Building a Tube Amp

[Eeyore]

Depends which stream you're calling "main". ;-) John probably likes
big bands and classics. ;-)

They need no amplification of course, except they tend to get it anyway
these days regardless.

Graham

 

[kevin93]

kevin93 wrote: ...

Another fallacy.

Most guitar amps run in push pull *Class B* (i.e AB'ish). The cancellation
can only occur when both output devices are active simultaneously. Most of
the time one device is inactive, so you can not get the I^2 - (-I)^2 effect,
except around the x-over point.

....
Surely not - if you have symmetry you cannot have any even harmonics.

If the two devices are not matched or you have asymmetry in your input
signal I can see that you could get even order harmonics. But the
same argument could be applied to solid-state amplifiers as well.

kevin (another one)

 

[Eeyore]

in

I have seen them melt the glass.

I have seen the plates melt.

Graham

 

[Eeyore]

Nonsense! You compared a toooob amplifier against some cheesy Radio
Shack solid state amplifier.

If you prefer the "warm" sound of a toooob amplifier go right ahead,
but don't offend our sensibilities with words like "sound quality".

Guitar amps are not about 'sound quality' they are about 'sound character'.

Jim's Alzheimer's is making him confuse the issue with hi-fi.

Graham

 

[Eeyore]

I will leave the microphone claim for someone else to have
fun with, but a typical home speaker is around 1% efficient
(electrical watts to acoustic watts). A JBL Model 4675C 1200W
cinema screen loudspeaker system is 6.3% efficient.

And compression horn loaded mid and HF drivers can be well over 10%.

Graham

 

[Eeyore]

Having said that, its so....... much hassle though, that I am back to stomp
boxes with "amp simulators". In fact, my new tascam 2488 digital multitrack
has a special guitar processor section, and I am actually quite happy with
it. You can dial up different cabs and distortion, echo etc.

But it's not the norm. And that's home recording anyway.

Graham

 

[Eeyore]

However, I am thinking of resorting to that to get my Marshall AVT to give
its full power into its own cabinet. Like, its just about impossible to get
single 4 ohm 12"s, especially at 100w+

So, I emailed marshal once and said , do you know of any sources of decent 4
ohm speakers to put in my amp. The replied, no, but why don't you just
connect up another cabinet...dah....

P-Audio.

Graham

 

[Eeyore]

Yeah, that is a really interesting comment from John. I do have some clean
guitar work, but by and large, I generally play solos with distortion. If we
went to see a band live, its essentially, a certainty that the band will be
playing with distortion. So, its ceratinly main steam...

However, statistically, how often is the guitar played with distortion
against without? I am not so sure on that one. The majority of music is not
Rock. apparently, its err "Bass and Drums".

That's the modern DJ shit. A passing fad. Makes up for the fact that kids today
can't play bugger all.

Graham

 

[Eeyore]

Nope. All of it can be done in software, and much of it can be done
with skilled application of solid-state electronics. Some of the early
attempts to make a transistor amp act like a tube amp when driven into
distortion were really bad sounding and left a bad taste in the mouths
of many musicians, but that does not mean that there is something
magical about a tube amp or speaker that cannot be modelled. This
is a matter of personal taste, but I have compared the sound of a Carvin
SX300H transistorized guitar amplifier with tube emulation against
the equivalent all-tube Carvin amps, and I think the solid-state amp
sounds better.

I think we're in personal opinion territory here.

Graham

 

[Eeyore]

Eeyore wrote

No there were right.

No they weren't.

Did it ever occur to you that if you listen to a recording
of one of those guitars with tube amps you like so much,

It's not my choice, it's the guitarist's.

that you hear it through a normal amp?

Yes to hear an accurate replica of the recording. It's obvious.

Graham

 

[Eeyore]

Eeyore wrote

It's not made of paper. And the tweeter is a gold foil leaf type.

and the plastic membranes of your headphone.

An excellent material for the job.

We

We who ?

had plenty of live performances form pop bands and star in the studio

Whose studio ?

yes with plenty mikes. And plenty volume too.
I did not look what was in their stuff, probably solid state.

Sometimes it is, sometimes it isn't.

Graham

 

[Eeyore]

Eeyore wrote

There is a small minority of tubophiles, audiophiles, that has their own
ideas and standards.
Those people fork out a lot of money for oxygen free cables, tube amps,
what not.

This is irrelevant to bands.

There is a whole business living from them.


That is why solid state is everywhere

In the control room rather than the studio.

Graham

 

[kevin93]

On Oct 15, 2:04 pm, Eeyore <[email protected]>
wrote:
....

Did you know theKT66was originally designed for radar PPI deflection coils ?

Graham

Seems unlikely as it was introduced in 1937 according to Wikipedia.

kevin

 

[Eeyore]

Eeyore wrote
always been a know-it-all 'bighead' and it really shows here.

Wow, the rabbit gets upset, well we will upset you some more, tubophile.

I'm NOT a tubophile. I just know what makes guitars sound best under certain circumstances.

I already said jazz guitar sounds best undistorted and hence SS amps are great for that.

Actually I think you know what you are talking about,and it is just
marketing talk for your own ideas,

Sadly I make no money from tubes at all.

unfortunately it stops innovation,
and misleads people into buying antique tube stuff.
And it has nothing to do with new design.

No new design is NEEDED.

It's like arguing over making a better daffodil. Which you COULD do now with gene slicing I suppose but
what would be the point ?

Graham

 

[Eeyore]

...
Surely not - if you have symmetry you cannot have any even harmonics.

If the two devices are not matched or you have asymmetry in your input
signal I can see that you could get even order harmonics. But the
same argument could be applied to solid-state amplifiers as well.

Tubes age fast and mismatch fast. SS doesn't.

Graham

 

[Simon S Aysdie]

So, there are nonlinear transfer functions that only overloaded tube
amps and speakers can make?

I wouldn't say "only." But tube amp design is straight-forward/simple
with more-or-less known results.

In music making (not reproduction) it really isn't disputed, even by
crusty contentious engineers, that the amp is part of the electric
guitar instrument, just as the body of an acoustic guitar is part of
that instrument.

 

[Simon S Aysdie]

And who's going to code every nuance of every control setting of every amplifier and speaker
combination ever made ?

It IS easier to use the real thing.

That is often the crux of it. I hate how gd heavy and bulky toob amps
are.

 

[Simon S Aysdie]

There is a small minority of tubophiles, audiophiles, that has
their own ideas and standards.

That pretty much sums up your confusion, and it isn't a small minority
in the realm of a few kinds of music, including rock guitar. A
musician is not an audiophile, and they aren't reproducing music, they
are making music.

Electric guitar players don't exactly enjoy lugging around tube
amplifiers, so perhaps they are doing it for a different reason. Harp
players too. A lot of harp players use toob amps.

 

[Simon S Aysdie]

Surely not - if you have symmetry you cannot have any even harmonics.

You are correct.

 

[Simon S Aysdie]

No it's part of the speaker. Does 'cone break up' mean anything to you for example ?

I've wondered about the output transformer in toob amps when driven
hard. They are usually very cheezy. I've wondered if the cores start
to saturate. Know anything about it?

I wonder about a non-linear output stage, a core starting to saturate,
and all working into the shit impedance of a cheezy speaker with an
open back cabinet. I'm sure someone can just write a formula and
easily emulate it. Right?