Zu Audio Soul Supreme
Room is 16 X 25 but very irregularly shaped, which is a sonic benefit.
Here is a SET amp option with enough power for most any “reasonable” speaker and room.
I use 300B amps in my system and listen mostly to rock / blues and it works. I have done the high power mega amps & Wilson speakers and about 3 years ago purchased a pair of Coincident Frankenstein 300Bs on a whim and backed into a horn loudspeaker. Wasn’t perfect but there was something special happening. So, the low power high efficiency journey. After a couple speaker upgrades and multiple preamps I think I have my final system in place. Whapping 8watt 300B’s driving BD-design coaxial horn 22kHz down to 250Hz then LaScala type horn woofers 250Hz down to ~40Hz driven by 400watts Class D plus a sub for 40Hz down. Oh did I mention that the Don Sachs pre is the cherry on top. The coaxial compression driver horns on 300B power, wow, extension without fatigue and the dreamy midrange real piano. Never going back.
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Great lead to follow up on! 45 watts/channel! Thanks.
Tinears1, was the BD-design a DIY project? BTW, thanks for the Don Sacks preamp reference. I’ve run across his name and products in other discussions and know how important the preamp has to be in this type of set up.
Is there any low level hum from the Coincident Frankenstein transformers? Its something I first noticed with the Audible Illusion Modules 3 preamp power transformer years ago. I found it again with a pair of KT-90 amps more recently and you can hear the hum from the listening chair when there’s no music playing.
You can buy the BD-Design speakers as either finished product or DIY. Yes the Don Sachs pre is very special. So much so that I sold my AR-ref-6SE. The Coincident 300Bs are dead quiet and that’s saying something considering the horns they are driving are 110dB. Best of luck on your HiFi journey.
Lots of good replies on here. @BillT - Per my reply above, most speakers folks have listed are quite large, which substantiates my guidance, with the exception of @RonP who is using similar Zu to what I had. While the Zu will definitely get loud, and they have some bass, I find them a bit lean. Larger enclosures or larger horns will allow for lower frequency extensions, and 300B will power them just fine in medium to larger rooms.
The Audio Mirror amps are not bad for the price, especially if you can get them on the used market for $3K or less. The owner, Vlad Bazelkov, is a good friend of mine and lives about three towns over. A few higher-powered SETs to check out are the Cary 805 AE and the Line Magnetic LM-805ia.
That said, while I agree with @stevensegal about the proper amp for the right speakers, a 300B SET ‘typically’ does accommodate a certain type of music better than others. 300B is known to be full of bloom and add color, while being a mid more rounded on the frequency extensions. This makes it more appealing to play jazz, female vocals, and simpler music which then is reproduced like you are there. It can at times struggle with faster music, such as classical or Led Zeppelin. I say at times, as there are some speakers, like the Zu that may be fast enough to compensate, but there is usually some drawback (like lack of a frequency extension) - that’s not fact, just my opinion, and everyone is entitled to their own
Some amplifier circuits and quality transformers do a better job of pushing the envelope, and there are also some decent 300B push pull designs on the market. Tubes of course also vary in flavor, with some like Sophia Electric Royal Princess being very warm and lush, and EML Mesh which are super dynamic.
Shameless plug - I do have both a very good upgraded Bottlehead Kaiju 300B SET amp and a Triode VP-300BD push pull amp in case anyone is interested. I was planning on listing them this week or next on Audiogon or USAudioMart. PM me if interested.
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I agree with your comments on my comments! Those are the types of music that avoid 300B limitations.
That said, I had the 300B-XLS that is twice as powerful and the standard 300B, also the tubes are twice as expensive, and there are also the EML 520B at $1,175 that I could have used.
My unit had Sowter output transformers that are crazy expensive.
The problems with valve amplifiers is that they are so dependent on component quality. They are very easy to build as a DIY project (if you know what you are doing) and so can be done for a sensible price with top quality components. If you want normal audio profit margins you have to use cheaper components or the product becomes stupid expensive and you get a lesser quality amplifier. The good news is that many tube amps have very poor resale value and can be bought relatively cheaply.
I tried some more powerful valves. See below. These were UK made, which I imported from Audiogon in the USA as they were broken and unserviceable, paying less than parts cost. I then got the original manufacturer to fix them, mainly 240v mains transformers and a few components. much of the damage turned out to be cosmetic. Even at 55w these were unsatisfactory, but at least it was not too painful a learning experience.
People do like valve amplifiers and Prima Luna seem to have got it right, with excellent design, high quality manufacture in China (in their own factory) where the same parts are much cheaper than Europe, and sufficient power such as their KT120 units.
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@stevensegal Are you still using Harbeth? If so, which one? I’m surprised you are so critical on tube amps, as I think there are many out there that do it right when paired with the right speakers (and tubes). The amp itself does need to have quality components, but I find the effort is really in rolling the right tubes, which is timely and gets expensive, and ensuring the amp is paired with the right speakers. That said, I personally love a bit of color and bloom because to me it makes it more involving and realistic.
I’ve found that while SS may get the dynamics and frequency extensions faster, it takes $$$ to get the realism, air and depth that tubes bring. I myself have found this moving from a tube pre / SS amp combos to all tube front ends.
PrimaLuna is very, very good for the money, but I’ve found better amps on the used market for much better and cheaper. I’ve owned three PrimaLuna integrateds including the Dialogue HP, maxing each of them out with tubes and fuses, but I admittedly haven’t owned the newer EVO. In a heartbeat, I would still pick a 300B Bottlehead Kaiju over them.
Here is one of my favorite resources for amp design, written by Ralph Karsten of Atma-Sphere. It gets away from the discussion of SET a bit but the thinking still applies between power and voltage. For SET and tubes in general, most designs fall in the power paradigm, and many SS amps (not all), fall in the voltage paradigm.
http://www.atma-sphere.com/en/resources-paradigms-in-amplifier-design.html
The Quad II is a valve amplifier that has been in production since 1953, with an upgrade in 2015, but Peter Walker saw the benefits of solid state and produced the 33/303 in 1967 He was fairly late in the solid state game, because he would not release a solid state amplifier unless it was as good as the Quad II. Bear in mind these amplifiers were designed to drive ESL57 and ESL 63.
I have nothing against valve amplifiers if you want the uneven frequency response, lack of bass (most of the time), high cost to buy, impracticality, high running costs and valve replacement costs.
I have heard some combinations I would love to own, specifically the Trilogy 995R and Wilson Sasha DAW. This is a hybrid amplifier, 40W with valves and 200w solid state. About $30,000 for s pair.
I don’t get the idea that you spend a fortune on something and the sound changes depending on what valves you use.
There is so much good solid state audio available, I just don’t see the need for valves, but a lot of audio is irrational.
I had Harbeth until very recently, now Wilson, which are a bit like Harbeth on steroids. Cosmetics were a big factor. Never liked the look of them, the wife even less. Sound great, had the SHL5+ 40th, the M40.2 were never an option due to their size and the M40.2 and Wilson are the same price.
TMRaudio has LOTS of used tube amps right now, the most I have seen at one time in browsing the last 1.5 years.
I went from a couple of Hegel H20 AB amps to a couple of SPEC W3 class D amps last autumn. What an upgrade that was. Even at only 100 W into 4 Ohm 88 dB/1m speakers (Vienna Acoustics ‘The Kiss’) they play louder than I will ever need. And they sound like tube amps (see review excerpts below from originally a French review, in a translated version on 6moons):
https://www.6moons.com/audioreviews2/spec/1.html
"… This design philosophy is radically different from amplifiers by Hypex, Pascal or IcePower. SPEC in fact design class D to closely approach the sound of single-ended tube amps where each component is chosen according to its sonic and not just measurable value yet enjoys the switching benefits of negligible heat and high power efficiency.
From the very first note I had the impression of listening to a very good tube amplifier because the sound was so liquid, transparent, fast and holographic. Then I realized that I could ignore the usual colorations of tubes, be those pleasant, unpleasant or invigorating. This in my opinion amounted to the closest transistor approximation of a tube amplifier I had yet experienced……
……I know that it’s rather common to compare a good solid-state amplifier to a tube device whenever one spots such liquid behaviour. The RPA-W3 EX however far exceeded this type of consideration. Its sonic DNA was much closer to a triode set and in a blind test, it would have been very easy to mistake it for a pure tube amplifier. This was an unprecedented achievement for a Class D amplifier."