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Fuzz Face Trannie Gain Ranges (hfe)

Started by PhiloB, February 15, 2015, 08:34:54 PM

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PhiloB

So I bought some bulk unsorted PnP transistors.  I've measured about half of them and I've started to pair them up for Q1 and Q2.
I read multiple articles on recommended ranges for each but I'm getting some conflicting info.
The only consistent thing I've read is that Q2 should be larger than Q1.
RG Keen's article recommends ~80 for Q1 and ~110 for Q2.  Or 70 and 120 as Mike fuller recommends.
I saw where Midwayfair suggests that Q1 sounds good at  2/3 of Q2.
Is there an accepted rule? 
Following RG Keen's logic, would Q1=90 and Q2=100 be acceptable?  With Midways 'formula' with Q1=90 then Q2=135.
I am going to audition some combinations later today but wanted to hear your experiences as well.
((Seems the more I research the more uncertain I become))


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PhiloB

So I tried out Q1=60 and varied Q2: 90 & then Q2: 125.
Honestly I couldn't hear a difference.



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chromesphere

I agree PhiloB.  There are many factors that contribute to the final sound of a fuzz face.  hfe is a subtle one.  I would say model of the transistor and leakage play a larger role.  But if you go too low gain, probably wont have the same sort of sustain though.  That's what I have gathered from my tinkering :D  Oh hey, this video might be appropriate to this thread:

Pedal Parts Shop              Youtube

PhiloB

Thanks Chromesphere.  In your experience, what is too low?


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chromesphere

No worries!  Its been a long time but I seem to recall 50-60's or under?  Someone else might be able to clarify.
Pedal Parts Shop              Youtube