Which is Better Sound From High Power: Single Tube SET or Parallel Tube SET?

LL21

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Dec 26, 2010
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Hello gents,

I can’t nor will I try to offer any attempt at answering the question directly, as I’ve never compared a SET of a certain wattage with that of a PSET of the same wattage, given the variables between the two are too great.

I can say this:

I have never liked big bottle tubes, including the 805, 845, 211, GM70 and 833 - at least not in any of the implementations I heard them.

I have also never liked PSETs using any tube (big or small), or push-pull amps for that matter (unless we’re talking guitar amps).

So despite a well-entrenched bias against big bottle tubes and parallel circuits in general, and a growing conviction that no big bottle amp or parallel topology would ever meet my criteria for ownership, that all changed when I heard an amp that used a tube that was new to me, the RCA 813, a big bottle tube of which two were used in parallel, driven by a single RCA 814. That amp is now my favourite by far.

That’s not to say I’ve changed my mind about big bottles or parallel circuits in general. Just that single variables in isolation usually tell us nothing about how those variables react and interact when brought together. Again, implementation trumps topology, and topology trumps parts selection, at least in my experience.

Best,

853guy

853guy

Is this amp you refer to the Aries Cerat Diana by any chance? Most intrigued!
 

853guy

Active Member
Aug 14, 2013
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853guy

Is this amp you refer to the Aries Cerat Diana by any chance? Most intrigued!

Hi LL21,

Yes, it's the Concero 65. I've not heard the Diana/Forte, but same tubes and similar topology.

Best!

853guy
 

LL21

Well-Known Member
Dec 26, 2010
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Hi LL21,

Yes, it's the Concero 65. I've not heard the Diana/Forte, but same tubes and similar topology.

Best!

853guy

Tell us more please! Would love to know more about this amp. Purely from discussions with people about their products, Aries Cerat are probably 1 of 3 names I would intuitively guess are ones I would consider looking at over my CJ GAT2/Gryphon Colosseum combination which continues to serve so well.
 

853guy

Active Member
Aug 14, 2013
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Tell us more please! Would love to know more about this amp. Purely from discussions with people about their products, Aries Cerat are probably 1 of 3 names I would intuitively guess are ones I would consider looking at over my CJ GAT2/Gryphon Colosseum combination which continues to serve so well.

Hi LL21,

I’ve shared my experiences with the Aries Cerat gear in previous posts. However, I’ve only heard the Concero in the context of an all Aries Cerat system, and twice with the Symphonia, so please take that into account for whatever it’s worth. And rather than repeat my impressions and divert this thread from its intended course, feel free to have a look at these posts here (Warning: Verbosity of a highly subjective nature. Reading may induce narcolepsy.)...

Private Brussels Audition

High End Munich 2017

High End Brussels 2016

Hope that helps!

Best,

853guy
 

DSkip

Industry Expert
Aug 26, 2013
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I have also never liked PSETs using any tube (big or small), or push-pull amps for that matter (unless we’re talking guitar amps).

I can definitely agree with the bolded. I haven't run across too many push pull that do it for me since diving into the world of single-ended designs several years ago. They don't sound bad, but they miss some of the naturalness of a good SE amp.

As for big bottle tubes, I find that it can vary depending on the needs of the speaker. For example, the Harbeth 30.2 LOVES the Dueventi with el34's and 20 WPC. Moving up to the Compact 845 or even the Evolution 845 actually doesn't have the same magic. However, on 90% of my other speakers (ones that require more power) I find that the bigger units really make the speakers shine and prove their worth.

For what its worth, everyone who has had a chance to compare the Compact 845 (SET, 30 WPC) to the Evolution 845 (PSET, 55 WPC) has come away completely understanding the differences and all favored the Evolution 845. The magic wasn't lost - quite the opposite actually. I've had clients move from the Compact to the Evolution and they felt the jump was anything but subtle and had no regrets with their decision.
 

Ron Resnick

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Are you suggesting saying that the 845 PSET sounded better than the 845 SET on every sonic parameter, or that, on balance (on a net basis) you gained more in dynamics and headroom with the PSET than you lost in transparency and delicacy with the SET?
 

DSkip

Industry Expert
Aug 26, 2013
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Arlington, TX
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Are you suggesting saying that the 845 PSET sounded better than the 845 SET on every sonic parameter, or that, on balance (on a net basis) you gained more in dynamics and headroom with the PSET than you lost in transparency and delicacy with the SET?

I can't speak for other brands, but I feel that with MastersounD, jumping into their higher powered offerings leave little to be missed (if anything) over the single tube products. I'll be honest - when I first looked at MastersounD I struggled to justify the price difference between the Compact ($8,000) and the Evolution ($18,000) until I heard them. It takes the same sound and makes it more dynamic with greater ease to the presentation. You also get a tighter, more controlled sound.

Now, if you are comparing the BoX to the Dueventi, they are completely different sounds with completely different designs. I would imagine the Dueundici and Dueventi mimic the Compact and Evolution jump, but I don't import the Dueundici currently so that is purely conjecture at this point.
 

Sablon Audio

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I always understood that the sound quality of a valve amp was largely determined by the quality and specifications of its output transformers. If so, then the question of whether it has single power tubes or multiple in parallel is a non sequitur. I have owned examples of both, albeit not of the same tube types at the same time.
 

Ron Resnick

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Hi Ron

i had the AM in my system for a demo a year or two ago. In my system it was very unimpressive. If i had taken that as the sound of SET then i would have given up there and then.

In my system at the time it sounded very detailed and fast, lean and with an exposed top end. It didnt sit well with me. View attachment 41168

With which other amps did you compare the AM amps in your system?
 

Ron Resnick

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Generally 833 SET reports, whether Wavacs or Am House, talk about wonderful midrange, no tipped-up high frequencies, etc. (the usual SET virtues). It is interesting you had a very different experience with the AM House 833.

WOW! Okay, well, please tell us some more comparative listening impressions among all of those other amplifiers!

PS: Absolare makes a PSET? I thought the higher power Absolare 845 model is push-pull?
 

pweg

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Jun 8, 2014
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you are correct - the higher power Absolare is PP. I opted for the PSET, as my experience with the Triode Corp TRX M845 demonstrated that there was enuff power coming out of 2 845's for my system.

quick analysis. The Viva sounded beautiful but just lacked weight and heft. It imaged beautifully and sounded quite magical - it just made my system sound very much less than full range. The Ayons were ok, hugely powerful but lacking midrange magic and didnt image stage as well as the SETs. The Cary PP was a revelation. Punchy bass with loads of texture, beautiful midrange but not the last word on imaging and spatial cues.

the Triodes proved the direction was right with PSETs. Deep strong bass with texture galore. Holographic imaging and beautiful midrange. The move to Absolare just turned everything up a notch.
 

microstrip

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May 30, 2010
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Although I have no experience with PSET I would expect that if the two tubes are precisely matched you will not have any degradation versus SET.

Although many push pull amplifiers (VTL or conrad johnson) do not need closely matched power tubes, I have found that selecting them for very close matching results in a better sound quality. If you put two very different tubes in parallel, even if you compensate it for DC equilibrium, you get a less linear system.
 

morricab

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I have had all kinds of SET: pure SET, SET hybrid, PSET, SEP and SE(Transistor) hybrid.

Currently at home I have the following:

JJ-322: 20 watts 300B PSET and this amp with the right speaker (read > 93db) it sounds very punchy and transparent with good deep bass. It has very nice and large double C core output transformers that assist in the clarity IMO. Sounds very good on both my Odeon horns.

MasterSound Dueundici: Little firecracker of an amp that drives my 96db Decware HDTs. Good bass and transparency but not the last word in soundstage depth or 3d imaging, which I think may have to do a bit with the pentode operation and/or the bit of negative feedback that it runs. Still, good clarity and fine for the late night listening duties. The larger DueVenti can also be run in triode and I think without feedback that should improve the sound over the Dueundici

Aries Cerat Genus: Our newest "baby" this SET has power out the wazoo and transparency that rivals the very best. Dynamics are also near state of the art. That said, the Diana Forte we have in our demo system is a PSET that is just as transparent and probably more dynamic. The Diana Integrated is a SET (same output power as Genus) and is just as good as the others. So, SET or PSET here there is no penalty either way. A customers PSET Conceros takes it a notch higher all-around though.


So SETs I have had in the past:

Cary CAD-572SE: Great sounding little SETs with a unique "big bottle" output tube. Smooth and liquid but not the last word in any parameter.
KR Audio VA350i: Had three of these in the past and these unique "reverse" hybrid SETs were dynamic beasts that drove most speakers well that we tried them on...worked great on my Acoustats and STAX electrostatic speakers... A really great amp.
NAT Symbiosis SE: Hybrid SET with one large MOSFET per channel for the output and another one for regulation of the output, which resulted in 4 huge heat sink towers (looked like the Battersea power station!). Never had quite the transparency of a top SET nor did it have a really open and sparkly top end but once it fully warmed up (the transistion from ok to WOW was very dramatic with this amp) it was almost psychadelic in its tone and 3d imaging and soundstaging. Bass was also better than most SETs...a truly interesting amp that I might have kept if it didn't take so darn long to warm up properly...and the power consumption was enormous!
Wall Audio M50 monos: PSET with 2 x 6C33C tubes per mono. This was the first PSET I had with this output tube and I can see why people like the sound of this tube. These were perhaps a bit lower in clarity than my other SETs but had a big bold sound that rocked on my big Odeon horns. Kind of regret selling them... but I needed more transparency ultimately.
Ayon Crossfire III: At first, I found this the most analytical of all the SETs I had before. It was leanish through the mids but did have a rather powerful bass and big output trannies. After tube rolling (replacing russian input tubes for NOS GE and the 6N30 driver for 6N6 and the stock rectifier with an Ayon 5U4G) the result was retaining that superb transparency, imaging and soundstage while getting the tone that one expects from a proper SET. The big 62B output tubes could deliver that big bottle umph with more delicacy and inner resolution of a 300B. Perhaps it was not quite as good as a 211 or 845 for grunt and perhaps not quite as good as a 300B or 2A3 for inner resolution and lit up quality but it was a good balance with plenty of both. All-around, this SET is probably the best I have had until going Aries Cerat. Stock not but with the tube rolling it got there. The KR VA350i is right up there as well. Both are lower in coloration than some of the others I have had or heard and that might make them less SET to the the Viva, Cary, Kondo crowd.

Other SETs I have significant expeirence with:

KR Audio Kronzlla SX and DM monos: Beasts and very good sounding...these are actually PSET "reverse" hybrids, whereas the VA350 is just SET hybrid. The DM monos I had for review in 2005 drove my Acoustats better than anything else I ever heard with them.

NAT SE1, SE2SE, SE3: Heard all possible variants of NAT's 211 based amps. On sensitive speakers the oldest SE1 version was the best sounding (it was also huge and had tube rectifier for the input/driver). For Apogees the oldest SE2SE version sounded the best to me (and was a powerful beast that bested CAT JL2 signature as well). The SE3 was also very good sounding and had power to burn. Both SE2SE and SE3 are PSET and didn't give up much on the SE1 if anything on ohter than really sensitive speakers.

NAT Transmitter: Powerful but not as pure sounding...possibly due to the output tube choice which is actually a tetrode I believe.

Cayin 845 monoblocks: These had a more stereotypical warm and full sound. Not overly transparent or energetic but gave a nice pleasing but somewhat colored sound.

New Audio Frontiers 845 integrated (SET) and monos (PSET): Heard numerous times at dealer on various speakers. Both have rich warm sound but very good holographic imaging and soundstage with superb transparency...just a bit of "golden" hue to the overall tone colors but something I think most could easily live with.

I am not convinced from experience so far that PSET is inherently inferior and there are some design advantages with regard to output transformers by going parallel that might more than offset the apparent theoretical advantage of a single tube vs. multiple tubes.

Two of the best SETs I have heard, Concero 65s (Diana Forte) and KR Audio Kronzilla DM monos were both PSET. The KR in fact is 4 triodes per mono because each T1610 tube is in fact a double triode to begin with and there are two tubes per monoblock.
 
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Ron Resnick

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Thank you, Brad, for that very comprehensive and very interesting survey!
 

Exlibris

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I have had all kinds of SET: pure SET, SET hybrid, PSET, SEP and SE(Transistor) hybrid.

Two of the best SETs I have heard, Concero 65s (Diana Forte) and KR Audio Kronzilla DM monos were both PSET. The KR in fact is 4 triodes per mono because each T1610 tube is in fact a double triode to begin with and there are two tubes per monoblock.

The Kronzilla SD is 22 watts while the Kronzilla SX is 50 watts. It seems that all of the other specifications are the same between these two amps. Is the power difference attributable to the fact that the SX runs the tubes as double triodes and the SD does not?
 

morricab

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The Kronzilla SD is 22 watts while the Kronzilla SX is 50 watts. It seems that all of the other specifications are the same between these two amps. Is the power difference attributable to the fact that the SX runs the tubes as double triodes and the SD does not?
No, my understanding is that the SX runs the tubes much harder to get the extra power. However, this likely shortens the life span of the tubes. The original 22 watt Kronzillas had very long tube life...not sure the tubes last as long in the SX.
 

Exlibris

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No, my understanding is that the SX runs the tubes much harder to get the extra power. However, this likely shortens the life span of the tubes. The original 22 watt Kronzillas had very long tube life...not sure the tubes last as long in the SX.
For the Odeon No. 33 I'm thinking the SX would be better. What do you think?
 
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morricab

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For the Odeon No. 33 I'm thinking the SX would be better. What do you think?
Yes, I think for the 95db or so speaker the more powerful SX would work better.
 
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