Old fuzz article from P.E.

[Doug B.]

I have uploaded a fuzz-tone article from the Jun '78 P.E. to my "web site" (hah -- such as it is):

 http://www2.marist.edu/~jzmc/AFTYEGOB.htm

Please let me know if you have any trouble accessing it or anything.  (If it looks fuzzy, just right click the images and view them.)  

- Doug B.

[petemoore]

Takes me back to the 'days'!!!
 Ive never seen a 741 used with a low supply voltage like this.

[zgrav]

:shock: Well this takes me back a ways.  This was my first project that I built about 15 years ago after I found the "old" article in a magazine in the library.  Those graphs showing the square wave output are pretty much right on the money.  No dynamics to speak of here, but plenty of gritty fuzz with long sustain.

[Rodgre]

:shock: Well this takes me back a ways.  This was my first project that I built about 15 years ago after I found the "old" article in a magazine in the library.  Those graphs showing the square wave output are pretty much right on the money.  No dynamics to speak of here, but plenty of gritty fuzz with long sustain.

so sort of like a muff fuzz?

Roger

[Rob Strand]

Thanks for that Doug, I haven't seen that one before.

I don't know about the pro and cons of DC output when used with a tube amp. Might be a good idea to put experiment with another AC cap or remove the DC resistors on form the output.

[Ammscray]

How come all those old schemes are written by Italian guys? Wasn't Barbarello the guy Travolta played on Welcome Back Kotter???

BTW I'm Italian so no offense..."pochi ma buoni"...  

[Peter Snowberg]

That's sure one way to reduce headroom.  

Wild, thanks for posting it!

I wonder how that would sound with diffeent opamps?

-Peter

[Mark Hammer]

THAT's the one I was looking for all these years!  If I'm not mistaken, that would be Paul McCartney's head that is chopped off the top of the scan.  I was a subscriber in those days and had that issue but gave my collection to someone when I had to move from one end of the continent to the other.  Over the years I somehow remembered it as having a FET and as being from some time in the early 1980's.  

Jim Barbarello, on the other hand is firmly etched in memory as the author of a surfeit of audio and music-related projects in P-E, R-E, and the various mags those two mutated into over the years.  Usually very simple but pleasingly clever circuits.

Looking at the circuit all these years later, I'm wondering how this is related to Jamie Heilman's "Angry Beard" distortion.  It doesn't use a starved op-amp like this one but the op-amp-into-single-tranny topography is similar. Where Jamie explicitly indicates a germanium transistor, Jim's circuit makes no mention of the transistor material.  Given the age and 3-digit number, I wouldn't be surprised if it was a germanium, though.  I just don't know at this moment.

Thanks, Doug.  You saved me a frustrating trip to the library.

[Mark Hammer]

Doug,

Given the image quality, I did some quick tweaking, and it's a bit more legible and about double the resolution.

I also touched up the PC mask and got it ready for PnP fans (i.e., negative version of what is currently posted, in mirror image).  You'd think the article came that way when you see it.

Feel free to snag it as a 2-Gif zipfile at: http://hammer.ampage.org/files/Aftyeg.zip and repost at your site.

The package is around a half meg.

[Paul Perry (Frostwave)]

Yep, that is a Ge tranny, thinnk the gain is 55 to 135 or so. (according to an old data book here).

[RickL]

I built this last night and it fired up first thing. I built it on perfboard using the PC layout as a pattern. It took all of about an hour to build.

It sounds kind of harsh and raspy with a high, buzzy overtone at maximum gain settings and despite what the text says mine doesn't clean up very well at lower gain settings or input volumes. One interesting thing is that it softly gates the signal as input volume dies off. Even with maximum gain and volume settings it's completely silent with no input signal.

For giggles I also tried it with a 3906 instead of the 2SB... (Hfe about 70) that I used for the transistor. It does work but it's a bit harsher and the gating is a bit more severe. I think I'll stick with the Ge.

[Mark Hammer]

Rick,

Given your tendency to build anything that can be drawn in schematic form (:wink:), did you ever build Jamie's Angry Beard, and if so, do you recall how it sounded and behaved compared to this?

Since this circuit uses an asymmetrical low supply voltage, and the Angry Beard uses a standard +9v with +4.5Vref , I'm wondering if it is at al possible or advisable to be able to select assorted supply voltages from a basic +9v battery supply, between the +3/-1.5 supply the P.E. schematic shows, and the full 9v the beard shows.  Certainly from a building perspective it is much easier to slap a 9v in there than a pair of battery holders to hold 3 AAs.

[RickL]

I haven't built it yet but I have worked out a perfboard layout for it (what do you do when you're waiting in line for ferries?). {For the Angry Beard II, I have to check and see if they're the same } I'll accept the nudge and do it tonight if nothing else comes up (Help you with your homework? No, daddy has to build another pedal  :wink: ).

I did think about using a single 9 volt  battery for the supply and still could I suppose, but I had the holders available so I went for quick instead of eligant.

[Rob Strand]

what do you do when you're waiting in line for ferries?

Classic, I can't say I've build electronics in public.  ...mummy mummy that mans making a bomb

[RickL]

Okay, I built it last night and it's a very different beast. It's much smoother than the +1.5/-3 volt version with none of the gating of the former. I didn't get much chance to play with it and I haven't swapped transistors between the two yet, or tried a Si in the Angry Beard so the answere isn't firm yet. I'll try the swaps this weekend as well as subbing a pot for the feedback resistor in the AB and report back in a couple of days.

I actually meant that I work on layouts while I'm waiting in ferry lineups although I have built pedals in my truck while waiting (inverter to power the soldering iron) and while on the ferry ride. Just after 9/11 I had a ferry official come up to me while soldering on the ferry and ask a couple of suspicious questions. I explained what I was doing and I didn't get hassled but I guess the sight of electronic components being assembled made a few of the passengers a little nervous  :lol: . I actually did hear some young kids making the "making a bomb" comment one time. I'm not sure how serious they were though...

[gez]

I guess the sight of electronic components being assembled made a few of the passengers a little nervous

Earlier on in the year, here in Blighty, a controlled explosion was carried out in one of the passenger carriages of a train when a suspicious device was discovered.  Hundreds of thousands of pounds worth of damage was done, not to mention severe delays to the network.  Turns out some schoolkid left his Physics project (guitar effect) on the seat.  Guitarist magazine gave him some goodies as a prize.

[Ben N]

Help you with your homework? No, daddy has to build another pedal  :wink: ).

So THAT'S how you do it!  I've got to practice.  "Help you with....."

Ben

[george]

Quote:
what do you do when you're waiting in line for ferries?

Classic, I can't say I've build electronics in public. ...mummy mummy that mans making a bomb

I worked on a Zombie Chorus on the train home one night (just placing components) and nobody said anything

Maybe because it wasn't a WMD (Weapon of Mass Distortion) ... :-)

[RickL]

I tried swapping the Ge transistors between the two units last night to see if the particular transistor was responsible for the gating in the first one. No difference in sound that I could hear, so barring more extensive testing I would say that's how it's supposed to sound.

I also tried a 3906 in the Angry Beard in place of the Ge and didn't notice much difference in sound, a little smoother with the Si maybe, so I'll use the 3906 and save the Ge for another project.

I replace the 1 meg feedback resistor with a 10 k resistor in series with a 1 meg pot. That was well worth doing. With the tone switch in the Normal position, 1 meg all the way down and volume cranked it's just above unity volume, with noticably less distortion. With the tone switch in the High position the 1 meg has to be turned up a bit to get unity volume.

Before I box these two up does anyone have any other suggestions for experimentation (Mark I'm not drilling any more holes after I've got the boxes painted  :wink: ).

[duck_arse]

an old thread, yes.

I was playing with the MXR distortion + circuit, for want of a more generalised name, and thought I'd be stupid not to try the angry beard III output transistor. so I did. here is the beard:



you all know the dist+, clipping diodes and all. and when I tried it bearded, with the collector and emitter resistors shown, it behaved a bit like I thought it might, ie it didn't. allowing for the upside-downedness or not of the transistor, are not the resistors in the wrong places? 100k for an emitter resistor? output from the collector is very small, whereas it looked quite large and healthy at the emitter.

and the reason I'm posting in this thread is because of the circuit in the first post, showing the same layout, but with 10k collector and 1k emitter. all those people (well, both, and some big names among) that built the beard, and no-one had output problems? or is it just me?