Hello,
Need to replace the input stage transistors (BC182L) due to some damage during my recent move.
I'm looking at BC550C as it has a much lower noise figure (I suppose that is a good thing).
Can someone advise if the BC550C can be a direct replacement for the BC182L?
Both are TO-92 with different legs orientations, but that's not a big deal.
Many thanks.
The specs are:
BC182L:
Collector-Emitter Voltage: 50 V
Collector-Base Voltage: 60 V
Emitter-Base Voltage: 6 V
Collector Current: 0.1 A
Collector Dissipation - 0.35 W
DC Current Gain (hfe) - 120 to 500
Transition Frequency - 150 MHz
Noise Figure - 10 dB
BC550C
Collector-Emitter Voltage: 45 V
Collector-Base Voltage: 50 V
Emitter-Base Voltage: 5 V
Collector Current: 0.1 A
Collector Dissipation - 0.5 W
DC Current Gain (hfe) - 110 to 800
Transition Frequency - 150 MHz
Noise Figure - 4 dB
Need to replace the input stage transistors (BC182L) due to some damage during my recent move.
I'm looking at BC550C as it has a much lower noise figure (I suppose that is a good thing).
Can someone advise if the BC550C can be a direct replacement for the BC182L?
Both are TO-92 with different legs orientations, but that's not a big deal.
Many thanks.
The specs are:
BC182L:
Collector-Emitter Voltage: 50 V
Collector-Base Voltage: 60 V
Emitter-Base Voltage: 6 V
Collector Current: 0.1 A
Collector Dissipation - 0.35 W
DC Current Gain (hfe) - 120 to 500
Transition Frequency - 150 MHz
Noise Figure - 10 dB
BC550C
Collector-Emitter Voltage: 45 V
Collector-Base Voltage: 50 V
Emitter-Base Voltage: 5 V
Collector Current: 0.1 A
Collector Dissipation - 0.5 W
DC Current Gain (hfe) - 110 to 800
Transition Frequency - 150 MHz
Noise Figure - 4 dB
If it makes you feel better; but modern devices in typical(*) input circuitry, I predict no difference in blind test. That spec for the BC182 must be 50 years old, and even then a CYA spec that all production would meet.
Hi, but not sure if I understand your comment. The reason I am looking for an alternative is that I cannot find any BC182L in where I am. Any advice on equivalent or better alternative would be appreciated.
BC550C is quite alright as a replacement.
You only need to use the correct pins: ECB
Because BC182L might have different pinning.
You only need to use the correct pins: ECB
Because BC182L might have different pinning.
Thanks, yes the BC550 has different pin orientations from the BC182L. I’ll have to improvise.
Now sure if BC550 will be better but I’ll be happy as long as it is not worse, and not going to blow my amp 🙂
Now sure if BC550 will be better but I’ll be happy as long as it is not worse, and not going to blow my amp 🙂
2SC1815 is also a 50V rated low noise amplifier and was used in many Japanese amplifier input stages as well as being a general purpose, small signal transistor. The reason to use this type and a few others from recognized, current brands like Unisonic or original Toshiba, is it's cheap, plentiful, a good audio performer and still easy to find in most countries.
Not sure whether he´s on the Equator, which goes around the Earth or in Ecuador.
If the latter, "European" transistors are in general easier to find in South America than "British", "American" or "Japanese" .
It is always important to state user Country, answers depend on that.
If the latter, "European" transistors are in general easier to find in South America than "British", "American" or "Japanese" .
It is always important to state user Country, answers depend on that.
I have the original Mullard spec. for the BC182L for what its worth its a much lower gain the 182L which is i120Hfe (min ) whereas the 550C is 420Hfe(min) .
The big plus is the BC550C is designed for low noise ( lower than the BC182L ) --maybe a negative is the BC550C has an Ic max of 100ma --half the BC182L .
Other spec . is near identical.
The big plus is the BC550C is designed for low noise ( lower than the BC182L ) --maybe a negative is the BC550C has an Ic max of 100ma --half the BC182L .
Other spec . is near identical.
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Hi JM, I'm in Singapore and we are just 137km away from the equator. It's hot and humid here 😱.
Thanks Duncan, what I like is the low noise level of the BC550, if the much higher Hfe going to be a problem?
Thanks Ian. I just checked the datasheet of 2SC1815 and it does not say about the noise level nor the output capacitance, hence I'm a bit worried.
Thanks Sajti, I had a look at the datasheet for KSC1845 but the noise level seems high...............
Hello Kptseng , the same low noise ( or near ) and 200Hfe (min) is available in BC550B/BC550BP, I would try them first before installing BC550C,s to give an audio "boost " as not all input designs will accept large changes in drive while designed for lower ranges of drive .
I am not saying BC550c BJT,s wont work --quite the opposite as I like them but watch out for small changes in distortion and maybe a slight "tweaking " of the compensation capacitor needed its all down to the circuit design .
I am not saying BC550c BJT,s wont work --quite the opposite as I like them but watch out for small changes in distortion and maybe a slight "tweaking " of the compensation capacitor needed its all down to the circuit design .
Original BC182L and 2SC1815 are now generic parts, meaning there are now several manufacturers all producing closely similar product that will be marked and also sold as other similar types that conform to or exceed the same general specification. Examples could be BC550, BC549,BC548,BC546,2SC945,2SC1845 and many more.
In this case, you can Google several datasheets from at at least six manufacturers but many are likely to be obsolete now. Here are examples of current product: 2SC1815 datasheet. http://www.unisonic.com.tw/datasheet/2SC1815.pdf
Virtually all datasheets show the same general specification of 10dB noise figure for BC182L. 2SC1815, 2SC945 or BC550C have even lower noise specifications. Be aware that noise specs are not simply one number. They vary with operating conditions and test methods so the datasheet figures quoted may not be directly comparable. FWIW, KSC1845 is super quiet whilst BC182 is more a general purpose type.
In this case, you can Google several datasheets from at at least six manufacturers but many are likely to be obsolete now. Here are examples of current product: 2SC1815 datasheet. http://www.unisonic.com.tw/datasheet/2SC1815.pdf
Virtually all datasheets show the same general specification of 10dB noise figure for BC182L. 2SC1815, 2SC945 or BC550C have even lower noise specifications. Be aware that noise specs are not simply one number. They vary with operating conditions and test methods so the datasheet figures quoted may not be directly comparable. FWIW, KSC1845 is super quiet whilst BC182 is more a general purpose type.
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While the noise factor (NF) depends on operating conditions it is a fact that a genuine BC550C of good quality can have a noise factor of =0.6 rising to 2.5 (dB) that why its classed as low noise in my books .
But think on a Mullard -ORIGINAL --- BC109 had a typical NF of 2dB which says something when that BJT is much older than the BC500 range .
( at =IC-0.2mA--VCE=5V--RS=2.0K ohms and even more to the point --f=30Hz-15KHz ) nearly the full audio range.
What I am also getting at is modern manufacturers with supposed higher quality methods are not exceeding and in many cases producing worse specifications than old school high quality manufacturers---"profit margins " --?
But think on a Mullard -ORIGINAL --- BC109 had a typical NF of 2dB which says something when that BJT is much older than the BC500 range .
( at =IC-0.2mA--VCE=5V--RS=2.0K ohms and even more to the point --f=30Hz-15KHz ) nearly the full audio range.
What I am also getting at is modern manufacturers with supposed higher quality methods are not exceeding and in many cases producing worse specifications than old school high quality manufacturers---"profit margins " --?
Duncan- The BC182L was a TI part, not a Mullard. Mullard might have made some I suppose, but I'm not aware of that.
Basically the 182 was a competitor to the BC107, and the 184 was the low noise version similar to the BC109.
I can't see the BC550C being a problem as a replacement, as long as the supply voltage is below the 45V rating. If you think that the high gain might cause a problem , I'd agree it may be a slight risk to be aware of , but in most circuits I'm sure it would drop in OK.
And the higher gain means a lower base current, which should give a lower noise.
(although without doing an investigation the Rb ona high gain device might be higher ... but still low enough compared with the optimum source resistance, which is as you say in the 1-2k region.
To play really safe you might consider a BC550B. If you can obtain them as easily.
Basically the 182 was a competitor to the BC107, and the 184 was the low noise version similar to the BC109.
I can't see the BC550C being a problem as a replacement, as long as the supply voltage is below the 45V rating. If you think that the high gain might cause a problem , I'd agree it may be a slight risk to be aware of , but in most circuits I'm sure it would drop in OK.
And the higher gain means a lower base current, which should give a lower noise.
(although without doing an investigation the Rb ona high gain device might be higher ... but still low enough compared with the optimum source resistance, which is as you say in the 1-2k region.
To play really safe you might consider a BC550B. If you can obtain them as easily.
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It was contained in a supplement added onto the book John , I did say the BC550C would work and in post #12 I did mention the BC550B.
Maybe I am being too cautious, its just force of habit as an audio design will have components complying with the designers initial tests on completing his design on checking on stability etc .
I think its the wrong audio philosophy to say -- "want an increase in gain ---just install xxxxxx with an Hfe of 500 or so " it doesn't always work out if we are talking about the input BJT.s which go a long way to deciding the characteristics of an audio amplifier you could end up with slight insipid oscillations .
Of course its down to the original design and just how stable it is initially---not all designs are.
Maybe I am being too cautious, its just force of habit as an audio design will have components complying with the designers initial tests on completing his design on checking on stability etc .
I think its the wrong audio philosophy to say -- "want an increase in gain ---just install xxxxxx with an Hfe of 500 or so " it doesn't always work out if we are talking about the input BJT.s which go a long way to deciding the characteristics of an audio amplifier you could end up with slight insipid oscillations .
Of course its down to the original design and just how stable it is initially---not all designs are.
I did not say you could just get a higher gain in a circuit by dropping in a higher gain transistor. Mostly, the gain of an input stage is controlled by any resistor in series with the emitter (whether directly or via a feedback network which may include a decoupling capacitor).
The gain of a second stage may increase with a higher gain transistor if the base resistance is low compared with any resistor, or active transistor load, which shunts it. Otherwise the increase in hie with gain partially offsets the gain increase.
In circuits using a transistor active load (current mirror etc) a higher gain transistor will increase the gain. I agree that that will or could risk oscillation if the gain causes the hf response to extend.
So it all depends on the circuit, really.
On your concern about modern manufacturers changing the specs, I too have a concern. Some NOS devices I have (BCY71) which I had no real use for since the BC557/8/9 devices came along used to have a reasonably good spec. (Philips/Mullard min gain 100 etc). Some "after manufacturer" specs seem to have reduced that to 50. The samples I have are actually microelectronics (a Hong Kong co) and only just scrape 90 at the test current. Maybe the registered gains were lower, but Philips/Mullard normally had the same spec. as registered with JEDEC or Pro-Electron.
The gain of a second stage may increase with a higher gain transistor if the base resistance is low compared with any resistor, or active transistor load, which shunts it. Otherwise the increase in hie with gain partially offsets the gain increase.
In circuits using a transistor active load (current mirror etc) a higher gain transistor will increase the gain. I agree that that will or could risk oscillation if the gain causes the hf response to extend.
So it all depends on the circuit, really.
On your concern about modern manufacturers changing the specs, I too have a concern. Some NOS devices I have (BCY71) which I had no real use for since the BC557/8/9 devices came along used to have a reasonably good spec. (Philips/Mullard min gain 100 etc). Some "after manufacturer" specs seem to have reduced that to 50. The samples I have are actually microelectronics (a Hong Kong co) and only just scrape 90 at the test current. Maybe the registered gains were lower, but Philips/Mullard normally had the same spec. as registered with JEDEC or Pro-Electron.
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BC182L is listed as available from futurlec see BC General Purpose Transistors The Toshiba datasheet came up when I clicked on the label.
It has been a while since I sourced parts from futurlec but the experience was painless. I dealt with a branch in Australia but don't remember if the warehouse was there or in the US.
It has been a while since I sourced parts from futurlec but the experience was painless. I dealt with a branch in Australia but don't remember if the warehouse was there or in the US.
Futurlec, based at Broadmeadow, NSW, both imports stock and ships direct from Thailand, according to past shipping details which tie in with long shipping delays on larger package quantities (3 months for me) and well, read the reviews for yourself.
Their datasheet reference for BC182L is Motorola's BC182/D 1996 document which shows BC182A,B,C with a much lower noise spec. than BC182L. They may be good on pricing but I don't think they have a clue what product spec. they're selling and neither will we, the customers.
For interest Farnell, Element 14 etc. sells multicomp product which may be a safer bet: http://www.farnell.com/datasheets/2861480.pdf
Personally, I use Tayda instead, for a similar product line from Thailand, with usually prompt service.
Their datasheet reference for BC182L is Motorola's BC182/D 1996 document which shows BC182A,B,C with a much lower noise spec. than BC182L. They may be good on pricing but I don't think they have a clue what product spec. they're selling and neither will we, the customers.
For interest Farnell, Element 14 etc. sells multicomp product which may be a safer bet: http://www.farnell.com/datasheets/2861480.pdf
Personally, I use Tayda instead, for a similar product line from Thailand, with usually prompt service.
Yeah I looked at Element 14 too they were accepting back orders while waiting on fresh BC182L stock to arrive on 8 May which is sooner than the 3 months you experienced with Futurlec. I did notice Futurlec list 2SC1815 in their stocks.
Thanks for mentioning Tayda I'll keep that in mind.
Thanks for mentioning Tayda I'll keep that in mind.