Need K129A sub. Dual FET Diff's for Sansui TA-500 Receiver

santacruztv · 14th October 2011, 12:31 AM

Hi folks, first time posting here. I've googled high and low for the parts and/or schematic I need to fix a Sansui TA-500 receiver... with no luck. It needs the FET Differential transistors replaced. It uses a K129A which is two unknown FET's coupled together in a metal housing (see pics). somewhere I saw a suggestion to use K117's so I tried them but now I get no sound and the voltages are all incorrect so I'm thinking the K129A uses some sort of FET pair as the orientation of the transistors facing each other and the board markings make me think it uses two different FET's paired. If anyone has any suggestions that would be great. Might be best to take a look at pics as I hope I've described the issue clearly.

Thanks,
Greg

santacruztv · 4th November 2011, 05:43 PM

back to the top....

anyone have any ideas?

sakis · 4th November 2011, 07:50 PM

Pioneer 2SK129A - Encompass Parts

2SK129A Part Info

2SK129A-L Part. Pioneer 2SK129A-L. Pioneer UNKNOWN PARTS

santacruztv · 5th November 2011, 12:21 AM

thank you for the reply. however encompass doesn't have them in stock and i've tried partstore (they can't come up with one either) the other link you gave is for a company that requires large quantity orders and likely won't have them either. I'm only looking for a quantity of two. another member did reply with a suggestions so I'll post back my findings.... although if someone has a couple originals they'd like to sell i'd be glad to buy them

thanks again
greg

homemodder · 5th November 2011, 12:43 PM

Quote:

Originally Posted by santacruztv

back to the top....

anyone have any ideas?

First try emailing this member, he has some of these parts and may sell some to you, sorry I dont know his name, only alias but you could just say youre from Diyaudio. movieandmusiclover@hotmail.com

I believe the 2sk117 could be used as replacement and are far easier to obtain. Im including a pic of the pinouts of the 129, make sure that you allign the pins correctly when trying the 2sk117, I havent checked if they are the same and the 117 is a single.

If it doesnt work it could also mean that you might have more problems somewhere else Im afraid.

Hope this helps.

sgrossklass · 5th November 2011, 12:51 PM

In fact, it is quite likely that there is another problem that toasted the original FETs.

santacruztv · 5th November 2011, 05:43 PM

Thanks for the replies guys. I've emailed that member and will see if he is willing to part with a couple. I am sure it will fix the problem as I've scoped it down to the K129's. (one was working and the other was intemittent, swapping them swaps the problem to the other channel). So, I'd like to just replace both to avoid future issues. Thanks again, Greg

ingenieus · 5th November 2011, 07:20 PM

Here is an old thread on this topic

Question about FET 2SK117 in old stereo receiver

dcsleeper · 12th January 2012, 01:18 PM

OP Did you ever find this part? Was it what you needed? Working on a TA-500 presently...

4th November 2011, 07:50 PM	#3
sakis diyAudio Member Join Date: Jan 2006 Location: nea makri athens greece	Pioneer 2SK129A - Encompass Parts 2SK129A Part Info 2SK129A-L Part. Pioneer 2SK129A-L. Pioneer UNKNOWN PARTS __________________ SERVICE ΙΑΠΩΝΙΚΩΝ ΜΗΧΑΝΗΜΑΤΩΝ ΗΧΟΥ www.eastelectronics.gr

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4th November 2011, 05:43 PM	#2
santacruztv diyAudio Member Join Date: Sep 2011	back to the top.... anyone have any ideas?

5th November 2011, 12:21 AM	#4
santacruztv diyAudio Member Join Date: Sep 2011	thank you for the reply. however encompass doesn't have them in stock and i've tried partstore (they can't come up with one either) the other link you gave is for a company that requires large quantity orders and likely won't have them either. I'm only looking for a quantity of two. another member did reply with a suggestions so I'll post back my findings.... although if someone has a couple originals they'd like to sell i'd be glad to buy them thanks again greg

5th November 2011, 12:51 PM	#6
sgrossklass diyAudio Member Join Date: Nov 2004 Location: Germany	In fact, it is quite likely that there is another problem that toasted the original FETs.

5th November 2011, 05:43 PM	#7
santacruztv diyAudio Member Join Date: Sep 2011	Thanks for the replies guys. I've emailed that member and will see if he is willing to part with a couple. I am sure it will fix the problem as I've scoped it down to the K129's. (one was working and the other was intemittent, swapping them swaps the problem to the other channel). So, I'd like to just replace both to avoid future issues. Thanks again, Greg

5th November 2011, 07:20 PM	#8
ingenieus diyAudio Member Join Date: Apr 2011	Here is an old thread on this topic Question about FET 2SK117 in old stereo receiver

12th January 2012, 01:18 PM	#9
dcsleeper diyAudio Member Join Date: Apr 2010	OP Did you ever find this part? Was it what you needed? Working on a TA-500 presently...

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