What makes an All Tube amp ?

R

richard parker

New member
If you look inside a simple single channel non-master volume amp it's not like there's nothing in it but tubes. There's lots of stuff in there that isn't tubes that presumably makes a contribution to the behaviour and sound of the amp. Are amps that use diode clipping not all tube amps ?

Just wondered.....
 
Re: What makes an All Tube amp ?

Tubes? Lol, I never really thought about it like that, you make a valid point? I think technically speaking if it uses diode clipping it's not "all tube" but that doesn't mean they don't call it an all tube amp. I was always under the impression that "All Tube" refers specifically to the power, pre amp, & reflector sections of the amplifier? Then again I've seen amps with S.S. reflectors advertised as all tube as well???
 
Re: What makes an All Tube amp ?

richard parker said:
If you look inside a simple single channel non-master volume amp it's not like there's nothing in it but tubes. There's lots of stuff in there that isn't tubes that presumably makes a contribution to the behaviour and sound of the amp. Are amps that use diode clipping not all tube amps ?

Just wondered.....
Click to expand...
In an "all tube signal path" there won't be anything but capacitors and resistors. The only solid-state diodes might be in the power section for rectification, unless the amp uses a tube rectifier.
 
Re: What makes an All Tube amp ?

Nostalgic Distortion said:
Tubes? Lol, I never really thought about it like that, you make a valid point? I think technically speaking if it uses diode clipping it's not "all tube" but that doesn't mean they don't call it an all tube amp. I was always under the impression that "All Tube" refers specifically to the power, pre amp, & reflector sections of the amplifier? Then again I've seen amps with S.S. reflectors advertised as all tube as well???
Click to expand...
Reflectors?
 
Re: What makes an All Tube amp ?

I've always figured an all tube amp uses tubes in both the pre and power sections. If an amp is using solid state devices in either, it's not all tube.
 
Re: What makes an All Tube amp ?

GuitarStv said:
I've always figured an all tube amp uses tubes in both the pre and power sections. If an amp is using solid state devices in either, it's not all tube.
Click to expand...
Isn't there a JCM900 that has clipping diodes in the signal path for more distortion?
 
Re: What makes an All Tube amp ?

If your gain isn't coming from the vacuum tubes, you don't have an all tube amp. That would make the amp some sort of hybrid.
 
Re: What makes an All Tube amp ?

GuitarStv said:
If your gain isn't coming from the vacuum tubes, you don't have an all tube amp. That would make the amp some sort of hybrid.
Click to expand...


what if some of the gain is from diodes and some was from tubes? Many of the amps Friedman makes are like this. Its a version of the much venerated "jose" mod from Jose Arrendo. Marshall has used diodes to boost gain starting with the Jubilee amps, also the 2210's and 2205 and the JCM900's

There are a ton of modern amps that use a combination of tube and diode gain. All of which are billed as "all tube"
 
Re: What makes an All Tube amp ?

I think the definition has changed a bit....or at least there is some tolerance there as to what is classed as all tube. Even with a clipping stage, you could still possibly get away with the 'all tube' designation as tubes control all the signal amplification.

And I'd still call an amp all tube if it had a solid state rectifier.....

Its one of those 'no consensus' issues, as there is both a literal and figurative definition at play.
 
Re: What makes an All Tube amp ?

Edgecrusher said:
what if some of the gain is from diodes and some was from tubes? Many of the amps Friedman makes are like this. Its a version of the much venerated "jose" mod from Jose Arrendo. Marshall has used diodes to boost gain starting with the Jubilee amps, also the 2210's and 2205 and the JCM900's

There are a ton of modern amps that use a combination of tube and diode gain. All of which are billed as "all tube"
Click to expand...
A 5150 is all tube (no diodes) and sure as heck doesn't need any boost. :firedevil
 
Re: What makes an All Tube amp ?

richard parker said:
If you look inside a simple single channel non-master volume amp it's not like there's nothing in it but tubes. There's lots of stuff in there that isn't tubes that presumably makes a contribution to the behaviour and sound of the amp. Are amps that use diode clipping not all tube amps ?

Just wondered.....
Click to expand...
Yes.....they are all tube. There has never been a guitar amp that did not have diodes in it.
"All Tube" refers to the fact (you can judge whether or not it is important) that all the amplification is via vacuum tubes.....no SS Devices such as transistors or Op Amps.
All the voltage amplification in the preamp is from tubes.
All the current amplification in the power amp is from tubes.
You are correct, of course, "all tube" guitar amps are full of components besides tubes. :)
 
Re: What makes an All Tube amp ?

GilmourD said:
Isn't there a JCM900 that has clipping diodes in the signal path for more distortion?
Click to expand...

yep. there are actually lots of amps that use that kind of configuration.

To the OP: there is really no such thing as all tube. Every amp need lots of other stuff including resistors, capacitors, wire, cabinets etc. I this sounds facetious but its true. So what this means is the term "all tube" is just marketing jargon and everybody has their own definition of what "all tube" means.
Some might say an all tube amp needs tubes in the preamp as well as the power amp. However, what if they have solid state rectification? Is that an amp that is no longer "all tube"? What about mesa boogies where you can switch rectifiers?
Many modern marshalls and other high gain amps have diode clipping circuits to get high levels of distortion with reliable running. Does employing clipping diodes make the amp no longer "all tube"?
How about amps that claim to have a tube preamp...but that it is really just one 12ax7, with the rest of the gain stages made up using transistors?
How about amps with no clipping diodes and a pair of tubes in the preamp, but a solid state phase inverter before hitting the power tubes?

Anyways....there is no such thing as "all tube". It just comes down to what each tube in an amp does, and how the amp sounds to your ears.
I have found that even some classic amps such as a 5e3 or princetons can be improved by replacing the tube recitfier with an ss circuit. In the end it comes down to taste and how the amp feels when you play it.
If you want to get as close as possible to the concept of "all tube" you have to look at the job of what tubes do, which is more or less the same job as what transitors do. So i guess the closest you can get to "all tube" would be an amp that only has tubes, and no transistors anywhere in the circuit.

Whatevs man...don't get too hung up on it. You need other things apart from tubes to make an amp work, so play a few and trust your ears.
 
Re: What makes an All Tube amp ?

richard parker said:
If you look inside a simple single channel non-master volume amp it's not like there's nothing in it but tubes.

There's lots of stuff in there that isn't tubes that presumably makes a contribution to the behaviour and sound of the amp.

Are amps that use diode clipping not all tube amps ?

Just wondered.....
Click to expand...

Nostalgic Distortion said:
Tubes? Lol, I never really thought about it like that, you make a valid point?

I think technically speaking if it uses diode clipping it's not "all tube" but that doesn't mean they don't call it an all tube amp.

I was always under the impression that "All Tube" refers specifically to the power, pre amp, & reflector sections of the amplifier?

Then again I've seen amps with S.S. reflectors advertised as all tube as well???
Click to expand...



I am not an electrical engineer, nor do i understand much about it, and this is only in my opinion, but to me (seen through my eyes) a valve/tube amp needing the help of diodes for clipping, in NOT an all valve/tube amp.

Again, i am probably wrong on a technical / amp engineering standpoint, but for ME, it is not all valve/tube.

That is why i get so frustrated when Blackstar Amps advertize their entry level amps as ''all tube'' units.
The box & manual should atleast say, ''all tube, with the aid of diodes''.
Why ?
Then there is no finger pointing for false advertizing.

Again, just imho.
 
Re: What makes an All Tube amp ?

richard parker said:
Some of the JCM800 amps had clipping diodes.
Click to expand...

YUP, the Silver Jubilee, is one of 'em.



GuitarStv said:
If your gain isn't coming from the vacuum tubes, you don't have an all tube amp. That would make the amp some sort of hybrid.
Click to expand...

That's what i believe too - and feel should be advertised as such, imho.



GilmourD said:
Isn't there a JCM900 that has clipping diodes in the signal path for more distortion?
Click to expand...

Correct. AFAIK, it was only the JCM900 SL-X, that was not diode assisted.
 
Re: What makes an All Tube amp ?

No way in hell is Blackstar's entry line all-tube. The inside of those guys would make Intel jealous. At least in my HT-5, the first input gain stage is op-amp based, as is the phase inverter. The preamp tube provides two gain stages, and art least one of those is clipped by diodes on the gain channel. Not even slightly all-tube.
 
Re: What makes an All Tube amp ?

I have a Jet City Picovalve and it is definitely all tube. I think that the same thing goes for my Carvin XV-212. That being said, an amp should be judged by it's tone not it's configuration. I'd like to see some one do a double blind, pro/am "taste test" between a few comparable (quality wise) amps and see what the result is. Though I agree that the one's that use a diode clipping stage should be termed "hybrids" the same a s using a tube preamp into a ss power section. And don't forget the Bogner/Line 6 collaboration that used a digital modeling section in front of a tube power section. I can't imagine that it sounds bad.
 
Re: What makes an All Tube amp ?

I know people who ABSOLUTELY HAVE TO HAVE an all-tube amp....

...so they can run 37 transistor and digital effects pedals in front of it....

Bizarre!

Bill
 
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