50w Single-Ended BAF2015 Schade Enabled

Hello Brother
Yes I understand the issues with the devices, I've had a chance to play with them, however I'm starting to think your original idea may actually work, since the more the bottom mosfet turns on the lower the voltage at the drain becomes which in turn lowers Vgs which stops it running away.
It has some level of self biasing.
Subconciously you were a genius you just didn't know it yet.
:D

Anyway I will test it out point to point first.

So far i only built Genergs circuit (BAF2015 #564) but with IRFP240. The thing is totally stable (and sounds good). The only problem i encountered was to bias up the lower mosfet. I had to change R11 from 15k to 5k because i used a low B+ of only 20V.

The current source is really rocksolid. It gave exactly the calculated amps when tested alone against ground.

Hence i think we need not worry too much about the lower mosfet. With Genergs genious circuit there is actually some level of self biasing.
 
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and here guys……:):)

this picture shows the IXYS IXFK120N20P successfully used in an Gato

amp. So we know that it is suitable for audio and not only switching.

Full review here at 6moons.
6moons audio reviews: Gato Audio AMP-150

and the best it us much cheaper….

Polar HiPerFET Power MOSFET IXFK120N20 / IXFK120N20P ( NEW ) | eBay

IXFK120N20P IXYS | Mouser

I bought 8 at Mouser, so the stock got down, some left…..

or



besides it does not have this monster look it seems to have similar data compared to the other candidates we know.
 

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There is also IXFK140N20P which is identical to IXFN140N20P but in TO-264 package

IXFK140N20P IXYS | Discrete Semiconductor Products | DigiKey

To-264 are cost economic but they don't have look of Digital-Do-Main 2SK77B :D
Schade version SIT simulation with hockey puck IXFN have similar triode curves,
all parameters and yes that " style" package.
I like it very much Sir Rothacher pcb's solution show on the photos above.Thx to Audiohobby.com.
Traditionaly after BAF 2015 Sir Pass write for Diyers new passionate article so i stay in tune....

Best regards
 

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To-264 are cost economic but they don't have look of Digital-Do-Main 2SK77B :D
Schade version SIT simulation with hockey puck IXFN have similar triode curves,
all parameters and yes that " style" package.
I like it very much Sir Rothacher pcb's solution show on the photos above.Thx to Audiohobby.com.
Traditionaly after BAF 2015 Sir Pass write for Diyers new passionate article so i stay in tune....

Best regards

Don't worry I already have a tube of the sot227 devices, but there is always some desperate soul out there that just doesn't have the funds to build such an amp (it's not a cheap amp), it's always nice to offer options for those that still want to play but don't have adequate funds.
 
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Don't worry I already have a tube of the sot227 devices, but there is always some desperate soul out there that just doesn't have the funds to build such an amp (it's not a cheap amp), it's always nice to offer options for those that still want to play but don't have adequate funds.

Hi Pico

Yes i agree with you always good to have possibilitys for build economical transistors version &
save funds for psu transformer.
What is amazing in " Schade 50 nuances of Mosfet " ?
Its probably the only SE 50 watts amplifier i know with one semiconductor in audio path [ and his CCS]
have 20 dB of gain so no need for preamplifier stage [ less costs ] , passive resistors potentiometer is ok if you use cd player or DAC. Need huge heat sinks or nice liquid cooling.... i have find two candidates for experiments.

 

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Hi Pico

Yes i agree with you always good to have possibilitys for build economical transistors version &
save funds for psu transformer.
What is amazing in " Schade 50 nuances of Mosfet " ?
Its probably the only SE 50 watts amplifier i know with one semiconductor in audio path [ and his CCS]
have 20 dB of gain so no need for preamplifier stage [ less costs ] , passive resistors potentiometer is ok if you use cd player or DAC. Need huge heat sinks or nice liquid cooling.... i have find two candidates for experiments.


Yes this one is very special. I'm still slowly gathering the rest of the parts for this amp.

You have some nice heat sinks there
 
@ Diyers

No doubt with biger Vfet build modified or similar amp to 2SK77B are possible but
all IXFN interesting aspect are how similar " triode sound "
we can obtain from " pentode " mosfet.
Guys into pentode tubes circuits say " triode " connection.
Mr Pass speak curves look very the same if compare.
I like very much single-ended topology , original B1a was push-pull.
 

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My Jensen transformers arrived. Still need to order a few other things.

You will need 2 x 400VA transformers putting out about 8V to 10V higher unregulated dc, cause it's adviseable to use a regulated supply.

pico, in post #6 you mentioned using a regulated supply. Why is it needed?
What would happen if a regulated supply isn't used?
Don't you think a regulated supply will affect dynamics?

Could a larger VA transformer act as a better regulated source?

Thanks,

Vince