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Tube watts

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#21
Sorry Unclejane, I have not experienced any of your breakdowns in the middle of a gig, and have been mainly using tube amps for 20yrs now.

But back to the topic at hand; I do all my subbing work with my 100w tube amp and sounds great, I could never do that with my old 100w ss amp.
I dont care if a watts a watt...it either works or is doesn't.
 
#23
I like solid state clipping. I've had several tubeless heads that sound great when pushed hard. I also think that tube watts are obviously louder than solid state ones. I have two gigging amps: one all tube, the other completely solid state. I love them both.

So, I don't know which camp I'm supposed to be placed into. How about the one who prefers a good sounding amp regardless of how many glass bottles are out back?
 
#26
I think a key to UncleJane's woe's is revealed in that he was using low Watt tube powered Bassman's that he borrrowed. I have a few tube amps including a Fender Studio Bass 200 watt head (Thanks JohnK !!!) that work dependably, and sound, and feel (touch sensitive power tube sag....mmmmmm good) absolutely great. With a cab that has relatively efficient drivers, there is more than enough headroom/volume also. And I wouldn't loan them out, unless it was to another musician who knew tube amps (how to transport them, how to match ouput and speaker impedances, and how to power them on and off properly). But when I bring that Fender to jams, every other bass player who tries it has something good to say about it. I'll bet it would even surprise you, UncleJane.
 
#27
Greyvagabond said:
Tube amps are louder than SS amps of equal to twice the rated wattage. That doesn't mean they put out more "watts" though; they're just louder. Which, after all, is what we're after, isn't it?
Click to expand...

How does one go about making one watt louder than another watt?

Heck, if I could do that I could conceivably make a 1 Watt amp that's as loud as an SVT.
 
#28
mongo2 said:
How does one go about making one watt louder than another watt?
Click to expand...

TC Electronics (maker of SS amps) explains it this way:

"The nature of tube amps is very different from that of transistor amps. Rather than suddenly hitting the distortion point, tubes gradually go into saturation and tend to ‘round off’ signals in a very soft way when getting to its maximum performance.
The overdrive created by tube amps is quite pleasant to our ears and is known by many as a central part of the highly complex ‘tube sound’ that have been pursued in many bass amp designs.
Again, looking at bass signals, the gradual saturation of tubes essentially ‘compresses’ or limits the high peaks of the bass with only little resulting overdrive thereby altering the original crest factor to become quite a bit lower than the original signal with a consequently higher perceived loudness at a lower power rating – this is a quite known effect by many users, usually referred to as the difference between ‘transistor watts’ and ‘tube watts’ .
In the example below the 400w tube amp has reduced the peaks, and hereby the crest factor, of the original bass signal, achieving a perceived level and power of 300w.
This means that the 400w tube amp and 800w transistor amp are perceived to have the same power even though they are vastly different in the actual power measurable."

here's the whole article:
[Invalid or Expired Link Removed]
 
#29
I percieve tube watts as being louder. Key words are "I perceive". I don't give a crap about specs, the math of it, watts is watts.....whatever. Someone here with better technical skills can put it on paper and put it in front of my face and tell me I'm wrong all day long.....until I plug into my old Mesa Boogie that is. My old Mesa Boogie Bass 400+ would CRUSH my old GK 1001RBII through my Mesa 2X15" (and any other cabinet I tried them with). I don't know why tube amps sound louder to me and I really don't care.....I just know that they do.

I don't have my Mesa anymore (miss it but not lugging it around).
 
#30
Boot Soul said:
I think a key to UncleJane's woe's is revealed in that he was using low Watt tube powered Bassman's that he borrrowed. I have a few tube amps including a Fender Studio Bass 200 watt head (Thanks JohnK !!!) that work dependably, and sound, and feel (touch sensitive power tube sag....mmmmmm good) absolutely great. With a cab that has relatively efficient drivers, there is more than enough headroom/volume also. And I wouldn't loan them out, unless it was to another musician who knew tube amps (how to transport them, how to match ouput and speaker impedances, and how to power them on and off properly). But when I bring that Fender to jams, every other bass player who tries it has something good to say about it. I'll bet it would even surprise you, UncleJane.
Click to expand...

No thanks, I'll stick to my SS's thankyouverymuch ;).

As for the Bassman I used, adequate power was the very least of its problems. It was plenty loud through my 2x15 when it was working. It was just everything else that was a problem. It was a nearly new head as in hardly used owned by the manager's wife (for reasons unknown, she didn't play).

When I finally got my Sunn from a pawn shop it was nirvana by comparison, even tho it had its own crappiness being a Sunn I never had to wiggle tubes or try to find replacement sockets and deal with all the rest of the yuck of dealing with a tube amp.

Another I borrowed was something that had Plush written on it. Made this strange crackling and thumping sound by itself all the time. That one had problems tho so it's not a good representative sample.

The current idea of having a 12ax7 in the preamp of an otherwise all SS amp is, IMO, much much better than an all tube amp. I've tried a few of these and sure enough when overdriven you can get the chocolately tube kind of fuzz without the harsh braap. If I had a use for that sound the tube preamp would be an option I'd consider.

But for actually playing bass and being heard, there's just no comparison between that stuff and our new SS amps. It's just night and day better in every respect. Even my rickenbacker gets a good, audible rick sound through my GK rig (which it's played by a good player and not me that is).

LS
 
#31
unclejane said:
But for actually playing bass and being heard, there's just no comparison between that stuff and our new SS amps. It's just night and day better in every respect.
LS
Click to expand...

For you maybe. I still think that a vintage SVT/8x10 would have a good chance of changing your mind, but to each his own.
 
#32
johnk_10 said:
TC Electronics (maker of SS amps) explains it this way:

"The nature of tube amps is very different from that of transistor amps. Rather than suddenly hitting the distortion point, tubes gradually go into saturation and tend to ‘round off’ signals in a very soft way when getting to its maximum performance.
The overdrive created by tube amps is quite pleasant to our ears and is known by many as a central part of the highly complex ‘tube sound’ that have been pursued in many bass amp designs.
Again, looking at bass signals, the gradual saturation of tubes essentially ‘compresses’ or limits the high peaks of the bass with only little resulting overdrive thereby altering the original crest factor to become quite a bit lower than the original signal with a consequently higher perceived loudness at a lower power rating – this is a quite known effect by many users, usually referred to as the difference between ‘transistor watts’ and ‘tube watts’ .
In the example below the 400w tube amp has reduced the peaks, and hereby the crest factor, of the original bass signal, achieving a perceived level and power of 300w.
This means that the 400w tube amp and 800w transistor amp are perceived to have the same power even though they are vastly different in the actual power measurable."

here's the whole article:
[Invalid or Expired Link Removed]
Click to expand...

That has more to do with perception than watts.
 
#37
I use a 33 year old SVT that I have been regularly gigging since I bought it 9 years ago. In that time I have had precisely 0 failures and have had to replace 0 components. I still have the original Magnavox coke bottle 6550s and they work just fine. I've spent a lot of time repairing amplifiers in my day and my experience is that failures are about equally common between tube and solid state amps. There are a lot of old tube amps out there that are working just fine with practically 0 maintenance.

I have a buddy who bought a well-respected gold coloured solid state amp at about the same time as I bought the SVT. In that time, it's been in the shop for various repairs 10 times or more. That's not a reflection on all solid state amps or even that manufacturer because there are plenty of them out there that haven't had any issues. It's just that particular one.

The unreliable nature of tube amps vs solid state ones is a red herring.


And tubes are actually inherently a lot more linear than transistors are because of their lower open loop gain. You can design a tube amplifier with effectively no negative feedback and it will work and probably sound pretty decent. You can't do the same with a BJT. The high open loop gain will make it unstable and even if it didn't, there'd be an awful lot of distortion. That being said, you can typically make SS amplifier circuits more linear than typical tube ones because you can use so much negative feedback to force them to be linear. With tubes, the amount of feedback you can apply is limited by low open loop gain, which limits ultimate linearity.

Some of the differences in the two types of amps at their linear limits can be traced back to the amount of feedback used in them.
 
#39
Mark Reccord said:
The unreliable nature of tube amps vs solid state ones is a red herring.
Click to expand...

Maybe for lucky you, but other industries have found a vast difference and incentive to move to SS for better reliability.

Zero feedback amplifiers are parlor tricks. There have been zero feeback SS amps created - but they're not practical. On the other hand, You would not be able to build a modern Op-amp with tube components.
 
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