Tube watts

[Korladis]

I have a solid state Acoustic Image Clarus head that I absolutely love and which has been a reliable workhorse for me for the past 8 years. After reading through this thread, I plugged it in to do some practicing. And it blew up.



How is that for irony?

That's horrible, yet hilarious.

 

[Mark Reccord]

Get your amp fixed. Surprising though as SS is much more reliable in general.

What exactly are you basing this assertion on? As I said before, ask any amp tech worth his salt and he'll say that failures are about even between the two. Put it this way: I have seen broken specimens of just about every piece of MI and pro audio gear in existence, tube or SS. All types of electronics fail from time to time.

And tell the FOH guys they should switch to tubes and see how long it takes them to throw up as they're laughing their heads off.

Horses for courses. Tubes amps are clearly not practical for that purpose.

 

[xk49w]

It's simple. Amps are rated at a low distortion figure, not at what they actually can produce. Pushed into distortion tubes have natural compression, and when pushed well beyond their rated power sound good. SS has no natural compression and pushed even a smidge past their rated power sound bad. With adequate processing you can almost duplicate the sound of tube with SS; with tubes that processing isn't necessary, they sound, well, like tubes.

+1.

Same old story, same old thread. Tube amp into distortion, probably acceptable. SS without limiting and into distortion, not so acceptable. If my SS amp isn't loud enough without going into distortion or compression then I'll buy another one, at 1/4 the price and 1/10 the weight of the tube version.

 

[Korladis]

Horses for courses. Tubes amps are clearly not practical for that purpose.

Indeed. Tubes do color the sound. For reproducing the sound the band is making, you don't want that, even if some of the band musicians use that coloration in their individual sounds.

Basically, as I understand it, tube amps and SS amps are both rated at the highest "clean" setting. Most SS amps can't really be turned up into the range of distortion and sound good, so that highest clean volume setting is, for practical purposes, as loud as it gets.

Tube amps, however, can be turned up far past the point where they're no longer "clean." Distortion enters the sound gradually the more you turn up. While some people don't like that sound, lots more like it than like the sound of an SS amp turned up into clipping range. I'm one of those people. Part of why I don't want a 70's SVT or SVT-VR is that it actually has too much head room, and so it's just too loud by the time it starts breaking up.

My SVT-350H was rated for 350 watts, whereas the SVT-VR and CL are only 300. However, that 350 watts is the maximum usable output of my old SS amplifier. With a 300 watt tube amp, that wattage rating is just how much power it's putting out before there's distortion. You can turn it up way past that point, and so end up putting out something like 650 watts.

 

[rbonner]

GUYs GUYs, hey.... Bill's analogy is sort of right as far as a brick wall, but didn't actually explain the issue.

Toob amps are tube amps, they put out real watts. Voltage times current to the speaker. Whether it is rated in peak, peak to peak or RMS watts. All are different forms of measurement.

When you crank up a Toob amp and push it "Too Far" the tubes allow compression and distortion naturally. The best sounding toob amps this process is done in the preamp stages.

SS amps. When a solid state amp clips, or is pushed beyond its rating components FAIL. A transistor cannot operate outside of any of its parameters without destruction.

***Back in the early days of SS amps the engineers took this limitation and rated a 100 watt SS amplifier equivalently the same loudness as a 100 watt tube amp, however... They had to build a 300 watt capable amplifier to do this. Why? Because the amp couldn't be pushed into the TOOBY GOODNESS region without destruction.

Then the frickin marketing department got involved. Its really a 300 watt SS amp so lets sell it that way... Patooie... Yes infact it will pass 300 watts, but 1 watt over a rating and you blow up.

This is why an SVT toob amp at 300 watts is pretty close to an SVT-4PRO at 1200 watts, actually the 4PRO is just under 400 watts of equivalent power. I've compared these before.

The 4PRO will actually make 1200 watts (1600 peak) But most of that power is provided to give the FET's headroom before destruction...

NOW, lets put a tube preamp on a SS final. You get your tooby goodness in the preamp and pass that signal, maybe even clipped to an SS final which linearly passes the signal and all is safe and good.

Unfortunately speaker manufacturers have jumped on this headroom type rating and we've got speakers melting in the field.

You just have to keep your head about things and understand why the industry has done this.

There is no toob watts and Solid State watts, but just remember the manufacturers have placed 3-4 times the power in their SS amps to provide the headroom necessary to avoid self destruction, That is all. Just ignore the marketing department, OK?

BOB

 

[seamonkey]

Tho if tubes hadn't gone obsolete for everything except very high power applications (like multi KW or MW RF transmitters), who knows how they would have eventually developed....

LS

Even there - eLoran the worlds most powerful radio transmitters have gone SS. See:
http://www.locusinc.com/library/2004 Nuts Bolts 2.pdf
Cutting huge costs in maintenance.

 

[Kelly Lee]

I didn't know my question was going to produce this debate!

Well, I guess you learned something today, huh? The FAQ's thread has links covering this topic thoroughly. I will add this one to it as well but this thread will remain closed.

One more thing. I'm rather annoyed that the same misinformation about tubes pops up in every one of these threads. I'm starting to think some of you are intentionally trolling. Just in case people don't remember the rules, trolling is not allowed here at Talkbass.