I got interested in Toshiba's 2SK2013/2SJ313 MOSFETs last year when estman, a forum friend, sent me generously a set of dozen j313s. They impressed me with their superior linearity of transfer characteristics but not until recently (when I got the N-channel complements - k2013) I could not try them in classical push-pull circuit.
Using them in F5 (3 pairs per channel at +/-20V, 400ma per MOSFET for total bias of 1.2A per channel) transformed it into amp that leaves no wishes open.
Schematics and pics are here:
Novi amp sa 2SK2013/2SJ313 - DIYAudio.rs
Using them in F5 (3 pairs per channel at +/-20V, 400ma per MOSFET for total bias of 1.2A per channel) transformed it into amp that leaves no wishes open.
Schematics and pics are here:
Novi amp sa 2SK2013/2SJ313 - DIYAudio.rs
I'm sure the Mastah will also enjoy your creativity.
Can't help mentioning the 6 amp peak output current limit, 5 pairs would be costly but balance the SK56 more, which is also expensive.
(If Dorian Grey would still be around he'd likely start a lengthy itinerary about 10 pair/ch balanced TXF5.
)
Bravo again, the dirty dozen rules the forum galaxy.
Can't help mentioning the 6 amp peak output current limit, 5 pairs would be costly but balance the SK56 more, which is also expensive.
(If Dorian Grey would still be around he'd likely start a lengthy itinerary about 10 pair/ch balanced TXF5.
) Bravo again, the dirty dozen rules the forum galaxy.
Just like other Japanese trannies, they are actually quite cheap if you buy in sufficient quantity.
The price of this pair I get from Avnet is even quite a bit cheaper than IRFP240/9240.
So everyone should be able to easily afford a dozen unmatched pairs without dropping a sweat.
The price of this pair I get from Avnet is even quite a bit cheaper than IRFP240/9240.
So everyone should be able to easily afford a dozen unmatched pairs without dropping a sweat.
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Thanks Jacco,
yes, 3 pairs per channel seems thin, but it's all I got right now 😉
Nevertheless, amp drives happily my speakers (Canton ct-1000 and Epos M5 which go down to 3.5 Ohms) and in burn-in test (24 hours at max power - 18Vpeak, driven with 10khz sine wave and loaded with RCL combo of 3.5 Ohms) temperature on MOSFETs never rose more than 26 degrees Celsius above ambient, so I think it's safe to build and use this amp.
Hi Patrick,
remember, we are still waiting for the result of "beast with 1000 JFETs" 😉
yes, 3 pairs per channel seems thin, but it's all I got right now 😉
Nevertheless, amp drives happily my speakers (Canton ct-1000 and Epos M5 which go down to 3.5 Ohms) and in burn-in test (24 hours at max power - 18Vpeak, driven with 10khz sine wave and loaded with RCL combo of 3.5 Ohms) temperature on MOSFETs never rose more than 26 degrees Celsius above ambient, so I think it's safe to build and use this amp.
Hi Patrick,
remember, we are still waiting for the result of "beast with 1000 JFETs" 😉
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You cannot use JFETs in the F5 output stage without large changes.
But you can parallel Zetex devices without problems.
But if you really want a detailed yet punchy F5 with lots of reserves, you should try UHC Mosfets.
Patrick
But you can parallel Zetex devices without problems.
But if you really want a detailed yet punchy F5 with lots of reserves, you should try UHC Mosfets.
Patrick
After this one, I tend to even more agree with device's-linearity-is-everything philosophy, and I finally have not a slightest complaint about the amp.
I might yet build a SuSy circlotron with LU1014 out of curiosity, but fiddling with ZVP/ZVN and similar small devices is definitely not my thing 😉
I might yet build a SuSy circlotron with LU1014 out of curiosity, but fiddling with ZVP/ZVN and similar small devices is definitely not my thing 😉
Of course it will, actually that's the first thing I've done - headamp with 1 pair 😉
It's very silent amp (even without cap multipliers) but you have to be aware of the heat 😀
I did play with the value of the bias current and, to my ears, these MOSFETs sound best at Id between 400 and 500 mA. If you are brave and lower a PS voltage a bit (say +/-16V) at Id=600mA you'll have additional advantage of zero tempco.
Also, in this case you don't have to worry about low Vds becaus parasitic capacitances are very low (compared to usual HEXFETs) and you just want to drive a single pair.
If you do it please post your results, it would be great to see a lineamp getting hotter than many power amps... 😉
naah - I meant - when I saw Sipi's pre and amp ...... little T092 devil produce more heat than 70-watter
Yeah, that's the one - supplied with shunt regs, it gives a small contribution to a global warming process... 🙄 😀
Thanks Juma for sharing.
Seems like a relatively simple project. I happen to have all needed transistor in my part bin. Will need to find a proper heatsink to start with.
I'll let you know the results, hopefully in a few weeks.
Bests
Seems like a relatively simple project. I happen to have all needed transistor in my part bin. Will need to find a proper heatsink to start with.
I'll let you know the results, hopefully in a few weeks.
Bests
Have you also tried IRF9610/610?
I actually had the same idea as yourself a while ago, but it is often hard to find the time, especially when you have too many ideas.
Great work, these sought of reports are a great contribution. It will definitely motivate me to try it out
I actually had the same idea as yourself a while ago, but it is often hard to find the time, especially when you have too many ideas.
Great work, these sought of reports are a great contribution. It will definitely motivate me to try it out
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