4. You could go either 1 or 2W. Those flameproofs of mine are 2W.
You won't use as much current with a MOSFET output stage
Thanks Os , on point 4, I should r114/115 be 10 ohm's, not 4.7 ?
You won't use as much current with a MOSFET output stage
Thanks Os , on point 4, I should r114/115 be 10 ohm's, not 4.7 ?
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Gooday all,
I just want to make sure. Any input stage developed with the slewmaster can be used when using the new version fet output stage. Is this correct ?
I just want to make sure. Any input stage developed with the slewmaster can be used when using the new version fet output stage. Is this correct ?
mine are done and tested with 1 pair.
ALL caps are 100v except maybe the 1 uf Vbe cap (35-100V).
It will work with a huge range for the big electro's.
I've measured almost no ripple at load with as little as 47u for the multiplier caps.
The OPS's don't have many different parts. Even as I am making a book ,
The PCB itself will have the values on the next round of boards.
Don't worry , this is the final slew EF3 - it will have a long support period.
(like winXP).
PS - I ordered 2 new extrusions , taps and drills for mine ... am waiting
to fire up the whole thing. Still4given , I think ... has them fully done ?
OS
I´d like to order some parts today... I am not decided, how much output pairs I will use... Mouser have NJW on stock...or any other "better" choice ? 😀
If you want ultimate power handling go for these.
2SA1295 - ALLEGRO SANKEN - TRANSISTOR,BJT,PNP,230V V(BR)CEO,17A I(C),SIP | Newark element14
2SC3264 - ALLEGRO SANKEN - TRANSISTOR, BJT, NPN, 230VCEO,17A, SIP (MT-200) | Newark element14
My 5 pair njw's = 200W/8R amp.
MJL's or IRFP's (Vfets) = 250+W amp
Sanken MT-200's = 400W amp
Roughly. quite a range ... huh !
Truly a "builder choice" project !
OS
so.... Now I have no idea, which output trans I will use... 😀 anyway, If I use lets say two/three output pairs, is it enough to use for VAS Toshibas 2sa/2sc ?
This is my question also.
Is it enough,these(2sa,2sc) for 3 pairs MT 200?
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Most likely the 1A+ SOA of the toshiba's can run even 3 pair
Sanken MT100 -200. Sankens have more current gain than the ON's.
Best to use the big fat mt-100's for 5 pair NJW/MJL.
680 runs 2 pair mt-100 with the toshibas with a 220R driver Re.
We have a larger heatsink on the slew (HK has NONE !)
OS
680 runs 2 pair mt-100 with the toshibas with a 220R driver Re
Do you mean a commercial amplifier uses 2 pairs mt-100 as output with 2sa-2sc as driver?
Re, you mean R113=220R?
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Attachments
Wow Jeff, these are good prices. Those Mt-200 from my local Element 14 cost 27 dollars each!!!!. Talking about being ripped off and being too far away from every one.
Quan
optimum 250W slewmasters ...
3 pair mt-200 or 5 pair NJW spread out optimally over
a .4C/W extrusion.
5 pair "arcwelder" (MT-200) , I would recommend double
the extrusion (.2C/W 300mm X 300mm).
Either way , a calculated and tested 40C idle , <50C heavy use
can be expected. Extrusions should be within 1C - end to end.
OS
3 pair mt-200 or 5 pair NJW spread out optimally over
a .4C/W extrusion.
5 pair "arcwelder" (MT-200) , I would recommend double
the extrusion (.2C/W 300mm X 300mm).
Either way , a calculated and tested 40C idle , <50C heavy use
can be expected. Extrusions should be within 1C - end to end.
OS
Attachments
Hi Os, what about the sankens 2SD2390/SB1560 ?. I got about 4 pairs on each board pulled from an old HK receiver. Can i use mje 15032/15033 with them?
Quan
Quan
Yes, but you won't have as powerful an amp. 2SD2390/SB1560
are 150V / 100w devices. Lower rails + 150W amp (4-5 pairs).
Also , MJE's would be ideal for those little sankens !
oS