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OC76 Transistor Values

Started by frankie5fingers, July 11, 2012, 09:41:17 PM

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frankie5fingers

Hi All.  Building a Pastyface.  I've built a few fuzzes and haven't cared for them.  I found the Ge FFs (AC127, BC108/109) too wooly, the Bazzfuss's too over the top.  I'm looking for a tamer, more refined fuzz - something Page-y.  I have a line on some OC76s that I can get in a variety of values.  I was thinking Q1 and 2 at 70 and Q3 at 90.  Fairly pricey so I'd love to hear anyone else's opinions before ordering.  Thanks, Frank

timbo_93631

If you want to have a tamer/less bonkers NPN setup try OC139 in Q1 and Q2 and OC 140 or OC 141 in Q3.  Not too expensive if you can stand the wait from England, look em up on ebay.
Sunday Musical Instruments LLC.
Sunday Handwound Pickups

frankie5fingers

In what values Timbo?  I wouldn't hate an NPN setup, but I heard an OC76 equipped MKII a million or so years ago and I remember it being articulate and clear, a great tone.  Unfortunately that was long before I wondered about the guts so I can't say what hFE they were.  Does the OC139/140/141 combo sound like what I'm descriibng (not very well)?
Thanks

timbo_93631

OC139, OC140, and OC141 are cool because they are not only NPN, but also "symmetrical " transistors meaning you can turn them around and make the regular collector the emitter and regular emitter the collector and you have two different gain ratings in one device.  The last batch of OC139's I got are marked Mullard made in France and others are marked Mullard made in Holland.  All in the 40/80 hfe range.  So in the gainier position they sound good in Q1 and Q2, with a 141 in the low gain position in Q3.  If you came across some 140's you could probably get nearly the same ratings in low gain orientation in Q1 and Q2 and high gain in Q3.  Here is a shortform of the OC series transistors.
Sunday Musical Instruments LLC.
Sunday Handwound Pickups