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Transistor Substitutions

rottalpha

rottalpha

Yamaholic
Subscriber

Vintage Gear Transistor Replacement List (last edit 11/18/25)​

I wasn’t sure if another list like this already exists on the forum, but I thought it would be useful to share what I’ve compiled. I originally stumbled across the Hudson Valley Hi‑Fi list while searching for transistor replacements (thanks to Mike from Hudson Valley Hi‑Fi for posting it — no affiliation).

Because many of us are restoring vintage gear, finding reliable substitutes for discontinued transistors is a recurring challenge. This thread is meant to serve as a living reference list. Please use it as a guideline only — always verify suitability for your specific circuit before making substitutions.

Please also post questions if you need to replace a transistor for which you did not find a replacement.

Sorry about the formatting. I obviously have this in Excel, but there are limitations on what can be uploaded. I will try to make it available on a shared drive in the future.

Vintage Gear Transistor Replacements

2SA493 → KSA992
2SA497 → KSA1013
2SA564A > KSA992FBU
2SA606 → 2N5416
2SA628 → KSA1013 *watch pin outs
2SA640 → KSA992
2SA720 → KSA1013 or KSA1220 *check voltages
2SA722 → KSA992
2SA725 → KSA992
2SA726 → KSA992
2SA733 → KSA733 or KSA992 ksa733 and ksc945 should be ksc945C and ksa733C. The C moves the collector to the center pin. Without the C the base is at the center pin.

2SA740 → KSA940
2SA763 → KSA992
2SA809 → KSA1220AY
2SA810 → KSA1220AY
2SA858 → ?
2SA909 → 2SB645, MJ21193G
2SA970 → KSA992
2SA998 → KSA992
2SA1050 —> MJ21193 (PNP)
2SA1051B —> 2SA1943
2SA1301 → 2SA1943, MJL1302, MJL4302
2SA1302 → 2SA1943, MJL1302, MJL4302
2SA1306 → 2SA1837, MJE15033
2SA1309 -> KSA1015 (different package)
2SA1352 → KSA1381
2SA1358 → ? Still available at B+D (but they usually need to be matched. An alternative would be nice)
2SA1115 → ?
2SA1117 —> 2SA1494

2SB507 → KSA940 or MJE15033G
2SB536 → KSA940
2SB539 → J21193G
2SC458 → KSC1815 KSC1815 is the exact replacement.. KSC1845 is a higher voltage replacement.
2SC485 → KSC1845 / KSC2073
2SC497 → KSC2383
2SC555 → MJ15022 or MJ15024 → MJ21193 or MJ21195 (edit 06/22/16)
2SC644 → KSC1845
2SC693 → KSC1845
2SC732 → KSC1845
2SC734 → KSC1845?
2SC789a → KSD526Y
2SC793 → MJ21194G
2SA839 —> MJE15035
2SC857 → KSC2310
2SC869 → KSC2310
2SC870 → KSC1845
2SC871 → KSC1845
2SC905 → KSD1616
2SC945 → KSC2383 or KSC945
2SC959 → 2N3440
2SC984 → KSC2383
2SC1000 → KSC1845
2SC1124 → KSC2690 (watch pin-out)
2SC1166 → ?
2SC1212 → KSC2690
2SC1213 → KSC2383
2SC1222 → KSC1845
2SC1312 → KSC1845
2SC1313 → KSC1815 2SC1313 should better be replaced by KSC1815 rather than KSC1845.
2SC1318 → KSC2690
2SC1328 → KSC1845
2SC1344 → KSC1845
2SC1345 → KSC1845
2SC1364 → KSC2383
2SC1384 → KSC2690
2SC1416 → KSC1845 (watch the pin-out EBC) or use 2N2484
2SC1448 → KSC2073
2SC1451 → KSC3503, KSC2690AY
2SC1452 → KSC3503, KSC2690AY
2SC1515 → KSC2310
2SC1586 → 2SD665, MJ21194G
2SC1624 → MJE1503G
2SC1775 → KSC1845
2SC1815 → ?
2SC2240 → KSC1845
2SC2460 —> MJ21194 (NPN)
2SC2461B —> 2SC5200
2SC2603 → ?
2SC2608 —> 2SC3858
2SC3280 → 2SC5200, MJL3281, MJL4281
2SC3281 → 2SC5200, MJL3281, MJL4281
2SC3298 → 2SC4793 or MJE15032
2SC3416 → KSC3503
2SC3421 → ? Still available at B+D

2SD287 → MJ21194G
2SD313 → KSC2073 or MJE15032G
2SD325 → KSC2073
2SD381 → KSC2073
2SD610 → MJ15023 or MJ15025 → MJ21194 or MJ21196 (edit 06/22/16)
2SD668 -> KSC3503, KSC3502
2SD712 → KSC2073
--------------------------------------------------------------------------------------------------------------------------

Notes & Warnings​

⚠️ Important: This list is a guideline only. Substitutions depend on circuit design, voltage ratings, gain, and package type. Blindly swapping parts without checking specs can damage your gear.
  • Always verify pinouts (many replacements differ).
  • Check power dissipation, voltage, and gain before substituting.
Community Contributions
This list is meant to be dynamic. Please add your own findings, corrections, or questions. The more we share, the more complete this resource becomes.

Below is a very good decision path example provided by @dlucy
Thank you Dlucy and others that have shared your knowledge and added to the list and to this thread!

Link to @dlucy flowchart for choosing a substitute transistor...this case a 2SA726
http://www.audiokarma.org/forums/in...tor-substitutions.688515/page-7#post-11865547

on this page you will find an updated substitute transistors list:
http://audiokarma.org/forums/index.php?threads/transistor-substitutions.688515/page-5
Thank you @dlucy, @Uncle Bambi, @Hipocrates, @ivandezande and all others that have contributed.

Thanks to @dlucy, @Uncle Bambi, @Hipocrates, @ivandezande, Avionic, EW, Ilimzn, Clinic, and all others who have contributed knowledge.
 
Last edited:
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Thanks Dave, I already noted that and ordered the KSC1845 for my B-2;)
I did not want to change his list.

Also, I saw in couple of places and this list, the suggested replacement for 2SC1451/1452 to be KSC3503. EW suggested KSC2690AY and KSA1220AY (for the 2SA809/810) which is what I an going to replace mine with.
 
It is also important to note that the 2SA733 is rated for 625 mW and the KSA733 is only rated for 250 mW.

The KSA1013 is better (900 mW) but its Ft is lower and gain is a little less.
 
Great Thread,,,,,,,,,, will come in handy I'm sure.
Seems a good place to request numbers for replacement in the future, and hopefully the OP will stay on it and keep a running up to date list in post 1.
 
I have edited the original posting with an updated list. Please post your comments, suggestions, corrections; all are welcomed!
 
I just arrived at this post, because I've been looking at replacing the original power transistors in my Marantz 2500. It's been quite an exploration, especially wrt components. The transistors, however, seem to have gone through more then one generation of replacements.

Marantz 2SC555 -> NEC or Motorola with same number (if you can still find them. In late 2015, some still appeared on eBay. I found NECs, but I do see that Marantz ones come up, very occasionally)

It seems that the 2SC555/2SD610 pair can be replaced by an MJ15022/MJ15024 (http://www.onsemi.com/pub_link/Collateral/MJ15022-D.PDF) pair or an MJ15023/MJ15025 (http://www.onsemi.com/pub_link/Collateral/MJ15023-D.PDF) pair. The latter having a little more power/voltage capability.

Now, the MJ1502n transistors seem to have been replaced with MJ21193/MJ21194 (http://www.onsemi.com/pub_link/Collateral/MJ21193-D.PDF) or MJ21195/MJ21196 (http://www.onsemi.com/pub_link/Collateral/MJ21195-D.PDF) pairs.

So, in your format:

2SC555 → MJ15022 or MJ15024 → MJ21193 or MJ21195 \_ Pairs run vertically
2SD610 → MJ15023 or MJ15025 → MJ21194 or MJ21196 /

I found the output characteristics graphs of the 93/94 pairs quite interesting, because they seem much flatter than those of the 95/96 pairs. Their Safe Operating Area (SOA) at 1 second is almost identical, yet most of the other characteristics seem to favour the 93/94 pairs for audio, if only by a smidgen in each case.

The THD graph appears to have been a cut and paste from one data sheet to the other.... A mistake in the preparation of the data sheet, perhaps?

Overall, from the graphs, I'd have chosen the 93/94 pairs over the 95/96 pairs for audio, even though I need any headroom the 95/96 pair might/not provide. Most comments I've read in my explorations seem to indicate the 2119n series over the 1502n series, but they made no comment about 93/94 vs 95/96 pairs.

Anyone have any thoughts about 93/94 pair vs. 95/96 pair?

Finding matched pairs of the MJ211nn series is not quite as easy as I expected. I guess I'll have to find a way to match them, myself. :)

HTH.

Trevor.
 
Thanks for posting the list. As you may know, transistors are becoming somewhat difficult to substitute.
 
TJacques said:
Finding matched pairs of the MJ211nn series is not quite as easy as I expected. I guess I'll have to find a way to match them, myself.
Click to expand...

You should not need to match them, the production tolerances are much better controlled than when the original output transistors were made. If you try to match some yourself, I think you will be unlikely to find enough 'spread' to make a choice from, as they will all be the same.
 
I'm not sure on the MJ21193/94, but on the MJ21195/96, while VBE matching is good, Hfe can vary a lot over a 100 piece tray. 2.5 to 1 on the NPN. Better on the PNP - just 1.5 to 1.
 
jblmar said:
transistors are becoming somewhat difficult to substitute
Click to expand...

Hmmm. Maybe worth stocking up on a few extra, for those days when I slip with the soldering iron. ;)

BTW, anyone want to opine on the MJ21193/94 vs. MJ21195/96 question? I'd be really interested to hear from anyone who's even vaguely knowledgeable on the topic.

Thanks.
 
The 93/94s maintain their gain better at higher currents. The beta matching between the NPN and PNP is usually easier to do as the 94 part is generally a bit higher in gain than the 96. They also look a smidge faster in the datasheets. The 95/96 are cheaper, have smaller capacitance (more so on the PNP), and possibly a larger SOA in some situations. If there's not a big difference in price, the 93/94 are probably the better parts for most situations.
 
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