I am interested in building a SE 6bm8 in STC topology (super triode connection). Has anyone built this type of amplifier? In this type of setup is the output higher also? In the cct. they have used paralleled opt's. Is this O.K. to be done? Any thoughts on this little project.
I also read about the so called "stopping diode/ linearizer". In the article it was mentioned that it "stiffens" up the bass and improves the performance of the opt's. Has anyone implemented the diodes in there designs? This is a link to the design I was researching.
Super Triode connection Circuit (STC) Vacuum Tube Amplifier
I also read about the so called "stopping diode/ linearizer". In the article it was mentioned that it "stiffens" up the bass and improves the performance of the opt's. Has anyone implemented the diodes in there designs? This is a link to the design I was researching.
Super Triode connection Circuit (STC) Vacuum Tube Amplifier
Schema from the site linked above:
dave
An externally hosted image should be here but it was not working when we last tested it.
dave
It appears that the triode (a diode effectively) in the "STC" shunt feedback will just make the output device's distortion higher. The current in the pentode output and the nonlinear feedback element would need to track for cancellation, but they are in opposition in the "STC", giving an S shaped response.
Perhaps what they meant to do is this, where the triode is used in inverted Mu form for feedback:
http://www.diyaudio.com/forums/tubes-valves/20686-se-sound-p-p-amplifier.html
This could be just a conventional LTP circuit driving a pentode output, with the neg. shunt plate feedback sent back to the plate load of the input side of the LTP driver.
(or put more simply, the top of the plate load resistor for the input side of the LTP driver connects to the plate of the output pentode, output pentode's grid is driven by the other LTP plate, cap coupled typically. CCS tail on the LTP would help linearity further)
Perhaps what they meant to do is this, where the triode is used in inverted Mu form for feedback:
http://www.diyaudio.com/forums/tubes-valves/20686-se-sound-p-p-amplifier.html
This could be just a conventional LTP circuit driving a pentode output, with the neg. shunt plate feedback sent back to the plate load of the input side of the LTP driver.
(or put more simply, the top of the plate load resistor for the input side of the LTP driver connects to the plate of the output pentode, output pentode's grid is driven by the other LTP plate, cap coupled typically. CCS tail on the LTP would help linearity further)
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