my best Hybrid 6922 and OPA541

[Stee]

Hello Gentlemen,
see this solution for easy and beautifull sound

[Stee]

the SUPERHYBRID tube - bjt and mosfet quasi complementary amplifier
(best audio scene)

[analog_sa]

Isn't the drv134 a bit ugly sounding? Does the cathode follower fix the ugliness?

Maybe i'm too easily scared but the "last IDEA" looks like something eager to self-destruct. And what happens to output offset when the tube is cold?

[AKSA]

Stee,

#2 is an interesting circuit, but when you place the tube in the nfb loop you strip away that lovely open loop tube sound..... if you are using such a low plate voltage that is probably necessary.

A better idea I have found is to run the 6DJ8 open loop from a B+ of 150V or so with a 10K plate resistor (around 8mA plate current) and then drive your output stage in open loop, without the VAS. Another, possibly better option, would be SRPP. A quasi like yours should cope well with this configuration; the sound will be even better.

I hope this is useful to you,

Hugh

[Stee]

thanks for your comments
now you can see version 3
best sound you can have with 6922 cathode follower (in reverse SRPP with JFET)
and two identical mosfet as final (quasi complementary configuration)

also it's possible put on R9 (in parallel) the volume POT 10K and adjust the gain without line resistors

---> the target is have best accuracy on sound's scene <---

[Stee]

Hi,
Version 4 - as tube PP amplifier need a toroidal 110V + 110V
and two 2SK1058 each channel WITH BALANCED SOURCE (XLR OUT DAC)

(at the moment I'm using a very good KT88 PP Yaquin china amplifier
with an extra output toroidal transformer 10:1 - 230V to 24V - 500VA to increase current - works very good)

this is the WAY

see the picture on
http://www.esafono.it/TORO.jpg

(only for those who want to hear a horizon between Left and Right channel)

[Stee]

the evolution of SuperHybrid

[Stee]

is a revolutionary
Device Tone Compensation
a SRPP with cathode output
and a balanced TDA
you can find it on ebay

[Stee]

in this new version
you can see some product from E-Bay
using first potentiometer just to set-up the saturation
the output stage configuration is mine:
The Quasi-Complementary System

[Stee]

CFP output stage works better if you have just one driver
so the complementary is an active load
like traditional powered VAS stage