Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Solid State Amplifiers => Tubes and Hybrids => Topic started by: solidstate2199 on March 09, 2020, 02:31:31 PM

Title: Amp project...Questions...Marshall Sl preamp +PI into SS Poweramp
Post by: solidstate2199 on March 09, 2020, 02:31:31 PM
Hello, my Questions for this Project for people
With better understading of Transistor Phaseinverters.

I want to build a Standard Superlead Preamp in one of my
Solidstate 2199 SS Amps, but i want to build it with the tube
 phase inverter stage. The thing is, if i build a superlead and put
A ppimv inside it, why do i need the el 34 and the output transformer
If i cant play that loud to beginn with? The poweramp isnt working
Until it probably to loud.

So i want to build this unit for homeplaying and small gigs, 30 watt
Out of that old marshall ss should be plenty.

But i have problems understanding transistor pamps...
The 2199 has a socalled quasi complementary design..
Is it possible to inject the tube phase inverted Signals
Into this 2199 power stage and where?

Thanks the schematic i could upload or just check it
At drtube website.

Cheers

Title: Re: Amp project...Questions...Marshall Sl preamp +PI into SS Poweramp
Post by: phatt on March 10, 2020, 01:09:23 AM
Without the output Tx cutting all the fizz I don't see any great advantage.
SS power amps are DC coupled and hence don't cut the fizz generated by over driven stages. :'(
The OTx is part of the magic of Valve amps,, most of the great Valve amps did not use hi spec OTx's and so they smooth out the hi freq crud.
Valve pwr stages also cut very low freq because of caps (AC coupled circuits) and maybe some miller effect.
Most SS pwr stages (Especially ones like you mentioned) are dead flat,,, So unless you have an intricate understanding of how to circumvent all that then my advice is leave the SS pwr stage stock and do all the fancy stuff in a well designed preamp.
Or just research some pedals there are plenty out there 8|
Phil.