SHOCKTAVE: help needed with transistors' equivalent

Started by Fuzz, August 30, 2005, 12:25:25 PM

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Fuzz

Hi guys!
Here in Italy 2N5088/9 are hard to find, while you can have barrels of BC series whenever you want  :wink:
Consequences are obvious: I used BC549C trannies in my Shocktave. Problem is I hear a very misbiased sound: if I play strong my guitar the sound is ok (and very good...great effect !!!  :D ), but when the note passes a certain threshold, the octave down disappears with some strange pitch shifting to silence.  :shock:
I think first two stages are ok: I used a 1K resistor in place of 1k pot, but the dry signal is ok, with much more volume than the "wet" one. So I suppose the problem is in the right bias of Q3 and flip-flop transistors...can someone help me? Would it be useful for me to know the trannies voltages of your Shocktave pedals? Thank you all brothers,

Ciao raga!
Fuzz
"...the day I tried to win, I wallowed in the blood and mud with all the other pigs..."

Fuzz

"...the day I tried to win, I wallowed in the blood and mud with all the other pigs..."

MartyMart

If you try some lower gain trannies for the "flip/flop" section, it should
work better.
I used the higher gain ones for the "fuzz" stage, but that too could be
lower, more "Fuzz Face" like !

Marty.
"Success is the ability to go from one failure to another with no loss of enthusiasm"
My Website www.martinlister.com

Fuzz

Thank you Marty! :)

I've tried to substitute the two BC549C in the flip/flop section with two matched BC549B, lower in gain...my problem is still there: the octave down sound seems very unbiased.  :(

I also tried the same substition for Q3 and Q2, without any improvement. So I picked my audio probe up, and discovered something intersting: turning the "mix" pot clockwise (to the wet signal direction) I can hear the same distorted an unbiased sound even at the very input of the effects!  :shock:  Is it strange or not?

As I said before, the dry output (pot at min, counter clockwise: 100% dry) is perfect: maybe a little muddy, but good.
Can someone help me? Pleeeeeaaase!!!  :cry:

Ciao raga!
Fuzz

PS to Marty: can you check and report your Shocktave transistors' voltages for me? Thanks again!
"...the day I tried to win, I wallowed in the blood and mud with all the other pigs..."