acceptable transistor substitutes?

[pazuzu]

for 2n5306?

thinking of breadboarding the scrambler from tonepad(http://tonepad.com/getFile.asp?id=31). i don't have these, i have:
bc599
bc598
bc547
bc338
bc327
bc397
bc102
c9012s
c9013s
2se1815


any suggestions would save me a LOT of tinkering. thanks guys.

[theehman]

1n456, 1n4148?

these are diodes.

thinking of breadboarding the scrambler from tonepad(http://tonepad.com/getFile.asp?id=31). i don't have these, i have:
bc599
bc598
bc547
bc338
bc327
bc397
bc102
c9012s
c9013s
2se1815


any suggestions would save me a LOT of tinkering. thanks guys.

these are all transistors.  1N4148 are pretty common diodes.  I think Radio Shack even has them.

[pazuzu]

oops, i meant 2n5306. i have all the diodes and the single npn transistor set aside, but i need the three 2n5306.

[pazuzu]

well, after a few hours of internet self education it looks like none of the transistors on that list will suffice. let me know if i am wrong, but they all appear to be bipolar.

[oldrocker]

If my memory hasn't failed me I believe the transistors used in the Scramblers were darlingtons.  I would try MPS13 or MPS18.  It's possible to make darlingtons from two bi-polars put together.  I could be wrong since I have never tried it but it's worth a shot.

[LP Hovercraft]

Mine has 2N3904's and it still sounds like http://www.youtube.com/watch?v=nnGZc0oHMkQ.  I wouldn't be too picky about transistor selection so long as the selected device has a gain of over 250.  The magic is occuring in the rectifier circuit around the texture knob.   If you must, smallbear.com has 2N5306's.

[pazuzu]

well, i am trying NOT to order parts. so i basically just picked a pedal that is composed of components i already had, but when i got to the darlingtons i came up empty. i will probably just trying pairing existing transistors which i have on hand, so i guess the question is, which ones to combine to make the pair. i have 6 each of everything on that list, so unless someone here knows the formula i guess i will look for the numbers later.

EDIT:

wiki math wrote:

"A darlington pair behaves like a single transistor with a very high current gain. The total gain of the darlington is the product of the gains of the individual transistors, hFEtot = hFE1 x hFE2. Some power transistors have a low gain and can require several amperes of base current to drive high currents, using two transistors in a darlington configuration is a simple way to achieve useful gain.

The base-emitter voltage drop is twice that of a normal transistor, VBEtot = VBE1 + VBE2.

Darlington pairs can be built using discrete components or can be bought in packages that look like normal transistors. Darlington arrays also exists in chip form like the ULN 2803 that also contains protection diodes. "

[rousejeremy]

I built a Scrambler using MPSA18. They work fine. Plus, you don't need to twist the middle leg to match the pinout on the PCB like the 2N5306.
If you really want the ultimate Octave Fuzz, breadboard the Foxx Tone Machine. If you like it, put the Anthony Leo Fuzz behind it and voila, a Prescription Electronics Experience.

[PRR]

2n5306 is a re-sort of MPSA14, which used to be very common.

Almosy any NPN Darlington will work. There's no stress on the part, and Darlington specs are inevitably very-very loose.

> well, i am trying NOT to order parts.

Pick two small general-purpose NPNs (BC547 is fine) and connect them in Darlington. Keep your head, and the leads, straight, or you will get mixed-up.

Q1 "could" be any N type J-FET.

I suspect it will "work" using plain ordinary hi-Beta NPNs for Q1 Q3 Q4, but may not work "just like" the original.

[pazuzu]

ok, i am going to use 2n2222 for q2, and 6 bc547's arranged in darlington pattern. thanks for all the help guys, i'll post a pic and some sound clips when i am done.

[pazuzu]

ok, a couple more questions, i am missing r8, 8k2, could i substitute a more common value like 10k?

and i am also short the diodes (1n456, 1n4148, etc.) , i have: 5.1, 6.2, 6.8, 8.2, 9.1 v, not sure if they are silicone, and 1n9007, 1n9198, 1n9009, 1n9001. would any of these be suitable or should i go get the specified components at the shack?