YADFF issue

[pinkjimiphoton]

hi guys,
i finally got sick of dealing with the crummy leaky crappy (yet toneful) nte ge's in my primary/fav fuzzface last nite, and swapped 'em out for a nice low-leakage set of russkie mp16b's (so technically, i guess it's a liberal komrade now, as the cct is pretty much identical), went with 97hfe in q1, and 117 in q2. i moved the 8.2k resistor to a chassis mounted 10k pot so i can tweak the bias if i need to...here in new england, the dang weather changes so frequently, it's become a must.

i did a dumb newbe thing AGAIN...and was wondering why i couldn't get the dang thing to fuzz right with the bias being tweaked. that's when i discovered i'd wired the FUZZ pot BACKWARDS.   

SO, it would only "blat" some fuzz when i beat the hell out of it. a quick fix with the old iron, and we re-achieved fuzz...and RIGHTEOUS fuzz, at that. sounds great,
the bias control is almost like a secondary fuzz knob, and highly interactive with the volume, as well. i threw it in my girl's toaster oven for a couple minutes and got it quite hot (don't tell her this, please, lol) and it still worked.

so i chucked it in the freezer (more like connecticut here this time of year) and pulled it out, and it still worked. so i guess mission accomplished. a quick tweak of the bias knob and i think i'll be good.

but...here's the thing that's like, sucking about it. it responds great to guitar knobs as it should (gets a smidge too "brite" when guitar is turned way down, and "woofy" when cranked, which it didn't do as much with the crappy leaky nte's ....which can be flipped 180  degrees on my meter and read almost the same..pretty high quality stuff for 8 bux a piece, huh?) and you can really dial in the stank. i love it. the fuzz knob actually works now, tho i love it pegged, i found with my stage amp, i didn't really need it over half way up...stock values, 1k and 500k. the volume pot is at unity gain at about 9:00!! plenty of balls.

but...as reported in the past on one thread i found with the search function, when the guitar is OFF, turned all the way down, i get the "ocean"...kinda like the "blow" from a cranked up marshall when it's on, a low-level of hiss (which is just loud enough to be noticeable between songs).

it's dead quiet once the guitar signal hits, beautifully quiet. no crackles, no glitches or frying bacon crap, all the way up to pegged...

but turn the guitar off, and the hiss comes up. wtf? as soon as the guitar is allowed to pass even the smallest signal, it's gone. all the resistors are metal oxide, and the effect is quiet when on...quieter on than you'd expect, even.

i tried running a tiny resistor as joe davisson advises in series with the input, but it made no diff whatsoever.

playing with the knobs on the fuzz, bias,fuzz or volume make zero difference. it's all just when the guitar is turned off.

anyone got any other ideas for things to try? last nite, i just stomped down on my fx17 vol/wah to kill the guitar signal at the ends of songs, but i'd like to find a little more pragmatic solution, so i don't have to be tied to my board at the end of every song...

thanks in advance. i'll try anything short of santria to make this happen.

hell, i may even try THAT.

[LucifersTrip]

I've run into that problem (hiss or oscillation with effect still on and guitar down to zero) only a couple times and it's always been the choice of transistors or the biasing. You already tried biasing, so the question remains: "will it still do that if you switch back to the other transistors" (ie, did you accidentally change something else when you put the Russians in?)

The only other thing I can think of is the power supply. I've had some odd problems when using a walwart instead of a battery....a small (~100 ohm resistor) coming in on the power supply usually solved that problem

[pinkjimiphoton]

tried all that, too, lu...
no dice. seems to happen to some extent with all the transistors i've tried in the circuit....some worse. the nte's are the quietest, but they make hash noise and RFI instead of shussssssssssssssshhhhhhhhhhhhhhhhhhhhh.

and it happens irregardless of how i bias the transistors. really freakin' weird.

wondering if maybe i should try and build in a "gating" daughter board, based on some of the "squelch" knobs i've seen on some vintage fuzzes.

[LucifersTrip]

I just remembered that I've also had the problem with effect on, guitar volume zero, but only with certain pickups (not bridge) and with the tone knob rolled back.

Is there any change with pickups or tone knob positions?

...and yeah, man...you have built a bunch of FF's and if this is the only one that does that, you obviously have something different somewhere. Wires crossed causing noise, too long wires, lack of shielding somewhere, different ground wiring scheme, etc...

Does this one sound good at ~4.5 - 5.5V?

Do you have another FF with sockets that works perfectly? If so, what happens when you put these (NTE, Russian) transistors in that?

[pinkjimiphoton]

this was the very first one i ever built, it's always been my fav. i just recently revamped it some, modified how it was wired.

it had ISSUES, bro...from me being a complete idiot and all, as originally wired, i was shorting the fuzzboard to ground, and somehow or other had the led indicator wired ala npn, not pnp. i dunno what i did, but it had issues. it worked, and sounded great...but didn't always play well with others.

so i re-did the bypass wiring with shielding and even a ferite bead to try and nuke rfi and crap, added reverse polarity and a filter cap, and like i said, i moved the bias trimmer to a regular pot. i kinda like that, cuz you can dial in pretty much ANY fuzz sound you want...from almost clear to screaming to very very quiet.

i didn't check the voltage, i prefer to just dial it in by ear...if memory serves, i seem to like it best about 6.3 v or something like that. not as fuzzy as dialing it down more. i play a lot of blues and classic rock, and love to be able to clean up the circuit quite a bit from the guitar, and my amp is always fairly crunchy when the guitar's up anyways. the fuzziest sounds are indeed about 4.5-5 volts tho...get it down to about 3 or so, and it gets very blatty, which just reminded me of something else i noticed while playing last nite.

now, with the new transistors, the TONE shifts as i turn the guitar down, too. full blast, it's dirty and stankin' , then it gets very bright and darker but differently...almost like sweeping a tone pot in parallel. it's cool, but different.

i'm sure i did something dumb when i did the layout, it was my first. gotta run, gig tonite, hangover from last nite's show almost gone.

thanks bro for the help.

[pinkjimiphoton]

hi lu, looking over your questions:

I just remembered that I've also had the problem with effect on, guitar volume zero, but only with certain pickups (not bridge) and with the tone knob rolled back.

Is there any change with pickups or tone knob positions?

i played it last nite, no, no change with different guitars/pickups/tone knob positions.

...and yeah, man...you have built a bunch of FF's and if this is the only one that does that, you obviously have something different somewhere. Wires crossed causing noise, too long wires, lack of shielding somewhere, different ground wiring scheme, etc...

entirely possible, this was the very first vero i ever layed out that worked. and that surprises me, as there's a lot of dumb mistakes i'd found when i revisited it. i can't really mess with it until this weekend, it's at the club i played at last nite and will be there til my gig friday's done.. i'll peek at it when i get it home. i don't want to add any snubbers, as the tone is good and it's actually very quiet except when the guitar is off.

Does this one sound good at ~4.5 - 5.5V?

yep, very fuzzy hendrixy. nice. i like it better up closer to 6v or so, but the noise doesn't change depending on the biasing of the cct. just the tone...lower gets fuzzier, higher cleaner and more compressed. turn the guitar off, and there's the damn ocean again.

Do you have another FF with sockets that works perfectly? If so, what happens when you put these (NTE, Russian) transistors in that?

the only other FF with sockets that's pnp i own (most get given away) is presently in deutschland with my brother mark, who's touring there. i suppose the easiest way is to just build another one. but i can't understand how or why the husssssssshhhhhhhhhhhhhhhhhhh noise comes when the circuit SHOULD be grounded... thanks for the help, bro..