TOSHIBA GT20D201 IGBT for Sherwood TEMA A-1 power amp

Do you need a pair of ... TOSHIBA GT20D101 / TOSHIBA GT20D201 ?


You will get both from Donberg (a German located at Ireland):
https://www.donberg.de/descript/g/gt_20d101.htm

or the website for the UK ...
https://www.donberg.co.uk/search?query=gt_20d101

The price seems to be high but these semiconductors are expensive ...

Good luck!
Carl

Thanks a lot Carl!

I've ordered these IGBTs from Denberg in Ireland in the past but they were not the Toshiba I wanted so I returned them and got a refund.
I checked his website and he only has the GT20D101 in stock which is not what I am looking for.

Any other helpful suggestions/tips?

Thanks a lot anyway

Cheers

How many pairs of those IGBTs are needed? Since the original transistors from Toshiba will nowhere to be found, it might be a good idea to look for a used or defective Palmer LX 2000 PA Power Amp. They have the same semiconductors in the output Stage (2 x 8 pairs).

Chasing down these IGBTs will be very diffucult, especially the p-channel types. I suggest to contact sherwood audio in Australia or US. Maybe they still have spares or at least a reliable source.

I've tried Sherwood US but they didn't seem to be able to help.
I've also tried contacting INKEL in S.Korea but they never responded.

Getting a few spare ones from a different defunct amp sounds like a good idea.

3 pairs of TOSHIBA GT20D101 / TOSHIBA GT20D201 would be enough I think.

Thanks

Hello,

did you find some pairs?
How could you tell the ones from donberg are not from toshiba?

http://shop.griederbauteile.ch/product_info.php?products_id=4384
https://shop.griederbauteile.ch/product_info.php?products_id=4383

Is offering some too.

Best Regards Adrian

Hello Adrian,

Thank you very much for sending me these links.

To be honest I don't know what to say.
Through my father in law who used to work for Toshiba copiers, I managed to get hold of 4 original TOSHIBA transistors from their stock which looked exactly like the ones on the link you sent me.

When my friend, who is much more knowledgeable than me, installed one of them in series with the remaining "original" ones, it overheated in seconds and we switched the amp off to prevent the transistor from getting burnt.
Could it be that the ones in the amp are a different make or are made of different materials to the replacement ones?
Are we doing something else wrong?
I really don't know.
The fact is that when he took out one of the "original" ones from one side of the amp and put it in the place of the bad transistor and isolated the channels, the amp was playing fine with half it's capacity. When he substituted it with the "new" ones, it overheated immediately...

We couldn't really find any other problem with the amp...
I'm gutted because it is really hard to find someone to have a look at it. It is really heavy, cumbersome and is a pain having to carry it around just just to be told that they can't mend it...

Cheers

Cheers

Hello,

its not necessarily an indication, that the IGBT's are not geniuine, if they are getting hot.

If the threshold Voltage of the units are different, some of them will have more bias current.
So it is very important to match the units (but therefore you would have to buy more than needed).

My suggestion would be: Buy 6 pairs (or even more) from one of the suppliers (but not in china) and hope
they are from the same batch.
The possibility is high, that they will be in the same region of threshold Voltage.
The left over ones, you could use as a spare part for the other channel.

Furthermore there are differnet generations which have been used.
The older ones have a green housing for the P type of IGBT.

Best regards.