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.
Oh i forgot...
It takes some time for the bias voltage to come up. The relatively big cap of 1000uF needs to be filled first.
It takes some time for the bias voltage to come up. The relatively big cap of 1000uF needs to be filled first.
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.
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.
Attachments
There is also IXFK140N20P which is identical to IXFN140N20P but in TO-264 package
IXFK140N20P IXYS | Discrete Semiconductor Products | DigiKey
IXFK140N20P IXYS | Discrete Semiconductor Products | DigiKey
Output Caps
Can't get hold of 100V TSHA caps anymore, so I am going with 2 x 3300uF Nippon Chemicon 160V LXS caps.
http://au.mouser.com/ProductDetail/...57At/8ILdyEM/QnyOLnzrw0viUHjDN1%2bUX3kDfBE6f8
Can't get hold of 100V TSHA caps anymore, so I am going with 2 x 3300uF Nippon Chemicon 160V LXS caps.
http://au.mouser.com/ProductDetail/...57At/8ILdyEM/QnyOLnzrw0viUHjDN1%2bUX3kDfBE6f8
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To-264 are cost economic but they don't have look of Digital-Do-Main 2SK77B 😀
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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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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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
Noob question,but,someone would have thought of sticking a 2sk180 in the place of 2sk77 in the BAF circuit?
I guess some changes will be required,but,its easy for you guys to implement and also,2sk180s are available from friendly members here.
I guess some changes will be required,but,its easy for you guys to implement and also,2sk180s are available from friendly members here.
@ 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.
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.
Attachments
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I remember ready see Diyers who used recycled car wheels in his builds class A from scratch but is rare high WAF situation i guess
Attachments
I'm wondering if you have tested "soon to be released" SIT device that you had mentioned before...
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