Gabevee's SS tube-like preamp

[needtubes]

Hi all... I have some questions about Gabevee's SS design that is supposed to sound like a tube amp... I am intrigued by it because it is simple, SS, and still offers tube-like sound... more info on it can be found here.

First off... is this running in class A?

Could it drive headphones directly (of any impedence from 32-300-ohms)?

Would it be possible to replace the output MOSFET to something with more current drive without changing the characteristic sound of the amp?

Anyone have an idea what value of cap the one by the 330 and 3.3k ohm resistors is?

Thanks

[Upupa Epops]

Questions : " class A " : yes . " headphones " : no . " replacing " : yes, but amp will be much slower. " cap " : about 100 micro. Conclusion : semiconductor circuit with all drawbacks of tubes.

[analog_sa]

Sound like tubes? Ha, ha. It may sound nice but certainly not like tubes.

Yes, it is class A. It will drive high impedance headphones.
A 100uF will be fine.

[Upupa Epops]

Maybe for some people is tube something like phalic symbol .

[thoriated]

I don't know of any transistor equipment that can truly emulate the superior sonic accuracy of a good tube design.

[millwood]

Originally posted by thoriated
I don't know of any transistor equipment that can truly emulate the superior sonic accuracy of a good tube design.

what is the "sonic accuracy" of a good tube design? does it really exist?

Take the JLH for example. Many people consider it as good as the williamson amp. but does tube sound really exist?

I have listeneed to tube amps and honestly I couldn't tell, other than the fact that they don't produce as much highs as ss amps.

[DrG]

The unfortunate truth of the matter is that there are competent solid state amps that outperform tubes, and competent tube designs that outperform solid state.

Tubes are lenient, forgiving devices which can reward small effort with great sound. Transistors require more design acumen and care beyond the obvious. But both can be used for excellent designs giving excellent performance. Both have strengths and weaknesses. The sonic signature of both will be influenced by the choices of equipment with which they are partnered. Those choices are likely to be different for ss and tube.

[analog_sa]

Tubes are lenient, forgiving devices which can reward small effort with great sound. Transistors require more design acumen and care beyond the obvious.

A rare occassion when we are in agreement

What attracts about tubes is that there are simple, albeit expensive recipes which produce stunning results. Anyone willing to put the effort and money can obtain truly spectacular sound without knowing much about anything at all.

Operating points in a preamp? You have to get way off to ruin the sound. Feedback phase margins? Ha, ha. Power supply intricacies? Have a separate transformer feeding each anode, add lots of chokes - as long as you use star grounding you just can't go wrong.

In contrast, to obtain equally stunning results with SS is really difficult and unless one clones a commercial product where all the ground work is already done the results are really uncertain.

Of course tubes always add this extra something which depending on musical preferences makes or breaks the deal. Tube sound is generally larger than life and always harmonically rich. It may well have something to do with microphonics - the biggest issue i personally have with tubes.

[millwood]

Originally posted by analog_sa
Anyone willing to put the effort and money can obtain truly spectacular sound without knowing much about anything at all.

I was wondering when that would NOT be true.

[Bas Horneman]

I'm not getting into the tube / ss discussion but do want to say this

a williamson amp is hardly a thing to aspire to...good but not what can be done these days with set or some of the better pp like Gary Pimm, Alan Wright etc, etc. or with modern day components and efficient speakers and SET.

a Williamson has so much feedback it will sound pretty ordinary...but still whip most ss amps

Cheers,
Bas