2n1307 - What could I do with these transistors?

[roseblood11]

Hi,

I just found ten old 2n1307  transistor.
Which circuit could I built using these transistors?
They´re germanium, pnp, hfe is between 180 and 190, low leakage.

Maybe a booster? Or better: 10 Boosters? But which circuit?
Or a Fuzz? But the hfe is to high for a fuzz face, tonebender or a rangemaster (...and I don´t need them cause I already built them )

Or does anybody know a mod (maybe for a Boss-pedal) that uses pnp-transistors?

regards, Sue

[Joe Kramer]

Hi,

Those are a good find!  IMHO, nearly all the 2N13XX transistors are really excellent for Fuzz Faces and the like.  I find that, within reason, the hfe isn't all that critical.  If you have a breadboard you can adjust the bias resistors by ear to get them sounding good.  As for projects, if you've got all the fuzzes you need, you might try something like Jay Doyle's discrete op amp booster that uses a Ge PNP in the circuit.  Have fun. . . .

Regards,
Joe   

[MikeH]

you could make a positive ground ge big muff!!

[roseblood11]

Hi,

I tried them in my fuzz face and it didn´t sound good. I´ve got a trimmer and a contour-pot in it (like Fulltone ´69), but I couldn´t find a sweet spot. I normally use  2n1307´s with hfe = 80 for Q1 and 120 for Q2  in fuzz faces and they sound really great.

@Joe: Could you please post a link to the Jay Doyle booster? I couldn´t find it...
@Mike: Good idea! Do you have a schem/layout for a pos. gnd Big Muff?

Sue

[petemoore]

  You could make 'perfbread' circuits, intended as something which could be 'finalized' by making some of the interchangable and trim components the fixed values you've chosen on the perfbread board.
 That way you can find a booster circuit which biases and sounds good with a transistor from batch which is most or...
 And a Fuzz Face in similar fashion which utilizes the 1rst two transistor choices.
 For both circuits the reads are at GEO, how to choose the transistors and bias them for instance.
 The booster/fuzz can also serve as 'Tonebender'.
 Having the FF which cleans up at the guitar Vol. as does the RM, then a TB, having it's 2 gain stages and 3 transistors [Fuzzface is a feedback loop, 2 transistor, high gain stage] fine tuned, should be a simple matter, both effects on [rm>ff] and some more fine tuning.
 I like the FF Not tuned for highest gain, but ability to get 'resolute' high gain and clean up at the guitar volume.
 Start with positive ground schematics for GE transistors, paying particular attention [to all connections of course] to the polarity markings.
 As with most things, GEO also has a GE TRansistor HFe/Gain testing jig, for sorting out the usability of the individuals.

[Joe Kramer]

Here 'tis:

http://www.diystompboxes.com/pedals/schems/DiscreteBoost.pdf

I've done something similar to this schemo, only using two BJTs, no input buffer xstr, and a 2SB54 Ge.  I'd expect the 1307s to sound quite good in that circuit, but your own ears will be the ultimate judge.

Joe

[guillernofear]

http://apocalypseaudio.blogspot.com.ar/2011/04/naga-fuzzdrive.html

[LucifersTrip]

Supa Fuzz


from DAM:

Not in a MKII. On vintage units it varies from around -7.6V - -8.9V.
Even seen em with 9.1V! I take measurements with Zinc Carbon batteries which are around 9.6 Volts when fresh. The original batteries used in the MKII's and its variants were PP4's (Eveready 226) which also read high at around the 9.6V level.
Hfe levels are usually higher also. For example my '67 Supa Fuzz measurements...

Q1 - 174
Q2 - 208
Q3 - 194