Discussion about the Korg PolySix synthesizer

I'm trying to locate a replacement for the 2sb744 power transistor on 
the P6 power supply board --
I know this component is faulty (successfully swapped in a working 
transistor from another unit).

This particular number seems to be obsolete, and I haven't had luck 
finding an equivalent.
Can anyone point me in the right direction?
Thanks.

~GMM

Would an MJE172 work?


On Thu, Apr 7, 2011 at 10:04 AM, klosmon <klosmon@sbcglobal.net> wrote:

>
>
> I'm trying to locate a replacement for the 2sb744 power transistor on
> the P6 power supply board --
> I know this component is faulty (successfully swapped in a working
> transistor from another unit).
>
> This particular number seems to be obsolete, and I haven't had luck
> finding an equivalent.
> Can anyone point me in the right direction?
> Thanks.
>
> ~GMM
>  
>


[Non-text portions of this message have been removed]

You could try an Motorola MJE253, but check the pin out (should go e-c-b).
This is a nice replacement for linear PSU circuits as it has a matched pair
MJE243 (NPN)  and both are in a TO-126 package.

Cheers,
Andy


On 07/04/2011 18:04, "klosmon" <klosmon@sbcglobal.net> wrote:

>  
>  
>  
>    
> 
> I'm trying to locate a replacement for the 2sb744 power transistor on
> the P6 power supply board --
> I know this component is faulty (successfully swapped in a working
> transistor from another unit).
> 
> This particular number seems to be obsolete, and I haven't had luck
> finding an equivalent.
> Can anyone point me in the right direction?
> Thanks.
> 
> ~GMM
>  
>    
> 
> 



[Non-text portions of this message have been removed]

Jed Jorgensen wrote:
> Would an MJE172 work?
Tried that, thanks.  Works with no load, but doesn't work when the 
modules are connected.
~G
>  
>
> On Thu, Apr 7, 2011 at 10:04 AM, klosmon <klosmon@sbcglobal.net 
> <mailto:klosmon@sbcglobal.net>> wrote:
>
>      
>
>     I'm trying to locate a replacement for the 2sb744 power transistor on
>     the P6 power supply board --
>     I know this component is faulty (successfully swapped in a working
>     transistor from another unit).
>
>     This particular number seems to be obsolete, and I haven't had luck
>     finding an equivalent.
>     Can anyone point me in the right direction?
>     Thanks.
>
>     ~GMM
>
>     
>
>



[Non-text portions of this message have been removed]

--- In PolySix@yahoogroups.com, klosmon <klosmon@...> wrote:
>
> I'm trying to locate a replacement for the 2sb744 power transistor on 
> the P6 power supply board --
> I know this component is faulty (successfully swapped in a working 
> transistor from another unit).
> 
> This particular number seems to be obsolete, and I haven't had luck 
> finding an equivalent.
> Can anyone point me in the right direction?
> Thanks.
> 
> ~GMM
>
Best place for vintage transistors and subs:

http://www.ceitron.com/semi/semi.phtml?part=2sb744

Almost always in stock 98% of the time

Hi,

The data sheet of the 2SB744 tells the important values:
PNP, TO-126 E-C-B, Ic=3A, Uce=45V (60V for 2SB744A), Ptot=10W (with heat 
sink)

Lets see what we can find:
BD180:
PNP, TO-225 E-C-B, Ic=3A, Uce=80V, Ptot=30W (with heat sink)
TO-225 looks from the drawings the same as TO-126.

BD438:
PNP, TO-126 E-C-B, Ic=4A, Uce=45V, Ptot=36W (with heat sink)

2N5195:
PNP, SOT-32 E-C-B, Ic=4A, Uce=80V, Ptot=40W (heat sink)
SOT-32 is the same as TO-126

all available at Farnell
klosmon wrote:

> I'm trying to locate a replacement for the 2sb744 power transistor on
> the P6 power supply board --
> I know this component is faulty (successfully swapped in a working
> transistor from another unit).
>
> This particular number seems to be obsolete, and I haven't had luck
> finding an equivalent.
> Can anyone point me in the right direction?
> Thanks.
>
> ~GMM
>
>
> ------------------------------------
>
> PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6Yahoo! Groups Links
>
>
>
>