HA!! Papa will know.......
SissySIT and Babelfish XA252 SIT are fooling around on the corner and chatting
In one moment they see Babelfish XA252, walking on other side of the street
Babelfish XA252 SIT sez : " That one could use some help ........ "


SissySIT and Babelfish XA252 SIT are fooling around on the corner and chatting
In one moment they see Babelfish XA252, walking on other side of the street
Babelfish XA252 SIT sez : " That one could use some help ........ "


Babelfish XA252 SIT - graphs , 8R load, BFR=22R
Today I had time just for first battery of tests, with BFR value of 22R
Happy Camper, will be even more campier tomorrow, after all tests and some mooooosic time
everything as before (rails 30Vdc, Iq 1A7), I've just mount necessary parts for SIT iteration and changed upper mosfet for THF51
as of recently - Ugs value of SIT is irrelevant, it's just niiiiiice to have them so-so matched by Ugs
graphs going up to 30W, at greater levels than 30W - Opto+Thyristor current limiter kicked in and entire OS gone Dodo ; obviously DEF specific current distribution of parts is putting heavy burden on Mosfet and I need to investigate how much I can increase protection treshold, without risk
I will also think of ways - maaaaaybe - how to slighlty increase power output ........ I don't want to change even a iota of natural DEF behavior, so I need to see how much exactly juice is going through Mosfet dynamically, and to accordingly declare new Iq point for that
rails are OK, 30 as is, 35 if one want to squeeze as much watts is sane from this amp
more to come these days about that
Today I had time just for first battery of tests, with BFR value of 22R
Happy Camper, will be even more campier tomorrow, after all tests and some mooooosic time
everything as before (rails 30Vdc, Iq 1A7), I've just mount necessary parts for SIT iteration and changed upper mosfet for THF51
as of recently - Ugs value of SIT is irrelevant, it's just niiiiiice to have them so-so matched by Ugs
graphs going up to 30W, at greater levels than 30W - Opto+Thyristor current limiter kicked in and entire OS gone Dodo ; obviously DEF specific current distribution of parts is putting heavy burden on Mosfet and I need to investigate how much I can increase protection treshold, without risk
I will also think of ways - maaaaaybe - how to slighlty increase power output ........ I don't want to change even a iota of natural DEF behavior, so I need to see how much exactly juice is going through Mosfet dynamically, and to accordingly declare new Iq point for that
rails are OK, 30 as is, 35 if one want to squeeze as much watts is sane from this amp
more to come these days about that
Attachments
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Babelfish XA 252 SIT 1W 8R.png31.7 KB · Views: 1,359
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Babelfish XA252 SIT only sch.png54 KB · Views: 1,160
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Babelfish XA 252 THD vs. Freq. 8R.png49.4 KB · Views: 896
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Babelfish XA 252 Freq. 8R.png45.9 KB · Views: 428
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Babelfish XA 252 SIT 30W 8R.png36.2 KB · Views: 413
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Babelfish XA 252 SIT 25W 8R.png33.3 KB · Views: 377
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Babelfish XA 252 SIT 20W 8R.png33.1 KB · Views: 709
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Babelfish XA 252 SIT 15W 8R.png32.7 KB · Views: 753
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Babelfish XA 252 SIT 10W 8R.png32.2 KB · Views: 758
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Babelfish XA 252 SIT 5W 8R.png31.7 KB · Views: 853
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Babelfish XA252 SIT - graphs , 4R load, BFR=22R
everything same, load changed to 4R
half of graphs in this post
everything same, load changed to 4R
half of graphs in this post
Attachments
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Babelfish XA 252 SIT 15W 4R.png32.8 KB · Views: 226
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Babelfish XA 252 SIT 10W 4R.png32.8 KB · Views: 222
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Babelfish XA 252 SIT 5W 4R.png32.2 KB · Views: 198
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Babelfish XA 252 SIT 1W 4R.png32.2 KB · Views: 190
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Babelfish XA 252 SIT THD vs. Freq. 4R.png49.6 KB · Views: 194
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Babelfish XA 252 SIT Freq. 4R.png46 KB · Views: 415
Babelfish XA252 SIT - graphs , 4R load, BFR=22R
second half of graphs
have a nice Sunday .......... I'm certainly having 🙂
second half of graphs
have a nice Sunday .......... I'm certainly having 🙂
Attachments
Will there be an autoformer version? EDIT I now see that there is. EDIT again - I too quickly read sit for SET.
With all of these used TOKIN devices it makes one wonder what are they being replaced with?
Thanks for bringing more excitement and confusion into my audio life, ZM.
With all of these used TOKIN devices it makes one wonder what are they being replaced with?
Thanks for bringing more excitement and confusion into my audio life, ZM.
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......
graphs going up to 30W, at greater levels than 30W - Opto+Thyristor current limiter kicked in and entire OS gone Dodo.....
did I said (yes, I did!) - Opto+Thyristor limiting/protection circuit is blatantly stolen from Pa

Woah - Babelfish XA252 SIT is looking gooooood. Well done ZM! I gotta build this one 🙂
from now on, you can call me Mad Hatter, or Campy Hamper, I don't care
I'm done, enough with audio, off from web


Wow, ZM. Very nice distortion curves for such a clean circuit...
It looks like the 35V version would match well Pico's 4U x 500mm chassis.
Will wait for the SIT results though. Bought some just for such occasion. Feeling spoiled here 🙂.
It looks like the 35V version would match well Pico's 4U x 500mm chassis.
Will wait for the SIT results though. Bought some just for such occasion. Feeling spoiled here 🙂.
Will wait for the SIT results though. Bought some just for such occasion. Feeling spoiled here 🙂.
SIT results start at post #65
tomorrow 2nd set of SIT results, this time with BFR of 510R value
but, looking at graphs wit 22R BFR, I'm not exactly holding my breath - these are dirty enough, don't want them dirtier
🙂
but, looking at graphs wit 22R BFR, I'm not exactly holding my breath - these are dirty enough, don't want them dirtier
🙂
SIT results start at post #65
Thank you. How could I have missed these? I guess I blinked. The SIT adds character (more 2d harmonic).
Zen Mod, please do you expect a big difference in distortion at higher frequencies between the two devices? I saw your frequency sweep but am wondering if the SIT geometry offers any advantage up there when pushed. (Probably not given they are both large devices but who knows...)
Too many attractive options here!
from now on, you can call me Mad Hatter, or Campy Hamper, I don't care
I'm done, enough with audio, off from web
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Joe Farrell did magical (perfect) solo on Humpty Dumpty!
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