not with the combo of those. Still, the MC² Audio T and S-series amps I've heard are smooth, highly resolved and honest sounding with an abundance of power at their disposal, so I can easily imagine them being a very good match with the 4367’s, also from what I know of the characteristics of the latter that I wouldn’t pair with dry sounding amps. Specifically I’d recommend the T1000 model as an outset, but the more expensive S800 and S1400 are excellent as well though sounding virtually similar to the T1000. The T1000 (depending on the measurement technique) is a 450W/8 ohm amp, class A/B topology, and I use two of them in my own setup actively for my main speakers + the larger T3500 sibling for the subs. The T1000 retails for about €1,700, but please: don’t let the low price scare you off. | |||||||||||||||||||||||||||
hi great choice in the 4367. i have used my 4367 speakers with Gryphon Diablo and then my Audio Note SET amp (211). the only reason i bought the 2nd hand diablo was because i had always wanted to own one and i wanted to know if my preferred amp (SET) was driving them well enough. i figured if not i might bi-amp. a few points #1 - imo solid state thru the jbl 4367 isn't default pleasant, even something with a reputation for some sweetness like the diablo. they are a neutral speaker and they don't lie or roll off much. they can sound hard. you can be listening, thinking "wow" but then 2 hours in you realise your ears hurt. #2- tonally the SET is wonderful. never anything hard or shrill etc. just extremely nice by default imo. i have around same size room as you 13 foot by 16 foot with 16 feet ceilings. #3 - in a comparison with diablo for music, i couldn't see that the 211 failed with bass woofer control. not at all. i didn't even bother bi-amping. the SET sound was brilliant and i was happy with it in comparison to diablo. for movie watching, i did however find the diablo sounded "better". i think this is because there is so much "atmospheric bass" in movies. so not an issue with 2 channel music in comparison but for movies etc it was discernible. but again the hardness would come in. so it was thrilling watching "the fly" for example with diablo and 4367, but also hurt ears slightly. this is thru a tubed abbas dac. #4 - the 211 amp i have has huge transformers and i think this helps the 20W of SET power get the job done with these 94 dB efficient speakers. #5 - i found good footers helped the 4367 be a gentle giant. i put CMS LS2.25 footers on it and this helped the whole thing. the speakers have disappeared now and i get a wide and deep presentation with great dynamics, resolution and tone. it's thrilling. having the speaker elevated is also critical. they were voiced up on cinder blocks as i recall. #6 - i do find i need to be at around 12 pm on the dial for them to be their absolute best and "come to life". having said that, maybe that's the room. 12 pm is not crazy loud at all (like 80 db kind of thing at listening). so it isn't a problem for me and i don't find that situation to be much different to any other speaker i've heard. | |||||||||||||||||||||||||||
I recommend you check out the Lejonklou HiFi solid state amplifiers from Sweden. They have an integrated amp, the Boazu 2, under $5000 and exceptional, yet relatively compact, mono block power amps at $6500 each, the Tundra Mono 3. Check Part Time Audiophile show reports for RMAF 2016 and 2017. In 2016 Rafe Arnott gave the Lejonklou/Nokturne Audio room Best Sound of Show with the previous Tundra Mono 2.2 driving a pair of JBL 3677 speakers. The following year he said the room was even better (although a subwoofer, also JBL driven by a third Tundra Mono had been added). I am the North American distributor for Lejonklou HiFi you might expect some bias. But I had never heard the JBLs sound that good with other electronics and they were my personal speakers for a number of years. Now I am running a fully rebuilt pair of Quad ESL speakers with the Tundra Mono 3s and they musically outperform anything I have heard on them. I brought an older stock pair of Quads to Axpona in 2019 with the Lejonklou electronics and John Atkinson said they were one of the highlights of the show. A review from Stereophile on the Boazu 2, along with our streamer, the Källa, and our MC phono stage, the Entity 1.2, should be out within a few months from Alex Halberstadt. I don’t know what speakers he will use but he owns Altec A7s and is a fan of horn loudspeakers. I believe he reviewed one of the newer JBL monitor speakers a while back and quite liked them, although I don’t remember if they were 4367s. | |||||||||||||||||||||||||||
Thanks for the feedback re: ChatGPT. I'm curious to know how accurate the response is. Rather than thumb your nose at it, offer constructive criticism. Why not use the Audiogon forum as input to the model and have a chatbot within Audiogon? | |||||||||||||||||||||||||||
There is no intelligence in AI, that’s supposed to come from the human performing the query. The output from ChatGPT will vary depending on how you structure your query. You present the ChatGPT output as if it was an Authoritative answer from a Superior Being. What if we all posted our ChatGPT output? Based on how we ask the question, we’ll all get a different response. Would you want to have to wade through that? The OP and everyone else can also query ChatGPT, so what value do you think you are providing? It’s one thing to treat ChatGPT as a research assistant but to not validate the output is pretty lazy. Fact checking is where the real work begins. Did you ask for sources? Where did ChatGPT get this data? From professional audio reviewers and trade magazines (ex: TAS or Stereophile)? If you don’t ask for sources you won’t know. I’d rather read the source directly so I can form my own opinion rather than have a Pattern Recognition Tool create an opinion for me. Finally, AI’s often "hallucinate" or lie. If you point out an error in ChatGPT’s output it will typically respond with something like "You make an excellent point! I’ll incorporate that change in my responses from now on." AI can be used for a lot of good purposes. I recommend you ask ChatGPT what it’s best use is, based on its strengths. Posting on Audiogon won’t be one of them.
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@mattmiller Wrote:
I agree! Mike | |||||||||||||||||||||||||||
OP I don't have your speakers but I heard JBL a lot. i grew up using them, used as always. and you seem to be searching an amp that will bring the best of this speakers to your Particular liking.. To me, you are on the road of needing to audition more amps to find what you are looking for. with that said, IMHO, i suggest the following..(in any order) 1) AtmasSphere Gan Amps 2) AGD Duets 3) Rogue Dragon. i heard the last 2 above and i think that AGD are really good. very musical and has great control on the woofers. Tube amps as you have said are too hot for summer. if you want to test the waters of Tubes, I truly believe that 845 SET tubes are the way to go, i have a clone 845 type amp and that runs too hot for summer use. i believe that what you are liking is more towards a class D as for the reasons of light weight and not too hot to use. thereby the list above | |||||||||||||||||||||||||||
@neonknight This is correct. But I think you might be missing the implication. What this basically means is that you can build a lower noise circuit using GaNFETs. This matters because you don't want switching noise messing with digital devices or leaking into your FM tuner. By using GaNFETs we were able to get our class D amps to have a lower radiated noise through the air or on the AC line than most tube amps. We also get a low noise figure from the speaker too; even on horns its hard to know the amps are on (which they can be all day and still be stone cold to the touch) until the music plays. | |||||||||||||||||||||||||||
Just wanted to take a moment and say thanks for all the posts, I have read and thought about every one of them.
Class A is intruiging but I am not wild about the heat generated in the summer. I have a closed off listening room and even with the Classe I get a fair amount of heat build up. I leave my SS gear on 24/7 and that is not a great idea with class A amps. I do shop the pre owned market quite a bit. I have always wondered about the Rowland Class D amplifiers, but it seems like most of those are earlier generation Ice modules, and I wonder how they compare to the new Purfi or Hypex offerings. I was reading a technical piece from the designer of the Purifi I believe, and his take on GanFet was quite interesting, in that the devices itself is not a game changer in terms of its relation to other output devices, but rather the circuit architecture matters more. Which leads me back to Purifi or Hypex. What seems to be the main variable is what is used for the input buffer, whether it be tube or certain kinds of high performance op amps. But on the other side of the coin folks seem to say good things about the Orchard Audio amps based on GAN Fet. One other thought I had is the Odyssey amplifiers. I have heard Klaus pieces at a couple of shows and they always intrigued me. I also remember a few posts of early failures on amps, but that was a number of years back. What I would like to stay away from is back breaking amps that take a huge amount of real estate in my system. Ideally I would like one I can house in my credenza.
The Classe leave in about 2 weeks. For an interim I can run a First Watt F7 till I find something that catches my eye. I do appreciate all your thoughts and insights. | |||||||||||||||||||||||||||
Most of the posts on this thread come from those much more experienced than I. However I’ve had a fair amount of exposure to older JBL’s , some small L19, some large, twin 15’s with a horn. Even though they show a reasonable Db output and sometimes state modest wattage, they LIKE POWER, BIG POWER ! I wish you lived close by as I have Rogue M-180’s Dark and a Hera pre. It would be interesting to mate them up. That being said and reading everyone’s opinion, My 2 cents is tubes 150 wpc or more. The Coda first then the Bryston 4cubed. If it was me i’d love to try those Atma-Sphere Class D monos mated to my Rogue Hera pre. In regards to that the Hera has a lot of gain, but it has 5 output settings. I’m running Tektons ( go ahead and shoot me 😆 ) , and they can run low power AND hi. So I’ve run a 50 wpc op amp for giggles and it’s great until it clips at 75-80 db. I have JBL 4312’s and 50 wpc Dynaco MK III’s will drive them to 85 db but the SQ is lacking. The First Watt would probably be nice for low level listening and the Pass would be pretty nice. Ask @hilde45 about his JBL’s he’d be spot on. So in closing maybe a pair of Class D’s and a First Watt or Pass to rotate. I live where it’s 100* today and I’m trying to scratch up $6K to call Ralph. Those Rogue M-180’s draw as much power as my pool and keep my living room warm in the winter. Bill at Rogue Audio paired the ST -100 Dark to the small Megapans , but I’m not sure they are powerful enough, you could call him. Damn I sure can ramble, Cheers , Mike B. | |||||||||||||||||||||||||||
I used to to own the 4367. They will play loud no matter what. The sensitivity has little meaning with them. The issue is what is needed to control the woofer, so it is as congruent as it can be with the midrange/tweeter. The woofer is the best part of the speaker, in my opinion. KT88 amps will not work well; I tried. The only amp I found to work was ML 532H. I am sure there are better amps, but ML makes for a good baseline for the 4367s to sound correct. Another 150 watt SS amp I tried was underpowered. | |||||||||||||||||||||||||||
You might consider an integrated amp from Rogers High Fidelity. I have similar high sensitivity speakers to those w/ big 15” woofers & horn loaded mids & tweeters (Volti Rivals) & his EHF 200 Mark II drives them superbly in a big room. The amp is hand made w/ point to point wiring w/ high quality parts & sounds excellent w/ lots of power (100 watts/ side in pure class A!). It’s is physically big & heavy & puts out some heat for sure & pricey but comes w/ a full lifetime warranty!! | |||||||||||||||||||||||||||
+1 on COD; but, their S5.5 model is probably a better match for your JBL speakers. There are 2 used ones currently listed on USAM, ranging from $4200 - $4,800. There is also one listed at The Music Room for $5,199* (retail is $6400). *FYI - The Music Room offers a "buy it - try option!" Best of luck in your search!! | |||||||||||||||||||||||||||
We can see that Chatbot gets things wrong. It listed our Class D, which employs a lot of feedback (about 37dB) so is not a 'zero feedback' design. I run a similar speaker (Classic Audio Loudspeaker T3.3) which also uses 15" woofers, bass reflex with a horn midrange. | |||||||||||||||||||||||||||
Being the heretic I am....Studio/stage speakers in the heritage, try a stage/studio amp or two....one can get both for what one would pay for one, used ’gently’ (maybe) to toe-dip into serious D-amps. | |||||||||||||||||||||||||||
Vinnie Rossi BRAMA Integrated Amplifier is Voltage gain adjustable! Mike Specifications______________________________________
(Vinnie Rossi reserves the right to change product features and/or specifications without notice to improve reliability, function, design, or otherwise) Travel CaseThe Brama Integrated Amplifier ships in an air-tight hard case with custom foam interior, 4-latches, rubberized handle and automatic air-pressure release valve. | |||||||||||||||||||||||||||
Usually one of the problems with efficient speakers is the gain in the amps, you have to much gain so the preamp has no room to work with. I had to "build " my own amps since the output from a modern dac or phonostage is very high so I would like to state that you shouldn't blame the amps of being to powerful ( you rarely have to much power) it's how you treat the throttle. Back on the subject I'm +32 or whatever on the first watt bandwagon 😁 | |||||||||||||||||||||||||||
Thanks for sharing the feedback you’ve received—there’s a solid mix of personal experience, enthusiasm, and varying levels of technical insight in the responses. Below is a critique of each post, offering perspective on what is valuable, what may need deeper examination, and how useful the suggestion is for your JBL 4367 application:
1. hbarrel — Class D Audio GAN Monoblocks
Summary: Recommends trying Class D Audio GAN monoblocks with a trial period. Reports initial improvement after 30 hours of play.
Critique:
2. ditusa — Vinnie Rossi
Summary: Brief mention of Vinnie Rossi as a potential choice.
Critique:
3. mattmiller — McIntosh MC275 or High-Power Solid State
Summary: Recommends the MC275 tube amp or going big with 400W+ solid-state monoblocks.
Critique:
4. stereo5 — McIntosh MC302 with GE Triton Refs
Summary: Shares personal success with a 300W McIntosh amp on 94 dB speakers.
Critique:
5. larrybemm — Audio Research GS150 with Vandersteen 5s
Summary: Enthusiastic endorsement of the GS150 driving Vandy 5s, paired with CAT SL1.
Critique:
6. cfarrow — ARC Ref 110 or 160, Levinson
Summary: Used Levinson amps with JBLs. Recommends ARC Ref 160 or 110 with Winged C 6550s.
Critique:
7. fthompson251 — Coda No. 8 or 16
Summary: Suggests the Coda No. 8 or 16 as under-the-radar high-quality amps.
Critique:
8. charles007100 — First Watt SIT-4/SIT-5
Summary: Likes his First Watt SIT-4 with JBLs; recommends SIT-5 if available.
Critique:
🔍Overall Takeaways
Would you like me to synthesize this into a refined shortlist or a side-by-side matrix including your past amps and how these compare in control, warmth, refinement, and synergy with the JBL 4367? | |||||||||||||||||||||||||||
From ChatGPT
You’ve got an insightful history with amplification and speaker pairing, and it’s clear you’ve put a lot of time into understanding synergy with JBL’s larger-format speakers like the 4367. Since you’re open to tube, solid-state, and Class D, here’s a curated shortlist of top-tier amp candidates across those categories that should be well-matched to the JBL 4367’s 94 dB sensitivity and impedance profile, with your room and listening setup in mind.
🔌Solid-State Amps (Class A / A/B)
Best for tight bass control and dynamic punch
🔋Class D Amps
Modern modules paired with well-designed front ends can sound extremely natural and dynamic.
🔥Tube Amps (Push/Pull)
Warmth, tone, and dynamics—but need the right power and control
💡Power Requirements for Tubes (Push/Pull)
The 4367’s 15” woofer and horn need damping and control, especially at low-to-mid frequencies. A SET amp, unless it’s something like a 211 or high-watt 300B with a powerful output transformer, will struggle. Push/pull KT88-class amps offer a sweet spot in dynamics and control for these JBLs.
🧠 Final Thoughts
If you’d like, I can build a table comparing sonic character, estimated price range, and match score for each of these amps to help guide your final decision. Would you like that? | |||||||||||||||||||||||||||
Nice speakers, I ran Levinson amplification when I had my Jbl’s and it was a great match. Power really opens them up and controls the bass nicely. You have many options and also consider ARC Ref 160’s or for less the Ref 110 is a great buy as well. I used one with NOS Winged C 6550’s and they it was a very musical amplifier with those installed. Good luck and enjoy those JBL’s1 | |||||||||||||||||||||||||||
I wouldnt hesitate to pair them with a 75wpc McIntosh MC275 tube amplifier. Also, you could go with a Clean 200wpc solid state amp. To tell you the truth these are super easy speakers to drive. You will find that the speaker will open up and be way more dynamic if you use a good solid state amp with double the power! You could go with a pair of 400+ watt mono blocks! Dont over think it just listen to at least three different ones.
Matt M | |||||||||||||||||||||||||||
Contact Class D Audio. They have a you have nothing to loose trial. Try the matched pair of GAN FET mono blocks? I was in the same boat whereas I needed some amps I could move around with ease. I have a new pair (14 pound ship weight) that arrived on Saturday. https://classdaudio.com/product-category/gan-monoblock-amps/ |