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Old 3rd April 2013, 01:22 AM   #41
Salas is offline Salas  Greece
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Kudos to Jeremy Siddons of Peak Instruments UK for extending the Atlas 75 firmware flash for Sic depletion. He had an auto new software reminder the other day, but with a bug for depletion Mosfets like DN2540 that we reported back. He fixed it in no time. When we mentioned that the device knows nothing of Sic depletion Jfet he asked for the reverse and forward PN junction graphs. Now a new update bell rang and what do you know, it recognized and traced the R085! Traced it in the very confined limits of mA and few volts it can of course, but it gives Vgs(off) for 1uA and Vgs(on) for 5mA. Basic matching for Vgs in other words. Interesting how it shows like a small triode valve in the wee region of the traces though. Don't mind the wobbles, its the software driven CVS play and the Semisouth Sic reacting. If two samples trace close in this small signal area will they usually match higher too? Don't know, but I have seen it in power BJTs as a good probability, when the fully traced matches on a Tek matched with the same samples on the Peak.
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Old 3rd April 2013, 05:25 AM   #42
stajo is offline stajo  Sweden
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Old 4th April 2013, 11:46 PM   #43
Telstar is offline Telstar  Italy
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Very nice variation and also great for my headphone use ( similarly to l'amp with 30V supply)

Quote:
Originally Posted by Salas View Post
I would expect the custom PapaFET to be the best tweaked one for audio.
Actually the unobtainium Yamaha sits are slightly better, according to Nelson's article in Linear Audio.

Oh, salas, I have the same Peak tester/tracer: does it recognize the sony k82?
I tested mines with other tools and I have a pair that were really close and would like to trace Em with the Peak (this weekend hopefully)
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Old 5th April 2013, 12:02 AM   #44
Salas is offline Salas  Greece
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That K77 has the most flat 45 degrees going curves indeed.

It should do K82 with firmware 9 because it did so with the R085. Just download the latest software from their website. It will reprogram the unit and update the PC. If it does not, email them. They are happy to try cover weird semis.
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Old 5th April 2013, 12:05 AM   #45
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The R065 is enhancemnt mode device, just has much lower Vt than R100. About half.
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Old 5th April 2013, 12:13 AM   #46
Salas is offline Salas  Greece
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The R100 it does it for sure because they had a sample on their early YouTube presentation. Depletion they did not have.
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Old 5th April 2013, 12:38 AM   #47
Telstar is offline Telstar  Italy
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Quote:
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That K77 has the most flat 45 degrees going curves indeed.
About double transconductance of a sit1, iirc.

Yep main reason I bought the dcp75 instead of the basic model was that it measured jfets
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Old 5th April 2013, 01:01 AM   #48
Salas is offline Salas  Greece
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Maybe that black 2SK77B monster with the screw terminals? Because the regular 2SK77 was 1.5 Siemens in Yamaha literature for 30V 2A 1kHz. When NP showed 2 Siemens for SIT-1 custom part in the SIT-Nemesis article.
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Old 3rd January 2014, 06:51 PM   #49
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Default Choke

Sorry for the stupid question, but can you tell me which kind of choke must be used in the PS?
I haven't seen such kind of chokes except for the x-over ones, can I use one of them?

Thank you very much for your help!
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Old 4th January 2014, 01:25 PM   #50
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Hi bonzo15011978,
It is OK to use X-over inductors in the appropriate sizes, preferably air-cored and wound with thicker than 16 awg copper wire.
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