A request from Mikko, who had very kindly done all of the tracing work - very nice job by the way, and photos below.
It's a Fuzz Face from Sonus using NKT MT57 germanium transistors, with an external bias pot and a couple of different component values (Jimi mods) - 2k fuzz pot and a 1k resistor instead of 470ohm.
As you can see I did two versions on tag board, one a bit smaller and one with a bit more room. Both have enough space for a mounting screw.
In addition to the battery, the Sonus pedal does have a DC input - I can see electrolytic poking out from shrink wrap, I'm guessing there may also be a diode hidden in there for polarity protection as well, but who knows. Not hard to add this off board or just go without if you plan on battery only - this a positive ground effect, so for some people DC is not an option.
SONUS JIMI MOD 1968 - TAG BOARD LAYOUT
TRACING & PHOTOS SUPPLIED BY MIKKO
Poking around the usual forums I see it has power filtering under that shrink wrap, a resistor is series with -9V, a Zener diode and a 100uF to ground. Is that why it costs 310 Euros? Seems a little steep :)
ReplyDeleteGotta make a living right.
ReplyDeleteLooks great!
ReplyDeleteI just looked at this again and I noticed the extra 47k across lugs 1 and 3 of the B50k Bias knob. That lowers the resistance of the pot to 24.23k but I suppose it also makes the taper weird.
ReplyDeleteI know - it is what it is, as they say
DeleteMany thanks for this one !
ReplyDeleteHi , has anyone built this yet ...how does sound .
ReplyDeleteThere’s nothing unusual about this one. It’s just a fuzz face with a bias control, so it will sound like a fuzz face.
DeleteAll values are standard, and like most fuzz faces, good transistor selection is key.