I'm working on an early Sansui 400 receiver, and I'm struggling with subs,,, I keep reading that KSC1815 and KSC1845 are subs for 2sc458,,, but the data sheets don't agree... 458 has Ic=100mA,, 1845 has 50,,, 458 has 115MHz,, 1815 only has 80...
Seems a 2n3904 has covered in all values, but I haven't seen it mentioned... Also saw a sub for 2SC536 is KSC1815,, but that falls short in frequency also... It looks like 2n3904 can cover this one also... I dont see 3904 recommended as subs for Sansui's,,, is it only because of pinouts, rather than a problem with the transistor?? It's pretty easy to just insulate and move a pin to use a very common and dirt cheap transistor, unless i'm missing something major...
Thanks for any input...
Seems a 2n3904 has covered in all values, but I haven't seen it mentioned... Also saw a sub for 2SC536 is KSC1815,, but that falls short in frequency also... It looks like 2n3904 can cover this one also... I dont see 3904 recommended as subs for Sansui's,,, is it only because of pinouts, rather than a problem with the transistor?? It's pretty easy to just insulate and move a pin to use a very common and dirt cheap transistor, unless i'm missing something major...
Thanks for any input...
2SC458 was a common dirt cheap transistor in its day. Also a POS that’s good initially, but goes bad and sounds like lightning and thunder when it does. Any newer process device was an improvement, even the 2N3904. They don’t like using the wrong pin out and bending leads in production, because it invites QC issues.
Thanks much for the confirmation,,, I thought I was missing something!!! 2N3904 is a very common, cheap and to my findings useful sub for many small transistors,,, Insulating and bending pins is the easiest part of trans replacing in my experience!!!!
Seems to be a better sub for 2SC536 and 2SC693 than the ones mentioned above, so I'll use it there also...
Seems to be a better sub for 2SC536 and 2SC693 than the ones mentioned above, so I'll use it there also...
Bending leads is fine in onesey twoseys. Just doesn’t work with 10,000 piece production runs, with the line staffed by trained monkeys. You’ll get a few shorts and misoriented parts, eating into this months profit.
That and the production was usually in Japan, the place where the 2SCs were cheaper than importing Motorola.
That and the production was usually in Japan, the place where the 2SCs were cheaper than importing Motorola.
I'm mainly a tube guy,,, I found this old sui for a buck at a big radio show,,, got the amp section sounding great,, FM working, MPX is spotty, but I'm working on it!!! Figured it would be a fun rebuild project as I have a Sansui 800 I picked up in the service in 1969, something to compare it to!!!
I figured there was a reason that 3904s were skipped over by rebuilders,,, but using numbers the were out of value cause they dropped in dont make sense to me!!!
Thanks again for the info/help,,, I'm changing out teh bad ones as we speak!!!
Rebuild thread if you're interested...
https://audiokarma.org/forums/index.php?threads/sansui-400-receiver.1030326/
I figured there was a reason that 3904s were skipped over by rebuilders,,, but using numbers the were out of value cause they dropped in dont make sense to me!!!
Thanks again for the info/help,,, I'm changing out teh bad ones as we speak!!!
Rebuild thread if you're interested...
https://audiokarma.org/forums/index.php?threads/sansui-400-receiver.1030326/
The other reason 3904’s are overlooked it they are only rated to 40 V. Often a part rated much higher is used in a preamp section, even though there is no need for more. BC54x’s work fine too. And if you want 250 or 450 guaranteed hFE you can get it if you use those.
Well,, I have KSC1815s and 1845s coming in from Digi in a week or so,,, do you think 80Hz is fast enough to replace 2sc536 at 115Hz.,,, they are good on all other values. 1815s are the most recommended,,,
I'm not really up on SS experience, so I'm taking data sheets at gospel!!! FWIW I've only used 3904s above what I'm replacing, 20 Vce so far...
Thanks again...
I'm not really up on SS experience, so I'm taking data sheets at gospel!!! FWIW I've only used 3904s above what I'm replacing, 20 Vce so far...
Thanks again...
I have KSC1815s coming in from Digi in a week or so,,, do you think 80Hz is fast enough to replace 2sc536 at 115Hz.,,, they are good on all other values. 1815s are the most recommended,,,
Any thought on these?? KSC 1815 are recommended subs for 2SC538,, but data sheets dont agree....
Any thought on these?? KSC 1815 are recommended subs for 2SC538,, but data sheets dont agree....
The 1815 was recommended as a blanket replacement for all sorts of NLA small signal transistors. It is to Asian semiconductors what 2N3904’s is to domestic ones. I’ve seen it called “ the most popular Asian transistor on the planet”. You see them everywhere, lots of people made them. I still have maybe two or three hundred out of a 1000 piece lot I bought 25 years ago.
Dont sweat 80 vs 115 MHz in a small signal audio stage. Speed is fast enough. Noise will be low enough.
Dont sweat 80 vs 115 MHz in a small signal audio stage. Speed is fast enough. Noise will be low enough.