BC549C in place of BC148 in Philips universal preamplifier

[Dibya]

I am trying to repair a old hi-fi amplifier from Philips . It is made around 1970 and I need to replace BC148 in input stage . Can I replace it with bc549c considering it is lower noise?

 

[Mooly]

I can't see any issues at all in doing what you suggest.

These transistor types date back decades and modern versions may well be slightly different anyway as manufacturing and doping processes change. Just make sure you fit one from obtained from a reputable source.

 

[Mark Tillotson]

The BC549 is 0.1A abs max, the BC148 is 0.2A abs max...



BC109C will do just fine I think, same die. BC109C is low noise (as I understand it its the same die as the others, but selected on the production line for low noise / high gain).


If the failed transistor is in a differential pair, might be worth replacing both, for matching and low noise considerations.

 

[MarcelvdG]

That should work fine. They are very similar, except for their packages and the fact that the BC549C can handle a bit more voltage and power (and is selected for low noise).

 

[MarcelvdG]

The BC549 is 0.1A abs max, the BC148 is 0.2A abs max...

200 mA momentary, 100 mA continuous according to bc107 bc108 bc109 bc147 bc148 bc149.pdf PDF datasheet. ALL TRANSISTORS DATASHEET. POWER MOSFET, IGBT, IC, TRIACS DATABASE. Electronic Supply. INNOVATION CATALOG. Service - which is just the same as for a BC549.

 

[Dibya]

I replaced all transistor and recapped power supply capacitor .
This thing sounds good , thought power transistor are germanium type .

 

[Mooly]

thanks for the update.