Tube Pre/ Class D Amp - Who has done it?

I’ve had terrible luck trying to get anything resembling music when pairing Class D amps to my tube preamp. I tried the PS Audio M700 monoblocks and the Orchard Audio Starkrimson Ultra. The M700 monoblocks sounded so dry and brittle I literally felt repulsed after listening to it, I couldn’t sell that thing fast enough. The Starkrimson was a definite step up in clarity...but was not to my taste. Admittedly I prefer the sound of tubes as I like bit of coloration. I dont like dark, dry or neutral sounding gear. But I haven’t given up. Excited to try Atma-Sphere Class D amps and the AGD Audio MKIII. I have a feeling they might change my mind.

@alexbpm

Interesting observation. What is your preamp and other components? Otherwise it is hard to put your comments in context. Thanks. 

@alexbpm

I dunno, it sounds like you never had a good Class D experience, which is your own experience but it doesn’t necessarily say anything about Tube pre amps with them.

Was there a solid state preamp you found worked really well?

For several years, I've enjoyed a PS Audio BHK preamp (which uses tubes in the input stage) along with a pair of M700 monoblocks. They were driving Thiel CS2.2 speakers, and they sounded great. Before I used the BHK pre, though, I had to be careful with the Thiels sounding a little too bright on certain recordings or with hyper-detailed cables.

A couple of months ago, I decided to try a different Class D amp, specifically the Atma-Sphere Class D GaNFET monoblocks. I've been really impressed with the transparency and mid/high frequency smoothness of the A-S amps, which has been achieved without exaggerating sibilance or harshness. The soundstage width and depth has been amazing, with great layering and separation of instruments and singers. The A-S monos also provide solid, impactful bass, although break-in on the lower frequencies has been a bit slower than for the upper frequencies.

I've found that that gain for the A-S monoblocks has been a bit lower than the gain of the M700s, but this has not been a problem and I'm now able to use a wider range of volume settings on the BHK preamp. Fortunately, the A-S amps are extremely quiet even at higher volume settings.

An even more recent change in my system has been a change from the Thiel 2.2s to the PS Audio Aspen FR10 speakers. The FR10s and the A-S monoblocks are sounding great together. The level of transparency without harshness is amazing, which speaks to the synergy between the FR10's planar magnetic tweeter and midrange combined with the speed, low distortion, and finesse of the A-S GaNFETs. Recordings are sounding very real and engaging. And my new A-S/BHK/FR10 combination can "rock out" at fairly high sound levels when needed. 

I quite like my PS Audio M1200 mono amps and preferred them to my PSA BHK250. It synergistically plays well with my DeHavilland UltraVerve and ModWright LS36.5 preamps. It also sounded great with the departed PS Audio BHK preamp. Sounds excellent with the solid state Luxman M700 as well. The ability to  change the M1200's input tube helps fine tune the pairing with each preamp. Plus, as I get older, I really appreciate only having to lift amps weighing 30 lbs. instead of 75 lbs.!

Hot-rodded VTA SP-14, with Bel Canto REF600M class D monoblocks into Proac D30rs

What a great question.   Sometimes this works, it's not always so easy.  I had a rogue tube pre going into 2 mono blocks from Auralic and it was very good, but lacked a bit of detail.  Soundstage was huge and imaging very good as well.  When I swapped in a solid state amp from ML when they were called Proceed, the sound was surgical in its precision, but lost some warmth and bloom.  

definitely worth experimenting, but IMO you can get superb sound with a SS pre and do not necessarily need a tube pre. 

I had an AR 150M (class D) with an AR LS26 (tube) running electrostatics and it sounded sublime.

I had a Modwright tube preamp with a Bel Canto class D amp----lots of power but I kept getting some noise out of the preamp. Traded them in for a Luxman integrated. 

I started with Rouge 7 and Bel Cantos m600’s.  The sounds stage was poor, midrange was very laid back.  Overall not very good.  I decided the Bel Cantos were not my cup of tea.  So I replaced them with AGD Audions and everything got better except the sound stage still sounded small and not tube like.  So I replaced the Rogue with a Cary SLP 05 ultimate NOS Tubes and now I couldn’t be happier.  

@ghdprentice I've gone through most permutations of Pass Labs amps, Coda amps, and Audio Note integrated amps (SOTO SE and Cobra being my favorite). Current reference is an LTA Microzotl Level 2 preamp as a reference McGary SA1E tube amp.  Before that I had a Supratek Cabernet.  

I use Class D Audio amps in my secondary theater system and even listen to music on them on occasion.  I preferred them over the PS Audio M700 which as I stated earlier I greatly disliked.  I've had the opportunity to demo the AGD Audion MKIII at Axpona over the course of a couple days and I loved them, but I need to try it in my space first.

ADG Duets fronted by a Ayon Audio CD-35 pre/CD player and I love this combo! Speakers are DeVore Super Nines.

I tried a D-Sonic amp with a Modwright 36.5 preamp.  It was a nice amp, crystal clear, excellent for home theater or background music, but sort of lifeless with 2 ch audio.  If you're not familiar with it, the Modwright is a  fine preamp (imo), but not particularly "tubey".  

Admittedly, I have been a tube guy for a long time.  Maybe it was asking too much - I mean, I gave up on solid state amps because to me, there is no doubt that tube amplification sound more like real music -  but it sure would be nice if cl. D were "good enough".  It soured me on class D, for now, but I haven't tried any of the newer GAN versions.  

For Class D I prefer GaN FET. We evaluated and worked with several Class D amps in the past while designing our preamps but being a tube guy, we found GaN FET designs not only sound exceptional, but with their higher input impedance, they mate much better with tube preamplifiers than previous designs.  With other Class D modules, they were either too warm with no sparkle or they were sterile sounding and only good for bass modules  

Personally , I prefer the combination of a DHT preamp and a Hybrid DHT/Gan FET amplifier. 
 

but with their higher input impedance, they mate much better with tube preamplifiers than previous designs.

The seemingly consistent feature among previous generations of Class D amps has been relatively low input impedance. 

In some cases I believe this is to allow for the OEM to produce their own high impedance input stage.  If you make pr eamps, maybe worth taking a gander at incorporating your own front-end. :) @response34 

In some cases I believe this is to allow for the OEM to produce their own high impedance input stage.  If you make pr eamps, maybe worth taking a gander at incorporating your own front-end. :) 
 

Thats what we have done with our Hybrids. 

That’s what we have done with our Hybrid amplifiers. One uses a DHT input stage. I didn’t want to go to far into that as didn’t want the post to look like a promo. 

@erik_squires 

The seemingly consistent feature among previous generations of Class D amps has been relatively low input impedance. 

FWIW the input impedance of our class D amps is 100K single-ended or balanced. Anything can drive them.

So - I’ve been (re)assembling my cabin system. It now consists of the Atmasphere MP-1 mk 3.3 preamp (tube) and Atmasphere Class D monos and I’m pleased to say it’s a very good combination. It’s different than my primary system which is solid state preamp going into a class A/B amp but they’re both very satisfying even though they bring different things to the table. 

I’ve had class D amps before (PS Audio Stellar S300, NAD M22, NAD M33) but they all failed to fully satisfy. They weren’t bad, but they also weren’t that great and I’ve since sold them. The Atmasphere Class Ds are notably more musical and a terrific value. I will say they’re not quite as good as my Class A/B amp to which i directly compared them. But they were also a LOT less expensive. 

So, my recent experience is a tube preamp/class D combo is a nice pairing.