The balanced hybrid.
Sajti
An externally hosted image should be here but it was not working when we last tested it.
Sajti
Wavebourn said:
"If the MOSFET has the gain about 0.95 that makes the anode resistor up to 50kohms..."
The MOSFET has transconductance such that the voltage gain will depend on the current. Interestingly, this should allow the triode to "see" some of the output load, including it's reactive character.
It would be interesting to see the dynamic load line with a loudspeaker load, i.e. an x-y trace of differential anode voltage vs differential cathode current (voltage across R5 or R6).
What if you drove Q3 and Q4 with inverse signal current like the Borbely follower instead of using them as CCS? You could cut the
dissipation in half for the same output power vs. load and stay in class A.
Cheers
Michael
Hello
Thank you Sajti .
I would like to ask one favor .Can you post or recommend a power supply for these X version .
What VA rating should be the transformer that it would be great to know .
What type of tube you recommend for these amp ?
I think even I design the PCB. layout I'd rather interested on the hybrid X
Thank one more time
Koszi szepen !
Greets.
Thank you Sajti .
I would like to ask one favor .Can you post or recommend a power supply for these X version .
What VA rating should be the transformer that it would be great to know .
What type of tube you recommend for these amp ?
I think even I design the PCB. layout I'd rather interested on the hybrid X
Thank one more time
Koszi szepen !
Greets.
Here is the psu I planned:
Sajti
An externally hosted image should be here but it was not working when we last tested it.
Sajti
sajti said:
I got my choke loaded IRFP150 hybrid up and working with a Tungsol 5687 . This used a 15k load , 250R bypassed cathode res and 125V B+ . Now I'm using a type 26 DHT with 33K load and 2R filament bias resistor . This completely stomps the 5687 in terms of sound at the expense of available gain but not an issue with the 93dB sensitive speakers I'm using
DHT sound is the sound to go for IMO316A
I don't know that much about hybrid amplifiers, and the schematic I am about to show is not class "A" but I would like to know if an amplifier like this could be turned into a hybrid, remove the FET chip pre stage for a tube one. If not I might try one of the other circuits but I would like to use the parts that I actually have, in this case a 100 watt LXI amp that already looks and sounds good but could be waaaay better. 
Pleas don't laugh at my insane question.
Pleas don't laugh at my insane question.
Attachments
CrazzyAbtTubes said:I don't know that much about hybrid amplifiers, and the schematic I am about to show is not class "A" but I would like to know if an amplifier like this could be turned into a hybrid, remove the FET chip pre stage for a tube one. If not I might try one of the other circuits but I would like to use the parts that I actually have, in this case a 100 watt LXI amp that already looks and sounds good but could be waaaay better.
Pleas don't laugh at my insane question.
Yes, it could be waay better if to use a different output stage.
So what would you suggest I do, I plan on upgrading the old Tohibas to newer ones. I have matched sets of 2SA1301's and 2SC3280's that I can parallel at the output, but I'm not sure about the input and driver stage, I just like the sound of mixing both tubes and solid state together.
I have some pictures and some other info on another forum, and I have allready planned for a tube preamp, but to Hybridise the amplifier would just be cool.
http://diyaudioprojects.com/Forum/viewtopic.php?f=10&t=871
I should make this into a new thread if my idea actually gets anywhere..
I have some pictures and some other info on another forum, and I have allready planned for a tube preamp, but to Hybridise the amplifier would just be cool.
http://diyaudioprojects.com/Forum/viewtopic.php?f=10&t=871
I should make this into a new thread if my idea actually gets anywhere..
If I was building the amplifier from scratch I would be using mosfets, but I am trying to spend as little money as possible, and use as much junk parts as possible.
From what I've read Wavebourn, any of the circuits shown here are single ended mosfet and operat in class "A" the amplifier I am working on operates in class "AB" as far as I can tell, and puts out 100 watts into 8 ohms, and is not a simple design to modify.
But I think that it would be possible for me to simplify the amplifier circuit a little, and using the knowledge that I have learned exchange the input stage for a tube one, say 12AU7 or 6CG7, 6SN7?
Whatever I do I will post my new schematic, and just maybe.... 
I will have to start doing more reading as well....
From what I've read Wavebourn, any of the circuits shown here are single ended mosfet and operat in class "A" the amplifier I am working on operates in class "AB" as far as I can tell, and puts out 100 watts into 8 ohms, and is not a simple design to modify.
But I think that it would be possible for me to simplify the amplifier circuit a little, and using the knowledge that I have learned exchange the input stage for a tube one, say 12AU7 or 6CG7, 6SN7?
Whatever I do I will post my new schematic, and just maybe....
I will have to start doing more reading as well....
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