Class D for a Tube Lover

I am joyfully runnings my AGD Audions with an Atma-Sphere MP-1.
Dead silent and superb phono stage. Think it is, perhaps, the best full function preamp available. Of its 18 tubes, 8 are for the phono stage.

+1 for the PS Audio S300 combined with a tube pre. I ran an S300 with a Rogue RP-1 that was upgraded to Mullards. I just recently sold the S300 for a QUAD class A/B that runs a little bit warmer than the s300. Im not sure it sounds that much better than the S300 especially at x2 MSRP. If I ever switch back to class D which I may do I will surely consider the S700 mono blocks. You can pick up an S300 for about ~$1K and a Rogue RP-1 for about the same. , RP-1 runs mildly warm. I also like the Rogue Hybrid integrated suggestions.

note: Rp-1 over on usaudiomart for $1.1K and a S300 for $950. Killer combo for ~$2K

@audiodwebe Another way of dealing with heat is to install vents in the ceiling and use ductwork to move the air out of the house. This is often less expensive than air conditioning to install; its certainly less expensive to operate and also makes a lot less noise.

As audiophiles I think we overthink things sometimes.  At least I do.

I bought a window AC.

My pre is a Joule Electra la-150 mK2... (used) Cost about a thousand more than the S300. More body, better, much bigger Soundstage... More organic, real. 

Essentially, give you best of both worlds... 

This sounds perfect. 
Thanks @ml... for letting us know your thoughts and impressions. I understand your preamp is LA300me, should be very good. Looks like that you have spent about 8 times more in your preamp than in your power amp right? 

Compared to PS audio DAC, I guess your amp gives more soundstage, gain/power, is the sound also  more clean and transparent?  

@niodari.....Sorry for the delayed response re. The S300...Haven’t had the chance to try a SS with it.... But did run direct from my PS Audio DAC (has a volume control)... Much much better with the pre there.

However, been using the tube front end trick with solid state amps during the years...Essentially, give you best of both worlds... And generally is less costly and involves less tube maint.  Also a good solution for those with power hungry speakers.  Very powerful (quality) tube amps can get very expensive, heavy, and hot.

Hm. You need to hear better preamps! The way to limit distortion (and colorations) with tubes is not unlike how you would do it with transistors- go fully differential. This keeps the even ordered harmonics down (part of the 'tube' sound) allowing for far more transparency. If you have such a preamp it can work fine with the very transparent class D amps that are now available.

You made me to reconsider a tube pre option with class D. @ml...  did you also try a non-tube pre with Stellar S300?

@atmasphere, this is also a stimulating note for me since i was and remain to be a tube fun.   I still enjoy very much my tube integrated. Could you be a bit more specific on "marching the distortions" and what kind of a tube preamp could be of a "right type"?

Atmasphere.... agree 100% with your.    “You need to hear better preamps!”

FWIW,I have  a Joule Electra pre in front of my PS Audio S300 ... absolutely glorious.

The Audions are the first and only class D amps that for ME i can honestly say that class D is in the big boy class of amps.

I took the 15 day in home trial and they are staying. After being on the class D merry go round for over a decade and wasting time and money the Audions have checked all of the boxes of what a great amp should sound like.

The Audions look very futuristic to me, like they somehow made improvements to tubes electronics.  

I hope lots of people buy them, tire of them, and sell them at discounted prices until bottom dwellers like me can afford them.

I'd like to hear them at some point.

I have the AGD Audion, incredible amps!

Here's a review link to the AGD Audion top amp and pre-amp.  https://positive-feedback.com/reviews/hardware-reviews/agd-productions-gran-vivace-andante/
I'd like to hear them.   My best friend uses a Channel Islands Class D amp (what he could afford) mated to an EAR 324 tube pre-amp.   He is also a part time remastering engineer (worked with Kevin Gray for years) and finds the amp to be quite satisfying.  

$2k is not much , Underwood wally has still Wired4 sound integrated amps  for around $1500 that originally were  $2500 and pretty respectable forthe money . Class D I have seen at $30 K 
like Merrill audio  waay over priced !class D should be fair priced gan transistors are great new technology buy they are not That expensive.the markup is in their engineering . I am very happy with the Coda CSIB integrated vs any class D, or other class amplifiers.

Hearing my AGD amps via a DHT pre with 300B or 45 tubes is pretty special. Class D and set at it's best.

While class D may give a clear very low distortion sound, tubes would always add a notable (for me) distortion that ruins class D clean sound. I prefer to use either pure tube setting or pure SS setting as I enjoy both kinds of sounds. Mixing tubes with class D gives some extra warmth but also a notable distortion which, for me, they are not compatible.

Hm. You need to hear better preamps! The way to limit distortion (and colorations) with tubes is not unlike how you would do it with transistors- go fully differential. This keeps the even ordered harmonics down (part of the 'tube' sound) allowing for far more transparency. If you have such a preamp it can work fine with the very transparent class D amps that are now available.

While my experience with Class D is limited. I've owned some Bel Canto DACs and integrated amps. While really trying to love them due to small footprint, low power consumption, etc...
It just didn't do it for me. I went back to tubes.
The closest I've heard to a warm musical experience was Jeff Rowland class D amps. I didn't own them, it was in a stereo shop and the system and room was set up just right. However, after that the salesperson played the Quicksilver integrated amp through some Watt Puppies and my jaw hit the floor.

Here's an article regarding the Jeff Rowland and the author comes to the same conclusion that Class D is close, just not yet.

https://www.hifi-advice.com/blog/review/analog-reviews/amplifier-reviews/jeff-rowland-class-ab-and-c...

This has been a very interesting thread. I've learned about all manner of great class D manufacturers. Good stuff.

According to my personal experience, it makes not much sense to mix class D with tube preamplification. While class D may give a clear very low distortion sound, tubes would always add a notable (for me) distortion that ruins class D clean sound. I prefer to use either pure tube setting or pure SS setting as I enjoy both kinds of sounds. Mixing tubes with class D gives some extra warmth but also a notable distortion which, for me, they are not compatible. 

And one more vote of PS audio Stellar S300. I use it in my third system with PS audio Gain Cell pre. I use this system not very often. Each time I return to it, it sounds better. They took quite a while, far above 400 hours, to come to the sound of that quality, which is clean alive and presential, live recordings sound especially good, the base it tight, mid and high frequencies,  dynamics are fine, there is nothing to complain about, especially for the price.  The difference as they sounded at the beginning and now is just drastic and the sound is still getting better. My initial confusion was also caused by the DAC incorporated into the pre, which is not indeed good I use now an external one. It is a rear case when one gets completely satisfied with what he has. 

I'm quite surprised there's been no mention of Jeff Rowland amps. They don't suck. Maybe the sub$2k price target is a bit off-putting, however a pair of 201 mono's could be had for that, and honestly you should be able to get the 501's for that price. I will state that they need to be run with the 'PC1' or your own assembly (easy to do) of the Power Correction modules-they are actually DC power supplies and make a huge positive difference, however the amps can be enjoyed without them. What I can say (I run the 501 mono's with PC-1 supplies) is they are very smooth, no sense of harshness at all and hold their own against fine AB amps (I've never directly compared to Class A). JRDG uses Lundahl transformers in the circuit, and who-knows-what-else in modifying the ICEpowerASP1000 (the 201's use the ASP500?). I haven't priced JRDG integrated amps lately - maybe something is of interest. Everything I've heard of Jeff Rowland's has held to his 'house sound' quite well, and I'd suggest it shouldn't offend a tube-lover.

From my experience with ricevs' EVS1200, he knows what he's doing/talking about

linndrum8086 posts Try this https://6moons.com/audioreviews/acousticimagery/1.html
Not in business any longer. Their class D amps are great. I owned them. Used them with Wilsons sounded great. Also use VAC amps as well .
They sound just as warm

Near the bottom you can see a photo of "Bruno Putzeys with circular NC400 board tethered to SMPS600 supply".

Now that's a nice amp that's still available.

audiodwebe
You bought what you wanted and that is great.

Class D has made great advances in the last couple of years and GaN output devices has made the greatest impact.

If your looking for great sound vs good it will cost more money i know i have been on the class D merry go round for over a decade and i have finally found a class D amp worthy of sitting next to my class A and SET amps.

My advice is to enjoy what you just bought and save for a good GaN class D amp.

FYI,
The NewClear uses stock Icepower ASP1000 modules.  These are older technology (at least 15 years old).  The newer Icepower IceEdge 1200 modules are the newest and also better sounding.  This is what PS Audio is using in their 1200 monos ($6K for the pair).  However, you can buy a dual mono stereo amp from Rouge Audio Design in Italy (model: Studio N-10DM) delivered to the US for $1550.....They use these newer IceEdge modules too.  Have me do some mods to them and you have a serious amp for a little over $2K. 

https://en.rougeaudiodesign.com/studio-n-10

Legacy Audio sells these same stock IceEdge modules as a dual mono stereo amp for $4350.  $1550 looks a little more attractive to me.

 

Out of curiosity, and after reading some very favorable reviews, I purchased a NewClear NC1000L.  I was interested in seeing just how Class D sounds.  Bottom line, this is an incredible amplifier,  period.  Beautiful tonality, unbelievable dynamics, and if you’re  a soundstage freak, like me, a huge soundstage.  I’ll let you read the reviews, but IMO, this is a wonderful amplifier that I love, and I’m keeping it!  My highest recommendation!  Definitely check this one out.  Links below.
http://www.newclearaudio.com
 
https://www.tonepublications.com/review/the-newclear-nc1000/
 
https://theaudiophileman.com/newclear/
 
https://positive-feedback.com/Issue71/newclear_1000.htm

I have been using tubes for years in both triode and ultra linear modes. I recently bought two Starcrimson monoblock amps from Leo at Orchard Audio who designed and built these tiny gems. I gave up my beloved warm tube sound for sound as clear as glass. I though I would miss that warmth, but I quickly came to love the utter transparency. 

The AGD Audions aren’t cheap but they’re worth every penny. The sound is stellar clean, transparent and tube-like zero fatigue. I thought I’d just dip in class D to see where we’re at so to speak. I was pleasantly(understatement) surprised.

Thanks, everyone, for the continued suggestions and information on the various amps.

Around what year, in your opinions, did Class D amps come into their own?  

On a side note, I suck!  Here I am getting all this info and I went ahead and ordered the BoyuuRang A50 Mk III because I'm curious about an amp with 300b output tubes.  I have amps that use the 300b as drivers and other tubes as outputs.

Damn Steve Guttenberg!

Sorry, everyone.  Please don't flog me, as I am still in the market for a Class D amp for the summer months.

@audioguy85
"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."

Not over blown for those who run larger high-bias / big transformer full Class-A amplifiers in the summer. Worse with monos or smaller rooms. It can absolutely impact room heat. Many high bias Class-A amp owners have secondary amps to rotate in over summer months.

Hence, all the recent interest in evolving Class-D designs again, even if it’s just "tolerable" to listen to. Glad to read Ralph @Atmosphere is working on this. Put me on the beta-tester list, tube amp guy builds Class-D, yes! 

Thanks for the update on the d-sonic.  Sounds like it is a player.  

I decided to sell my KRELL K-300i integrated today so that freed up the long speaker cables I need to test out my new Class D stereo amp.

https://www.d-sonic.com/product/m3a-800s-stereo-amplifier/

It is now connected to my difficult to drive Thiel CS3.7 floor stander. I first tried my new Gustard X26 Pro (an incredible DAC) into my Benchmark HPA4 preamp and then to the D-Sonic amp. It was more powerful, detailed and a touch warmer than my regular Benchmark AHB2 monos (my reference). However, there was a little edge to the sound that I noticed that is not there in the all Benchmark stack.

I then removed the preamp and went direct to the D-Sonic amp. That edge or hardness was reduced, almost eliminated. I always prefer the volume control on the HPA4 preamp but the Gustard DAC was not bad as a preamp. The D-Sonic benefited with HPA4 removed removed. The Benchmark and D-Sonic do not seem to mix well.

So I now have a $1500 amp with a $1500 DAC and the sound is almost as good as the $9000 of Benchmark gear + $1500 for Gustard  I had before. I think the D-Sonic amp is better served on the Thiel’s than the AHB2 which are not officially rated for 2 Ohm speakers in mono.

I have a SET based preamp coming next week (I hope) that should be great with the D-Sonic. Anyways, this amp has given me confidence to move my great Benchmark stack to my living room system with a speaker that maybe is a better match for the AHB2 specs.

As I mentioned in a prior post the D-Sonic was bought to be used with RAAL SR1a headphones which needs a warm amp to tame that beast. It did do that and now I tested it on the floor stander which was also a winner.

I have always admired the Cary 805. I would put the money into NOS or quality new stock tubes. The sound of the 805 is definitely warmish and musical. In many ways it is the opposite of a Class D amp. If you like the 805 sound, don’t loose it. Especially changing to a Class D for $2K or less. You are almost guaranteed to go down in SQ.

Why not try the VTV 1ET400A Amplifier with VTV Vacuum Tube Buffer. Granted it’s between $2,229.00 – $2,279.00 new, but you do tend to get what you pay for...

IME class d does not like difficult loads. If you have semi efficient speakers with a fairly benign impedance curve will sound good especially with a tube preamp. 
I had the Lyngdorf integrated and it was an amazing product....... for certain speakers. Ran out of gas on some Dynaudio C20s I had and just sounded soso on some Focals. On some Tektons it was a match made in heaven. I think the amplification section was nothing special but the room correction was fantastic. 

I’m currently looking for a preamp with room correction to pair with my Parasound A21. 

I would also concur with SPEC amps.  As Bjeisen said they are not cheap.  Also they like a higher impedance load.  I would not describe them as tubey but they do sound richly toned with higher impedance speakers like Zu Omen and DeVore O93.

Why not check out the VTV Purifi Amplifier with custom input buffer. Select the Opamp or Tube input of your choice. Check out my Youtube channel DIY HiFi Life for details.

https://youtube.com/playlist?list=PL3kctOR1C3QqHG0IjdHi9_mQlY5XGmuJl

Keep telling yourselves it’s amazing. 

    Class D is so far below the sparkle and relaxing tube sound. 
   It’s a Yugo  against a bmw M5.    There is no comparison!

ATI makes nice sounding solid amps that last forever. 

The small and mighty AGD AUDION GaN monoblocks. They changed the way I look at class D. I could write at length about them but as a class A/SET lover, I hold them on the same hollowed ground. Never thought I’d be expressing that sentiment about class D...These are keepers. 

Hi my friend! Don't by a used Class D amp. They are all made before the newest and best generation of Class D amps were developed. You can buy new for under $1400. If you catch a "sale" price, even less. The big deal is that Class D amps have finally come to fulfill the promise of the concept. The new generation are really a lot more like AM radio transmitters than a conventional audio amps. Once some fellows who understood UHF and radar gear turned their attention to audio, amazing things began to happen. Purifi Audio (Denmark) now produces an output module that is wining acclaim in other people's products. Starke Sound (USA) offers a complete, ready to go, four channel amp (perfect for two way speakers used with electronic crossovers) that is not tiny and cute, no chrome, no sculptured casework, uses a conventional power supply, is big and heavy, and sings like a bird. To me, the Purifi and the Starke sound nearly identical, and as good or better than anything I ever heard. If anything, the Starke may be very slightly sweeter on the top end. Very.

To paraphrase Meredith Wilson, either amp will, "Grab your woofers, grab your tweeters, in the arms of a dominating irresistible grip and deliver the clearest, cleanest music you have heard in your home." I admit that's a pretty outrageous paraphrase, but it gets the point across, without resorting to "techie" talk. It is the music we want to hear, isn't it?

What amazes me the most is how whatever speaker I drive with either amp, they sound very similar. I have about 12 sets of speakers in the house to play with (and a very tolerant wife), DIY and commercial (Shahanian, Wharfdale, Golden Ear, Spika, a couple more, bookshelfs & floorstanders, There is not a wide difference in "flavor" between them. The amps CONTROL the speaker. These amps are switching tiny bits of 100+ volt "juice" into the voice coils. No speaker can fail to respond to that! And the amps, through the use of large amounts of feedback (the Purifi module has only 13 db of gain), can detect and correct any errors the speaker makes almost instantaneously. The result is extremely low noise, extremely low distortion sound from whatever speakers you are using. Of course, quality matters; but these new Class D designs will get the most from any speaker connected to them. Read the reviews. Best of all, the Starke AD4.320 (four channels, bridgeable at the flip of a switch, phono & balanced inputs, sells for under $1400, brand new, delivered to your home. It's worth a try. The NAD M33 is about $5000.Easy choice? I am interested in the best sound for the money. Ah well, that’s all for now. Happy Listening.

I do not have a great frame of reference for this but I added my new D-Sonic amp to my RAAL SR1a headphone system yesterday. The system is composed of the following gear, AudioMirror Tubadour III SE tube DAC | Benchmark HPA4 preamp | D-Sonic m3a-800s.

https://www.d-sonic.com/product/m3a-800s-stereo-amplifier/

I do not plan on using the D-Sonic on my floor standers since I do not have speaker wire that is long enough for a stereo amp (need monos).

However, with the SR1a, which is something that needs taming on the top end. The D-Sonic performed way better than my reference Benchmark AHB2 amp with the SR1a. If 100/100 means 0 fatigue, the AHB2 had 50/100 in the fatigue factor with the gear mentioned above, the D-Sonic was about 90/100. I am very impressed by this amp.

The D-Sonic is definitely a little warmer than the AHB2 which is what I wanted. The power and detail retrieval were exemplary, especially the power provided to the SR1a. On some albums with prominent percussion I thought the sound was more powerful than I have ever heard before on these albums (Signals and Distant Early Warning by RUSH)

For the SR1a system, I will be replacing the HPA4 with the warmer yet CODA 07x preamp and I think that will be the winning combo. The Benchmark gear stays with the floor stander, no fatigue with that speaker and the Benchmark.

I will be another to recommend the obvious: tubed input stage, Class D output. Rogue and PS Audio do it, and I’m sure some others in what seems to be a growing trend. Or a Class A input, Class D output as an option. Just FYI, I bought the Musical Fidelity amp mentioned earlier and found it brighter than the Class D Teac A-H01 it was supposed to replace (tho the MF had very energetic sound, a nice amp). Just remember that your ears and preferences are yours alone, so maybe get some ideas from others and find the one that suits you. 

Following up on my new(used) NAD M32. So far, it betters my last DAC/amp combo, the PS Audio DSD DAC + M700 monos. It does so many things right (insert a long string of audiophile descriptors here) and very few things wrong - in fact, nothing to my ears, yet. It is not *warm* but I agree with JA in Stereophile, "[...]what emerged as a consistent signature was a clean, clear quality of sound that stepped out of the music’s way[...]" and "Highly recommended." Purchased for $2450 used, and SafeandSound (a NAD authorized dealer) sometimes has refurbished ones available.

I love my Lyngdorf what was chosen in side-by-side comparisons against both LTA tube amps and a couple of class A and AB amps. I couldn't believe it was the best of the lot, but it absolutely was. I have the TDAI-2170. And another advantage is, you don't need an external DAC so you can save a ton of money on that front too. My analog inputs to it include a Feickert turntable with a whestTWO.2 preamp feed to the analog inputs of the 2170. The analog inputs do not sound "digital" at all. Closest thing I've found that acts like a wire with gain. Seems to add or subtract noting from anything you feed it.

Ditch the amps you have and just get a PS Audio Sprout100 or a vintage Fisher 500-C with the budget you’ve got.  Will blow away any preamp you can get for your current amps.  

Don't give up on tube amps.  Two that come to mind that have a control circuit that allows the tubes to run low temps are Carver Crimson 275 and Linear Tube Audio.  If you're hooked on the tube sound class D may not satisfy you, but try Digital Amplifier Company (DAC) and their lineup.

A sincere 2nd vote for the NAD M22 Class D Amp. I have Class A SS, Tube A/B and the NAD Class D and I find compelling reasons to like them all equally well. The NAD does put off some heat, not sure what amp doesn't honestly. Good luck and if possible, demo before making a final decision. I've been amazed at what a blind listening test will unveil in a familiar room.

"I run a PS Audio Stellar S300 with a tube pre and find the combination excellent."

Me too, just the same set-up. It's the best sound I've ever enjoyed, so much so that I feel no inclination to leap for the M700 monoblocks. There is something very right about this S300.
I also run vintage Quad II tube amps and the S300 gets much more listening time. It runs cool and is built beautifully.