I spotted one interesting moment , from all graphs ....
anyone else ?
edit: disclaimer : all measurements above 10W were made with 6db autoformer inline with soundcard output ; also - older measurements (THF iteration) are sorta "hairier" , most probably due to some interference of everything around with my non-metalic boxed interface for measurements .....
anyway , I'm (now looking at graphs and numbers ) not worried more about any significant THD difference between THF and 2SK ....... but there is something other interesting to catch ....
anyone else ?
edit: disclaimer : all measurements above 10W were made with 6db autoformer inline with soundcard output ; also - older measurements (THF iteration) are sorta "hairier" , most probably due to some interference of everything around with my non-metalic boxed interface for measurements .....
anyway , I'm (now looking at graphs and numbers ) not worried more about any significant THD difference between THF and 2SK ....... but there is something other interesting to catch ....
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yes .... but logicall and irrelevant this time
anyway , what I already wrote , when I posted measurements of DEFiSIT is that I realized that DEFiSIT is having lower THD on 4R than on 8R load , while SissySIT (THF) is opposite- having lower THD on lighter load
interesting ..... Sissy with 2SK182ES in output is behaving much as DEFiSIT , having lower THD on 4R than on 8R load ......
easy and not, to explain , in layman way of thinking and talking - I was explaining that difference with known history about Pass SIT-1 production - Papa literally ordered parts with these U-I characteristics , shooting for audio purpose oriented part (best behaved in U-I area of interest) , while big SIT is industrial workhorse ......
so , it seems - 2SK is sorta more inclined to be audio friendly than THF ....... if one succeed in using it in adequate circuit (Ugs seems to be sorta critical for Sissy , so needing strict sorting )
though , talking strictly about load/THD dependence trend ...... I'm not planning to conduct listening test comparisons between THF and 2SK , and I doubt that my by elephant-farted ears can hear difference
anyway , what I already wrote , when I posted measurements of DEFiSIT is that I realized that DEFiSIT is having lower THD on 4R than on 8R load , while SissySIT (THF) is opposite- having lower THD on lighter load
interesting ..... Sissy with 2SK182ES in output is behaving much as DEFiSIT , having lower THD on 4R than on 8R load ......
easy and not, to explain , in layman way of thinking and talking - I was explaining that difference with known history about Pass SIT-1 production - Papa literally ordered parts with these U-I characteristics , shooting for audio purpose oriented part (best behaved in U-I area of interest) , while big SIT is industrial workhorse ......
so , it seems - 2SK is sorta more inclined to be audio friendly than THF ....... if one succeed in using it in adequate circuit (Ugs seems to be sorta critical for Sissy , so needing strict sorting )
though , talking strictly about load/THD dependence trend ...... I'm not planning to conduct listening test comparisons between THF and 2SK , and I doubt that my by elephant-farted ears can hear difference
Just wondering, if the speaker's impedance stays above 8R for the whole frequency range, would the THF SissySIT be the better setup? 2SK for low impedance speakers and THF for high impedance speakers?
In theory of course, as you had mentioned the actual difference to the ear may not be noticeable.
In theory of course, as you had mentioned the actual difference to the ear may not be noticeable.
A pair of NOS THF-51S from Tomo and a quad of used THF-51T from Pras.
Hopefully i'll get at least two usable SITs out of this, if not i'll have to get more.
And, maybe if get more than two that are suitable it will give me some options for the future, all i need now is a current-limited PSU for measurements. Want to minimize risk in case i mess up, that way i can have beer before/during measurement
Wonder if the last letter is indeed just the "batch", for example 2SK182E i have found in datasheets, 2SK182ES could mean "S" series? Same with THF-51, "S" and "T" could refer to different manufacturing batches?
Hopefully i'll get at least two usable SITs out of this, if not i'll have to get more.
And, maybe if get more than two that are suitable it will give me some options for the future, all i need now is a current-limited PSU for measurements. Want to minimize risk in case i mess up, that way i can have beer before/during measurement
Wonder if the last letter is indeed just the "batch", for example 2SK182E i have found in datasheets, 2SK182ES could mean "S" series? Same with THF-51, "S" and "T" could refer to different manufacturing batches?
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I offer here two pairs THF-51 and one pair 2SK182ES I do not need any more.
https://www.diyaudio.com/forums/swap-meet/328462-tokin-sits-pairs-thf-51s-2sk182es.html#post5568017
Suitable for the SissySIT.
Thanks Zen Mod!
I got two good pairs with higher Vgs from Chul and one from pras1170.
Thanks friends!
https://www.diyaudio.com/forums/swap-meet/328462-tokin-sits-pairs-thf-51s-2sk182es.html#post5568017
Suitable for the SissySIT.
Thanks Zen Mod!
I got two good pairs with higher Vgs from Chul and one from pras1170.
Thanks friends!
THF-51S 2SK182ES
Want to learn something if you have a chance
These are all good, I don't use a tracer, I don't use a curve traceI offer here two pairs THF-51 and one pair 2SK182ES I do not need any more.
https://www.diyaudio.com/forums/swap-meet/328462-tokin-sits-pairs-thf-51s-2sk182es.html#post5568017
Suitable for the SissySIT.
Thanks Zen Mod!
I got two good pairs with higher Vgs from Chul and one from pras1170.
Thanks friends!
Want to learn something if you have a chance