I want to start playing with audio circuits (power amps mostly) so I need some "generic" transistors. I will need small signal, drivers and power (NPN and PNP). I want to start with BJTs. I know there are thousands of transistors out there but I only need a couple of version of each type. So I guess maybe 10 or 12 specific transistors. Should be easy right? So I thought. I decided to go with BCE560 as one of the transistors. Went to the Mouser site and searched for BCE560 and 18 different transistors came up from 3 different manufacturers with prices varying from 10 to 60 cents per unit. For me to look thru all the data sheets and compare them would take me an hour. That times 12 transistors seems like a lot of time and I would still be guessing. So I decided to use this wonderful resource and ask the ones with experience.
Heres what I need. Good for audio, not real high voltage, not expensive, decent noise (for the small signal at least), available, (lead solder?) and the exact model number and manufacturer. Thanks in advance.
Heres what I need. Good for audio, not real high voltage, not expensive, decent noise (for the small signal at least), available, (lead solder?) and the exact model number and manufacturer. Thanks in advance.
Common easy to get types if you are just starting out. Nothing exotic, nothing expensive... things that will work 🙂
Noise isn't an issue... that depends more on the circuit itself unless you are working with microphones/tapeheads/rf amplifier front ends etc.
2N5551 npn small signal
2N5401 pnp small signal complement to above
MJE340 npn high voltage suitable for driver
MJE350 pnp complement to above
MJ21194 npn high power TO3 packages output
MJ21193 pnp high power TO3 packaged output complement to above
[these are available as flat pack packages as type MJL21194G and MJL21193G if prefered].
BC546 npn small signal
BC556 pnp small signal
That's 8 to be going on with and would let you build most designs on these forums.
TIP41C and TIP42C general purpose npn and pnp power types are useful for regulators etc.
The letters on the end of a device eg BC556C usually imply a gain group and C is the highest. That said any circuit should be designed not to be super critical.
Noise isn't an issue... that depends more on the circuit itself unless you are working with microphones/tapeheads/rf amplifier front ends etc.
2N5551 npn small signal
2N5401 pnp small signal complement to above
MJE340 npn high voltage suitable for driver
MJE350 pnp complement to above
MJ21194 npn high power TO3 packages output
MJ21193 pnp high power TO3 packaged output complement to above
[these are available as flat pack packages as type MJL21194G and MJL21193G if prefered].
BC546 npn small signal
BC556 pnp small signal
That's 8 to be going on with and would let you build most designs on these forums.
TIP41C and TIP42C general purpose npn and pnp power types are useful for regulators etc.
The letters on the end of a device eg BC556C usually imply a gain group and C is the highest. That said any circuit should be designed not to be super critical.
2STC5200 + 2STA1943, less than $1US at Digikey
2STAxx and 2STCxx Transistor Series - STMicroelectronics | DigiKey
Wherever you live, buy the locally made brand.
Anything touched by an importer might be fake.
Especially famous brands, however great the
real thing might actually have been...
Nothing wrong with Mooly's MJ2119x except price, $5 ea
2STAxx and 2STCxx Transistor Series - STMicroelectronics | DigiKey
Wherever you live, buy the locally made brand.
Anything touched by an importer might be fake.
Especially famous brands, however great the
real thing might actually have been...
Nothing wrong with Mooly's MJ2119x except price, $5 ea
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Thanks kenpeter, since knew to this I expect to burn a few transistors up, so cheap alternatives that are close are great. As far as local transistors, I dont know if there are any here in Vancouver. What about using Digikey or Mouser?
Hey, 2STC5242 and 2STA1962 only 65 cents...
Digikey and Mouser are reputable distributors, not manufacturers...
They won't sell you a known fake, but they do sometimes get fooled.
I don't know who manufactures in Canada, probably same as US.
You can only order from a distributor anyway...
I was only saying, if I lived in Tokyo, I'd buy Toshiba, Hitachi, or Sony.
If I lived in Texas, I'd buy ST... Fewer greedy hands in between.
-------------
Nevermind my local company is better conspiracy theories.
http://www.st.com/internet/com/about_st/st_company_information.jsp
Everyone makes stuff everywhere, there's no telling.
See map 2/3 down...
Digikey and Mouser are reputable distributors, not manufacturers...
They won't sell you a known fake, but they do sometimes get fooled.
I don't know who manufactures in Canada, probably same as US.
You can only order from a distributor anyway...
I was only saying, if I lived in Tokyo, I'd buy Toshiba, Hitachi, or Sony.
If I lived in Texas, I'd buy ST... Fewer greedy hands in between.
-------------
Nevermind my local company is better conspiracy theories.
http://www.st.com/internet/com/about_st/st_company_information.jsp
Everyone makes stuff everywhere, there's no telling.
See map 2/3 down...
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MPSA42. Small signal for LTP, current miror and constant current source.
MJE340/350 VAS.
IRFP240/9240 high power mosfets.
MJE340/350 VAS.
IRFP240/9240 high power mosfets.
It depends on what's available to you really, there are some transistors that will improve on Mooly's suggestions (as far as I am aware) and they wont cost any different, but they aren't critical I guess unless you're really trying to fine tune or push performance to the limits.
Something like the 2STC5949/2STA2121 would make for a good alternative to the power devices. These tend to be what are expensive so perhaps would be the one device you might want to get picky about if you want to save a few pennies.
Different low noise small signal transistors will give you a small benefit, but as Mooly points out this is circuit dependent. A higher beta/hFE on the input pair should help with matching and create less offset but this can also be circuit dependent and also controlled via additional circuitry.
Often when you get 10 transistors of the same type from the same manufacturer it will be because of the hFE classification. I don't think I've encountered a situation (I'm not that experienced with this stuff I must say) where a lower hFE is actually better, but they sort the transistors into batches of different hFE, if you can buy ones with higher hFE, without paying that much more, then I think it'd be recommended for you to do so. Something like the KSC1845 and its compliment the KSA992 would make for good small signal transistors and they cost peanuts.
Something like the 2STC5949/2STA2121 would make for a good alternative to the power devices. These tend to be what are expensive so perhaps would be the one device you might want to get picky about if you want to save a few pennies.
Different low noise small signal transistors will give you a small benefit, but as Mooly points out this is circuit dependent. A higher beta/hFE on the input pair should help with matching and create less offset but this can also be circuit dependent and also controlled via additional circuitry.
Often when you get 10 transistors of the same type from the same manufacturer it will be because of the hFE classification. I don't think I've encountered a situation (I'm not that experienced with this stuff I must say) where a lower hFE is actually better, but they sort the transistors into batches of different hFE, if you can buy ones with higher hFE, without paying that much more, then I think it'd be recommended for you to do so. Something like the KSC1845 and its compliment the KSA992 would make for good small signal transistors and they cost peanuts.
2STC5949 NPN is definitely priced right at 95cents,
2STA2121 PNP compliment at four times the price! that gets you...
Beware, many of the complimentary pairs are priced asymmetrically.
NPN are slightly higher SOA, and so may be priced for broader use.
2STA2121 PNP compliment at four times the price! that gets you...
Beware, many of the complimentary pairs are priced asymmetrically.
NPN are slightly higher SOA, and so may be priced for broader use.
stay away from intersil and nte.* they are ok for learning purposes, but cheap quality.* international rectifier, STMicro, fairchild, motorola, panasonic.* the big thing about nte and intersil is the phisical qality, they can physically break with ease, and that will be real bad for someone that is going to be playing with them, likely many times per unit.
MG chemicals (a serious brand) is listing R.P. electronic components Rupert St vancouver BC , also Burnaby, BC as both a retail and internet operation. Don't know anybody that has used them. I've bought from mouser Texas, got genuine MJ semiconductors from Mexico.
Thanks for all your replies. Thinking about using Digikey to buy, but the small transistors seem to be sold by the thousand or 50 cents each and I want to buy 50 of them! The 2N5551's are as much as the MJE350's. Any other suggestions for buying the 5 cent transistors?
Sounds expensive over there,
FAIRCHILD SEMICONDUCTOR|2N5551|SI-N 180V 0.6A 0.31W TO92 Q14 | CPC
--|MJE350|TRANSISTOR, PNP, TO-126 | CPC
They've been around for a long time, but I have yet to find a medium power driver complimentary driver pair I like just as much for audio as 2N2905A/2N2219A. TO-5 package. 3W. For outputs up to 50 WPC I like D44VH10/D45VH10 (15 A 80 V TO-220)
(Used to be RCA made, now On Semi) The most ubiquitous pairs are MJE3055/MJ2955. Then 2N4401, 2N3904, of course 2N2222. Last of 10 is 2N2369A (hey, I do some RF stuff.)
I've been collecting more modern part numbers here, but have yet to run most though real applications or even a curve tracer.
Doc
(Used to be RCA made, now On Semi) The most ubiquitous pairs are MJE3055/MJ2955. Then 2N4401, 2N3904, of course 2N2222. Last of 10 is 2N2369A (hey, I do some RF stuff.)
I've been collecting more modern part numbers here, but have yet to run most though real applications or even a curve tracer.
Doc
I'm building single supply amps since I don't like blowing up speakers and can't program SOA comparing microprocessors. In TO92 package newark has NPN MPS8099 at $.11 each right now, and PNP MPSA56 at $.06. All On brand. All capable of holding off 80 V. The compliment to MSP8099 is MPS8599, but they are $.53 right now.
5 cents transitors
Check BG micro /Westfloridacomponents very decent prices ,many of the 10
ones can be found at BG micro @ $ ,06
Check BG micro /Westfloridacomponents very decent prices ,many of the 10
ones can be found at BG micro @ $ ,06
You don't need a microcontroller for DC offset detect. Also you can still use a coupling capacitor on symmetric supplies for safety tests.
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