Funny guys , was age of engineers crazy experiments.
Mr. Pass never stops
I don't see many designs for small SIT's Sony 2SK79 , they matched pairs are available
http://www.diyaudio.com/forums/vend...-rare-toshiba-transistors-18.html#post5053635
With two 2SK79 matched pair can we build useful front-end for stereo 2SJ28 DEF power amp stage ?
http://www.amplimos.it/images/2SK79_data.pdf
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Other concept is SET equivalent like in tube world.
Something to amplify antique radio oh just joke !
Anyway create from the orpfans one family.
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with my very cheap and little speakers (20 euro 30Watt open baffle fullrange without crossover) in my studio the ACA-amp almost beats the Vfet (wich hasn´t seen real speakers due to lack of transportable case). It quite like changes with bigger speakers, but i guess it must have to do with SE magic. So I vote for little SE-kitchen-amp 🙂
How about a mu follower with the sit in the driving seat and a MOSFET for the other?
... Or did I just take all the imagination out of the BAF schade design of Mr Pass? 😀ummy:
... Or did I just take all the imagination out of the BAF schade design of Mr Pass? 😀ummy:
Mating an amp with speakers is the key. The little ACA with a linear supply is almost as good as the BA-1 I just finished. Almost. The V-fet is an extremely good amp with the right speakers but with my horns I lean towards a SE . A good friend with big horns loves the V-fet better. Personal preference comes into play along with the choice of music. I love SE with my horns. The exception would be my F4. Rules are made to be broken. So many more options with efficient speakers. Even a 5 watt amplifier is more than a enough.
simonms told me the SIT amp with the 2sk79 pairs are quite good, so I guess STI amp would be a good build with these vfets.
A power amplifier by Shinichi Kamijo:
Amplified triode
and here is a single-end vfet amp with 2sj28/2sk79 from amplimos:
http://www.amplimos.it/images/2SJ28%20SE%20AMP2.bmp
A power amplifier by Shinichi Kamijo:
Amplified triode
and here is a single-end vfet amp with 2sj28/2sk79 from amplimos:
http://www.amplimos.it/images/2SJ28%20SE%20AMP2.bmp
A simple Schade feedback Bastode amp?
I don´t have any spice model for the 2SJ28, so all the resistor values is just guesstimates.
Cheers,
Johannes
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4 parts and a power supply constitutes a feed forward error correcting (SUSY-ish) power amp with very low levels of distortion. 2 X voltage gain.
It has a very good damping factor, due to the feed forward EC and the NFB.
If the 2SJ28 needs a gate resistor then the amp needs 5 components per channel plus a power supply.
L1 and L2 are two windings (bifilar) on an aircored choke. Since they are very close magnetically coupled together they will force the two outputs to closely follow each other in anti-phase (hence the SUSY-"ish" feed forward error correction).
Cheers
Johannes
I simulated this amp with an IRFP9240.
11.2 volts P-P output with 0.10% THD into a resistive 8 ohm load.
A nice balance of the harmonic content in the FFT graph.
All this is a simplified simulation, and should only be taken as a crude approximation of a real amp driving a real load.
Cheers,
Johannes
Uncle Mike SIT Modeler software get presented 2SK82 data.
Good start for creation of new 2SJ28 spice model by the experts
We could approximate one by flipping a couple of the polarities in the behavioral model like so. Close enough for government work. Don't try to land a probe on Europa with it. 🙂
As presented, it's simply a mirror of the 2SK82, feel free to adjust to taste.
*--------------------------------------------------
*2SJ28
*GENERATED BY SIT MODELER @ AUDIOMAKER.TECH
*MODEL RANGE: -55V, -5A
*--------------------------------------------------
.SUBCKT 2SJ28 D G S ; Drain Gate Source
+ PARAMS: MU=7.3 X=1.51 K=0.157 N=2.24 VCT=0 RG=2MEG
*--------------------------------------------------
B1 D S I=-1*(K*PWR(URAMP((-V(G,S)+VCT)+(N*LN(-V(D,S))+(-V(D,S)/MU))),X))
*FOR LTSPICE
R1 G S {RG}
CGS G S 0P
CGD G D 0P
CDS G S 0P
.ENDS 2SJ28
*--------------------------------------------------
Plug in you favorite interelectrode capacitances if you're going to fool with bandwidth stuff.
As presented, it's simply a mirror of the 2SK82, feel free to adjust to taste.
*--------------------------------------------------
*2SJ28
*GENERATED BY SIT MODELER @ AUDIOMAKER.TECH
*MODEL RANGE: -55V, -5A
*--------------------------------------------------
.SUBCKT 2SJ28 D G S ; Drain Gate Source
+ PARAMS: MU=7.3 X=1.51 K=0.157 N=2.24 VCT=0 RG=2MEG
*--------------------------------------------------
B1 D S I=-1*(K*PWR(URAMP((-V(G,S)+VCT)+(N*LN(-V(D,S))+(-V(D,S)/MU))),X))
*FOR LTSPICE
R1 G S {RG}
CGS G S 0P
CGD G D 0P
CDS G S 0P
.ENDS 2SJ28
*--------------------------------------------------
Plug in you favorite interelectrode capacitances if you're going to fool with bandwidth stuff.
yeah
especially Mighty Moi adjusting that
I'm not talented even for agricultural work around LTSpice models
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Speaking of things already invented, perhaps someone will post a +/- PS amp that borrows Papa's TL431 reg from Sony Part2?
