Amp Observations

[Ducatista47]

I was participating today in answering the questions of a listener new to tubes. The major input came from a couple of long time audio professional who sell both tube and solid state gear. The list of advantages that presented itself is worth repeating, I think. The last thing on my mind is to start anything; I just want to share what transpired.

He asked, when told about clipping, if that is how a transistor amp protects itself when asked to produce too much power. Well, in a way, yes, I said. To “protect” itself, it destroys your speakers’ voice coils. This stops the unreasonable demand for watts and volts – it disappears – along with your speakers, of course. Tubes clip so gently, they are nearly incapable of perpetrating this act. Tubes produce predominately even order harmonics, much less harmful than the odd order products of solid state distortion. Not to mention much nicer sounding.

When a transistor amp fails catastrophically, it often sends a neat DC current down the line. This does a really thorough job of destroying any pesky ac devices in its path. Like your JBL’s, for instance. When a tube amp fails, it stops creating output.

When said amp needs to be repaired, it goes like this. Transistor amp: be very good at this stuff, or pay someone who claims to be very good for a lot of labor to find the problems. Then pay him a lot more to track down output transistors NLA for a decade or more. Tube amp: test the tubes and replace the one that failed.

How about the sound? Well, the triode is the lowest distortion audio device on the planet. Ask Steve Schell. But what about the overall distortion specifications? The audio pros around here with many years under their belts have noticed that, even back in the seventies, the transistor amps and receivers that measured so-so for distortion sounded OK, while the ones with the .001% specs sounded at best un-involving, more typically like crap. The tube amps generally benched terribly but sounded very pleasing, involving and musical, with ungodly wonderful soundstages and imaging clarity, and no listener fatigue. This has not changed to this day. It seems that measuring distortion by watching instruments does not necessarily have a direct connection to the activity of actually listening to music. Where perception is concerned, the complexity of the human brain seems to render a different reality than electronic “ears” and processors do. This has not changed appreciably in the intervening years, either.

For what it is worth, the fellow liked the tube sound a lot and is going to bring in his Altec Fifteens to do some direct listening. I'll keep you posted if anyone is interested. He'll be in around Christmas time. Me, I've found tubes to be an "electronic Aquaplas" for Altecs in particular and compression drivers in general.

I expect he would like PassLabs amps, but they cost too much for him and he has no time for DIY.

Me, I have liked solid state until I directly compare it to tube gear. I have gone from all SS to half and half to all tube.



Clark In Peoria

[BMWCCA]

Bringing his speakers into a sound shop to audition amps? I guess I did it all wrong back in 1974 when I was fed up with having to replace tubes on my Fisher SA1000 when RCA quite making them. My shop, Hi-Fidelity Showroom in St. Louis, let me take home every amp I was interested in to audition in my listening environment, with my system. Of course my C37s might now have been the easiest to transport but what's to be gained by isolating your speakers from the rest of your system and listening room?

I'll let others pick apart the tube/transistor argument here (if they feel it appropriate) and I'll just say the SA1000 went away in favor of a Crown D150 (couldn't afford the DC300 at the time) and the Mac C20 got replaced by a Soundcraftsmen PE2217 when McIntosh stopped the clinics(still own the Mac though, just for giggles, not for sound). Personally I feel the argument as stated here would be moot if the transistor amp just had adequate power, and that's not hard to do with our speakers and most quality amps. The only failure I've had with a JBL in over fifty years of listening (later foam surrounds excepted) is a blown 075, and that, according to JBL, was from a high-frequency oscillation from a receiver I got rid of by buying the Mac C20 and Fisher SA1000...over forty years ago, and repaired for free. Remember that JBL lifetime warranty?

There may be a compelling reason to buy modern tube amps over transistors today but I'll bet it has little to do with protection and more with perception of sound quality, actually coloring of sound, and hype. Probably sound better with real expensive speaker wire, too!

[Audiobeer]

I transition between the 2 over the years. For my ears Solid State driving my JBLs were what I was into. Most folks who walked into the room asked me to turn it down as the wanted a conversation. In other I liked it loud and slamming.

I'm back into tubes again as I don't really need a lot of watts to appease my volume needs these days. Jury's still out with me when it comes to the musicality (Not a word I'm sure) of one SS over Tubes. There 's never been an argument in my mind.which was more practicle. The tube experiment continues when I can find a preamp match for the MC-30s and I hook them up to the Apollo's.

[Ducatista47]

Well, since I interjected myself into the end of the story - I need to stop doing that - I should have mentioned why I keep going back to tubes. It is the sound quality, but to be fair I am an unusual listener.

I don't listen at very high SPL. Most - not all - of my music is acoustic; jazz combos, unamplified stringed instruments, and sometimes voice. I use high efficiency speakers. Bottom line, not many watts required. One thing that never seems to change is the far superior presentation of tubes at lower listening levels, and at low power levels to high efficiency transducers. I've been doing this for fifty years, and that seems to be carved in stone somewhere.

With my sources, all analog amps with no eq or other signal processing, and given the music I play, microdynamics and natural sounding, accurate presentation are very important to the listening experience here. Given these conditions, I can tell you that tubes are going to deliver better sound no matter what else is going on. You might say that there is no second choice that a working stiff like me could ever afford.

Senseless Rant Over!

Clark

[Ducatista47]

Bringing his speakers into a sound shop to audition amps? I guess I did it all wrong back in 1974 when I was fed up with having to replace tubes on my Fisher SA1000 when RCA quite making them. My shop, Hi-Fidelity Showroom in St. Louis, let me take home every amp I was interested in to audition in my listening environment, with my system. Of course my C37s might now have been the easiest to transport but what's to be gained by isolating your speakers from the rest of your system and listening room?

That is how I do it too, but I get to hear a fair selection of gear regularly. This fellow wants to bring his Altecs in so A) the speakers can be checked out, and B) he can check out all the amps he is interested in in one stop. The listening environment, while not being his, is stable and unchanging, inviting comparison. Living at home with an amp gives a through impression, but an impression is not a comparison. Too much time passes between listening sessions. If you don't get to hear different gear much, A/B is better, I think, to narrow down the choices. Then you can take home the ones you are torn between and decide what your room likes best.

This shop has transistor, MOSFET, tube pre/transistor out hybrids, and all tube amps. All the guy has heard lately is Japanese receivers, so he wants an overview of what is out there.

All that is missing is solid state pre/triode out, a class of one line as far as I know. Probably the finest sounding iron in the world, but I can't afford them, and Central Illinois could not support a dealership. I have not been privileged to hear them, but people I trust say they have never heard better, or as good. Check out the Kronzilla line. http://www.kraudio.cz/
This company makes the 1610 tubes that they and others (ie Cary) use.

Clark