Or just use an independent bias string for the top output FET; maybe a CCS diode feeding a resistor (R1) to set a voltage, then a sizeable resistance (R2) feeding the gate stopper resistor (R3). From the junction of resistors R2 and R3 connect a capacitor to the amp output node. In essence very similar to what the tube guys do on a hybrid 'mu follower'.
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Circlotron demystified
It seems to me that John Broskie's article "Cars, Planes, and Circlotrons" provides the keys to understanding the circlotron because of its behavioral equilavence to the totom pole topology. Unless I am totally missing something, there isn't any "Quantum weirdness" here.
It seems to me that John Broskie's article "Cars, Planes, and Circlotrons" provides the keys to understanding the circlotron because of its behavioral equilavence to the totom pole topology. Unless I am totally missing something, there isn't any "Quantum weirdness" here.
Of course. I was being facetious, but at the same time we can
note that a good percentage of people who "get" a push-pull
follower are still scratching their heads over circlotrons.
😎
note that a good percentage of people who "get" a push-pull
follower are still scratching their heads over circlotrons.
😎
SIC JFET Spice models?
Does anyone have Spice models for any of the SIC JFETS, particularly ones that might be used for a J2-like amplifier?
Does anyone have Spice models for any of the SIC JFETS, particularly ones that might be used for a J2-like amplifier?
Hopefully supply will be abundant and is able to keep up with demand from outside audio so as not to drive the price higher...
I am not Nelson, but I retrofited my F2, It's Q1.
Additionally - From Nelson Pass
The F2's that I have updated with the JFETs need the
following changes:
R6 = 47k
C1 = 10 uF
Z1 removed
The potentiometer must be re-adjusted for minimum
distortion at 4.5 watts (symmetric clipping) and readjusted
after an hour..
cka,
Generg and myself have had success using the BA-1 output stage as a power follower if you follow that thread. Same idea, put using R100's for output on top part of circuit. Leaving IRFP240's on top as Current Source.
Generg and myself have had success using the BA-1 output stage as a power follower if you follow that thread. Same idea, put using R100's for output on top part of circuit. Leaving IRFP240's on top as Current Source.
I would guess it would with plenty of sinking, but I would think a current source of IRFP240 would not. The IRFP240's are recommended to run less than 65c. The math escapes me on what the F2-F2j is doing for output. I think it's 65watts total per side, so that's roughly 33 watts a device? Someone else surely has a more precise answer.😱
Some high praise here for XA100.5 and FirstWatt J2 from Tone Audio.
http://www.tonepublications.com/MAGPDF/TA_030.pdf
Check out page 158. I cannot copy text from it, must be protected.
Anyways, My first half-decent speakers were a gifted pair of Maggie MG-I's, restored by Magnepan.
http://www.tonepublications.com/MAGPDF/TA_030.pdf
Check out page 158. I cannot copy text from it, must be protected.
Anyways, My first half-decent speakers were a gifted pair of Maggie MG-I's, restored by Magnepan.
