It is expected that the offset keeps moving a little bit around. If you blow on the MOSFETs it will vary more, but then come back to where you had set it.
Once you start tonight's listening session don't be too surprised when you realize it is already 2:00 AM and you did not see the time go by.
Once you start tonight's listening session don't be too surprised when you realize it is already 2:00 AM and you did not see the time go by.
I am sure you already have it printed and plastered on a wall, but here is a link to the relevant article anyway.
http://www.firstwatt.com/pdf/art_mos_test.pdf
http://www.firstwatt.com/pdf/art_mos_test.pdf
Yes by Mr Pass
in article about mosfets testing.Page text and graph show by courtesy of First Watt
http://www.firstwatt.com/pdf/art_mos_test.pdf
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I try both Siliconix IRFP9240 and Harris and i agree with Papa conclusion.
Nothing to be excited too much about it
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Those parts Nelson is referring to in that article are not Siliconix parts.
They are the original International Rectifier parts.
What I am wondering is if there are differences between Siliconix and IR.
Vishay now own both product lines.
To be specific, I wondering if there are differences between Sihfp9240 and irfp9240
They are the original International Rectifier parts.
What I am wondering is if there are differences between Siliconix and IR.
Vishay now own both product lines.
To be specific, I wondering if there are differences between Sihfp9240 and irfp9240
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Yes, they have not original IR package logo, but inside is the same.
IR = Vishay= Siliconix
Vishay - Company Info - Vishay History
the stuff we find at Mouser for example are IRFP9240PBF and is RoHS compatible now.
This new Pb free version don't mean is not the same old IR semiconductor technology line product inside.
Vishay is packaging and this Guy's doesn't invest any money to make them perfect for audio
because this applications is not the big market place purpose.
Equivalent transistors can do the job and Rochester 8K pcs of Harris wait for Diyers.
Could we find some IXYS brand pairs maybe for M2 ?
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I like IXTQ36N30P and IXTQ36P15P, which seem a pretty good match to me. Kind of like two IRFP240/IRFP9240 glued together in one package, but with higher transconductance and a better junction-case thermal resistance.
Haven't tried them in an M2, though they are currently serving nicely as source followers in another of my amps.
Yes, and I have a few thousand of them. Same chip as the plastic.
That character of P channel types was an IR phenomenon - Harris and
Samsung and a couple others do not exhibit the transconductance shelf.
I seem to recall that at one point Samsung parts were acquired by IR,
so there were examples of IR parts that didn't have it.
The IR parts work, but you can measure a difference, which shows up as
an alteration in the distortion character between lower and higher
frequencies. Not a big deal, more of an issue for no-feedback amplifiers
and Common Source use.
Last time I tested Vishay IR's, the parts behaved the same as earlier.