X FUZZ

[deadastronaut]

yes, well its still early stages with it, i need to spend a little time with headphones on and tinker really..

but i'm off for a weeks break tomorrow, ....but i'll be back on it when i get back.

experiment guys...

[duck_arse]

I had a quick look at "this" today, just sig gen and cro, no listen. with 3 leds K to collector, the output was just about all square wave. with the K's pointing to base instead, there was some distinct and assymetric "batman-ing" appearing in the top of the output waveform. mine was unstable as hell with zero sig in, needed 100pF on Q1 and I had a 39pF across the leds, but I also had 2M2 C-B resistors.

[Will.mendil]

Did you get a similar sound to him?

[samhay]

I had a quick look at "this" today, just sig gen and cro, no listen. with 3 leds K to collector, the output was just about all square wave. with the K's pointing to base instead, there was some distinct and assymetric "batman-ing" appearing in the top of the output waveform. mine was unstable as hell with zero sig in, needed 100pF on Q1 and I had a 39pF across the leds, but I also had 2M2 C-B resistors.

That all sounds about right.
I noticed the 'batman-ing' when I simmed it too, but haven't looked with a scope yet.

I think it has potential - especially when the gain is cranked, but until it is boxed up, it is a bit hard to know how well behaved it is likely to be.

[duck_arse]

I have only cro-ed so far, no listening, to his or mine. soon.

@sam - were you using bi-directional leds at one stage? if yes, what did sim show?

[samhay]

I only ran the sim with one LED in one/both directions.
With an LED cathode towards base you get batman-ing at high gain. An LED oriented in the other direction doesn't do anything.

[deadastronaut]

hi guys, i'm back from my travels...had a great break up north, went trekking around  newcastle, whitley bay, amble, alnwick, rothbury  and hadrians wall , kielder forest , northumberland national park etc..stunning scenery and fresh air..nice.

did just under a thousand miles in my poor little skoda....man that's a long drive from up there back to london...


anyway, now i'm  back to my beloved  breadboard at last....i missed it big time....

any tinkering been going on?...

[Will.mendil]

Cool trip mate. I do need a holiday.

I personally was on another project an still awaiting a couple parts to rerere....retest the xfuzz ( yep I'm still there I bother you )

[deadastronaut]

cool, bother away man..

[deadastronaut]

another swell clip, with 182k on Q2....this time i got rid of the 1uf going to leds..

https://dl.dropboxusercontent.com/u/7464107/XFUZZSWELL..mp3

[deadastronaut]

ok here is the XFUZZ ...

i added a 'bias' pot for a splatty swelly synthy option

when the 250k is full on, the sound is that of the vid page 1...when anti clockwise its buzzy synthy stuff.  (the 250k coud be a 100k-500k) but i chose to split the difference. (if you just want fuzz leave the 250k pot off)

as you can see i tacked on a recovery stage to bring up the volume...

i put a 220pf across Q2 C/B to tame hi fizz

i also added a 4.7k on the gain pot so the gain doesn't go all the way off (silent)

and used a 470k lin pot for gain.



put it on ya breadboard!..

[bluesdevil]

Just rocked this out on the breadboard.... good job, Rob!!
May I ask what the hfe is on your 2n5088's?
Mine are really low, under 300 hfe. Gain buckets on the transistors from Tayda are a bit wacky..... the 2n3904 I got from them measure higher than the 2n5088's!
Pulled out some 2n5089's that had gains around 400 hfe and that gave it a bit more kick to make the gain knob more useable instead of just full up.
   I like the "Synth" control a lot, gives some really cool textures, but I wished they made  a 125k pot, that would be the perfect useable range, I think.
I gotta say I enjoyed playing this one enough to box up.... now on to the "SpitFire"!!!

[deadastronaut]

nice one bluesdevil bill...

i'll check my hfe's and post up ok...

i now have the X ROCK back on breadboard..and i love it, goes great with a crybaby in front , i just cant stop rippin over it....you may want to try this before the spitty while you have it on bread..

really cool for heavy blues, rock, hendrixy stuff...great on neck single coil, and a nice bite on bridge hummer.. cleans up lovely too..

clip: neck then wah....then bridge then wah..(clip at max gain, tone at 12'oclock..) recorded into mixer , no amp...need more coffee for amps..

https://dl.dropboxusercontent.com/u/7464107/XROCK.mp3




btw i'm sure we can get a 250k to be a 125k by sticking a 250k resistor across its lugs..

on the x fuzz i liked the synthy option at 182k IIRC...

if i can i'll try to get both XFUZZ/XROCK into one circuit, with switching...


edit: my 250k trim pot is actually 270k...i stuck a 220k across its lugs, now we have 120k...  so whack a 220k/250k across your pot to halve it. or to taste.

Q1 hfe 333 - Q2 hfe 327. (i actually used a 3904 for recovery stage,,)

[Brymus]

Awesome,I really like the wah in front sound better.
That does have a very cool OD sound to it,like a cranked up amp,it's on my list of stuff to BB.

[deadastronaut]

Hi Bryan, yeah man, well worth breading...

[bluesdevil]

Hey Rob, thanks for checking your hfe's..... sounds like I'm in line with those. Also will try the resistor across the pot to get my favorite range out of starve/synth pot.
Yeah, I gotta try the X Rock while the circuit's on the bready..... great idea about using some switches to flip between the two!!
I'll be tagging along on this thread for sure..... keep rocking!

[deadastronaut]

yeah i think i'll have to switch between 2 Q2 sections to do it though...unless there is a more obvious solution that i'm overlooking...

or just make 2 pedals i guess....

[Will.mendil]

These a pretty small circuits the easy way of doing it would be adding another 3pdt and put the two circuits in parallels wouldn't that work? It is indeed not the smart way but should work. If I can get the xfuzz working though :p hhoj

[deadastronaut]

heres what i was thinking, use an spdt,

one half of the spdt switches input caps 4.7/10n'..

other half of spdt switches straight out of Q1, to the other Q2 section  at the same time...possible?..hmmmm....

[duck_arse]

I might be looking at the wrong things, but ....

wire the 1M and 3 leds as drawn. put the back to backs and the 220k on the collector, and the 1uF//220k junction on the switch N/O. common to the base, away you go. whether you switch the input caps or not is up to you and your switch.

if it don't work, "you ain't seen me, right?"