Just wondering why industrial output packages like this aren't used more often. very high power so just a few should be able to make highpower class A correct? Or where am I going wrong? Would love to drive my maggies with a 200-300WPC ClassA power amp. I know what this entails as far as power supply concerns. This is DIY though. I would even look at complete industrial design with all electronics in an industrial controls box, fan cooling, 3-6kva trannie. Nothing about looks just sound quality. In high HP VFD design that I work with there are IBGT's in single packages rated to 600v and 400-600A. What about something like that? Probably just showing my ignorance.
Mithrandir is certainly one who can comment it best , now having two successful products using Big Pucks
I personally know only for Gamut , using those Biguns ........ but far from that , that I invested any time in searching for others
I personally know only for Gamut , using those Biguns ........ but far from that , that I invested any time in searching for others
I built up a single channel in F4 beast builders, it was fairly easy, just didn't get around to boxing it all up.
I also did another one with 3 international rectifier TO247 devices in parallel, again also very easy. I actually figured this was the better solution as transconductance was about the same but much lower capactances to deal with. Of course you now have to match devices but that is the fun part in diy, maybe not so much fun for manufacturers.
I also did another one with 3 international rectifier TO247 devices in parallel, again also very easy. I actually figured this was the better solution as transconductance was about the same but much lower capactances to deal with. Of course you now have to match devices but that is the fun part in diy, maybe not so much fun for manufacturers.
That is definitely noise at low power not harmonic distortion.
Maybe he created a ground loop with his testing equipment.
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Something is off on the INT-25 we see .02% at 200 mW. The XA-25 is about 003% at the same spot. Some kind of noise hard to say.
Also noticed his 4 Ohm measurement has 1/10 the distortion of the 8 Ohm. And some strange noise on the residual.
Also noticed his 4 Ohm measurement has 1/10 the distortion of the 8 Ohm. And some strange noise on the residual.
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Wayne is it ok to ask, did you create the 2nd Harmonic shown in those measurements, in the line stage, front end, or output stage of amp.
I am kind of thinking it was a front end or line stage tweak. Maybe in the line stage, then the rest can be identical to xa25.
I am kind of thinking it was a front end or line stage tweak. Maybe in the line stage, then the rest can be identical to xa25.
Probably incorrect grounding of his test equipment.
floating/ground switch not correctly set, I am guessing
One should think that before publishing of measurements you should be very sure you have done it correct. It would be best if such measurements was performed by certified labs with calibrated equipment etc..
What I miss is a measurement on test signal used to be sure input is "clean"?
What I miss is a measurement on test signal used to be sure input is "clean"?
It is a sum of all three, nothing intentional just how it ended up. The pre section has 6dB gain closed loop and not much more open loop. Of course with 6dB gain it kicks the noise up a bit but still only about 105 uV total.
I have the impression that the H2 added by the Pre section gives the INT -25 a bit more H2 dominance than in the XA25.
You would think that just as I did. However, a lot of the big packages
are designed solely around switching, and we see reliability issues
from hot spots on the large die with the processes they use to achieve
the best switching characteristics. Used as a switch, no problem. Used
as a linear part, you will find some rated at 800 watts which nevertheless
croak at 1A @ 30V. You have to look at the DC SOA spec, assuming they
show you one...
I have attached a couple of documents about this reliability issue.
When you pick carefully through the few offerings that will work, you see
some pretty high prices, which could be one of the reasons.
Although it's looking better for the future of using high power switching parts in linear applications, of the list in the IXYS whitepaper, the parts seem to be some combination of expensive, low transconductance, highish input capacitance, expensive, out of stock or expensive (over $40 ea).
I'm learning but still a Dodo here. The one that looks interesting is the
IXTH24N50L
About $20
2500pF input capacitance
7 transconductance
Vgs between 3.5 and 6V
TO-247 and the IXYS datasheet says to consider max Tdp to be 192W in linear operation so is there anything to say this would be better than IRFP240?
Should we only consider the SOT227 packages? Am I looking at the right parameters for consideration?
I'm learning but still a Dodo here. The one that looks interesting is the
IXTH24N50L
About $20
2500pF input capacitance
7 transconductance
Vgs between 3.5 and 6V
TO-247 and the IXYS datasheet says to consider max Tdp to be 192W in linear operation so is there anything to say this would be better than IRFP240?
Should we only consider the SOT227 packages? Am I looking at the right parameters for consideration?
... I guess I should put some context around expensive - expensive for experimentation but maybe not expensive if one were building a known, tested build. Especially true compared to the price of Semisouth parts and even the Tokin SITs now with both approaching or surpassing $100.
I'll be digging through the F4 Beast Builders thread if anyone's looking for me
I'll be digging through the F4 Beast Builders thread if anyone's looking for me