RM Stone Fuzz Built, and some questions (a Fuzzy subject again...)

[snyder80]

Well, according to the schematic found in the gallery i built the Roger mayer stonefuzz on a perfboard.

I used the FF vero PNP layout and addded the 47k trimpoti and for the Q2 Collector i used a 10ktrimmer instead of the plain 10k resistor. When i first checked the voltage with that 10k resistor i had about 2,4 V DC instead of the 4,3 V DC as mentioned in the schematic i found (the clean layout witch voltage readings). So i had to trim down to about 6,2k to get the desired 4,3 V for Q2 collector. So after all, its a fine built and sound nice and squishy with fuzzpoti on max. Also a grat amount of volume boost can be controlled by volumepoti.
By the way, i used the 10n output cap.

I tested it through my podxt and find it good sounding, but with the volume low it gets quite dark. THe same happend to my other fuzz buildings. So i have to test it on my tubeamp.
But its strange, that (like with any other Fuzz i built) i only have the fuzzy tones with the fuzz knob dimed. All the other settings sound much more cleaner. I used BC559C witch hfe:419/445. I also tested it with a BC557B (witch hfe from 250 till 300), but i couldnt find any differences in tone.

IN the end i found out, that while playing the voltage for the Q2 Collector went bigger, from 4,3V till nearly 6 V DC...seems strange to me, or is this normal, cause it has to drive/clip Q2 ? When i set Q2 Collector to 2,4 V, the fuzz poti acts much more smooth, but i get some sort of fizz/dirt when i roll down my guitarvolume. at 4,3 V the "noise" is gone, but i can only fuzz with the fuzzknob from 8,5 till 10....

Cheers,
Snyder80


PS:Actually i like the fuzzcentral axis fuzz more, since i can use it as a treble booster when i back up my guitar volume....but its got the fuzzpoti-bug as well....mybe i realy need some much more highgain pnp´s

[tcobretti]

I am glad you built it.  I have meant to for some time because I generally love his pedals.  I would certainly try the 100n output cap; the schem I saw was by Gottfried (Analogguru) and he certainly knows his stuff.  The 100n cap will fatten the tone.

IMO, the fuzz knob syndrome you describe is part of the FF design.  If you build one of the crazy 60s fuzzes like the Orpheus or Fuzzrite, you'll have fuzz across more of the fuzz pot's travel.  If you like fuzz, one of those 60s fuzzes will likely work very well for you if you tweak it.

[snyder80]

Hi tcobretti!

Befor starting my build i saw many of your posts and suggestions about fuzz, so thanks for your 2 cents on my build. Before i did the stonefuzz i made the RM axis fuzz, but it seemed to have a slicghtly octaver effect when the fuzz was dimed..should it be like that? You also mentioned, the rm axis fuzz should be with quite a lot of mids and highs, but mine seemed very bassy, too. The stone fuzz is much more what i like...going to try the 100n at the output, but i saw, the schematic tells it could be a 10n (also the gutshots) and the classic fuzz got a 10n output cap, too.

but i got 3 more questions:

1. Is the Dunlop Fuzz (face) witch BC108 with more "fuzz" across the fuzz poti ? Or should i try the fulltone/boutique 70 (ggg) for more different fuzz strength across the fuzzpot?
(i want it to get from a heavy overdrive or distortion till fuzz when dimed)

2. I had a morley wah in front of my stonefuzz (wah seems to have a buffer inside) but i didnt "wah" that much. Is the RM axis (if well build) not so picky about the wah in front of the fuzz.

3. If the lowest hfe for my Q1 pnp in the rm axis fuzz ist about "260" (2N3906, BC237, BC557 B, BC559 C), should i use my 2N3904 with only a hfe about 286, a BC107 B with 270/345 or my BC108 C with 500/550/600 hfe Or hunt after a common 60-90 hfe Q1 pnp

Greets,
Snyder80

[tcobretti]

I haven't heard the Stone Fuzz, but I am pretty sure the Si FF with BC108s is going to be more distortion and less fuzz.  I personally don't like any Si FF except for the Fuzzcentral Axis Face (which is a fantastic Si FF if you haven't heard it).  That's why I want to try the Stone Fuzz.  From looking at the Stone Fuzz, I believe it should sound fuzzier and more Ge-like than a plain Si FF, which is why I need to build one.

I still think that if you want distortion that turns to fuzz, the RM Axis Fuzz is the pedal for you.  However, remember that the sound of all these pedals is entirely dependent on the guitar and amp you use.  People who use brighter amps usually don't like the Axis Fuzz.  I love it.  I think it is just fuzzy enough to be interesting, but I much prefer it with my humbucking guitars.  With my single coil guitars, I prefer one of my fuzz faces or one of the weird 60s fuzzes.  I think the HFE in the Axis Fuzz doesn't matter much above 200-300, but I don't think I would use less than that.  If you want to tweak the Axis Fuzz, a larger input cap will likely make it fuzzier, while a larger output cap will fatten its overall sound (these rules apply to most fuzzes/dist).  I personally have built two Axis Fuzzes and have never heard the octave, but others have mentioned it before, so you aren't alone in hearing it.

Wahs don't like most fuzz pedals.  The solution is to put a buffer in between them.  Many tack the buffer on the end of the wah, but I suspect you will get a better result if you put it on the front of your favorite fuzz.  If you put a buffer in front of the fuzz, you will certainly hear the difference.

[snyder80]

Well actually i built the RM axis, as i mentioned above. And besides the Rm axis had that octave thing it was much more less "boosting" the highs with the guitar volume low. The fuzzcentral axis did that much better. Maybe i need to debug my built bit i made it after the Vero layout you or torchy posted on one topic. i cnat find it no more, but im sure you know the one...also tried the 220E to 220k and 47k to 22k/27k but it reduced just the volume of the circuit.

Grrr, fuzz pedal look simple but need so much tweakin...

Maybe i start a gallery for my stuff and i could post a sample of the stonefuzz if your interested in...

PS: since i cant live without edits - is the dirty sanchez still recommend (saw the post below) to build or is it much more "experimental" sounding???

[tcobretti]

I think the Dirty Sanchez is amazing.  It is as tweakable as a fuzz face in that you can get a very wide range of tones from simple mods.

[col]

OK I know this is an old topic but I found the info in it useful when de-bugging my build for this and thought I'd add my findings.
I decided to build an NPN version a few months ago and it sounded crap! This week I had a bit of spare time and decided to have another look at it. I replaced one of the 10k resistors to T2 collector with a 10k trim pot but had to turn it further down than Snyder80 with a value of approx 3k to get the voltage as specified on the schematic. I then fine tuned it for sound and ended up with a value of 2.9k.
The transistors I thought sounded best of the ones I tried were a BC547B for T1 and a BC107B for T2. I used the 100n output cap as suggested and the sound is very dark, but this circuit has incredible sustain, rivalling a triangle muff.
Low output pickups sound poor with this, but my SG sounds immense. I wondered if it could do with a buffer or further pre-amplification stage, I might try that before it gets boxed up.
The sound is quite distinctive and I can't think of much use for it outside of stoner rock but it's a very simple circuit and I'm glad I managed to make it sound the way it's supposed to.