2SC2631/2SC1953 & 2SK109 equivalents
 

Hi,

I'm servicing an old integrated SU-V4 Technics amp. I already replaced one of the output IC stages but it seems that was not the only problem. I did some measurements and found out that there are 3 transistors around which I get strange voltage measurements. These two transistors are 2SC2631/2SC1953 (2 pcs.) and 2SK109. Does anybody know a substitute for these two. I would rather use European substitutes if they exists. I think the bigger problem is 2SK109 because is obsolete double transistor. I'm not sure if any company is still making this kind of transistors. Maybe it is possible to replace it with two transistors of the same type.

P.S: I wrote '2SC2631/2SC1953' because in the service manual it is written 2SC2631 and in the amp it is 2SC1953. It seems they used an equivalent already. :)

Sorry for my 'rusty' English.

http://img59.imageshack.us/img59/6346/ampd.jpg

Edit: I added a picture of these two transistors if someone found it useful.

For bipolars replacement, I am sure you can find plenty of suitable parts (including European). I will give you several numbers, staying with Panasonic parts:
2SC1953 S, or T - 1.2W
2SC5346 S - 1W
2SC2632 S - 1W
2SC2631 S - 0.75W
These are the same transistors, just different packages (power dissipation).
For (still can be found) 2SK109-D FETs replacement:
(u)µPA68H K2××, or L
2SK150 GR
M47F
2SK389 GR

Thank you for your answer. Now I just have to find a shop which has these transistors in stock. I'll let you know when I find one.

2SK389 = N-FET (double)
2SJ109 = P-FET (double)

Replacement for 2SJ109 is 2SJ74, but you need two pieces, they should be thermally coupled with matched Idss.
Only BL grade
GR/BL/V grade

PS: Andrej, raje naroči uparjene, bo najmanj problemov.

Thank you, stormsonic. I will use 2x2SJ74 in worst case.

P.S: Tudi sam bi najraje uporabil dvojne tranzistorje, ampak nevem če bom dobil nadomestnega. Trenutno iščem kakšno pametno (spletno) trgovino, ki prodaja predvsem japonske polprevodnike. Pri nas je itak vse skupaj bolj bogo. Imaš mogoče kakšen predlog?

look at the photo again ...
the part in the picture is 2SK109, which is a dual n-channel jfet.
(the 2SJ109 is a dual p-channel device)
steveoh gave good info!

mlloyd1

Mlloyd1, thank you, my mistake, replaced letter J with K. :(
Need new glasses :o

Dear andrej123

I have two 2SK109 which I don't have any plan on using soon. The rank is C instead of D with Idss ~2.6 mA. I bought them almost 20 years ago in Akihabara. If you are interested, drop me a PM. I prefer to send both of them out, so I won't have just one in hand...

Regards,
Satoru

Hello guys I have an old Toshiba SC-665 and I want service I want to replace all 2SK150A "two of them", what equivalent can I use to replace them? :D

Regards
vargasmongo3435

are we talking about 2sj109 or 2sk109?