Author Topic: Repairing old amplifier, trying to source alternative transistors/Mosfets.  (Read 6038 times)

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Offline AlfizzleTopic starter

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Hi  :)

This is my first post here, i watched Dave's videos on YouTube for quite some time but haven't signed up here till now!

Im repairing an old amplifier of 90's vintage, it currently has two toshiba k1529 and two toshiba j200.

I have been looking for suitable replacements, as the originals seem pretty expensive (this old amp im repairing is only a cheapy)

Could someone kindly inform me of a cheaper alternative to the two mentioned parts above?

Im not an expert, but im pretty competent at repairing items by replacing faulty parts with the same original model part's (in this case it will be false economy to do that).

Apologies if my format/way i have asked my question is incorrect. please tell me if i need to make any changes to it or add any more information.

Thank you.
 

Offline ignator

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Re: Repairing old amplifier, trying to source alternative transistors/Mosfets.
« Reply #1 on: September 19, 2014, 04:13:27 pm »
When I searched for "K1529" I found a application note (national semiconductor ap note 1645) for LM4702. This is an audio driver IC that called out this transistor and it's complimentary J200. It has a table that I snapshot below showing other transistors they tested for compatibility.  Look up the international rectifier components data sheet and compare to your parts data sheets.  My quick look found the IRFP240 was the same package size and pinout as the 2SK1529. And better voltage and current capability.

Device Pair                Manufacturer
2SK1057 / 2SJ161     Renesas
2SK1058 / 2SJ162     Renesas
BUZ900 / BUZ905      Magnatec
BUZ901 / BUZ906      Magnatec
2SK1529 / 2SJ200     Toshiba
2SK1530 / 2SJ201     Toshiba
IRFP240 / IRFP9240   International Rectifier
 

Offline AlfizzleTopic starter

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Re: Repairing old amplifier, trying to source alternative transistors/Mosfets.
« Reply #2 on: September 20, 2014, 05:51:17 am »
Thanks for your reply, ill look into that now.

 

Offline keland_uk

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I know this is an old thread, but did you or anyone else have modern drop in replacements for J200/K1529 and similar replacements?

 The list in this thread look like contenders. Just wondering if any sucesses?

cct diagram of a sony amplifier from late 90's that use them attached

Maybe someone could point to what things may need changing in the circuitary to support some of the other MOSFETS identified? (the IRFP240 / IRFP9240   seem to still being manufactured)

or any other MOSFETS.

Any pointers appreciated


 

Offline David Hess

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Starting with p-channel MOSFETs led me to the IRFP9240/IRF240 as the best match and place to start because of slightly lower threshold voltage than the alternatives.  The circuit may need to be adjusted for the higher combined threshold voltage.
 
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