Class D for a Tube Lover

First, I'm sure this has been asked many times but searching the subject wasn't too helpful to me.

So apologies in advance.

I enjoy tubed electronics and class A amps, which tend to be a bit warm.  My current Cary 805s warm my small (12x16) music room even in the cool/cold of winter.  I've got other amps that don't produce much heat, but am looking for something that produces no heat.  Living in a home with no central AC the room gets uncomfortably hot during the summer months.

So...I'd like to try some Class D amps.  Stereo or mono is just fine.  And my speakers aren't difficult to drive so I don't need a thousand watts.  But if that thousand watt amp sounds great, I'm not adverse to that, either.

I'd like to keep the price under 2k used.  

Please help.


I've been very surprised how good my Class D Audio amps sound. I now use them for center and surround duties, along with a custom tube 3C24 amp built for me by Paul Birkeland of Bottlehead, for my main drivers, custom-built Tannoy HPDs.

They can be had rather inexpensively as kits, if you enjoy DIY. They would give you an idea what to expect with Class D.

I hope you find what works best for you, regards,
If you can wait, Ralph Karsten is close to completing his Class D amps.
If he can build tube amps that sound great, I have no doubts his Class D amps will be just as good.
I own a Pass Labs Aleph 30 (30 watts, Class A) that is exceptional. And, it’s also an exceptional space heater. On a whim I recently purchased a PS Audio Stellar S300 amplifier for the sole purpose of trying Class D amplification. After about 100 hours of use I can say that the amplifier generates little to no heat and so far I’m feeling like I gave up little from a performance perspective. Insert all of the audio descriptors here…

In addition, not that it is necessarily a priority (for you), but PS Audio has a generous trade-in program and the direct purchase process was excellent. Zero affiliation, just passing on a very positive experience.

Class D sounds good but is good good enough? If your a critical listener most of what is out there is not going to make you happy. Paul of PS Audio has several videos about class D and he said more than once that he likes the sound of his AB amps over his class D amps, use this to give you an idea of what you might experience.

I have heard class D that is outstanding but it is not in your budget.

My best advice is do not buy until you hear.
I use both. Valves in the cooler months with class ds doing bass duty. Then in the summer I change to a LOT cooler running class ds for the monitors. I use a Cary V12r and Mac C2500 for a front end with tone control.. With tone control, you'll get what you want, without it.. I'd doubt it..

I use Nord NC500 with Sparco 2590s OpAmps and rev d buffers.
Purifi is all the rage, To tell the truth, My NC500 are pretty tough to beat..
I'd like to give Nords ET400A a run with Nord buffers though.. The 9 NC500 modules I have, I've NEVER had a problem.. Sound wise.. pretty friggin good, for the 4 months a year I use them.. BUT they are not valve amps.. They don't sound like valve amps either..

Lot of Mac and a few Cary's in my gear chain..

Thank you, everyone.

I’ve not heard of Ralph Karsten or Nord but will look them up. Will also check out the PS Audio amp. I’ve got a few PS Audio products and like them very much.  
I have Nuforce Reference 9 V3 SE mono amps w/ TDSS level 3 upgrades.  The Ref 9's I bought used for $1400 for the pair about 5 years ago.  Liked them so much I had TDSS do it's upgrades which made very good amps a into super amps and more stable.  They have bettered very expensive amps in every system I've compared them to at friends houses or at a dealers.  Obviously the standard Ref 9's are well within your budget and if you wanted to at a later time, you could go the route I did.

Look into the XTONEBOX Silver 6011.  Made in Spain, small operation.  I just got one.  Lots of mid detail.  Pretty good for $800 IMO.  Tube pre-stage.  60wpc I believe into 4 ohm?  Small footprint with decent Bluetooth and phono stage.
Ralph Karsten is the owner and designer of Atmosphere OTL tube amplifiers as well as a frequent poster on this site.  
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You’ll have to spend way more on Class Ds to get the results you’re hoping for. I have an idea of what you’re seeking but unfortunately you won’t attain it without a high-end Class D. 
Having owned both, I would say the PS Audio M700 monoblock's are a big step up from the S300 and are pretty darn good (esp. for the money). Tube-like is sometimes said about them, but I wouldn't go quite that far. But I would say that they are quite listenable, even for someone (like myself) who is repelled by the thin and edgy sort of sound some folks associate with Class D amplification.  

A pair can be had for 2K used plus or minus a couple of hundred.  You can also get a pair new with warranty from PS Audio for $2100 if you have something to trade in that originally cost $900 or more.  (The key to making maximum use of PS Audio's trade in program is to find something to trade in that isn't worth much on the used market any more but that had an original MSRP near or above their maximum trade in allowance -- $900 for a pair of M700's.  It seems unnecessarily complicated  --why not just a discount? -- but it's worked well for me several times). 
Amps with ICEpower modules.  They tend to be very warm sounding, almost syrupy. If you like the way the Parasound A line sounds, you'll probably like these components a lot.
I’ve had two icepower amps and would not  call them either warm or syrupy. 
e j sarmento’s class d icepower module amps under the wyred 4 sound brand, st series, are definitely voiced smooth warm and full sounding, yet with excellent impact and good clarity

they are also a great value for $... they can be found occasionally used on this and the other used gear trading site
I have not head any Class D amp so far in my own experience sound warm or syrupy - I would consider that sound from tube McIntosh as warm and syrupy but that is my opinion and my own personal experience.

If I was looking for a Class D amp I would contact Tommy O'Brien with Cherry Amps and get something he offers with a trial period.  I just heard the tiny mono blocks he manufacturers (125wpc) on Klipschorns (highly modified) speakers and they were open, with nice details and sweet sounding.  No they did not sound like the 1 watt 45 tube amp or the pure Class A 30wpc mono blocks but not bad overall.  Very listenable.

Happy Listening.

I saw another thread about the AGD Audion.  

How'd they get all that stuff inside a tube?  It's like those ships in a bottle.  Black magic, I say.

Intrigued.  Saw price.  Intrigued no more.

Class D amps have lots of terminology associated with them that I haven't heard before.  It's like being new to audio after 40 years.  Kind of cool.

Thanks for all your suggestions.  I really do appreciate it.
I also wanted to try some warmish Class D amps. So I was led to try this one. It was shipped on Saturday and I will try it on a 30 day trial.

Stereo | D Sonic (

Do keep me (us) informed.


tcatch:  What made the M700 better than the S300 in your view?
I have a Bel Canto e1X amp and have found it to be incredibly clear, detailed, and smooth.
I'm using a pair of Belcanto M300 as summer amp in replacement of my Audio Research Reference 110. The sound of these little cold boxes is surprising when a good tube preamp is driving them (ARC LS5 MKI with some mods in my case).
I own a Nord Ice Power 1200as2 based amp and I have no complaints.  I want to upgrade my bedroom system and I'm going with Purifi this time around. I'm looking at an Apollon Audio Purifi 1ET400A MINI Stereo Amp because I love the design.  I'm also considering VTV's Purifi offering because I "love" the price!   I can recommend Nord Acoustics products and service.
I just purchased a pair of Purifi based monos, don’t have them yet. I just want to experiment with them. But, it seems these are the latest greatest when it comes to class d amp modules. Look for them. It seems PS Audio is a bit high on the price side for what you get... There are several brands. I bought mine from March Audio out of Aus. Alan, the owner, will go over your entire system to put you in the best overall amp choice.
Classe Audio Sigma Amp2 (200x2) would fill the bill and a mint used one comes in under your budget. 
I have a used NAD M32 on order that should be here mid/late next week. I've read good things about NAD's newer class D amps and will try and remember to post my thoughts here. I can also vouch for the PS Audio M700s. I would describe them as balanced and neutral (in a good way) more than warm and syrupy (to continue using the term, lol). However, they are fairly smooth, grain-free, and lacking edge. I would have to agree with the comments that 1) you probably won't get "warm" with a class D (at least under 2k?) - at best you'll get smooth, and 2) it would probably be best to add warmth with a tube pre. Happy hunting!
OK AudioDwebe, Id first ask what speakers will you use , What genre/ how do you listen, and is there one point or characteristic about the Cary 805 you have that you would not like to lose ? We are talking about coming from a 50W Class A Single Ended Triode Vacuum tube monoblock amp to a very different Transistor based Class D amp. Im rather confident a $2K Class D will not run with this big Dog, though it possibly may depending on what’s important to you. . The deciding factor will be what you are after ultimately. There is one class D that I know of that will be able to recreate and surpass all that your 50W Class A SET can, yet have much lower distortion and have quicker transients. plus be like one tenth the weight and have no heat. I am however committed to no compromise quality combined with good value. Therefore my solutions are not stopgap. I offer solutions that fix it for good. No looking back. but there is no way for me to help without a little more information please. Anything Ice module will behave close to the same way and my experience with 250 ASX2 says nothing syrupy or even close to dark. Its a very good module. Whomever designs the input stage makes or breaks this design.
Please let me know what speakers you will be using and what about the Cary do you not wish to give up ?
Try a Rogue Sphinx. Class D paired with a tube pre-amp section. Fits your budget nicely and sound real fine. I owned 2 and really liked them. Very basic analog amps that are made in the USA with a great reputation.
Look for an Audio Research DS225 or DS450. If anyone should know how to make Class D sound close to tunes it'll be them. It's not modules put in a different box, it's their own design.
Check this out  Purifi amp mods (

I own his EVS 1200 after having owned the PS Audio M700s, which I quite liked, but the EVS provided almost 3Xs the power with tweaks no manufacturer is likely to implement 

FYI, class D takes 100-1200 hours to break in. Buying used is actually a plus

There is no class d amp that will sound like a class A or tubed amp, sorry. The heat thing with class A is over blown in my opinion. Yes, they generate some heat, but not near enough to impact your comfort in the summer time. No way would I give up my class A Sugden, especially for a cold and lifeless class d. However, if you must, the Rogue Sphinx v3 would be the way to go, as it also has tubes. 
Not class D, but I bought a Musical Fidelity M3si class AB integrated for hot weather duties. Sounds wonderful and is the coolest running AB amp I've ever used, nearly no heat. I tried a Rogue Sphinx V2, but sent it back, It sounded ok, except for the hiss that I could hear across the room. (98dB sensitivity speakers)
I run a PS Audio Stellar S300 with a tube pre and find the combination excellent. In addition, the build quality is superb. I'm told that their M1200 mono blocks are tremendous performers but are 2x the price. I believe those amps have a tube on the input stage and Class D on the output stage. Reviews have been excellent, though I have not heard them. 

Modern high quality Class D designs are on par (dollar for dollar) with the equivalent Class AB design. They have come a long way and many people still deriding Class D need to get with the times.

Just my $.02
I would second the Classe Sigma Amp-2, they sound beautiful, but if you have low impedance speakers - ones that dip down to 1 to 2 ohms - I do not think it will have the bass control that some people are looking for.  After trying many amps, I went with AB Rowlands.  I moved the Classe to home theater to drive Klipsch - does a wonderful job there - smooth, warm.  I have a friend that has the Belcanto amp, says it was $5000 and hates it, not sure which one - he has it driving a set of outside speakers now.  My preference is tube on the front end, SS on the back.
I'd like to suggest you give one of the Digital Amplifier Company Cherry Amps a try.  They don't use a class d module purchased from a 3rd party, instead they have their own class d circuitry.  There are several versions, all with similar voicing and a few that are near or under the $2k mark...and the company often has specials.

I own the 2Cherry and would characterize it as having some of the better characteristics of tube+solid state.  There are a number of professional reviews...but maybe what the actual owner say might mean more.  Here are a couple of links that might be helpful.

UPDATED: 🍒 Maraschino, x-CHerry, and MEGAschino REVIEWS (

Digital Amplifier Company 2-CHerry Power Amplifier The light amp that packs a heavy punch! Review By Frank Garofalo (

Cherry Amp HOME PAGE | cherryamp

Tommy O’Brien Digital Amplifier Company (
I've enjoyed the sound out of the NAD C286.  80 Watts per channel or you can run two of them in bridged mode at 300 Watts per channel. I've bought one and plan to add a second [for bridged mode] when the time is right. $899 each [new] and some retailers offer 60 day money back guarantee [so you can try it out]. Very clean noise free sound.
Buy an air conditioner! Or a fan sitting on a block of ice. Class d is like pushing needles in your ears after 1/2hour of listening. Yes they are popular for HT but brutal for two channel. I am not going to beat the dead horse on people having only one system for HT and music. It can’t be done!
Get a Class D with a tube input stage.  I would look seriously at a used Rogue Hydra.  You should be able to find it used for $1500 to $1800.  Then roll in a pair of NOS Cifte or Mullard long plates and be shocked at how much it sounds like a tube amp.  There are more expensive options from AVM and others but the Hydra is a tremendous value and fits your budget.  I have owned one for six years and it is an amp I will probably never sell.  It won't be exactly the same but is a reasonable facsimile. 

I am a dealer but have no affiliation with Rogue Audio.  Just a happy owner.   
Ignore ALL recommendations. The only way to tell is in your system in your room with your music.

There are far too many technical issues to list, but anyone who claims Class D can sound like tubes does not have a very revealing system.

I have Class D & tubes.
Don't ignore all recommendations....BUT realize that we all have our own sense of what sounds "right".  Instead, recognize that everything that has been listed above has a fan and therefore MIGHT meet your needs...but as you know and has been said, the only way to know is to try.  And the good thing is that most of these companies have either trial periods, demo models or both.
I am driving a pair of Vandersteen Treo’s with a PS Audio Stellar S300 Power Amp and am very satisfied with the performance. Class D output stage and Class A input stage. I needed a smaller amp and it has plenty of power, sounds great, and no heat. others have mentioned that PS Audio has two higher levels of Class D amps the 700 and 1200 and the 1200 has a vacuum tube input stage. I also have a PS Preamplifier and am very happy with that also.
I have owned a Rogue Sphinx v3. It was a nice sounding amp, but a little bright for me. However, it was nowhere near the sound of either my McIntosh nor Raven amps which were both just as smooth and revealing without being bright.
The stock JJs that Rogue ships with leave something to be desired.  If you put a good set of NOS tubes in, all Rogue class Ds get much better. Expect to pay $250 for a good set. 

I have had my Hydra with NOS Ciftes side-by-side with VTL MB-185s, Art Audio Quartets and Art Audio Opus 4s and again it is not the same, but it is not bad.  It is far more satisfying than other SS amps I have had through here during the same period. 

In the end, only the OP can be the judge.  But I will say that getting a Class D with tube input stage will be closer than a straight Class D is going to be.  I don't think that is at all a stretch.