• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Equivalent for NEC 2SA1383 needed

TEKWRX

TEKWRX

Active Member
I'm repairing a Sony TA-N77ES power amp and we have determined the faulty components. I'm having trouble finding a 2sa1383 transistor. I see a few on eBay, but I'm not sure they're compatible and reading the sellers feedback it looks like there is a problem with fakes and DOA parts. I'm ordering the other parts I need from Digi-Key, so I'd like to find something from there that is compatible, but I'm still very new at this kind of stuff so I'm not sure what I'm looking for. Can somebody point me in the right direction? If nothing at Digi-Key will work, that's fine but i need something to replace it with. A USA supplier would be a plus.

Here is the part number from the service manual: Q359 8-729-104-91 TRANSISTOR 2SA1383
And here is the part in question:
20170423_150609_HDR.jpg

Here are some I found on eBay:
http://www.ebay.com/itm/2SA1383-Enc...408660?hash=item1c277a4494:g:7MgAAOSwmrlUxaHk

http://www.ebay.com/itm/2SA1383-Tra...614442?hash=item5d6e9b0fea:g:SmgAAOSwAuNW8A2f

http://www.ebay.com/itm/NEC-2SA1383...022064?hash=item5d6f1b5a30:g:2yAAAOSwXeJYDvdc
 
Register to hide this ad
I have been looking for transistors like this with fT=200MHz for a while, the only ones that come close is 2SC4883 and 2SA1930 BUT both are discontinued. I have enough for myself only. If you can find an equivalent, I love to get some too.

Audio transistor is not easy to find, market is too small. All discontinued.
 
I was doing a search for a similar part over the weekend, and while I didn't find anything close to 200MHz, I did find some 60MHz parts that looked pretty attractive. Currently available. Complementary by design. 200V/1A/20W. Insulated TO-220 package. I would have totally used them, except that the part I was replacing was 25W, and I didn't want to risk going lower. If I was replacing a 2SA1383, I would use the PNP part without hesitation.

Here's where I reveal that I'm playing the devil's advocate - darned near literally, given the general AK opinion about this supplier:

The parts I have in mind are NTE2576 (NPN) and NTE2577 (PNP).

Ducking and covering :),

chazix
 
I found Sanken 2SC4883 that is close, but no PNP. This is the list in Digikey:

https://www.digikey.com/products/en...t=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25

That's the problem, market for high end audio is so damn small no manufacturer is interested in research and produce high end audio transistors. We'll be in a different dimension if they have power transistor that is over 150MHz and driver transistor over 300MHz. We will be able to get the THD way down and so much easier to tame the amp.

But very few people are interested in high end audio. You guys buy 5 at a time!!! I am actually a big consumer buying 60 at a time!!!! With this tiny volume, you blame the manufacturers drop the line of high end audio transistors?

Another thing is the fact that we MUST have through hole transistor is another big limitation factor. We need to mount the driver transistors on the heatsink with the big power transistor to track the temperature. Using SM transistor will present a whole new set of problems.
 
Last edited:
Thats a video transistor. You might be able to get away with a KSA1142 depending on the power dissipation requirements. If the original is freestanding, you can just add a heatsink. The pinout is E-C-B vs the B-C-E of the original though.
 
That's weird. Why would a video transistor be in a power amp? But I will look into the KSA1142 and see if it is a match. Thanks
 
The video transistors have properties (high voltage, low capacitance) that make for good voltage stage and pre-driver transistors in audio amps.
 
I tried to look for 2SA1142, can't find in Digikey, That is a small transistor. If OP can use this small, there is KSA1381 that is very popular and readily available everywhere:https://www.digikey.com/product-det...iconductor/KSA1381ESTU/KSA1381ESTU-ND/1050068

150MHz, 300V, cheap. I use it in my amplifier. But these are only about 7W dissipation even with heatsink. they don't have metal pad under, heat transfer is not very good.

If anyone know a good TO-220 PNP transistor that is over 150MHz, 150V, let me know. The only one I know 2SA1930 is discontinued. I still have like 25 of them, I use 4 per amp, I want to keep a little more in stock.
 
Last edited:
The complimentary transistor to the 2SC4883 would be the 2SA1859, which is readily available at at least Digi-Key.

The typical fT is 60MHz, which indeed is lower than its NPN sibling, but where in a TA-N77ES would you need more than 60MHz fT?

If I was repairing this amp I would just try it (of course all important other parameters should match too, I did not check this case further than looking for the complimentary part of the 2SC4883).
 
jeromach said:
The complimentary transistor to the 2SC4883 would be the 2SA1859, which is readily available at at least Digi-Key.

The typical fT is 60MHz, which indeed is lower than its NPN sibling, but where in a TA-N77ES would you need more than 60MHz fT?

If I was repairing this amp I would just try it (of course all important other parameters should match too, I did not check this case further than looking for the complimentary part of the 2SC4883).
Click to expand...
Yes, if you are willing to go down to 60MHz, you have choices. It is very important to have fT as high as possible for stability and low distortion reason. 120MHz is a lot better. I actually consider using A1930 and C4883 as power transistors, stacking 20 each side. It's so much easier to stabilize the amp when the transistor is faster.

You want to have feedback gain as high as possible at 20KHz to lower THD, with faster transistors, you can design faster amp and have more feedback gain at 20KHz.
 
You must log in or register to reply here.
Back
Top Bottom