Trace Elliot AH300 outputs

[pontiacpete]

This amp has a blown output. It has the BUZ901/906 output transistors in the TO-3P case.
Is it possible to use the IRFP240/9240 as a drop in replacement?

Thanks
pete

[malukaluis]

Short answer...no.
the BUZ901/906 is TO-3P and the IRFP240/9240 is TO-247. The drain and source are opposite to each other.if you did "drop" them in you'd have to cross the the D and S over each other, not ideal but can be done so long as their characteristics were with in the same parameters. Here's what i use as my Bible....

Datasheet catalog for integrated circuits, diodes, triacs, and other semiconductors, view

[Steve Conner]

The characteristics aren't the same anyway. Better to use the BUZ901/906, or the ECX series from Profusion which are identical. I think there is one other pair that might do, 2SK1058 and 2SJ162, but the bias circuit might need modified.

If you want to know the reasoning behind this, read Rod Elliot's article "Hexfets in Audio".

[pontiacpete]

Has anyone ever tried the BUZ901/906 sold on ebay from china?

[Enzo]

Wow, an obsolete part type, hard to find, and with only a couple substitutes, found cheap on ebay from China. I can't imagine more red flags flapping on something than that.

[pontiacpete]

ok,, back from left field..
I was not straight with the packaging.
They have written on them BUZ901P/906P

Did some searching for info on another amp and found this:http://music-electronics-forum.com/t29141/
So these are TO-247 case?

Steve, are these a good replacement ECX10N20R
ECX10P20R

Thanks everyone for the help, always appreciated.

[Ted]

I tried the IRFP 240 approach as an experiment on a scrap AH300 a few year back. They worked. But not for long.

[pontiacpete]

Got the mosfets installed and the amp fired up without problem on the light bulb.
I went with the exicon's.

Are there any voltages that I should be looking for?
They are getting +/-82 with out light bulb and it' s holding. And is sounding good
Should I make any adjustments on the trim pot with a signal into the amp?
any help?

Oh,, and the wave is looking good on the scope.