Mosrite Fuzzrite noise problem

[Der Groovemeister]

I built the Mosrite Fuzzrite from the Dragonfly Vero-layout
""http://aronnelson.com/gallery/album144/MOSRITE_FUZZRITE_001""
It sounds great. Really filthy! The only problem is that it generates too much white noise. I only use battery power, I have short leads, I cut the tranny's legs very short. When i roll back the volume on my guitar I can also receive a german radio-station with it (allthough I'm living in Holland).

Does anybody have an idea how to fix this noise and radio-reception thing?

Thanx.

[Der Groovemeister]

Oh, and the noise stays the same level if i turn the fuzz or volume-knob.

Anyone?

[BoostAddict]

Does yours squel?  I also get that radio noise.  I searched before and someone mentioned swapping the 10k resistors to 470k but I don't have any spare resistors.  What trannies are you using?  Mine are the 2n3904. 

What kind of pots did you use for distortion?  What's weird is, I'm using Linear Taper 24mm from smallbear.  When I turn the dist. down, it gets louder and sounds like more distortion.  When I turn it clockwise, it gets quieter. 

[Der Groovemeister]

It squeels only when i turn both pots all the way open. So that's no problem for me, 'cause that's far too loud (actually it squeeled more when I just finished it, but since I cut the wires shortest possible it's much better). I saw that post too about switching the 10K's to 470's, but if you read the messages under the layout (the link I sent) Dragonfly says that he changed the value of these resistors to 10K to work better with modern transistors. I used 2N3904's also. I also tried the 2N2222 and the 2N5088, but the 3904's sounded best. I used a 500K linear pot for Dist. and I had that same problem. I switched the wires on lug 1 and 3. It's a mistake in the layout. But do you also have that white noise?

[BoostAddict]

yea I also get that white noise...so the lugs are soldered backwards on the dist pot?  NO WONDER!  going to fix that.  Is it a common trait with fuzzes?  My fuzz factory makes the noise sometimes, but my big muff and double muff don't.  I'll try swapping 10k to 470k and ill let you know.  Let me know if you fix i tsomehow too.

[Der Groovemeister]

Before this I built a Fuzzface with Fuller mods (actually the 69 pedal from Fulltone) and that has no white noise or squeeling or radio reception of whatsoever, and it uses germanium transistors! (A wonderful pedal btw. I sold my Little Big Muff!)  I'll let you know if I found something (I've also posted a thread in a Dutch stompbox-forum).

[brett]

Hi
It's worth remembering that old 2N3904s had about half the hFE of modern ones (200 vs 350).  So the original circuit uses 2 x 470k collector resistors to squeeze the last drop out of them (Q1 especially).  Put modern transistors in there and it goes weird.  Also, the 470k resistors minimise the collector current, which may add some sweet extra harmonics to the sound.

To reproduce the old sound, you can go for high hFE transistors and the 10k collector resistors.  It would also help to add a little emitter resistance (47 to 100 ohms would be good).

If you want the original, less raspy, sound, the best way to get there is probably to use the original circuit and use low hFE transistors, which might even "respond" to the low Ic.  Medium-power transistors fit the bill, and a useful and common example is the BD139, which has a hfE about 150.  (Try them in a fuzz-face, too).
cheers

[nightingale]

Hi Guys,
I have built a few with the 470k's and they were a little noisy but, no more than a FF. A friend built the 10k version and it squealed like crazy and was really noisy, but on the other hand the output volume was much louder with the 10k resistors.
I really like this family of circuits: foxy lady, orpheum, etc.  The walco fuzz generator is the only one I have not built yet?

Hope this helps,
ry

[analog kid]

Noone's building this one as the Original Fuzzrite?? If you want RAUNCHY!...  anyway I own an original Ge' Fuzzrite , even though I believe only the first 200 made were this design then switched forever to the silicon cause of trouble on concrete floors.  I had thought the thing had bias issues forever but it's just the way it's designed to work.  the way it gates and the Q2 vltgs being  Collector and Base both under 100mV had me bewildered!   I found that playing with the C/B resistor value wouldn't hardly affect these vltgs, nor the gain of the tranny. but using a Q2 with a different leakage WOULD give a more normal higher Collector vltg (ie; .5v or more)  but even then Hardly any affect on the sound /behavior of the fuzz.
also the Q2 C vltg rises up to near Vb along with input signal/striking strings  regardless of where the C/B vltgs sit normally. rather 50mV or .5v  Just a very different Fuzz design AFAIK
anyway I built a 'tester' circuit to research playing with bias r's and different gain/leakage trannies , I believe I did this from a Vero Layout the Andy did of this original Ge' version as well  ( NICE WORK BTW!) which is why I was asking, and whatta you know!?  It sounded for the most part THE SAME.   aside from possibly slightly tighter slighlty less gated decay likley due to use of modern 1% mf resistors.    the trannies in the Germ were Q1  2n2316 and Q2 2n408 FWIW
  Good fuzzin' all

[Der Groovemeister]

Hey thanks guys for the info! I just ordered two 470K resistors. Hope it works. I'll let you know.

To Nightingale: I'm thinking of building an Axis/Foxey lady next. Does it sound smoother and opener than the Fuzzrite? And is there a difference with the Roger Mayer Axis fuzz (in sound)? I'm hoping it's somewhere between Fuzzrite and Fuzz face.

[nightingale]

I agree,
The germ version is a more interesting fuzz box in my opinion, to my ears the Si version is almost a "raggedy" sounding distortion. The germ version really gets fuzzy, and the tone control seems to be more useful [more like the orpheum]. You can really dial in some nice thick bassy fuzz tones with the germ version.

Here is that link to that cool Japanese site with the germ pics/schemmo: http://eu11.stripper.jp/pulcino/blog/images/fuzzrite.gif

fuzz on,
ry

[nightingale]

DG,
In my experience, the axis/foxy lady circuit has way more "fuzz" and sustain that any of the other "fuzzrite-family" pedals. It almost sounds like a big muff with the tone knob turned way to the bright side, and the fuzz/sustain at 70% or so? Even with low gain SI transistors. Just a bright bucket of bee's type sound?
However, if you get the blend pot right in the right spot, it has a really good octave up! Another interesting thing about the blend control is that you can almost dial in a spot where you can hear a clean note mixed with a background type of fuzz. Which can be expected if you look at the schematics of these types of circuits. The signal literally has two paths it can travel.

The RM axis is a bright SI fuzz face. It cleans up really well and can get you into that 60's sounding buzzy fuzz for sure. It also can have an octave up sounding effect. It just has a different type of intermodulation sound at really high volumes. I have seen it described as "splatty" sounding on this forum if that helps. All of the RM series rocket pedals are all really solid sounding in high volume strange type applications in my opinion.

There are tons of threads/opinions on this forum about having the right amp to go with the RM axis fuzz?  Some say that fender amps are to bright to accept the axis fuzz but I think it sounds great right into an old twin reverb,  bassman, or especially a closed back dual showman piggyback? I guess I should mention that I don't mind ear piercingly bright fuzz drenched in echo and reverb!

Another cool fuzzrite family circuit is the shin-ei-companion fuzz. It is really really bright, and a total "one trick pony" but it has its place for sure!

I hope all of these weirdo descriptions make to sense to you.

be well,
ry

[nightingale]

Woops,
That should read "stage applications" not "strange applications"
Too late to modify my post.
ry

[Der Groovemeister]

I replaced the 10K's for 470K's and it sounds very tame now! The noise is gone, but it's not the sound I hear from Iron BUtterfly or the Doors, especially not Davie Allan. All the gain is gone! it sounds like a cheap distortion pedal! I tried different trannys (2N2222, 2N5088) and it doesn't make much difference.     HELP!!!

[fixr1984]

I didnt like 10k in mine either. I used 100k and swapped out both pots for 100k as well.
Pretty mean sounding.

[Der Groovemeister]

To Fixr: How did the sound change when you switched to the 100K's  and the 100K pots? And is the white-noise gone?

[fixr1984]

I have one made with Dragonfly's layout. To me that one is kinda tinny and very buzzy sounding.
My father in law plays the older surf stuff and loves that one. I made another one using the 100k resistors
and both pots 100k. To me that one is way fatter sounding, a little more gain. I would say that the white noise is minimal.
If I can figure out a way to upload a mp3 somewhere I can give you an idea what it sounds like.
Otherwise PM me your email and I will send you a clip.

[Der Groovemeister]

The last thing I want to try is using the original value pots. I have to place a resistor parallel to the pots. I calculated that i need a 1200K res to transform a 500K pot into 350K and a 120K to turn a 50K into 33K. I'm not sure how it should be connected. I hear different stories. Should it be on lug 1 and 3 or on 2 and the other one that's not the input.

Can anybody tell me what 's the right way?
Thanks!

[fixr1984]

Across the outer lugs. (1 and 3)

[Der Groovemeister]

I finally nailed the white-noise problem (and the radio-reception)! In recent posts I read something about putting a small cap over the input and ground to get rid of radio reception. I tried a 2.2nF and that did the trick! The noise is almost gone and no more radio! 

I also put a 1.5 M resistor over the fuzz pot to mimick the original 350 K pot. That didn't do much except for a tiny bit smoother attack. I liked that, so I left it in.