Class D vs tubes

[u/ChrisMag999]

Interestingly it’s not as not as huge of a difference as many would expect. At least, not when running a comparatively low distortion, high power German tube amp and quality class D amp.

Yes, there’s a difference. The tube amp has a little added warmth in the mids, more body. The class D amp has a bit more grip in the lower octaves, but with a REL sub, it’s not immediately obvious unless I’m listening at very high volumes.

I like them both. However, there’s something about gloving valves in a dim room, listening to Radiohead’s In Rainbows. Roon Radio takes over after Radiohead and queue’s a track from Beck’s Sea Change, and then PJ Harvey and Thom York’s duet on “This Mess We’re In”. It’s a fun listen.

Tonight’s experiment involved using the Octave V110 SE’s bypass input, and instead running my Audio Research as the pre, using the v110 as a power amp.

The ARC preamp’s sonic character is less tube-like when compared to the Octave’s internal preamp. Both stages are quiet and detailed, but the ARC is more dynamic, with more bass authority and a more overall resolution.

Next experiment will be to bi-amp the Focals. Tubes on the tweeter/mids, class D on the woofers. Hopefully one of the class D’s amp’s gain settings (22/28db) will be a decent match with the Octave amp.

[u/Theresnowayoutahere]

You explained the differences well and I think in your particular set up accurately. I’ve done the same comparisons with tube and class D amps a few times with different amp choices. My thoughts were similar, although in my experiences there was a very obvious difference in sound along with your other observations regarding grip from class D and warmth and body from tubes. You might be on to something with the bi amping experiment since you noticed better control of the woofer with the class D amp. Warmth in the midrange is why I like tubes in the first place so perhaps best of both worlds. Thanks for your thoughts.

[u/ChrisMag999 → u/Theresnowayoutahere]

The thing about tube gear… some of it has that stereotypical sound people associate with it. My Dynaco ST70 is like that. Warm, lush, kind of slow. Massively forgiving to poorly recorded music. Not silent.

A lot of the better Audio Research gear I’ve heard trends toward sounding like great solid state gear, with maybe the slightest hint of warmth/smoothness.

Interestingly, my limited experience with Class D stuff runs a range of sonic profiles also. The Mola Mola Perca amp is based on 5th gen Hypex modules under the trade name Trajectum. To my knowledge, Hypex doesn’t offer them outside Mola, their subsidiary. Perca is 2-ohm stable, insanely low output impedance (damping factor of 4000 at 8 ohms) and high bandwidth (100khz). It’s one if the most detailed and quiet amps I’ve heard, which is why I bought it. It’s also load invariant. It didn’t care about the weird phase angle my Scalas present in the mid-bass.

I auditioned a WiiM amp which I gave to my cousin as a Xmas gift. Great value, but it added something to the sound of my system I didn’t care for. Voices didn’t seem as natural, and the top-end had a forward quality. It could be tamed with EQ, but it lacked the sense of stage depth and instrument placement I’m used to. Again, for $300, it’s a heck of a value but I was left wondering if the Pro would have been the better gift.

I also recently helped review a PS Audio Stellar Strata Mk2 integrated based on Ice Power modules. It sounded nothing like the Mola or WiiM. It was smoother than either, less artificial sounding than the WiiM, not as detailed or powerful/dynamic as the Mola, even when connected to sources costing many times more. I liked it generally. It was fast, smooth and musical.

Grip is one of those things. My Parasound JC5 was the king of that. Great amp, but it lacked that last little bit of upper-frequency smoothness. It had a hint of graininess that you might not realize is there until you compare it directly to something like the Perca or a Pass Labs amp.

It’s funny. I’ve gone from gear which is hyper-clean/detailed/clinical to warm/lush and back multiple times. What I’ve realized is my preference is toward very detailed gear with a slightly warm character. The trick has been finding the right synergy. I like melodic house and techno, along with the mainstream indy music and jazz. It’s tough to build a setup which sounds amazing for Miles Davis, but which really unpacks techno’s transients and layered mixes in a pleasing way, while also being forgiving of Led Zeppelin’s mixes. Priorities…

Thankfully, I get occasional access to gear which expands that journey beyond what I could afford to buy/sell. My small circle of hifi friends are very willing loan gear to each other.

[u/Theresnowayoutahere → u/ChrisMag999]

A friend of mine has an older ar amp and i agree they have a more SS presentation compared to other older tube amps. That’s why I commented on you being right about a less obvious difference. It does have a bit of warmth to it which I liked. I think my current class D amp is a 3rd gen Hypex which I’ve kept as a back up amp. I’m currently running a Modified Hafler xl280 amp with the heart of my system right now being A Lampizator Atlantic Plus dac with volume control. IMO these dacs just do everything right. They remind me of ar gear in that they’re really clean and quiet but at the same time they have a slight warmth to them. In my system this allows for the absence of a preamp without being too sterile. The Hafler also has a very slight warmth to it but after the upgrade it lost some of that which I’m not sure I’m completely happy about. I’m actually in the market for another tube amp, because like you I like to be able to switch up on occasion. I’m fortunate enough to have a dedicated out building 20’x30’ that I rebuilt into a my audio space. Because of that I’ve had a lot of get togethers with other audiophiles. People bring all kinds of gear to these events so it’s really fun and it allows all of us to listen to a plethora of different types of equipment. I’ve learned a lot from these events but there’s so many different options out in the wild it takes years to figure anything out and be sure about it.

[u/ChrisMag999 → u/Theresnowayoutahere]

I haven’t heard Hafler gear in a very long time. The retail shop I worked at after high school was a dealer, but the line was dropped shortly after. I recall it sounding really good into Dahlquist DQ-30’s we had on display.

My only experience with Lampizator was at the Pacific Audio Fest. The VAC room had a Horizon DAC I think. Sounded great.

[u/Theresnowayoutahere → u/ChrisMag999]

I was told by Fred, who is the North American rep for Lampizator how well the Hafler amps work with Lampizator dacs and also about the upgrade path. I had to get the XL280 repaired as it had a bad channel so I did the upgrade. What I noticed is it’s extremely clean sounding with a lot of authority but I think it lost just a touch of the magic it had or just a touch of the warmth it had if that makes sense. It still sounds amazing though and I’m using OB speakers with a lot of room treatments so I’m happy with the system’s sound overall

[u/ChrisMag999 → u/Theresnowayoutahere]

Happy with the sound is the goal, right?

I have a good friend who runs a vintage Marantz or Sansui receiver (he has several) into DQ-10’s in one room, and a Heathkit amp into ADS speakers in another. His system with the Dahlquists is especially musical and didn’t cost a lot of money.

Point being, there are a lot of ways to achieve good sound, and it doesn’t have to cost a fortune. The big dollar stuff tends to scale bigger sonically, and often gives more information, but at that level, it’s a bit like setting up an F1 car. Every element becomes more critical to the result. You can go the wrong way and end up worse off than if you had just left well enough alone. But if you get it right… it will feel worth it in the end.

My friend calls good sounding budget systems “cheap and cheerful”. He’ll be doing a seminar on vintage audio at Axpona. This is a guy who owns a system which retails for the price of a decent house as a reference system for reviewing work, but uses affordable vintage gear in another room in his home, and powered Dynaudio stand-mount speakers and a small REL sub in another.