FET TWIN+Chipamp compared to small tube amp

[kin0]

Have anyone tried to build the FET TWIN (http://diyfactory.ru/index.php?option=com_content&task=view&id=89&Itemid=47) with a chipamp as a poweramp? If yes, how is it compared to small tube amp (like black heart) in terms of sound and working with pedals (mostly high gain dist).

[J M Fahey]

It's unnecessarily complex for what it does.
After all, it's only a Fet version of the Normal Channel on a Twin.
You will end up with something very close to a JC120 or one of the Gxxx Yamahas which in many of their incarnations were basically that.
You might copy one of their preamps to drive any SS power amp.

[teemuk]

Am I the only one who gets the feeling that this is kinda like asking how do apples compare to oranges in taste.

Also, "chipamp as power amp" and "small tube amp" are kinda loose definitions, don't you think?

[kin0]

It's unnecessarily complex for what it does.
After all, it's only a Fet version of the Normal Channel on a Twin.
You will end up with something very close to a JC120 or one of the Gxxx Yamahas which in many of their incarnations were basically that.
You might copy one of their preamps to drive any SS power amp.

from looking on the jc120 schematic it looks much more complex than the FET TWIN.  BTW which chipamp do you recommend for the 50-100Watt range (so it would be enough for gigs and rehaursals but also not too loud for home use)

[joecool85]

LM3886 is the chip of choice for most of us.  50-68w depending on supply voltage and driven load.

[J M Fahey]

from looking on the jc120 schematic it looks much more complex than the FET TWIN.

Sorry, my fault.
I should have been more specific.
O course the full JC120 (or the Yamahas) preamps are very complex, what I was talking about was their "Fet Twin core", without the extra bells and whistles.
Definitions:
I call a "Twin preamp" the basic Normal channel, made out of: 1st  triode gain stage -> "Fender" tone control -> Volume pot. > 2nd triode gain stage -> (optional loop/extra clipping/Master volume) -> power amp
The SS version would be about the same, substituting simple FET stages for the original triodes.
The Russian "Fet Twin" tries to do that, but uses cascode gain stages, which have too much gain, too high output impedance, and in general are even further from a triode than a simple Fet stage.
Its last stage even needs an extra Fet buffer to lower impedances into real world (specially SS world) levels.
It uses 6 Fets for what can be (better) done with 2.
Some examples of what I call "the Fender heart" hidden in popular and good sounding SS amps:
1) From the Roland JC120 (well, some of its versions)

2) From the Roland Cube 60 Bass (which is the same than the guitar one, minus the horrible distortion (you won't miss it) and the reverb):
In fact I recommend you to build the full Bass 60 amplifier, substituting the original Power Amp with a Chipamp. *Killer* clean guitar amp. (Of course, using *guitar* speakers):

3) The Yamaha preamp.
It's a little too complex , so later on I will correct it into the simple one you need, but to start with the original one:

4) The corrected Yamaha preamp.
I just copied and pasted within the image, you should print it and tidy it up somewhat, but hope it's clear that after a 2nd Fet stage, basically the same as the input one, you go on into loops, extra clipping or whatever (or straight through) into your chipamp.

BTW which chipamp do you recommend for the 50-100Watt range (so it would be enough for gigs and rehaursals but also not too loud for home use)

What joecool suggested.
LM3886 are noble beasts, with little trouble, and being an SS clean power amp, can be used at *any* level, from bedroom to stage.
Tube power amps often have a sweet spot which is very loud; SS amps sound always the same, within its power rating, and dirt comes from an external good pedal, in a simple amp such as this one.
Good luck.