madbeanpedals::forum

Projects => General Questions => Topic started by: Jimihendrix1987 on March 21, 2012, 12:00:19 PM

Title: Darkside transistors HFE
Post by: Jimihendrix1987 on March 21, 2012, 12:00:19 PM
Hi there,

I'm about to build one of those tone machines. Today dealing with my electronic supplier he asked me about the BC549's hfe, because he has 3 "models":

- BC549a = Fairchild. TO-92, 50V/100mA, hFE: 110~220.
- BC549b = Fairchild. TO-92, 50V/100mA, hFE: 200~450
- BC549c = Fairchild. TO-92, 50V/100mA, hFE: 420~800.

Which ones should I order to obtain the best of this effect ?

Gracias  ;D
Title: Re: Darkside transistors HFE
Post by: madbean on March 21, 2012, 12:10:03 PM
Use BC549C.
Title: Re: Darkside transistors HFE
Post by: Jimihendrix1987 on March 22, 2012, 04:12:42 PM
Thanks Brian !
Title: Re: Darkside transistors HFE
Post by: masterlk on April 27, 2012, 11:44:39 AM
I just bought BC549B from Tayda for my Darkside build....what can I expect different from the "C" version that Brian is recommending? Or, do I need the "C" version for this build?

Thanks.

Nick



Use BC549C.
Title: Re: Darkside transistors HFE
Post by: jkokura on April 27, 2012, 11:56:00 AM
You don't need C versions, but that's Brian's recommendation.

Check out the data sheet on the BC549 and you'll see that the difference between B and C transistors is essentially the HFE average. C would have a higher average than B, and A would be lowest average.

Jacob
Title: Re: Darkside transistors HFE
Post by: masterlk on April 27, 2012, 12:55:30 PM
Jacob,

So how does this effect the sound?

Nick
Title: Re: Darkside transistors HFE
Post by: Ang3lus on April 27, 2012, 01:43:00 PM
My guess would be more gain with the BC549C, using the B version it would be like turning the knob from 10 to 8, C would start @ 10, B would start @ 7.5-8.

I remember reading someplace, that the transistors averaging 600 hfe is what you should use on muff type pedals.
Title: Re: Darkside transistors HFE
Post by: Jimihendrix1987 on April 30, 2012, 09:47:05 AM
That's true... Transistors above 600hFE to build MUFF fx... My G2 sounds amazing, athought it is a lil' dark (even after I did the brighty mods)

 ;D
Title: Re: Darkside transistors HFE
Post by: madbean on April 30, 2012, 10:29:28 AM
I've built one with the B variety. It sounds good but not terribly gainey. The C is the better choice and is what the stock unity uses. Most of the hFe for the G2 measure around the 550 range, IIRC.