OTOH, I notice that UFO owners have been relatively quiet on this thread. Again, they may not be in a position to compare, but are concerns about the UFO as beautiful, but possibly falling short in the power dept, valid? Are the reviewers only saying power's ample because they don't have 20 watts of Decware push/pull to compare it to?

I can’t speak on behalf of all UFO25 owners and I have posted.  The over forty years of experience with ss and tube amps, with 2.3watts to 250 watts has taught me some things.

One fundamental thing is: IT’S NOT ALL ABOUT POWER!

Another is that power alone does not give the flexibility that one may assume it should.  I’ve had high power systems that were anemic and lifeless.

It’s about the system as a whole from front end to the speakers.  When friends listen to  my UFO25 centric system they often ask, “what’s the power of the amp? 100watts at least?”  One of my friends said “you’re insane” after I told him 2 watts.  Never gets old.

That’s why I’m hesitant to make recommendations.

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This is my experience, so FWIW, YMMV and all that. I had 100 Watt Nelson Pass Aleph 2s and Totem Mani 2 signature speakers in my smallish room for many years. They sounded great until they literally started to wear out. The Manis were somewhat famous for having great bass for a small stand mounted monitor and also being wickedly inefficient, but the Pass amps could drive them well, while still giving me all the detail and transparency I wanted.

I had been thinking about replacing them for years, and I knew there was no way my Scottish Heritage would pay for current production Pass amps so I needed something else and came across Decware and Omega speakers during some late night web surfing. Long story short I decided on a pair of UFO amps and Omega Super AlNiCo monitors. I wanted a pair of UFOs (configured as balanced monoblocs) because I wanted a balanced signal path and short speaker cables, I didn't do it for the extra watts but they are a happy bonus. I bought the amps and speakers "sight unheard" (as I did the Pass/Totems), they cost a fraction of what I paid (used) for my previous system and I was hoping they would be close to the same quality. So no way was I prepared for the new system blowing the doors off of my previous one. It had more of everything: more detail, speed and transparency, more impactful bass and extended highs and more of the gorgeous liquid tonality that I though the Pass system did better than anything else.

The above is 2 paragraphs of rambling preamble before I answer your question, was I worried about power? and the short answer is no. The back of the envelope said 5 watts and 94 dB speakers ought to be in the same ballpark as 100 watts and 84 dB speakers and I wasn't wrong. I also new a smallish room went a long way to make a system sound more powerful than it is on the oscilloscope. But for me it was an easy choice, the only Decware option was a pair of UFO amps because they are the only amps that could be configured as balanced monoblocs, which is the only kind of amp I would buy. If I had a bigger room I don't know that I would have been so eager to go the low power/single driver speaker route sight unheard, but knowing what I know now if I had a bigger room there is no question I would still get a pair of UFOs and even more efficient speakers.

That's my story, but of course at the end of the day you've got to go with what makes sense to you.

I agree with most comments/preferences in this thread, but since some are prone to the Torii and some the SE84, this to me indicates, with Decware's clarity and usable power range, and fast/efficient speakers, big wattage is not necessarily the deal it has been made out to be over the years.....but depending on all else, it can be an issue. Like Joman suggested, an amp's power abilities depends on the whole, including the room....that is, as long as the amp does it all right in speed, spectral, spacial and harmonic balances. And clearly, in Joman's system and room, he gets all the beauty balances plenty enough to make friends think it has way more power.

And I think Steve had discussed similar "it depends on the whole" thoughts illustrated with his comparisons... And from my experience with earlier Decware amp versions, the 10x power part (or in my case about 3-4x) Steve mentioned, can be a notable factor... providing more power behind all aspects of the sound, including bass, fullness and weight, but also to the rest, and this can make a notable difference depending on the speakers used, the rest of the components, cables, etc, and how the room is setup and treated.

Also, looking a little between the lines of Lon's comment about the ZRock2 being beneficial for his (lower power) setups, (and if I am remembering correctly, Joman uses one too?), I think this adds to the story some. To me, the Zrock2, to get the harmonic/space lift, it is best within a relatively narrow gain range starting not a lot past unity gain....so that the ZRock sound design is activated, but without enough bass addition to shift the overall balances so much as to change bass notably more than the rest. In this range, to me, the stock version with only VR mod did tend to fill in/enhance many aspects of the sound, giving a "bigger" sense, while still being pretty nicely spacious and articulate within this using clear leaning and slightly powered up tubes with complimentary Zrock settings... not the same, but not altogether dissimilar to how a more powerful and well balanced tube amp can power up everything, but without adding headroom like a more powerful amp. So I am reading into this, but guessing Lon and Joman's different SE84 setups with a ZRock2 (and/or other Decware pre stages), the pre stages probably fill in the foundational amp sound some. Please correct me if I am wrong on this Lon and John.


This was quite a few years ago, but in my first Decware experience, in my biggish room, with 94 dB MG944s, the SE34 I had was not quite enough for all recordings. So I traded it for a very early Torii MKIII. And after talking with Steve about it some years later, also having integrated some modified HR-1s (92.5 dB), and my then, two systems being much more refined with improvements in rooms, cables, vibration, tubes, front ends, etc, I decided to try SE again with a Taboo MKIII. But with these two speakers, in my two fairly large rooms, the Taboo was not even loud enough (the way I listen) to fully evaluate, most likely making it appear leaner than it would have been with more appropriate speakers for my rooms to work with it.... It also made it clearer that my HR-1s in particular benefit from more power, presumably getting the drivers going harder, enlivening the sound more.

So getting the right more efficient speakers, or staying with more power was the choice, and since I had tuned so much to get the open lucidity and speed I loved with these amps (Torii MKIII and IV) and speakers, I sat tight for a while. But the itch to retry SE still there, and my systems much more refined, we thought a Rachel might just be enough. And it was better, but after having growing used to Torii power, and having adjusted my rooms and systems to utilize my earlier Torii's balancing toward bass depth/fullness to bring out more space, clarity and complexity bottom to top, I found I loved having more everything from more power, including headroom.

That said, once all was relatively sorted here, as I interpreted Steve's post talking about all aspects of the sound being relatively close with his amps, I feel similarly from my much more limited explorations. Once tuned to the system and room, previous versions of his PP and SE designs seemed more variations on a theme than seriously different in terms of space and harmonics. To get to hear this similarity though, I had to shift the spectral balance, doing pretty much work to get the Toriis and speakers and rooms bass managed well enough that it did not sound dark/full for me, especially on dark leaning recordings, while overwhelming spatial information and the finest detail. And as the bass grew tighter and more articulate, less full and thick, the whole opened with the subtler finer detail aspects of textures, space and harmonics more present. But even then, the power adding more everything, in my rooms, the bass and weight was the most obvious spectral difference from more power with the versions of Toriis and speakers I have.

So with these amps, in these rooms, and with Bob's speaker designs, there was a pretty big difference in how the power effected the whole sound, especially initially in going from the SE34 to one of the first Torii IIIs without much room treatment. With basically the same setup, the SE34 bass in the balance had almost no issues, not thick, but also not lean... just a little boom and extra darkness on occasional recordings. But with the Torii III, room challenges became clearer, and bass overwhelmed the rest too much for me, not fast/clear enough without a fair bit of work with tubes, cables, room and speaker adjustments mostly, followed by carefully found EQs to more completely finish solving room interaction issues. But once bass was managed, I got a clearer sense of what more power across a pretty balanced spectrum can do with my setups.

And headroom, the Torii III, with my then 94 dB MG944s was plenty, even with partially toned down tubes. But I would say headroom was not excessive for playing more effortlessly across all recording styles.... enough reserve power to get me to the highest listening levels I use for serious listening....mostly averaging in the middle 70 dBs with peaks in the lower 80s, and very occasional fast transients getting closer to 90.


But these amp designs have evolved since then, especially the Torii MKV and the SE84UFO25 (which I would love to hear with all their thoughtful design improvements), so this is a general comment using older versions, and from rooms with not nearly as much traditional treatment as Steve's, but still carefully tuned... And in the last five years or so, I made a lot of modifications in my amp, pre stages, and speakers to more fully bring out speed, resolution, harmonics, hit, etc, an aspect of this seeking ways to refine bass complexity and speed further. And it is working, now more than ever my sound being quite real and seductive across across most recordings. That said, had the SE34 had more headroom here, I did really like the sound, and I did not feel it lacking in bass and weight, while actually being notably easier to fit its bass into these rooms.

So like Joman suggested, it all depends on the whole. And if you have speakers that are very efficient, especially in big rooms, I can fully imagine how the SE84UFO25 (or two), with optimized power supply and all Steve's accumulated efforts for speed, clarity, resolution, and musicality throughout could be really seductive, beautifully compelling and complete. But also, like Groovysauce, who has had both the SE84UFO25, and Anniversary modified Torii IV in his system, and was leaning toward the Torii, I can also imagine that if both have enough power, it finally might be a matter of personal preferences and how the amps are fine tuned in our own systems and rooms that decides it.

So, I guess trying to figure this out hypothetically, it takes a fair bit more than judging from how one person or another likes this or that in their rooms, and for their listening preferences....

Also, I agree, the seductions from whatever Steve's various development threads are unveiling are big, Steve's excitement as he discovers new ways to improve his designs contagious. But also, at this point, after going deep into refinements with the SE84UFO25th, and integrating innovations he had discovered over years as a collective foundation for the new design, and then discovering more refinements as he went..... I guess that like all his development explorations, the UFO25th set up a more advanced and refined basis for tuning all that followed.

So, some time later, when he went deep again on the Torii MKV, he was working from within an expanded sonic, technical, and design foundation, his thirst for beauty and creative exploration always widening and deepening his foundations in what he hears, wants, and has learned more how to try to get. So I find the Torii MKV thread is pretty seductive too, and looking at that design, and Steve's comments, I can imagine the overall similarities Steve hears between his SE and PP amps having been narrowed with the recent refinements to the Torii, likely notably reducing the differences that I experienced and sought to explore from many angles to solve for my Toriis in my rooms....

Apologies Will… not will.  Too rushed, gotta slow down.

Question, when ran as balanced monos, how do the UFO25's volume knobs work? Given that each amp has 2 volume knobs, do you just match all 4 knobs any time you change the volume?

Based on my experience the answers is: it depends.

I sent my CSP3 in for the A-mods.  With it out of the chain the ZR2-A went directly into the UFO25 and I adjusted the volume with the dual controls.

Once the CSP3-A was back in the chain I used the volume controls on the UFO25 as part of gain riding or gain structure.  I set the my ZDSD gain level then the gain levels on the CSP3-A and then the volume level on the UFO25.  Once that is set I rarely adjust the volume with the volume controls on the UFO25.  That is then done on the CSP3A.  The objective for me is more gain (density) less volume.  At this time the volume level is about 50%-60% on the UFO25.

The other benefit of the dual volume controls is that I can use them as a sort of balance control without the negative effects of a balance circuit.  My speakers are not equally distant from from the room boundaries.  One is set a little higher than the other.

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Not necessarily. If you have a perfect room then yeah, probably all of them the same makes sense. But for me, and I have the stepped attenuators,  I use them as a balance control so the right side a one click louder than than the left. And, with the stepped attenuators and in balanced mode you can have one channel a click louder or softer to fine tune the volume of each channel.