2N3904 or BC547 in Big Muff PI triangle?

[dcjim]

Hi folks

Run out of 2N5088's. I've some BC547's around 300 HFE and some 2N3904's around 330 HFE. Which is the better substitution or are neither really suitable?

Thanks
Jim

[haveyouseenhim]

I'd say just use some sockets and experiment. I've been having all kinds of fun with my terribly underused breadboard lately

[duck_arse]

out here in australia, I always think bc549c whenever I see 2n5088 or 89, and bc547 when I see 2n3904 or 2n2222, mainly because the bc series is our garden variety.

[Kesh]

both are fine

[JebemMajke]

If you are after modern muffs go for bc 549c or bc550. Should you choose to make civil war go for bc548b, bc547b. Don't forget trimpots.

[LucifersTrip]

I experimented with a bunch and it's pretty much only the hfe that counts. Once you hit 150-200, the collector voltages change slowly.

Though, I liked it better with lower gain ones around hfe 100, which puts the collector voltages closer to 5V. The data sheet for the original button style transistors show an hfe as low as 60, but as high as 1000, though, the original ones I have rarely had hfe over 150.

Here's a thread that shows the collector voltage change with hfe
http://www.diystompboxes.com/smfforum/index.php?topic=98421.msg860597#msg860597

[asatbluesboy]

I find 3904s sounding less creamy and more grainy than your regular Muff. No idea why, though.

[dcjim]

I used BC547s. Sounds great and not any different from another I built with 2N5088s but I don't have 'golden ears' for this sort of thing - hey it's a fuzz pedal as long as it makes you want to ...

ROCK

... who cares?