Am I in need for Mullard transistors ?

[warioblast]

Hi,
I put a tone bender MK2 on my breadboard. I used 2 ASY25/3 & an AC122. No matter how I bias the transistors I still can't get that legendary decay. Are Mullard the only way to go ?
Cheers,
Fabrice

[petemoore]

  no..read GEO technology of the Fuzz Face.
  and Q1 in the TB...IIRC it needs to be a little leaky to bias right?
  Testing GE Transistors of different Hfe for the FF section [Q's 2 and 3] See above read for more info, and Q1?...try some different ones there.
  Check ROG, they have target voltage measurements for the TB MkII Pro, perhaps having a handful of Ge Transistors and doing some bias...
  First thing I'd do is check Q3 collector voltage, but measure all the transistor voltages and post like
  Q1
E .2
B .7
C 3.8
  Q2
E  .0v
B  .43
C  1.2v
  and so on
  Q3
  Are Mullard the only way to go ?
  No...Smallbear electronics sells TB MkII Pro Ge Transistor sets, tested for leakage/Hfe/calculated bias values.

[Dragonfly]

  no..read GEO technology of the Fuzz Face.
  and Q1 in the TB...IIRC it needs to be a little leaky to bias right?
  Testing GE Transistors of different Hfe for the FF section [Q's 2 and 3] See above read for more info, and Q1?...try some different ones there.
  Check ROG, they have target voltage measurements for the TB MkII Pro, perhaps having a handful of Ge Transistors and doing some bias...
  First thing I'd do is check Q3 collector voltage.

yep...as dumb as it is, Q1 is "leakage biased !"  Yet another reason why you cant just drop a silicon PNP in there and expect it to work.

AC

[petemoore]

Yet another reason why you cant just drop a silicon PNP in there and expect it to work.
  Not without adding a resistor to create a V+/- bias string on the base a'la Ricky Vance Si TB.