• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

HYBRID- Schematic

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jacco vermeulen

jacco vermeulen

Member
Joined 2004
here is one designed with IRFP240 and IRFP9240.
(now IRFP9140 would be better, thanks to our fellow diyaudio members.)

25/8 -50/4- 82/2, on 17Vac output transformer, 35Vac and 17Vac for the PCC88
 

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R

rfbrw

Member
Joined 2001
jleaman said:
Anyone got any hybrid schematics they want to share ? I have a few but always looking for more and other schematics to concider building. Im looking fora tube front end and a fet out put stage I have yet to find a class a output stage only Class A-B..

Any one ?
Click to expand...


DC300B Tube MOSFET 150W/Channel from Audio Amateur 1989
 
anatech

anatech

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That would make the variable gate charge thing less of an impact, but it would still be there. Buffers are easier. Still the effect. I found a bipolar stage is more linear to drive for sure. THD measurements and listening both confirm. Other ears say it's like night and day, and they originally bought the unit for the sound. The units in question are Counterpoint using 6DJ8 in follower to drive the mosfets.

0% of other listeners prefer the mosfets to bipolar in this configuration.

-Chris
 
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jleaman

Banned
Joined 2002
plus.google.com/photos/104656656065604242634/albums/5725366675475046257?banner=pwa&gpsrc
Tyimo said:
Hi J!

I have built and it was totaly instable and disaster:The fets and some resistors and some caps was blow out! I know also few diyers who built it and got the same result!! I know only one man who could got to working the amp: Alexander from Zeuslab-Russia.
There are some old threads where you could find "negativ" infos about this amp: PassHybrid.
I also spoken with the original designer: Mr. Erno Borbely and He told me that this cicrcuit (Generoso Cozza's) can not working as it is.... (even not the kit version from Cozza!, because Ralf bought it and the result was the same)
The story is long, you could get some info from TubeCad too.
Greets!

I would like to ask about the TubCad Hybrid version: could I use IRFP240 instead of the BUZ900?

Tyimo
Click to expand...

I dont know about your circuit you used but the Guy ont tube cad sait it work but lacked a few things i have read both his articals on this matter about 6 times over and i'm also going to try his schematic too.
 

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