Sonic qualities of SET output tubes?

Ralph, Thank you for this great post. I enjoy your posts as they are always so informative.  

Atmosphere > as the power goes down the sound improves.

Blindjim > Atmosphere thanks so very much Lemme see If I am getting this correctly.

Many or all of the output tubes predominately used in SET amps more or less, possess about the same electrical criteria, bandwidth,linearity, so the apparent sound or voice we hear from various Triode amps output tubes comes mainly . as the result of how well or badly they match up with the transformer being used, and how much they are being pressed to output power?


I will suspect too, the limitations of pouwer output makes their transformers either larger or smaller by comparison to other Triode output tubes.


Lower power = Better sound.


OK. Period paragraph?


I know the A’gon bottom line here… “ya gotta try it or them to really know”. Fine. I’m merely looking for directions now, not whose name gets put on the check or to whom I hand the plastic.


PP amps are certainly an option for me.
Here’s my inference….
Every pre or amp (s) I’ve owned was a transformer coupled arrangement.
In previously owned multi tube line stage fully balanced preamp, and one entirely SE, switching in and out the same tube type, but from a different era or from another Brand, always changed the sound.


Sometimes the performance being realized was improved too, not always though. At times, the gains were marginal, sometimes though, immense. Those earmarks were more silky, more or less smoother, more bottom end, more or less dynamic, more or less perceived extension.


It was either that or I’m deaf as well as nuts.


I swapped out 6922s to other brand 6922s and the sonics were altered. I switched out 6922s for 7308s (an electrically appropriate replacement tube) and the change was not subtle. Only the era of the tubes were different, otherwise, they were the same maker, Amperex.

In that same preamp I replaced RCA or Phillips ? 6L6 with Tungsol 5881s and again, there was improvement in several areas.

In the SE preamp merely replacing the 12AT7s and 12AX7s from JJs to RCAs to Amperex Bugle Boys, realized an increase in performance each instance, respectively. The Amperex BBs unquestionably were the top choice for overall performance increase.


Once more in a pair of mono blocks using EL34s in Ultralinear, moving out the JJs to CED Winged Cs made me a much happier camper.


Even when an amp was running in Ultralinear I preferred the EL34 to a KT 88 amp of similar output and expense.
.
Along the way, I have seen thru various brands and iterations, each tube model had a specific or IMO indemic fingerprint on the sound and its presentation albeit to lesser or greater degrees. Always however, the flavor of the sound became altered with the rolling in and out of even likewise tubes.


Other tubes came and went I simply do not recall them all, but my rationale for posting this question or inquiry for feedback on Output tube ‘Flavors’ was the direct result of those experiences.


Enjoying the sound of ‘glass’ from my experiences a good bit more than what I’ve heard from completely SS powered affairs, I’m nearing the cross road of making the choice to go this way or that with a projected system build. Tube power, tube and SS power, or simply go all in and use tubes for control and power on limited funding so only one option is possible.


… and we’re back to the original Q… which 6550, 300B, EL34, KT88, 211, etc., is it going to be?

As such, and it seems tubes have the present vote, then Which tube preamp would be a likely prospect for me with my musical preffs which range greatly?


I can only surmise, it will likely be PP, not single tube power amp.



Kenny. > more of your setup info is needed.
Blindjim > I’ll be needing speakers and amp (s). other items too for sure, but mainly those two items to begin.


Medium sized room (14W x 20L X 9H) closed off completely. This will certainly change to a somewhat larger overall room too. I’d opt in for one a bit wider to 16 or 17ft, and about the same for depth, 20 – 23ft. or so.


Listen to everything but Rap, Hip Hop, and what is being called present day R&B, but I do like old school RB. Not big on show tunes, opera or classical just now, but I do enjoy some. Defaults are CW, Folk, Americana, Blues, RB, Classic Rock, some POP. Not keen on curren themes on many of the standard genres. Even country ain’t country any longer. Love bluegrass. Singer songwriters like Simon, Morrison, Chapman, Baez, Prine, Zimmerman, Stapleton, EJ, Cash, Yokam, etc. Jazz, Reggae, and solid Rock bands such as AC/DC, Def, Zepplin, Airplane, Santana, and so on. Big bands doing jazz and R&B, and Rock. And others.


Speakers are as well another Question mark if a tube amp does get elected. Otherwise, I’ve a short list for those speakers I’d think a solid choice, all of which appear to need or enjoy significant power and or ‘damping.

All of them will be off the table if I opt for another tube amp or amps.


A great concern is acquiring a ‘too lush’ sounding triode amp or amps that are counterintuitive to the genres I dig. And, or being forced into buying horns for this or that amp and then being sentenced to life with the pairing or taking an enormous loss on a later sale of either or.

If you are asking about SET amps, I don't think the question of speakers is a secondary one. I've heard speakers that can play with SET amps but aren't really sustained by them and benefit from greater power. I think you have to treat the amp-speaker combination synergistically. Don't mean to sound patronizing, I gather you have been around the block. 
I'm listening to two very different systems right now- a horn system with Lamm SET amps and a Quad ESL with old Quad II amps and top notch glass. Both are marvelous, but the amps are working well within their parameters and mate extremely well to the specific speakers. 

Whart is spot on. The sensitivity of the speaker is vitally important and that must be known before picking or considering any amp. For example, a speaker with 89db sensitivity at 8 ohms will require far more power than a speaker with 98db sensitivity at 8 ohms. The first speaker will need at least some 50 watts,  while the second will work with perhaps 3-8 watts.

As the sensitivity goes down the need for more power goes up significantly. I know you are aware of this due to your seniority and experience here.

Knowing how loud you play your music and the type of music played are also important considerations. Can a 30 watt tube drive a 89db sensitive speaker to 75 -78 db comfortably in a modest sized room? Yes most likely. But if you want db levels approaching 90db on average on some listening sessions with orchestral scores, then absolutely not.

I have read some great stuff that Ralph at Atma-sphere puts out on the watts and db relationship with tube amps and speaker sensitivity. Perhaps he can repost that here.