Sansui G9700 output transistors

[RAMIRAMI68]

Hello
Sansui G9700 output transistors...I purchased mine without...
Which one do I need and where to buy original or replacement and not fake?
link to purchase please?

thanks.

 

[Double T]

I recently bought from mouser MJ21194G to replace the 2SC2607 NPN and MJ21193G to replace 2SA1116 PNP. Both are On Semi units. I have had good performance from them.

 

[kevzep]

We have just been discussing this in another thread about the AU717.
The MJ21193 and 94 will make the amplifier work, but they are not suitable replacements as they compromise the performance of the amplifier due to the fact that the original transistors are 20mhz devices as opposed to the 4mhz of the MJ21193/4.
The speed of the amp is compromised, TIM Distortion, THD and slew rate are all compromised. It makes a definite audible difference and you lose the performance the direct coupled high speed Sansui amplifiers are famous for.

There are no TO3 devices currently manufactured which fit the spec's.

The only two options are to buy NOS, there are transistors out there if you look hard enough, or you can buy new TO3P Sanken transistors from Digikey and with some small modification, fit them to the amplifier. Search out my BA-F1 thread to see how I did it.

I have done this to G9000's, G22000's, AU517, BA-F1 with great results.

Download the Datasheet for the original transistors, then go to digikey and search out the closest specs.

 

[gizzyman47]

Good info!

 

[divu]

After reading a lot, according to what "kevzep" says:
Originals, or
2SC2607 NPN = 2SC3857 (TO3P)
2SA1116 PNP = 2SA1493 (TO3P).

 

[divu]

Sanken.

 

[RAMIRAMI68]

Thank you all for responding
I prefer to not make any changes to the installation of other transistors.
If anyone can give a link to buy the replacement Normal size ..( Not fake )...?
thanks.

 

[AUD101]

Try contacting - Sansui Vintage Parts ---> https://www.sansui-vintage.com/product_info.php?cPath=15_16_28&products_id=110

 

[Hyperion]

Try contacting - Sansui Vintage Parts ---> https://www.sansui-vintage.com/product_info.php?cPath=15_16_28&products_id=110

The above is just about the only source that I would trust without question.

Note that these transistors are a seriously dwindling resource, and very difficult to get hold of now. Therefore consider installing a (sacrificial) set of MJ21193/94 into your amplifier until it is working properly (if they get destroyed its no big deal) - then and only then, fit a replacement set of original transistors - look after them they are precious.

I know this would be an extra expense, but how bad would you feel if you accidentally destroyed a replacement set of originals - you may buy the very last ones that are available...

 

[ghazzer]

The OP purchased this G9700 missing the output transistors.

Has anyone tried the suggested TO3P replacements in a G9700: 2SC3857 & 2SA1493?

 

[AUD101]

See post #3 above from kevzep - he suggested TO3p as replacements...note that the 2SC3857 & 2SA1493 are MT200 case styles...but would be very suitable replacements if they could be made to fit

 

[Hyperion]

The OP purchased this G9700 missing the output transistors.

QED.

 

[Hyperion]

See post #3 above from kevzep - he suggested TO3p as replacements...note that the 2SC3857 & 2SA1493 are MT200 case styles...but would be very suitable replacements if they could be made to fit

Might need to drill screw mounting holes for the MT200's

 

[kevzep]

I wouldn't use the MT200, there is no need to, you can find the perfect TO3P to do the job which means no drilling holes and minimum fuss, there is a reason the legs on the TO3P are spaced exactly to fit a TO3 socket.

 

[kevzep]

Thank you all for responding
I prefer to not make any changes to the installation of other transistors.
If anyone can give a link to buy the replacement Normal size ..( Not fake )...?
thanks.

Welcome to vintage audio where often the original style parts are no longer available and often other solutions are needed, all good to have a preference to want to use original style, but sometimes that option is not available.
TO3P style transistors can be made to fit TO3 sockets very nicely, have a look at this thread here I did on the BA-F1 https://audiokarma.org/forums/index.php?threads/ba-f1-on-the-bench-first-look-here-we-go.880419/


You might get lucky and find NOS original, but be warned about these amplifiers. They are very high speed designs, whenever there is a blown output transistor, there is likely to be other issues which caused the failure, just fitting new OP transistors might only be the tip of the iceberg.

If you do find NOS transistors, you should use MJ21193/4 to get the amp working and stable, then fit the proper transistors.

 

[Hyperion]

My thread here:-
https://audiokarma.org/forums/index.php?threads/ba-f1-restore.798969/page-5#post-11192741 (see post #88 and #91 onward)

Pre-dates kevzep's one and shows exactly how to perform the upgrade.

 

[Double T]

Looking through the messages above I could go for the TO3P change over. I have some original Sanken transistors but only enough for one channel, hope some others will come along. I am using the MJ21193/4 units. The MT 200 case units are not an option they are too large for the small indented space that the G-9700 has for each TO3 unit and I will not be drilling holes. I went to the Sansui website listed above but the United States does not come up in their Country list to open an account. Is there a cross for the 2SC2607 / 2SA1116 to (TO3P) or is that a new project. Thanks to all.

 

[kevzep]

Looking through the messages above I could go for the TO3P change over. I have some original Sanken transistors but only enough for one channel, hope some others will come along. I am using the MJ21193/4 units. The MT 200 case units are not an option they are too large for the small indented space that the G-9700 has for each TO3 unit and I will not be drilling holes. I went to the Sansui website listed above but the United States does not come up in their Country list to open an account. Is there a cross for the 2SC2607 / 2SA1116 to (TO3P) or is that a new project. Thanks to all.

There's no need to use the MT200 devices, I don't know why they were suggested in the first place.

You'll need to go to Digikey, use the data sheets from the original transistors to select a suitable Sanken TO3P device.
Or you could use some Onsemi TO3P devices which are 30mhz NJW1302 and NJW3281.

 

[Hyperion]

I went to the Sansui website listed above but the United States does not come up in their Country list to open an account.

Unfortunately this is a very small company, thus it does not have a country selectable International website. Their parts stock is small - and all that you see are the very last parts like this available almost anywhere. What you do see only results from the site owner's excellent contacts in vintage audio electronics.

Is there a cross for the 2SC2607 / 2SA1116 to (TO3P) or is that a new project.

Post #5 contains suggested TO3P substitutes, and post #6 contains a cross list.

The MT100 case style seems to be an alternative name for TO3P, and is thus compatible, there are more Sanken choices available in this case style.

As previous posts have mentioned you can get Sanken OP transistors from Digikey or Mouser.

Another source is
https://www.profusionplc.com/brands/sanken
https://www.profusionplc.com/news/sanken-audio-components-guide/ - interesting cross reference tables on this page.

 

[Double T]

I think I will go with the Sanken 2SA1294 / 2SC3263 pair to replace my old 2SC2607 / 2SA1116 pair. Yay or Nay appreciated.