I'm Gonna Kill My PN2369A Trannys!

Started by brianwenz, November 04, 2006, 04:42:14 PM

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brianwenz

Hello Hello--
        I've been messing with the PN2369A  in Fuzz Face circuits for around 2 years or so and really like the low-gain attributes.  The problem is NOISE!!  These things seem to be inherently noisey  [attract radio signels, too...] 
   Anybody found a good QUIET silicon  NPN [or PNP] with the same HFE?? [around  70 - 100hfe].
Anybody else notice the noise problems??
Brian.

brianwenz

Hello Hello--
       ANYBODY OUT THERE???!
Brian.

Dragonfly

Quote from: brianwenz on November 04, 2006, 04:42:14 PM
Hello Hello--
        I've been messing with the PN2369A  in Fuzz Face circuits for around 2 years or so and really like the low-gain attributes.  The problem is NOISE!!  These things seem to be inherently noisey  [attract radio signels, too...] 
   Anybody found a good QUIET silicon  NPN [or PNP] with the same HFE?? [around  70 - 100hfe].
Anybody else notice the noise problems??
Brian.

2N3903...typically 90-120hfe....cheap...sound good

brianwenz

Hello Hello--
      Hi DF!
      Have you had noise issues with the 2369??   They seem pretty troublesome as Q1 in a Fuzz Face circuit.
Brian.

R.G.

Did you perhaps get all of your PN2369A's from the same source?

:)
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

Meanderthal

 2n2222a, but they're not particularly quiet. Generally a tranny with an "a" at the end will be the low gain version. Unfortunately, it seems all the low noise ones are also relatively high gain. There may be exceptions, but none I know about.
I am not responsible for your imagination.

mac

I have 2369s from different manufacturers and they all have the RF problem. Which is annoying because they fuzz nice in a FF and TB mkII and 3-knob.
I posted about some nice low gain Si, mostly metal can:

http://www.diystompboxes.com/smfforum/index.php?topic=50831.0

mac
mac@mac-pc:~$ sudo apt install ECC83 EL84

amz-fx

I ad a similar experience with the PN2369 being sensitive to RF...  everytime I played my YAFF I would get Cuban radio stations.  I found that a couple of ferrite beads on the input wire would eliminate the interference.

regards, Jack

brianwenz

Hello Hello--
     R.G. --  Yes, they are all  from the same batch that I got from Mouser awhile back.   I was thinking about that, too.
   So, it seems that other batches all have the same characteristics??   What about the "A"  designation??  Any experience with the  PN2369A  versus PN2369 ??
I built a Tonebender MK  circuit using  the PN2369A and I don't get the same noise and Rf problems as I do with the FF circuit.
   Thanks for the post on the trannys, Mac!
  Jack--  So the ferrite beads do the trick, eh??   Any particular ones ?
Thanks!
Brian.

Dragonfly


nightingale

Brian,
I have been using the "central" brand transistors since I found them in the mouser catalog. They have a few other  tranny's that have the same gain characteristics as the pn2369a. [min hfe=40--------------max hfe=140] and they have some neater packages than the to-92.  I have also noticed that the PNP version of the 2369a [can't remember part # right now] seems to be less prone to the RF problems for whatever reason.

hth,
ry


be well,
ryanS
www.moccasinmusic.com

brianwenz

Hello Hello--
     Thanks Ryan!  [how have you been doing, by the way???]
Brian.