Building a Tube Amp

Not long at all: I wrote him: (here's his pic:

------ There's a discussion going on in one of my newsgroups (news:sci.electronics.design) about the virtues of tube vs. solid- state (i.e., transistor) amps, and some guy was wondering what's in typical use today.

So, what kind of equipment are you guys using, and what have you historically used? (I want to contribute something other than fluff to the discussion, and, I guess, brag on you (Hey! My brother's FAMOUS!!!!) ;-)

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And he responded

------ Solid state is used for almost everything with the exception of a lot of guitar amplifiers. I use a 40 watt amp that has 2 tubes. I guess I'm "old school" feeling that the basic design they used in the forties and fifties was the pinnacle. Tube amps give you a nice warm sustain without the harsh edges. They work well for blues for example. Those big stacks of Marshall amps in hard rock concerts are all tube amps.

When I was playing a lot of country music, I used a solid state amp. Nice and bright for that "twang".

The most up to date stuff in concerts now is having no amps on stage, but a wireless feed to processors that digitally "model" any number of amp sounds, then sending it back to stage in the monitor mix. They are getting awfully close to the classic sound. It's a matter of taste, I guess.

After all, some people think that vinyl records sound the best.

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Hope This Helps! Rich

For distortion tubes are the winner... A good ss/modeler isn't bad and usually has more variety but it just can't be the distortion. This is not to say that one day it might change... but not today. Although it is getting to a point where many people will sacrifice the tubes for a ss for the economy.

Um, I had that amp! SELL IT!! It is a POS. Surely you can do better? A purely modeling amp does better!

For clean sounds tubes don't matter as much but for distortion they are required... so if you are not using it for distortion then the point is moot.

Um, you put the volumn pedal in front of the amp! You do realize that some effects go before the amp and some in the loop?

You don't put chorus/reverb/delay/phaser/etc.. before the amp to be "distorted" or amplified(you could if purely clean amplification) and you don't put volume pedals(you could though), wah pedals, compressors on the loop!

The loop is for effect's after the pre-amp and before the power amp. These are basically effects you don't want to distort. For effects all other effects they go before the pre-amp. (and some could go either way)

I don't have to imagine it. I have been there. The answer is to ask who will be evaluating your work and to make it a requirement that he go to an audiologist and get his hearing tested. If you are the only person in town who has a good reputation in a particular area of expertise, they will do whatever it takes to get you. Often that consists of putting the 22 year old who does the mixing in charge of evaluating your work rather than the 59 year old electric guitar player with the blown out ears.

Then you are not overdriving yours enough. If you never get a pretty red-orange glow from the plates you are not using your tube amp correctly. ;;==D

err. or if have just turned 50 and can't lift what you used to pretend you could lift.

Kevin Aylward

Again, this is your personal opinion.

As I said, I am quite happy with it. Its small, and sounds fine. I gave my fender twin reverb to my nephew.

This is debatable. Many consider a tube amp set "clean" has more "warmth". It is well known that sound can be improved for many by the use of aural exciters. These processes deliberately add distortion, but, paradoxally, actually make the sound sound more clean. This seems to be the approach in the Marshall.

For some, but not for others.

I think you misunderstood. The ECC83 is not being used for the preamp distortion circuit, but I do use that internal Marshall distortion as my main distortion. The valve is only being used as noted above.

Not at all.

Did you misread my post? I use the pre-amp distortion *of the AVT150*, therefore a volume pedal before the amp input jack is quite useless. In that position, it really only effects the amount of distortion, not the volume.

Fundamentally, if anyone uses the distortion of any amp preamp stage as their main distortion, the volume pedal *must* come after that distortion. I do note though, that many, never adjust their volume throughout a set or a song, and just go full belt all the time.

I don't put any effects before the amp. In my view, all effects, should be after any distortion (ignoring possible desired stage output distortion). Distortion tends to level everything up such that the effect of any effect unit is generally reduced.

Chorus and phasers crucially depend on having *exact* cancellation" of the dry and processed signal at specific frequencies. This is done internally to the effect. Having some always on side bleed totally destroys the depth of these effects. Therefore, a || loop is quite useless. You need to completely break the connection, hence a series connection is required.

I use the chorus/reverb in the AVT, which is after the pre-amp distortion.

Of course you should, although I realise many don't because of lack of knowledge..

You want the volume pedal after all the crap, so when you turn the pedal down, it stops all the hiss and buzz. You want to have the signal up as large as possible all the time, just prior to clipping to get the best signal to noise, and have the largest signal possible driving any effect. For example, the guitar pot should always be full up.

The best place to put a noise gate, and a compressor is precisely at the pre-amp main amp point. The noise gat is to to err.. gate the noise of all the effects.

It should be used for all effects. It keeps all signals at the best level to minimise noise. I do realise that many unskilled in elecetronics or the basics of signal processing, for example, many musicians do not do this. This is often due to lack of knowledge, or unfortunately, many effects are designed as guitar level only, not line level, and so distort if placed at a higher level point in the signal chain. Indeed, by Behringer pedal has this problem.

Sure, if you like to have non optimum set-ups, feel free to do this. However, if you want an optimum set-up, you should seriously consider placing all of your effects in line at the series effect loop point, with the volume pedal last in the chain. Indeed, I use a special twin cable to my volume pedal to do this.

Kevin Aylward