Transistor replacement for green pre

Hi all

I have problems locating the BC560 locally, I can get hold of BC557, is this ok as a replacement or can any recommend something else. I am looking for quality parts and are reluctant to compremize on noise level.

Regards
Frode

Use NPNs, not PNPs! BC550 is an NPN.

BC547, 548, 549 will all work, noise figures vary.

Peter

Hi again

and thanks for quick replies.

The BC560 is a PNP, why should I replace it with a NPN?

Regards
Frode

[quote author="frezen"]Hi again

and thanks for quick replies.

The BC560 is a PNP, why should I replace it with a NPN?

Regards
Frode[/quote]

Interesting question...
Do you also want to know why gear doesn't work when you insert batteries reversed ? :wink:

Kidding aside, for now think of it as the 'polarity' of transistors. And try to read about 'bipolar transistors', 'BJT', semiconductors in general etc.

Bye,

Peter

[quote author="frezen"]
I have problems locating the BC560 locally, I can get hold of BC557, is this ...... I am looking for quality parts and are reluctant to compremize on noise level...[/quote]

Hi,
BC560 is used here in the CS circuit in LED display. Almost any TUP will be good for this purpose.
The BJT's noise figure here isn't important.

Regards,
Milan

[quote author="moamps"][quote author="frezen"]
I have problems locating the BC560 locally, I can get hold of BC557, is this ...... I am looking for quality parts and are reluctant to compremize on noise level...[/quote]

Hi,
BC560 is used here in the CS circuit in LED display. Almost any TUP will be good for this purpose.
The BJT's noise figure here isn't important.
[/quote]

I was obviously mistaken, was just thinking of the signal-path, not the LED-circuit
Indeed, about any Si-PNP will be fine there.

The BC560 is a PNP, why should I replace it with a NPN?

Click to expand...

You shouldnt! Sorry, my bad.

Peter