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Question about booster in the tube and solid amp

Started by JackSkellington, November 08, 2022, 10:47:26 AM

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JackSkellington

Hello, I have a question about the difference between boosting a solid state amp and tube amp.
I have only solid state guitar amps, so I play, make my tests and experiment with circuits with just those amps.
I'm wondering if the behaviour of the two kind amps is different when I push them with a booster.

In particular, I put on my breadboard the CE-1 preamp. On Low mode it based on op-amp has a good amount of clean volume, until it starts to clip in a not so musical way (op-amp clipping, I assume).
(In the high mode it there a BJT booster in front to push it even more, with more volume and more distortion. But the sound is more or less the same).

When I watch demos of some replica of the CE-1 preamp what I can hear is it get in overdrive nicer and milder, without push just in volume.

When I test this (or other) op-amp booster circuit with my solid state amp I got a big volume boost with distortion at higher setting of gain, (it depends from the circuit).
In a tube amp should I expect less volume boost and more natural overdrive of the tube preamp caused by the push of the booster?
«Just because I cannot see it doesn't mean I can't believe it»

mauman

You are right, tube amps respond differently to high-level inputs than solid state amps, in the same way you hear on the video demos.  Tube amps can give you pleasant overdrive sounds, while most solid state amps just get louder, then create an unpleasant distortion.  I usually test my pedals with both solid state and tube amps, and the results can be quite different.  For example, in addition to the overdrive differences, my tube amp is more sensitive to switching pop noises and charge pump noise than my solid state amp.

EBK

#2
Tube amps also tend to compress the input, which is another reason they don't simply get louder with stronger signal. 

Tube amps may also be more sensitive to input impedance variation.

Not all solid state amps are equal, of course.  Some can be pleasantly overdriven, but I wouldn't specifically shop for such a feature when buying solid state.  The best solid state amps (in my opinion) are beautifully clean, with plenty of headroom. 
"There is a pestilence upon this land. Nothing is sacred. Even those who arrange and design shrubberies are under considerable economic stress in this period in history." --Roger the Shrubber

JackSkellington

Thanks.
My solid state amp is a 120w, so I guess it has a lot of headroom.
Anyway, the overdriven I hear is the op-amp clipping for sure, because I tried even with a master volume control in the op-amp circuit, so there's no much signal in front of the amp, but is the gain in the circuit to clip the op-amp. I hope I told it clearly.

I'm a bit sorry about the noise of a tube amp. I didn't know it. In general my DIY pedals don't have noise problem, if the project is good and I built it fine.
«Just because I cannot see it doesn't mean I can't believe it»