Sonic qualities of SET output tubes?

Thank you for the very interesting answer!
Will have to study it a bit.
I did the swap using only 1 cut for a quick comparison.
What you say seems to correspond with what I heard.
Speakers are Revel F206. Even though nominally 8 ohm, the impedance curve looks mostly around 5 ohm or less.
http://www.soundstagenetwork.com/index.php?option=com_content&view=article&id=1238:nrc-measu...
Will need to experiment a bit more.
I really appreciate your response.
Leo

Inna > I mentioned LAMM and Wavac.

Blindjim > huge thanks Inna can’t say how much I appreciate all your feedback. yes, you sure did. I’ve been reading furiously on every suggestion, and all the technical data. I am getting confused with all the input I’m gathering, though I do have notes on nearly everything so far.

Saw at least one LAMM amp needs manual biasing. For me that’s a deal breaker. Its ticket is another I suspect, for now at least.


Grannyring > Did you buy that set of Thor TPA30s on Audio Mart?

Blindjim > sorry man, no. Not able yet to do anything worthwhile yet. Still waiting.
Yep. Bone stock, they were the best sounding little goobers I’ve heard to date, and on run of the mill Eff spkrs. That sound is why I bought the TPA 1000 Mk II line stage, and those VR4 JR spkrs. Although not in that order.

If or when possible, I’d buy them or the 60wpc versions in a heartbeat depending on a few buying selling issues.

saki70 > take a look at those with built in amps for the bass units

blindjim > Thanks man. Got it. I’ve seen a few but have decided to go only partly in on low power high eff as a secondary system now.
It could change, though the odds say it won’t, but all of the jury isn’t back yet. So we’ll see. Mostly it looks like a PP amp.


Leotis > So I used the 4 ohm taps on my PrimaLuna HP Int to my "8 ohm" speakers
is there a simple explanation for the difference between the 4 ohm and the 8 ohm outputs?

Blindjim > Leotis, been there and done that myself.
When an amp has optional output taps, the amp is designed to output the total voltage and or current it produces into that load. Ie., 60wpc amp via 4 ohm tap = 60wpc. Same thing for the other taps provided the load or IMP of the speaker is similarly matched, unlike SS amps that automatically see or ‘feel’ the changes and react differently.
.
Essentially, using a lower output tap or lower IMP on a higher IMP load or speaker will cut the power output by 50% or so. In any event it will be less power to the speakers if set up that way.

Speakers should be transparent enough to reveal upstream and room concerns, changes, and problems. For them to do their job as such, they need the right amount of power and the correct electrical operating environment, or as best is possible.

You can look at speakers like rocks. Look at an amp like a bulldozer or truck.

As strong as is a truck or bulldozer, it can only push a particular size of rock. Sure, it can easily push little rocks, or medium sized rocks, and even a larger 4 or 2 imnpedance sized rock but it has to match up to the rock as well with its gearing too, not merely its engine.

Using lower IMP taps sends less power to the speakers, IF the speaker IMP is much higher.

Highs will roll off, bass will be more bloomy, and usually the sound will be smoother and warmer because the speakers are being starved and can not fully demonstrate what they are capable of providing. Resolution will suffer, leading edges will get rounded off.

The sound will tend to be darker and more euphonic than normal as the speaker lacks the power to yield speed and fully demonstrate the entire bandwidth properly.

I did that mismatch with a couple different amps trying to get them matched up the best way possible. You don’t truly know what the imp curve is on many speakers, but amps do. They will tell you IF you pay attention and try the amps various taps..

Usually, the spkr maker gives you a really good indicator of what a nominal IMP for their spkrs run but that’s at one particular freq at one designated voltage. Like 1KHz at one watt, or 2.8 volts or so.

But what about power needs at other freqs? ImP will change then and music is made of many frequencies and volumes.

Its at times a best guess scenario so we use the amp to tell us what it likes, and we listen for the best match.

I liked the mismatched setting on a pair of speakrs I had as they were brand new and not fully run in. they sounded bright and thin on the right 8 ohm tap so I slid them onto the 4 ohm tap. Sounded much better then albeit a whole lot darker though.

after about three or four months I switched them onto the higher IMP tap and whoa! Night and day different! By then they were run in quite well. I begin getting loads of resolution, impact, better dynamics, more transparency, greater extension, every aspect of the reproduction improved. Thankfully they were 93db and an easy load of 6 – 8 ohms and I did not push them hard so the obvious lack of power did no harm to the tweeters. From clipping.

following the uptick to 8 ohm taps, and the greater resultant transparency ai was able to determine what did or did not work well in the system. Wha twas making things bright, rolled off, was buzzing, if there was a ground loop causing the trouble, more exactly how wires were contributing to the affair, etc., bedcause then I could hear things better.

Until then, I was like the system mostly in the dark. But for a while, it sounded OK to me. lol

So I take it that higher impedance speakers make tubes sound better somehow.
So I used the 4 ohm taps on my PrimaLuna HP Int to my "8 ohm" speakers instead of the 8 ohm taps, giving the speakers relatively higher impedance vis-a-vis the amp.
And it does sounds better. More presence, more nuance, fuller sound, more real sounding.
But what is actually happening? Is it lower voltage and more current? Or vice versa?
Maybe it doesn't really matter, but is there a simple explanation for the difference between the 4 ohm and the 8 ohm outputs?
Thanks.

Leotis, 
You are welcome.  Balanced AC electrical power is a major asset for audio systems in my opinion.
Charles  

Thanks Charles dad,
Didn't realize this had gone to 2 pages when I posted. Will check it out.
(BTW, thanks for the balanced power tip on a different thread.
I now have 4 EquiTechs. Balanced power seems to be one of the best kept secrets in audio.)

Hi Leotis,
I posted a list of potential speakers on this thread yesterday. I don’t know what your specific budget is but the Tekton Double Impacts and the Coherent speaker a floor standing 2 way (Canadian)are in the 3000-3500.00 dollar range. Different design approaches but both are said to mate  well with a 300b SET amplifier. Worth looking into I believe. 
Charles

@blindjim 

Did you buy that set of Thor TPA30s on Audio Mart? If so, killer deal and good for you. I owned this amp twice. I have done numerous upgrades to them and they represent some of the best PP tube sound one could ever purchase. Wonderful el34 design getting the best out of this tube. I wanted so badly to buy them again and upgrade the film caps, but not enough power for me. 

Replace those Hovland caps with good copper foil PIO caps from the likes of Jupiter, Duelund, and Audio Note. Very nice improvement for sure.  

Interesting info re: tube amps.
Lotta talk about speaker compatibility.
Anybody got a short list of favorite tube amp compatible speakers?
I struggled to find speakers for a 300B Woo WA5 but finally gave up and now just use the headphone output.
Also have a PrimaLuna HP Integrated. More power but still swapping speakers in and out. Not completely satisfied so far.
Any suggestions would be appreciated.
Thank you!

Yup, not paying enough is the biggest mistake audiophiles make. Paying too much is the second biggest mistake.
SETs done right? I already mentioned LAMM and Wavac. Never heard the latter but some here did.

blindjim > Kenny. no problemo.

life is a learning process and with any past time learning is key. it will diminish the hurt of buying the wrong thing or things, or paying too much... or not enough.

so long as I keep learning, I reamin young. to stop learning, allows the aging to progress.

blindjim,

Thank You for starting this thread,
It's been a wealth of knowledge for me and others.
There is a bunch of high quality tube amps on the market nowadays and sometimes it just makes picking one that much tougher.

I look at myself traveling down this audiophile road and I know It's a journey and my ears are in the drivers seat while the rest of my body just kicks back and enjoys the music,because all of this gear we buy and or talk about is really just the "Means to the enjoyment of music playback in our homes"and for me It's all about the music.

I wish you the best of luck in your journey of finding the sound that gets you a closer connection to the music you Love.

Kenny.

Upon further review….
Until I gain more personal exp this project will be done on a much more limited basis. So it’s a secondary system effort for me going forward.

I simply don’t feel confident enough to move ahead all in with the limited exp I presently have. This means too, speaker choices should have grown a bit.

To date, both EL34 amps I’ve heard I’ve really really loved their sound. The Thor 30’s in triode, and the Dodd monos in ultralinear. And, in that order.

Going forward, speaker choices will attempt to will lend themselves towards easy IMP curves, and higher sensitivities so a future triode amp might could swing with them occasionally.

Blindjim > Charles > your list is quite welcomed. Thanks.

Blindjim > Swampwalker, THX for the nod to Columbia, you’re right. The very next step will be to travel. Do a show or two. Hopefully things will settle up before CES.
BTW… I sort of figured all along relieving the what ever amp of duty below 100 - 120Hz was just about a given, and subs would take over from there down.

Maybe there are some nifty dealerships around the Birmingham area I can check out as that is my next stop for a follow up on some medical issues in a couple months or so.

Inna > One thing is certain - more powerful SET amps done right are very expensive.
Blihndjim > Inna would you mind shooting in a few SET amps done really right options here?

I see nothing with regard to how should I say it, more main stream high eff speaker makers like Coincident … Daedalus… grand Venna… etc. being submitted? Do these ‘main stream’ units pale by comparison to the ones just now listed?
Not efficient enough?

I’m putting Ayon triton III INT, Coincident’s 211 monos, the top Prima Luna monos, Atmas monos, Bernings amp, on the so far short list of tube amps. Manley, VAC and VTL come and go from it periodically. I’ll count out no one at the moment. Nor dismiss buying pre-owned. It ain’t gotta be monos. My pride will accept a 2ch one chassis amp. I just won’t tell anyone about it. Lol

All of the Input here has been and is simply fantastic. And greatly appreciated.

Ralph, would you like to tell us about disadvantages of OTL amp design? 0.5% distortion at full power is quite an achievement.
One thing is certain - more powerful SET amps done right are very expensive.

Charles, that is a shame.Seems to work for me and others? Ok, I have a listing for a grab bad of DIY stuff here on the gone. Only a couple of listings there and mine will be easy to find.  Look under the DIY stuff as I will add it there for a day or two.....it is the last of 6 pics.

Inna,
I wholeheartedly agree there are power amplifiers with sublime sound quality that utilize the output transformer.  I do sincerely appreciate the high quality of the Atma-Sphere,  Berning designs.  There are however other extremely talented amplifier builders who do superb work with other topologies. 

Bill, I was unable to download the picture of your unique amplifier 😊
Charles 

If " dumping the output transformer " were the best way - everyone would be doing it. Ralph and Davis are not the only capable tube amp designers in the world. This is a complete nonsense.

wolf,

You should have stayed with the dual toaster outputs,probably wouldn't have issues.LOL.


Kenny.

I tried dumping the output transformers and the amp exploded and nearly destroyed my double wide. Lesson learned.

Great list from Charles1dad, to which I would add
Classic Audio
Audiokinesis

Also Ref 3A are not true high eff but are definitely tube friendly due to part to minimalist crossover. 

Also note that not all horn-loaded speakers look like the Avant Garde horns. 

A couple of other thoughts:
Another way to skin this cat in terms of using moderate power tube amps is the way I am going at the moment...Atma S-30 driving quasi-full range Feastrex field coils above 60 hz.  NHT X-1 Active crossover  250 wpc Class D ss amp driving 2, 10" woofers per channel.  These are DIY open baffle speakers bought from an A'goner in CA.  You reduce the power demands on the tube amp by not requiring it to reproduce deep bass. If you've ever had an amp w power meters, you can watch them swing in time w the bass line. A somewhat simpler way would be to use monitors or single drivers and a pair of powered sub-woofers with built-in crossovers. 

As far as finding desired products in close proximity and/or being able to buy a "turn-key" system at a good price, I'll repeat what I mentioned above...go to one of the good high-end shows.  Despite all of the known problems of auditioning there, you will NEVER be able to hear as wide a range of speaker/amplifier combos at one time as you can at, for example, RMAF or T.H.E Show.  Never been to Capitol or Newport, but they seem to be similar.  If you hear a combo that floats your boat, you can probably cut a good deal on the show demos. 

@charles1dad

Here is a picture of the one box solution I referred to especially conceived for you. In fact it was inspired by your system and posts. I see you as the DHT evangelist. Yes, this is a compliment of the highest order Charles. Introducing the 1DaDDHT music making tour de force! 

Ok, I am not talented enough to make this hybrid digital, Class D, DHT, DSD dac, room correction one box unit that I dream of for you and others.

Here is what it could look like if Lyngdorf made it.

http://s1097.photobucket.com/user/grannyring1/media/1DadDHT%20mod/DHT%20Mod_zpspmsxhs4w.jpg.html?sor...

Dumping the output transformer is the key to getting the very best out of tubes.  I have a David Berning pp 300B integrated that puts out 20-25 w pure Class A drives my Rockport Aviors (89.5 db) with ease. The sound is absolutely stunning with Genalex 300Bs.

Blindjim,
Here’s are a few more,
Horning
Vaughn Speaker
TonIan Labs
Sonist
Ocellia
Trenner-Friedl (certain models in their line)
Audio Note
Tekton
Coherent Speakers

Charles 

has anyone established a reasonably current list of High Eff spkrs anywhere?
All I can think of are: Zu; Coincident; deVor; Avant Gard and some horns, which I sure don't mean to dengrate at all. it is merely their esthetic that is a tad hard to take.

Grannyring > The trying not exceed 20% of an amp's power was specifically mentioned by Ralph for SET tube amps …. His statement does not include SS, Class D, OTL and other type amps.


Blindjim > thanks a lot. Now that makes more sense. I knew I was missing something. Just like the part on “lower power, better sound”.



saki70 > Have you given any thought to PSET's ? in your area, Where would you go to hear different tube amp demonstrations? Good Luck .


blindjim > thanks. The learning experience continues and that is always enjoyable. Getting there is another story.
Yes. In fact higher output tube amps or PP amps were and are my only exp with tube amps I have owned. They are the first amps I thought about before trying to learn more on the SET platforms, so I might minimize or eliminate a very big mistake.
As well, the PP glass amps just made more sense given the speakers I was admiring or dreaming about. All had or have mostly decent Eff, but low IMP.
The only SET ish amps I’ve heard to date were the Thor TPA30s at. a dealership in Clearwater largo area. Years ago. In a room near my size, they were driving a pr of VR4 JR pretty well. I’ll never forget that sound.
Apart from that joint, there are not any venues I know of nearby at all. Friends in a local club have some tube gear but its not the more prevalent setup. Most there like Panel speakers and Pass amps. There are likely others I’ve not met that may have glass power running. One was using AR lots o watts amp tube monos to drive their panels with, another was using Avant Gard Unos.

My ‘radar’ is on for any and all Triode and Ultralinear amps, INT, MONO or 2ch.



Atmosphere > This is all about distortion, which all amps make so the ’percentage of usable output power’ has to do with the **kinds** of distortion that are particularly objectionable to the human ear. These are the higher ordered harmonics (5th and above, particularly the 7th), IM distortion, and in the case of class D, inharmonic distortion (caused by intermodulations with the scanning frequency; similar to aliasing in digital audio).
Its my opinion and also my experience that four ohms has no place in high end audio (IOW if high quality audio production is in fact the goal). The cables are more critical and all amps sound harsher and less detailed on four ohms as opposed to eight or sixteen all other things being equal.


Blindjim > Whew!! Super. Got it now. Thanks.
Nearly every spkr I’m growing more fond of have 4ohm IMP!! So its appropriate to echo Charleton heston, kind of, “Damn you speaker makers! Damn you all to Hell!” lol


Atmosphere perhaps you could PM me or enter a link to which speakers your exp has shown are amenable to lower powered glass amps. Certainly, yours and perhaps others too.


My usual approach before this thread was to force a #12 foot into a #10 shoe, amp & spkr, respectively. Merely Add more watts to either overcome the low IMP of the spkr and try to avoid .clipping and or distortion, or with easier spkr loads yield better driver control. Control is an often overlooked facet. Its undeniable when listening however, if its absent.


I’d sure like to see a chart that reveals the equivalency between glass watts and SS watts. SET; OTL; PP; etc.

If tube amps could only manage higher damping factors it might make this affair an easier task.


I’m looking at or trying to figure out just which road, and then which block to land on by making one upscale purchase, and be done. Not at all a ‘cost no object’ affair, but then a ‘destination’ for me, may not be a or the destination for you, though we will both wind up with our own destination arrangements. Unless we just can’t leave well enough alone.


It do get complicated once all the factors are taken into account trudging down the road of better sound. Rooms, $$$$, esthetics. Amp & spkr matching. Topologies. Personal preffs. Logistics. Auditions. Sheesh.



charles1dad > The irony is that the vast majority of high End speakers are in the 4 ohm range. I do believe Ralph's assertion that higher speaker impedance is beneficial to all amplifier topologies. It seems many speaker builders would disagree with him given the predominance of 4 ohm speakers in the marketplace.


Blindjim > sure seems like it to me too as nearly every one on my short list is 4 ohms. Over 90DB but still….
And NONE of them are under $14K, several are above that point. Well above it.



wolf_garcia > Silverline Preludes (allegedly 91 db) with 2 REL subs You can simply turn the amp up to test the limits (at a certain point it just loses it's mind… absolute clarity at the levels I choose to listen, and I'm very picky about noise and distortion


blindjim > My previous Silverline Sonata IIIs were relatively an easy spkr to push too. Current iterations in that line up have just lost their ever loving minds with price increases. OMG.
Congrats with the Pre’s & Rels. You bring up a great point saying two subs are in use.



Swampwalker >   It was this whole issue of sounding "loud" when a system should not sound loud when turned up. Rather, the performance should simply swell and grow with greater impact etc....


Blindjim > Illuminating! About exactly what I needed to see/hear. It troubles me that you and I are on about the same wavelength pretty often. In fact, it should concern you even more. Lol


My impression here is semantics. What if we interpose subtlely ‘irritating’ for too loud, or just ‘loud’, or refer to it as ‘‘subliminally grating’ ?

My first forays into putting t together a stereo commonly ran into OK at low levels, above that, not OK.

Loads of factors abound that were influencing those sonic annomolies. Lots. Not merely ‘synergy’.it was a pretty harsh and lengthy learning curve. Thereafter, from this venue, I found all the answers I needed. Latter rigs never showed themselves as anything but ones I could listen to for any length of time.

Presently, it sure looks likely riding down the middle of the tube road is where I’ll land once more…. Moderate power, moderately high eff speakers with an easy IMP… if I feel its doable.

To that end, the main item to avoid IMO is a glass power train that emulates SS sonics. It would be absurd!

Regardless, the info from this thread has so far been in a word, ‘revealing’.



charles1dad > In addition to the VAC REN amplifier, believe that the Atma-Sphere S-30 , M-60 and the Linear Tube Audio ZOTL 40 would serve Blindjim well


blindjim > I’m eternally grateful for any and all mentioned amp options or possibilities as much as thoughtfulness and home work are required to pursue ANY system errection, logistics too play a big part. The greater the budget the more concern there will be for making or introducing errors or an outright failure in synergy.

Of course, one might just stumble into a room and find it all right there but that seems a long shot IMHO. Would be nice, a turn key outfit along with a pretty fair bargain. Done.

Otherwise, its just a best guess scenario. Regularly. You can have all the specs in hand and still it doesn’t butter your bread at the end of the day. Might be very close too! Just no cigar.


Even finding a few possibly desired items in close proximity to each other seems daunting at the moment.



Swampwalker > Of course, you COULD opt for the WAVAC HE-133 150 wpc SETs @ $77K. That would maximize your choices for speakers, if in fact you had any $ left over to buy speakers ;-)


Blindjim > the goal is to get in and out for way less than what those amps run. Way less. The longer I fuss around with it, the lower I want to go $$$ wise. Lol

Given my ‘front ends first’ approach, I’m all about a solid amp selection and a great source choice. Then… very nice spkrs. What ends up happening is a true mystery at the moment. What where and even when are still in the fog.


Naturally, the amp & spkr combo will be reciprocally introduced.

Regardless, my ‘approach’ works. Has worked well. More than once. It will work again.

More will be revealed.

anyone have exp with Pure Audio Project loudspeakers?

Bill, 
 Okay I see. Yes I  know the Sound Labs speakers.  Your Crescendos are a  very different scenario. 
Charles 

Charles, I did, but that was with completely, totally, absolutely, different speakers! Soundlab M1s with all manner of dramatic impedance swings. 

Ralph, thank you, appreciate your response.
So.. 8 ohm average 89db two way speakers with one 8" woofer and 1" tweeter schould work well enough in a medium size room, generally speaking.

Hi Bill,
I’d truly be honored to be a beta tester for this "unique " 300b-digital (all in one audio product). This sounds unusually interesting . Bill I thought you had tried the Zero transformers in the past and had mixed results. If I’m mistaken then my apology.
Charles

Stfoth…Mine came with the Gold Lion KT88s, an Amperex USA 6SN7GTB from some NOS vintage, and a JJ 5Y3S rectifier. I've since bought another Amperex that sounds identical to the supplied one (different getters, but labeled a USA tube), a new issue Gold Lion GZ34/U77 rectifier which works great with the 88s, and the 274B which sounds like the GZ34 but looks cooler. I also have a set of JJ KT77s but they lack the resolution and sparkle of the 88s in this amp. Note that none of these tubes are particularly expensive (the Shuguang 274B was 18 bucks shipped from China), and you need less of 'em for this amp anyway.

Ralph, besides Classic Audio, what would you recommend to use with your amps? Also, do you believe that short length Mogami RCA cables are just as good as XLR? I mean 2497 wire.

If you keep the cables short you can do pretty well with single-ended connections. I can't comment about the single-ended Mogami- not tried it.

Regarding speakers, Audiokinesis, older Quads (newer ones need the ZEROs), Sound Lab (with our bigger amps), Coincident, Devore, Lowther, PHY (will need a speaker protection fuse as they only handle 20 watts), most horn systems and single-driver systems, AvantGarde, Merlin, Magnaplanars (use ZEROs, Eminent Technology (may need to use ZEROs) Vandersteen, Certain Avalons such as the Eidelon, JM Labs, Rogers LS35a, certain Sonus Fabors, Pipedreams, and many more.

The trick is similar to what you look for with an SET or any tube amp using no loop feedback, which is to say that the woofers should be the same impedance generally speaking as the midrange. Dual woofer systems that are 4 ohms in the bass and 8 ohms otherwise don't work so well. The difference between our amps and SETs is that we can work with speakers of much less efficiency, but personally I do prefer efficient speakers as I like to crank the hell out of the system once in a while and don't see the point of struggling to do that.

I had his Firebottle amp with the KT150 tubes. Tried to drive 92db sentitive speakers in a large space and the combo did not work. I like the build quality and Dennis very much. I was actually selling the amp for a friend and put it into my rig.  Wish I could of heard it on speakers better suited for it. 

I have no idea how many watts my HO generates, although as a recent one it’s maybe 17 watts (it’s not a "Hot Rod", although those claim about the same wattage as mine), but at least 12…I currently prefer it with KT88s and  a Shuguang 274b rectifier (I mean really…a cool looking tube), and these amps come with zero published specs other than what can be gleaned from forum conversations and Had’s comments (and a published log book page  of Hads with various parameters noted in pencil…great stuff…), a somewhat unique thing with no warranty or anything other than good faith from Dennis. Also it wasn’t expensive…relatively...

Kenny, I am working on a 300b mod to my Lyngdorf unit. I will update once finished. I call it the "1DadDHT" mod package. Pictures coming soon! Charles, you will be asked to beta test. 

Gentleman,

Keep the Knowledge coming,

Best thread on audiogon presently.

I'm getting good factual info that were kinda grey areas to me and this thread has educated me well.

I thank you all,

Kenny.

Good points @stfoth,

We have to remember 50 watts with an 805 tube etc, is still a SET amp and the 20% rule comes into play. Speaker matching is still critical. Will it work with a 4-8 ohm, 90db effecient speaker? It depends. Big room, like to listen at 85-90db levels at times, sit 10-12 feet back, then it won’t.

Small to moderate sized room, 70-80db listening, 8-10 feet back from the speakers, then it may work wonderfully indeed. Once the room gets bigger and you want to turn it up more often, then you enter a real risky area. Sometimes your happy, sometimes not with that system. Can be a frustrating place to be.  

No need for Wavac. LAMM ML2.2 would do for many situations. Only $20k or so used.

Well great question. Since the OTL amp does not carry the 20% of rated power caution that Ralph has been talking about, and I have experienced, then the Crescendos can use all the watts available in the M60. Better said, most of the power available.

Also, adding the Zero autoformers actually increases the power output of the M60s by some 50%. So the speakers would be utalizing, in effect, 90 watts.  Yes indeed this would work great.

Just have to decide if I want that many output tubes. I suppose it would be better to get a 12-16 ohm, 95db or better sensitive set of speakers😬

However, I did love the sound of Ralph’s amps. Uncanny resolution and sense of being right there in the midst of the performance.

@grannyring- I forgot about the 300b monos. 
@blindjim  - Grannyring and I went the same route; from 8-9 wpc 300b to 12 wpc EL-34 SETs with the same results.  My speakers were quite a bit more efficient than his (92-95 dB/w/m, 8 ohm nominal, flat impedence) but we both found that Atmasphere was right; when you are down in 10 wpc range, you need +/- 100 dB speakers and/or high impedance speakers if you want more than moderate volume levels in a mid size room.  I know Charlesldad (and others) have had great luck w 300b SETs driving somewhat lower eff speakers, but IIRC, his speakers are 16 ohm. 

Of course, you COULD opt for the WAVAC HE-133 150 wpc SETs @ $77K.  That would maximize your choices for speakers, if in fact you had any $ left over to buy speakers ;-)

Bill,
Would their 60 watt output satisfy you given what you described as the demands (89 db and 6 ohm impedance load)  of the Crescendos?
Charles

I owned the MA1s when I had my Soundlab speakers. Great amps. I don’t want quite that many tubes. The 60s may be my only real choice.

Hi Bill,
I'm very familiar with the Atma-Sphere MA-1 mono blocks,  are you considering these or the M-60s with your Crescendos?
Charles 

Yeah, Ralph confirmed what I have always felt. SET amps are not for most of us, this includes cost. Low impedance speakers is not how it should be.
Ralph, besides Classic Audio, what would you recommend to use with your amps? Also, do you believe that short length Mogami RCA cables are just as good as XLR? I mean 2497 wire.

@swampwalker, +1 big time!

I have been talking to Ralph at Atma recently as I do want a second amp and want for it to be tubes. SET amps will not work with my current speakers. 6 ohm, 89db sensitivity in a very large room.

In order for a SET amp to work for me, it would need to put out 100 watts. Some amazing SET amp! An OTL or PP tube amp could do the job at 60 watts. Especially OTL with the Zero autoformers by Paul Speltz. 

@swampwalker I remember the amp! I purchased a set of 300b monos from you also! I think we have sold each other gear several times over the years.

Hi Swampwalker,
Nice comments, I also suggested the VAC Renaissance 30/30 or a high quality moderate power class A push pull tube amplifier. As you note they do offer increased speaker choice flexibility and are easier to build a system around for most people as well. 

SET will frustrate some people and will require more of a thought out plan of action. It’s worked out very well for me but I knew what was needed and was prepared for it. By the way I am not saying that you weren't prepared for SET,  it just didn't meet your particular needs. 

In addition to the VAC REN amplifier, believe that the Atma-Sphere S-30 , M-60 and the Linear Tube Audio ZOTL 40 would serve Blindjim well. Wolf Garcia seems to be getting results/outcome quite similar to mine.
Charles

Blindjim- I found the same exact thing as Grannyring when I was using SETs (no surprise, one was the same exact amp, and neither of us has ultra-high eff speakers):

The music was wonderful at lower volumes, and they did drive my
speakers to go very " loud " I was initially impressed, only to find the sound not to my overall liking longer term.

It was this whole issue of sounding "loud" when a system should not sound loud when turned up. Rather, the performance should simply swell and grow with greater impact etc....

My mistake was not the particular SET amp, but pairing the amp with a 4-8 ohm speakers with sensitivities ranging from 89-93db.  My 8-20 watt SET amps, while playing these speakers loud, always fell a little short of greatness. 

I have zero and I mean zero technical knowledge but everything that Atmasphere has posted has turned out to be true in my experience.  If you do not want to be confined to ultra-high efficiency speakers I think this means you can rule out the 2A3 and 45 amps.  If you want to go SET, you will probably want something 6C33C, 211 or 845 amps with a moderately high eff speaker (95--96 dB).  I found that 300b and EL-34 SETs did not cut it in my 14 x 23 x 8.5' room, driving 95-96 dB speakers, listening mostly to the same type of music as you do.  Great sound at low-moderate volume, but when you get grooving and want to go a little bit louder, the sound starts to get less enjoyable and fatiguing.  OTOH, my 300b push pull that makes 27 wpc (VAC Ren 30/30) or my 6AS7G OTL that makes 30 wpc (Atma S-30) sound fantastic. 

I think it should be obvious by now that if your speaker or your amp selection is priority one, then you have to get a "matching" amp or speaker.  If you go moderate efficiency, or 4 ohm on the speaker, you are going to want a reasonably large, SS amp, of which there are many.  OTOH, if you decide first on a 45 SET, you are going to be restricted to a fairly small group of very high eff speakers (>100 dB/w/m).  Those are the two extremes.  If a tube amp is your first criterion, and you don't want to be restricted to the v high eff speakers, IMO, you will want something in the 25-30 wpc range (or greater) paired with moderately high eff, 8-16 ohm speakers.  To get that, you can go OTL or you can go push-pull.  The very high output transmitter tube SETs are, I believe, out of your (very generous) budget. 

To get back to your original question, I am persuaded by my limited experience and the technical explanations of others, that the differences between the "voice" of different output tubes is outweighed by the requirements of your amp/speaker combo.  Particularly with SETs, the power requirements dictate the tube choice.  As you go to push-pull or OTL designs, you have more flexibility in terms of both output tube and speaker efficiency.  Both Berning/LTA and Atma-sphere offer a range of power output options in OTL designs and some variation in tube types.  Push-pull designs offer the widest range in tube types and power output, giving you the widest range of tube-friendly speakers to choose from.