The Bazz Fuss

You know a pro­jec­t’s been lin­ger­ing too long when your son — who could­n’t care less about gui­tar or effects ped­als — won­ders into your office one day, points to a jum­ble of wires and com­po­nents, and asks “are you ever going to fin­ish this thing?”

That “thing” is the bazz fuss cir­cuit I sol­dered onto a perf­board sev­er­al months ago. I had watched Paul of DIY Gui­tar Ped­als put togeth­er his “5 minute fuzz” effect and had read an arti­cle on Sey­mour Dun­can’s site about build­ing the effect with some nice mods to the orig­i­nal cir­cuit. Some more details about the orig­i­nal effect are avail­able here, but essen­tial­ly it seems Chris­t­ian Hem­mo devel­oped a fuzz effect for the bass that used the fewest com­po­nents pos­si­ble (and still gen­er­ate a decent effect, any­way). The design is extreme­ly ele­gant and pro­duces a nice “dirt” fuzz effect (prob­a­bly per­fect for bass gui­tar). Hem­mo’s orig­i­nal site is long lost on the inter­net (ah, Angelfire.com! — still avail­able via Archive.org, though, of course) but his cir­cuit lives on.

The bazz fuss effect on a bread­board with labeled con­trols

I built my first attempt at a Bazz Fuss effect by wiring the com­po­nents in my bread­board, fol­low­ing along with the Sey­mour Dun­can arti­cle (seri­ous­ly can­not rec­om­mend that arti­cle enough). I went through the var­i­ous iter­a­tions on the bread­board in the arti­cle and end­ed up with the “mod­ded” ver­sion there-in. I even tried adding a bat­tery sag con­trol as well, to emu­late a bat­tery los­ing its charge which sounds good on some effects. This par­tic­u­lar effect is one in which it basi­cal­ly just no longer has enough volt­age to make any noise, so it just kills the sound below that thresh­old. This is the bread­board­ed effect that I used to demon­strate my test rig, in fact.

Inspired by this Make video on cir­cuit skills on using perf­board to quick­ly build a cir­cuit, I fig­ured I’d try sol­der­ing the com­po­nents down. I just bent over some longer leads and sol­dered them to make more-or-less a ground rail and a pow­er rail, and then built the cir­cuit from there. I sketched it all out on graph paper before hand, but the cir­cuit is so sim­ple I had near­ly half of the perf­board free after sol­der­ing every­thing.

My ini­tial perf­board cir­cuit

And so this sat on my shelf for months until my son asked about it. I fig­ured I real­ly did need to wrap this thing up before mov­ing on to any oth­er projects. I had pur­chased a blue pow­der-coat­ed enclo­sure for my treme­lo kit ped­al and had already trans­ferred the guts of that effect to its new home. So I had an enclo­sure that only need­ed a cou­ple of holes made larg­er.

I should note here that I use exter­nal nut AC jacks on all my builds. Yes, they stick out fur­ther and are less attrac­tive. But, here’s my rea­son­ing:

  • all the oth­er exter­nal com­po­nents (except LEDs) already have exter­nal nuts
  • I found that the extra 1/4″ of depth pro­vid­ed using an exter­nal nut AC jack real­ly helped in a 1590A enclo­sure, such as my Micro Amp clone
  • most impor­tant­ly: I can pull the guts of a ped­al out with­out hav­ing to cut a sin­gle wire; noth­ing is actu­al­ly even nec­es­sar­i­ly wired after going into the enclo­sure at all this way!

In the spir­it of recy­cling old parts, one of the resis­tors I had pulled from my Cry­Ba­by Wah mod was the right val­ue for the LED resis­tor! I don’t even know why I both­ered sav­ing it, but I was glad I did. I use some of the spare space on the perf­board to mount the LED and the resis­tor. I used a bit of hot glue to hold the LED in place (in fact, that’s the only thing hold­ing the entire board in place!).

The LED hot glued into the enclo­sure — note the old tan, 5% tol­er­ance resis­tor

I did use sock­ets for both the diode and the tran­sis­tor. I don’t know that I’ll ever swap them out, but I have that option. In fact, Paul of DIY Gui­tar Ped­als has an entire video just com­par­ing dif­fer­ent com­bi­na­tions. Though my ped­al does­n’t have a ton of gain, it sounds pret­ty good using the BAT41 diode and MPSA13 tran­sis­tor. You can see where I used a sharpie to mark the ori­en­ta­tion for both, as well, because I won’t remem­ber should I ever want to swap them out. On the sub­ject of trou­bleshoot­ing, I spent a lot of time trou­bleshoot­ing this build only to ulti­mate­ly deter­mine the A100k put for the vol­ume was just a bad pot! So I def­i­nite­ly don’t want any more headaches try­ing to fig­ure out the cor­rect ori­en­ta­tion for a diode or tran­sis­tor. I even got so para­noid, I lined the back of the pots and the back of the perf­boad with elec­tri­cal tape to ensure noth­ing shorts!

Over­all, it’s not the pret­ti­est build I’ve done but it is com­plete, works, and sounds pret­ty good. I’m proud that I was able to lay­out the com­po­nents in an effi­cient way (which is of course impor­tant to print­ed cir­cuit board lay­outs, which I hope to try out at some point).

The fin­ished wiring. What a rat’s nest!

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