Hi, Liybin!
You better take a look at reliable source of higher-grade 2SC2922/2SA1216.
Maybe MJL3281/MJL1302, their small brother MJL0281/MJL0302 and their big brother MJL4281/MJL4302.
Being tight matched in quads/sixtets/octets those transistors can open straight way to non- or low-feedback amps with excellent sound.
Lets take a look inside an amp.
1. We have input stage, IPS, something like 2SK170/2SJ74 or BC550/BC560.
First can be buyed matched, second cheap as dirt to be matched by builder.
2. We have voltage amplification stage, VAS, with something like 2SC3503/2SA1381 (2SC3423/2SA1360, 2SC2911/2SA1209) or similar TO-126 fast transistors with very small Cob and Cre. They are also adequate priced and can be buyed already matched.
3. We have output stage, OPS, usually so-named Triple, firstly designed by Bart Locanthi. 2SC3503+2SC5171(2SC4793, KSC2690)+power output transistor in TO-247/TO-264 case. First two can be buyed matched, the last is the point of interest.
Power transistors are comparatively high priced to be buyed in quantity for matching so, say, i'm preferable buy already matched from huge amount for +30+50% of the stock price, than measure/match by myself.
Also, small quantities are overpriced due to resorting/packing/shipping/customs.
You better take a look at reliable source of higher-grade 2SC2922/2SA1216.
Maybe MJL3281/MJL1302, their small brother MJL0281/MJL0302 and their big brother MJL4281/MJL4302.
Being tight matched in quads/sixtets/octets those transistors can open straight way to non- or low-feedback amps with excellent sound.
Lets take a look inside an amp.
1. We have input stage, IPS, something like 2SK170/2SJ74 or BC550/BC560.
First can be buyed matched, second cheap as dirt to be matched by builder.
2. We have voltage amplification stage, VAS, with something like 2SC3503/2SA1381 (2SC3423/2SA1360, 2SC2911/2SA1209) or similar TO-126 fast transistors with very small Cob and Cre. They are also adequate priced and can be buyed already matched.
3. We have output stage, OPS, usually so-named Triple, firstly designed by Bart Locanthi. 2SC3503+2SC5171(2SC4793, KSC2690)+power output transistor in TO-247/TO-264 case. First two can be buyed matched, the last is the point of interest.
Power transistors are comparatively high priced to be buyed in quantity for matching so, say, i'm preferable buy already matched from huge amount for +30+50% of the stock price, than measure/match by myself.
Also, small quantities are overpriced due to resorting/packing/shipping/customs.
Hi Pav, nice to hear from u again [emoji1] unfortunately, 2sc2922 and 2sa1216 are difficult to get.
Yea, Happy New year!
I know, of course.
Small DIYers are not interesting for corporations, but let me show what we can do.
Semicon-Sanken distributors:
http://www.semicon.sanken-ele.co.jp/en/sales/bp/
For example, Digikey:
For amounts ~1000 pieces price is $3,6.
Please let me apologize, that many of DIYers would demand those or similar power transistors at ~$7 (as per-piece regular price) being matched at B-grade and ~$10 being matched A-grade. So amplifier with 2-pairs output stage would provide mean bill at an order of ~$80. 3-pair ~$100.
I suppose, you can create a theme with some kind of interest check for power output bipolars.
Yes, i understand common case - use OPS devices without matching, but this is only because them are hard to find from reliable source. There are a lot of fakes, so buying is a some kind of lottery.
May be you are interested in occupying this niche?
Yea, Happy New year!
I know, of course.
Small DIYers are not interesting for corporations, but let me show what we can do.
Semicon-Sanken distributors:
http://www.semicon.sanken-ele.co.jp/en/sales/bp/
For example, Digikey:
For amounts ~1000 pieces price is $3,6.
Please let me apologize, that many of DIYers would demand those or similar power transistors at ~$7 (as per-piece regular price) being matched at B-grade and ~$10 being matched A-grade. So amplifier with 2-pairs output stage would provide mean bill at an order of ~$80. 3-pair ~$100.
I suppose, you can create a theme with some kind of interest check for power output bipolars.
Yes, i understand common case - use OPS devices without matching, but this is only because them are hard to find from reliable source. There are a lot of fakes, so buying is a some kind of lottery.
May be you are interested in occupying this niche?
Hi pav, thank you very much for the excellent suggestion~! [emoji106]I am certainly interested to do it, if there are enough ppl who want to get the parts [emoji16]. Let me do a check later.
Hi, Liubin!
Than you must need to know some history.
Lets start from 1970-s. Toshiba has developed the very unique 2SC3281/2SA1302. For that times achieved specs was unbelievable, but price too.
So, Toshiba take this in mind and provide more cheap and, say, civil version - 2SC5200/2SA1930.
Some time later, Toshiba was start to sell licensing for 3281/1302 for many suppliers. For example OnSemi.
NJW3281 - semiconductor crystal are 1 mm smaller, Cob - too, so this transistor are higher-frequenced.
MJL4281 - crystal are 1 mm larger, Cob greater, but hFE (beta) are greater too, up to 200-250.
5200/1943 are in production by KEC, you can pay for any marking you want. But this are good licensed crystals with +- original specs.
Fairchild are providing them too, with KSC/KSA or FJL/FJA marking.
Original Toshibas are marked now as TTC/TTA.
Most common are samples from Indian USC, i know some China production fabrices. Good, licensed, clones.
But there are many unlegal fabrices in China, India and Brasil. They take relatively cheap crystal from, say MJE15032, and incapsulate it inside huge TO-264 case.
This is real fake.
Now another world, MJL21193/MJL21194. They are low-frequency power transistors, but they have one good property - low dependance of fT from collector current.
This transistors are good, but they usually can't be used in most modern amps just because of low fT.
Some words about Sanken. They are good in specs and good in sound representation. But there are no world-retailer except Digikey. You must understand, that Digikey are remote supplier and i have no doubt will ship lowest-grade ones. So, there are only one way - Allegro or good working contact with achievable supplier. Local meet, bottle of good French cognac, jamon + parmezan - and you're in deal.
Of course, after group buy or interest check.
Now, i think, you are enough informed to develop your plans, estimate risks and evaluate efforts.
wah, Pav, thx for the detailed information. I guess i will buy a few to check the quality before deciding to buy in bulk
Hi, Liubin!
Than you must need to know some history.
Lets start from 1970-s. Toshiba has developed the very unique 2SC3281/2SA1302. For that times achieved specs was unbelievable, but price too.
So, Toshiba take this in mind and provide more cheap and, say, civil version - 2SC5200/2SA1930.
Some time later, Toshiba was start to sell licensing for 3281/1302 for many suppliers. For example OnSemi.
NJW3281 - semiconductor crystal are 1 mm smaller, Cob - too, so this transistor are higher-frequenced.
MJL4281 - crystal are 1 mm larger, Cob greater, but hFE (beta) are greater too, up to 200-250.
5200/1943 are in production by KEC, you can pay for any marking you want. But this are good licensed crystals with +- original specs.
Fairchild are providing them too, with KSC/KSA or FJL/FJA marking.
Original Toshibas are marked now as TTC/TTA.
Most common are samples from Indian USC, i know some China production fabrices. Good, licensed, clones.
But there are many unlegal fabrices in China, India and Brasil. They take relatively cheap crystal from, say MJE15032, and incapsulate it inside huge TO-264 case.
This is real fake.
Now another world, MJL21193/MJL21194. They are low-frequency power transistors, but they have one good property - low dependance of fT from collector current.
This transistors are good, but they usually can't be used in most modern amps just because of low fT.
Some words about Sanken. They are good in specs and good in sound representation. But there are no world-retailer except Digikey. You must understand, that Digikey are remote supplier and i have no doubt will ship lowest-grade ones. So, there are only one way - Allegro or good working contact with achievable supplier. Local meet, bottle of good French cognac, jamon + parmezan - and you're in deal.
Of course, after group buy or interest check.
Now, i think, you are enough informed to develop your plans, estimate risks and evaluate efforts.
second batch of 2SK170-2SJ74 matched quads are available now.
Take note 2SJ74 for this batch are taken out from NOS 2SJ75 (as normal J74 are running very low...), so these is no marking on them. Rest assured that these are 100% genuine 2sj74, and the quality is as good as J74 with markings. Pls refer to the excel file for matching details. Price for quad is $38, $2 cheaper.
link:
https://docs.google.com/spreadsheets/d/1NQBNxXzeLCg5lHdsOGTEjAQPOVxfNMWcXTrJjVyhfr8/edit?usp=sharing
Take note 2SJ74 for this batch are taken out from NOS 2SJ75 (as normal J74 are running very low...), so these is no marking on them. Rest assured that these are 100% genuine 2sj74, and the quality is as good as J74 with markings. Pls refer to the excel file for matching details. Price for quad is $38, $2 cheaper.
link:
https://docs.google.com/spreadsheets/d/1NQBNxXzeLCg5lHdsOGTEjAQPOVxfNMWcXTrJjVyhfr8/edit?usp=sharing
You are welcome!
Not so simple, as say. But i have some suggestions.
The most easy way is to check Safe operating area (SOA).
No one fake producer will put big (and, of course, more priced, keep in mind) crystal inside a real fake.
So, we can put transistor in marked conditions for 10 minutes (with huge heatsink, i know you have them enough).
The next additional check - is to estimate fT. You need to build breadboard of emitter follower with current source in load.
This:
Ie can be provided with following current limiter:
In Q1 position you must place equal power transistor, in Q2 - more high frequency with adequate dissipation, say 2SC4793/2SA1837.
So, after building this scheme you can check fT in those current regions:
Apply Vin from high-frequency generator and check Vout with adequate widebandness oscilloscope.
And the last - is to measure hFE. Check two main points, 1A and, say, 10A.
After this checks will be done - you can be absolutely sure in answer to forever question - "to be, or not to be".
Read as "genuine or fake".
Last edited:
You are welcome!
Not so simple, as say. But i have some suggestions.
The most easy way is to check Safe operating area (SOA).
No one fake producer will put big (and, of course, more priced, keep in mind) crystal inside a real fake.
So, we can put transistor in marked conditions for 10 minutes (with huge heatsink, i know you have them enough).
The next additional check - is to estimate fT. You need to build breadboard of emitter follower with current source in load.
This:
Ie can be provided with following current limiter:
In Q1 position you must place equal power transistor, in Q2 - more high frequency with adequate dissipation, say 2SC4793/2SA1837.
So, after building this scheme you can check fT in those current regions:
Apply Vin from high-frequency generator and check Vout with adequate widebandness oscilloscope.
And the last - is to measure hFE. Check two main points, 1A and, say, 10A.
After this checks will be done - you can be absolutely sure in answer to forever question - "to be, or not to be".
Read as "genuine or fake".
[emoji106][emoji106][emoji106][emoji106][emoji106]
Much relieved to know that most of the parcels sent during Dec have arrived recently, after some delay (one parcel took one month to reach one of our friends in Ireland...sigh...).
Friends from Canada, sorry that you may have to wait for longer time...Apparently you are the only ones left T.T... there was a union strike by canada post last year. I guess this could delay all parcels sent to Canada. I have raised enquiries for all delayed parcels to Canada and will update everyone of you once I hear anything from the post offices.
In view of delay of post to Canada, I will stop sending parcels by normal post to Canada from now on, until we know the parcels sent earlier can arrive safely.
Thanks all for your kind patience. I very much appreciate that.
Friends from Canada, sorry that you may have to wait for longer time...Apparently you are the only ones left T.T... there was a union strike by canada post last year. I guess this could delay all parcels sent to Canada. I have raised enquiries for all delayed parcels to Canada and will update everyone of you once I hear anything from the post offices.
In view of delay of post to Canada, I will stop sending parcels by normal post to Canada from now on, until we know the parcels sent earlier can arrive safely.
Thanks all for your kind patience. I very much appreciate that.
I think so. They have quite close specs. K1530 has high current and voltage rating than k1529.
Would you please quote a price for twelve each of the 2SK1530 and 2SJ201. Matching isn't critical in this application.
The power amplifier these are used in is a Borbely 50 Watt Class-A. Five N type in parallel and five P type in parallel.
Hi, unmatched is $15 per N/P pair. If u use them in parallel, isn't it better to use matched N and P?
For Borbely amp match all the N's to other Ns and the P's to all the other P's. You don.t need to match P to N ( but nice if you can get it) if you can't get good matches use .1 or .22 source resistors.
Which Borbely 50 watt? Easy to convert early Borbely 50 watt to Borbley ribbon 50 watt or even Millenium with a little pc board surgery
Which Borbely 50 watt? Easy to convert early Borbely 50 watt to Borbley ribbon 50 watt or even Millenium with a little pc board surgery