Enough SET Power for Rock and Roll


I'm still trying to figure out what SET amp would sound best for Rock and Roll (and other music but especially Rock) on Klipsch Cornwall II speakers (101dB efficiency) in a room about 18x13 (with kind of medium acoustics - not live, not totally dead.) On a Marantz 2230 (which sounds very good, surprisingly good for being ~35 years old and 30 watts of solid state) I found that when I crank up the Rock and Roll on the Cornwalls I'm listening from about 89dB to 97db, but frankly if I wasn't worried about clipping or blowing out the speakers or receiver I could probably enjoy an occassional 100 dB :) - but if I have to live at 97 dB and below I could. (Measurements made with a Radio Shack meter set on fast, C weighting - taken from 1 meter away from the speakers, and also at the main seating position which is about 10-11 feet from the speaker plane.)

From many posts here and over on AudioAsylum it sounds like a 45 SET amp would sound great but might not have enough oomph - although that isn't 100% certain. It seems that a 2A3 SET amp would have a better chance of handling the loud music and the "complexities?" of Rock (and orchestra music) vs. say simple instrumentals and vocals. Next up would be a 300B SET, more power but some people seem to think it gives away some of the "magic" of the 2A3 and especially the 45. It isn't so clear to me from reading the various posts how any of these tube types do on the low end; I think low end (reasonably deep and tight) is needed to do Rock and Roll well - but so is good midrange and highs, so it's a balance, of course.

What do you think, more power and listen loud with ease, ie go with a 300B, or can a 2A3 or possibly a 45 do it all? Or is it possible that SET just can't do Rock and Roll seriously with 101db speakers in a 18x13 rom? In which case, next up is what kind of tube amp? If SET makes sense, I'd like to give it a try but I don't want to push physics or the budget too hard with experiments that aren't likely to work.

Thanks!
hi_hifi
jetex,

Audio Note always has one of teh best sounding rooms at shows I’ve been to.

They seldom have rock music playing, but the larger bass driver and box used and corner placement combined with efficiency and overall quality is a very good example of a system built to be able to do most all things very well.

I’ve stolen the corner placement idea from them and use it with other box speakers I have of similar concept and the bass reinforcement corner placement provides alone might help push a system not otherwise built for rock music over the hump. Along with all the rest.

The only penalty paid I think is depth of soundstage in some cases but most people can probably live with that tradeoff.  Most traditional box designs are not champs at soundstage depth in particular to start with.
you'll find yourself turning it down to 50-60 decibels and about 2-3 watts per channel,
There is a reason that it appears that you don't need the power if you have SETs. It has to do with how they distort and how the human ear/brain system uses higher ordered harmonics in order to gauge how loud sounds are.

SETs don't have measurable distortion at low power levels (the source of their 'inner detail'); as power is increased the 2nd, 3rd and 4th come into play (the source of their 'warmth' and 'bloom') and after about 20% of full power is reached the higher ordered harmonics come into play (at full power most SETs make about 10% THD; if anyone claims less its either because they spec the power at a lower level or because they are running feedback. Because our ears use the higher ordered harmonics as loudness cues, the amp might appear to be more 'dynamic' (since the loudness cues or excess distortion is on the transients where the power is) or it might sound 'loud' simply because of this distortion.

If you take away that distortion it won't sound loud anymore and you will naturally turn up the volume, perhaps by as much as 15 db or more depending on the amps and speakers! Note also that by me telling you this, you will now be aware that distortion is why the amp sounds loud and dynamic so the experience might not be as pleasant as it was before. The cerebral cortex is funny that way. So I might have ruined it for you.

FWIW, about 90% of the time audiophiles are talking about 'dynamics' (and usually the plural not the singular) they are really talking about distortion, and as a result the word 'distortion' can safely be substituted into the sentence without changing its meaning.

Since it really is about high end audio sounding real, the solution is of course either more power or more efficiency or both. The thing is, the real challenge is bass (the holy grail of both SETs and high efficiency loudspeakers), which lacks more as the amplifier power is increased. The bigger the amp, the less bandwidth. That's why the 300b was king 20 years ago, but by 15 years ago the 2A3 supplanted it (sounds better due to greater bandwidth in the output transformer) and finally that got supplanted by the 45. IOW there is an economy of scale! The result is unconvincing bass (I played string bass in several orchestras for many years- I'm hard to please in that regard) and no way around it. The smaller amps play bass better but the speaker efficiency you need to really show off what the amp does means you can't have any bass. This is excluding the use of a subwoofer of course.
Atmasphere, I have read your posts on this subject of loudness in a SET amp over the past few months and started to listen for those queues of loudness in my system. It may be because I am running at slightly over 10 watts ( 375v plate to heater, 85ma, 2700ohm primary on my audio note output transformers) but I rarely hear those loudness queues you are speaking of. Even on very dynamic orchestral music I hear power and it even seems that there is additional headroom to spare.

My sound is very different than that of a large horn system. I've heard a large horn system with sub woofers and it can play at concert levels without strain. Sounds like real instruments. That's the focus of this particular horn system. I've heard CH AMPS and YG speakers and this seemed to have more headroom than mine. But these systems also don't have the touch and texture and layering of my system. My system doesn't do instruments at concert levels, and if it did I would have the police knocking on my door here in Brooklyn ny. Honestly who can stand live concert hall level music in their living room anyway. I've listened to a string sextet in a large living room and the group put out a lot of sonic energy and many times it sounded loud...too loud. If that's the goal of your system your hearing will be gone very soon. That's not the goal of my system, my system does take me inside the music to the heart in a most addictive way. 

Mapman, I’ve heard speakers like volti Vitoria that are based on klipsch Lascala that are more immediate sounding than Audio Note. There are lots of speakers I’ve heard but that do many things better than AN, but as you say they do many things well and play lots of different music and do well with 8watts. It’s difficult to find speakers that are good at getting to the heart of many types of music.
jetrex yes I've heard the Volti speakers at shows as well and understand what you are saying.