Transistor question

[flanagan0718]

Hey guys,
   I've been thinking of doing a wolfshirt...looks like a cool / fun build. I had a question regarding the transistors. I notice it takes a 2N3565, I don't have any but have a ton of others. I was wondering if the BC109C would do the trick? Looking at the data sheet it said at 5v dc the hfe is between 420 and 800. Would this be pushing the limit or should I stick with something like the 2n3904? Thanks.

[drolo]

Hey guys,
   I've been thinking of doing a wolfshirt...looks like a cool / fun build. I had a question regarding the transistors. I notice it takes a 2N3565, I don't have any but have a ton of others. I was wondering if the BC109C would do the trick? Looking at the data sheet it said at 5v dc the hfe is between 420 and 800. Would this be pushing the limit or should I stick with something like the 2n3904? Thanks.

In my experience, the transistors don't make too much of a difference in this circuit. In the Giant Hogweed, that uses part of the octave section of the FTM, I tried 2n5089, 2n5088, 2n3904 and it sounded all the same to me (I may not have the best ears though). What seems to make a difference in the clarity of the octave is matching the components around the second transistor, the collector and emitter resistors, those 100k resistors, the 2 diodes and 2 caps.

[flanagan0718]

In my experience, the transistors don't make too much of a difference in this circuit. In the Giant Hogweed, that uses part of the octave section of the FTM, I tried 2n5089, 2n5088, 2n3904 and it sounded all the same to me (I may not have the best ears though). What seems to make a difference in the clarity of the octave is matching the components around the second transistor, the collector and emitter resistors, those 100k resistors, the 2 diodes and 2 caps.

Hmm that's good info. I'll have to take a look at the schematic and see. I do have plenty of the 2n3904, 2n5089, and 2n5088. I'll look and see the what differences are. Thanks David!

[Bret608]

I did mine with 2n3565s and they were all in the 200-300 hfe kind of range, pretty close to 2n3904 or 2n2222. I can imagine any number of transistors would work well as David mentioned.

By all means build it though! It's got a huge fuzzy gain like nothing else. I find that when the gain is past about 2 o'clock, you can get this almost backward-sounding swell effect when you bend and sustain a single note (with the octave-up off).