Found on John Bronski´s site :
SuperTriodes & Inverted ES Speakers
Can a tube really drive the output transistor if a powerfull output is needed, like for a speaker!
Can some one explain to me how it works, what about termal run away in the trasistors? and idle current?
Is there a working amp on the internet somewhere i can learn from?
Regards Allan
SuperTriodes & Inverted ES Speakers
Can a tube really drive the output transistor if a powerfull output is needed, like for a speaker!
Can some one explain to me how it works, what about termal run away in the trasistors? and idle current?
Is there a working amp on the internet somewhere i can learn from?
Regards Allan
Seems to me that the only thing the tube does is drive the gainclone-type amp as a cathode follower or buffer. Since the gainclone has a high input Z, that's a no brainer. So, your question should really be directed at a gainclone amp, not at the tube.
The tube isn't really required but does impart a 'tubey' sound (tube-type distortion spectrum) to the output.
jd
The tube actually looks like it's in the feedback loop, the gainclone is just a current booster. I've got a PCB for this design in the works, when I get it built, I'll report on the results.
Sorry guys for not beeing precise enough. Please take a look at the middle of the page. subject "SuperTriode Meets the Aikido".
Look like a good idea tube sound with current of gainclone. Do we need high voltage swing to drive the super triode with gainclone.
Fenris - Please report back when you are done.
Fenris - Please report back when you are done.
Please keep the gain clone of of this, I refer to the circuit in the middle of the page, with an akido tubeamp with NPN or a PNP output transistors added.
Can the tubes really drive the transistors. I guess the transistors will only have 25-50 time current gain.
Can the tubes really drive the transistors. I guess the transistors will only have 25-50 time current gain.
I think MOS-FETs would have been a better choice due to the gain of Beta*Ib of the bipolar transistors (Yes 25-50 is probably a good range).
However, the combination of source follower on top and common emitter on bottom is going to give some additional non-linearity and the output impedance of the two is quite different.
However, the combination of source follower on top and common emitter on bottom is going to give some additional non-linearity and the output impedance of the two is quite different.
mosfet has to worry gate blowout when the cathode is cold.
PNP at the plate by itself is already perfect, no need to fix.
PNP at the plate by itself is already perfect, no need to fix.
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