Little Buzzy fuzz [mini HYBRID Buzzaround]

[midwayfair]

This was an adventure.

First, this is partially dedicated to jimmybjj, who I recently discovered is an apiarist! He and his father rescued a wild hive, so the eco system owes them a debt of gratitude.



All black and yellow and white! Except for the metal film resistors. I don't tolerate noise enough to risk using carbon film. I considered painting them to stay in theme ...

My friend Keith was gassing for a Buzzaround some time ago, so I made a mini one. It's not necessarily for him (I might just make him another one, because I really love the art on it.)

It's built to Brian's schematic except with reverse polarity. When I first played it, I had a few complaints: It was a little spongy, and there was absolutely no cleanup. I read a lot of stuff on the Buzzaround, and a lot of people had opinions about the leakage of Q3 and said that for the most part the circuit wasn't picky otherwise. This is pretty much true, except I think what I ended up with makes it even easier to build but does confirm that there's always room for experimentation to get the sound you want.

I tried some different resistors, and every Germanium I plugged in sounded similar, to the point where I pretty much thought that the circuit just didn't care what you used. That's true to some extent.

Eventually I got around to testing silicon transistors. First experiment was in Q1 and it just shot the noise floor through the roof. Lower gain silicons didn't help matters at all. So I put the circuit aside for a bit while I figured out what else to mess with.

More recently I picked up some 2N5134 from Smallbear, because I like low-gain transistors and this was about as low as they get. I tried it an Q1 and, again, the noise floor shot through the roof and the cleanup was no better.

Finally I just plugged it into Q2 to see what happens. I'm not sure why -- Q2 is part of a feedback circuit on Q1 -- but this was the magic I was looking for. The signal-to-noise ratio greatly improved, and despite being a three-transistor fuzz with diode clipping, lower sustain settings even offered some more fuzz face-like volume knob cleanup. The pedal still saturates with the best of them, though! Some further experimentation showed that higher gain silicon transistors, even in the 50hfe range, were just too loud and brash in Q2, much louder than Germaniums of comparable values even with low leakage.

The diode is a 1N34A. I was pretty limited since I had to pick something with a black stripe to match the color theme. I did find that the diode matters a LOT here. I also eventually ended up putting mine in backwards. I tried a bunch of different forward voltages between .2 and .37 and the diode that ended up in there sounded like it "focused" the clipping for lack of a better explanation. It sounded a little rougher with any deviation or when the diode was flipped around. I don't have a scope, so I really can't say exactly what's happening, but I suspect it messes with the overall symmetry of the distortion.

Edit: Ge transistors are 2N445A and MP38A.

So that's my Buzzaround adventure. buzz buzz!

I kinda hope my friend doesn't want to keep this exact build, because I really like the artwork and I'm not sure I could duplicate it.

[jimmybjj]

How can i not like the this one Seriously, the artwork is great! I love your build reports, your circuit details and experiences are a great help.

[Bret608]

I am a big Buzzaround fan so I like what you did here! What did you use for the ge transistors? Also, am I seeing correctly that the 2n5134 has the same package as a 2n3565?

Thread hijack alert--Jimmy, my parents-in-law (who are originally from Laos) brought my wife and I some honey that was literally wild-harvested from the jungle over there! A relative sent it as a gift.

[midwayfair]

I am a big Buzzaround fan so I like what you did here! What did you use for the ge transistors? Also, am I seeing correctly that the 2n5134 has the same package as a 2n3565?

Ge transistors are 2N445A and MP38A. (I edited the original post to include this.) To be honest, they werent' chosen for anything except generally low leakage (I don't keep leaky trannies for the most part anyway). I just stopped plugging different ones in when I didn't hear any variation after the first five in each position. I decided that they weren't worth fussing over in this circuit.

And yup, the 2N5134 is a dot package. I'm going to get more of them with my next Smallbear order.