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Crescendo ampilifier elektor1982

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Hello everybody,

I'm new here.
I almost have finished my Crescendo amplifier. It took me 5years to build this beast.
It uses 2x (2 x 2sk135 en 2x 2sj50) mosfet's from Hitachi. You can visit my homepage, where you can find some foto's. In the same enclosure, I builded also 4 smaller amplifiers. The supply consists of 3 toroidal's from 500VA each and a total of 130000µF on capacitors.

http://groups.msn.com/BenJanssenBensen's homepage
 

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Well, I can't really compare this amp with many others. But I've build also the crescendo ME with the newer output devices. And my opinion is that the "old" amp sounds better than the new one.

I can't realy describe how it sounds. I think this comes from these devices, many say that these are one of teh best audio MOSFET's ever made.

One question,
C
 
Oops sorry,

One question: Can anybody explane me the difference between Audio mosfet's (2s51530/2sj50/2sk1058....buz900...) and the regular mosfet's (IRFP9240/9140/240/140...).
Because I'm designing a new amp, and I can't choose between BJT's (MJL4281/4302) and the cheap IRFP.... devices.


Thanks
 
Which Crescendo 250W??

1) Crescendo mini with 1 x 2SJ50 and 1 x 2SK135, 45Vdc
2) Crescendo 1982 with 2 x 2SJ50 and 2 x 2SK135, 75vdc
3) "1Kw" Crescendo with 4 x2SJ50 and 4 x2SK135
4) Crescendo ME

5) And there is somewhere on a Italien site an article of a crescendo with 3 x devices that claims to have 350Wrms/4ohm?


I have of each of these amps the circuits. From the crescendo 1982 I have the total article in Dutch and from that italien one the article in Italien.
But all of these file's are to big to poste also in ZIP format.

I wouldn't build the crescendo 1982 with only 2 devices in parralel, in 4ohm, you are far over the SOA curve off these devices.

Greetz
Ben
 
hi

i dont know how much this would help but we have driven the crecendo with 2 X 750 VA ie 1 750 Va per channel with a few mods as higher voltage rating input trannies and 1 with a seperate suuply for the original input trannies while the mosfet output was fed with 750 VA

We Had Used Only J 56 & K 156 , they yet rock after 13 years and are going strong as ever

we use these for testing drivers - have fed them all type of wave forms - short circuited the out - put - when our test drivers have blown !

no probs with the amps - rock solid

suranjan
 
Hi Bensen,
some like BJTs and others like lateral FETs, some even like vertical FETs particularly for their low cost and reliability. But I hear the problem with them is trying to obtain anything even close to a complementary pair. For this reason the VFET fans often choose to go Nchannel and develop circuits to try to get the best out of NVFETs. Lots of past threads to choose from. Good luck.
 
AndrewT said:
Hi Bensen,
some like BJTs and others like lateral FETs, some even like vertical FETs particularly for their low cost and reliability. But I hear the problem with them is trying to obtain anything even close to a complementary pair. For this reason the VFET fans often choose to go Nchannel and develop circuits to try to get the best out of NVFETs. Lots of past threads to choose from. Good luck.

Kanwar, Quasi, Lars, and few others are NMOS VFET fans;)
PVMOS is really a hell with loads of disadvantages associated along with it.....
 
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