In all of it’s throwback glory, the Black Sheep. Dirty, mean spirited and a blast to hang around with. You can’t help but feeling a bit dirty when you plug in.
Essentially it's a modded BeeBaa with an input cap selector like you see on the Black Arts Black Forest. One thing I will say is that if you notice in the demo videos the fuzz knob is never turned up to the max, that's because it will start to feedback on itself like a mother.
Different transistors change tone of the effect. I messed around with different ones, and settled on MPSA18. They tamed a bit of the metallic decay that I heard with the 2N5089.
And here I am, not giving an overdrive or fuzz away to friends if it feedbacks turned up to the max... ;)
ReplyDeleteThanks for the layout!
yea man. i'm not sure if it was my rig or what, but if the gain is maxed, and i take my fingers off the strings they would start vibrating and the fuzz just took over creating a vicious cycle of angry feedback fuzzy goodness. i'm sure it doesn't help i was running it through my 600watt mesa m6, but yea it was wall shaking.
DeleteWell, wall shaking can be a fun thing too haha. Have had that too though, built a box of hall verb with a dead astronaut fuzz in one box and it went crazy with oscillation. It was a birthday present, so i told the guy: Sorry man, just see it as a bonus, wild feedback noises past 3 o' clock. He never had any problem with it, ever. Maybe the rig, who knows
DeleteThanks for this, the BeeBaa was on my todo list for a while, but this seems to be a better alternative. I have however spotted an error comparing to the schematic on FSB: on the first transistor (the leftmost on your layout) from the base 100k goes to 1k which goes to the VC and 10k goes to the same 1k resistor from the collector in the schematic. On your layout they are the other way around: 100k goes from the collector and 10k from the base. Unfortunately with your version the first transistor would be biased wrongly I think. Those two needs to be swapped and then all is good I think.
ReplyDeletefunny that you mention that thread, because i'm the one that made the schematic from vince (who's also part of this community), who bought one and took it apart.
Deletein any event. nice catch, i must have swapped them while making different versions of the effect and didn't realize.
been fixed and updated.
Zach, you gotta build an HM-2 to experience the intensity of the feedback with all knobs cranked :0
ReplyDeleteEven with both hands muting the strings, it's going crazy lol
haha that's amazing. i wasn't sure if i was going to find a used one or just build one. lol
DeleteYou can tag this as verified. Thanks for the post, the pedal sounds great, definitely getting boxed.
ReplyDeleteOnly a couple minor tweaks to the layout, the transistor lettering is right, but the flat side should be on the other side for 2N5089's and I can't really tell because of the transparency, but it looks like the 1n4001 is cathode to ground and it should be anode to ground.
awesome job on verifying this one. i made the corrections you mentioned and move a few components near Q3 to make it a little less tight near the transistor.
Deletebtw, with the gain pot cranked does it feedback? just curious
I just got to play with the pedal during the day so I could turn my amp up and yes, there is feedback with gain cranked, but its very musical for lack of a better word, it builds up slow and is controllable, not just a bunch of chaotic squeals.
DeleteAlso, I really like the range of the tone pot, it's usable through the whole sweep, nothing too extreme at either end.
Great. That's exactly how mine is. I was really worried something was going on with my amp.
DeleteCan't remember how many times I have said to myself to build something else than fuzz or od and here we are again :) I did build this infact sometimes ago allreadu but for somereason it didn't work. Now reading this post decided to debug it...and it just worked,no idea why but good enought for me. A big high five to all the people creating these. Must be the most visited webpage in my browsing history.
ReplyDeleteNothing to add. U are just right.
DeleteAm i missing something here. Where is the fuzz pot you mention?
ReplyDeletehey gavin. the sustain pot is the gain or fuzz pot. similar terminology to a big muff.
DeleteGood sound Thx !
ReplyDeletedumb question. what is SWA for the offboard wiring? thanks- i'm sure its obvious to everyone except for me.
ReplyDeleteSWA is the common pole of the Rotary switch (the lug in the centre)
Deletejust to add. if you look at a rotary switch that has more then one pole you'll see different letters. so a 3 pole rotary switch will have the letters A, B, and C for the lugs. so if you use a 3 pole 4 position rotary switch for this you just want to use the A pole in the center, and #1-4 for each of the Input Caps.
Deletegreat. thanks much to both of you for the explanation.
DeleteI feel dirty !
ReplyDeleteHi!
ReplyDeleteWhat's the purpose of that 10nF cap on the top on the right ("Q"column)? One leg goes to the ground, but the other seems just hangin' in nowhere, nothing else connected on that strip. Or i missed something?
Good catch. Move the top leg up one row to the 47k/22k junction.
Deleteoop, fixed. as ciaran already said, good catch.
DeleteWow! This is a beast. Just finished it up and was taken back by the thunderous output. Thanks.
ReplyDeletetotally. the only downfall, if you consider it a downfall is that the feedback when the gain is maxed. glad it worked out and you dig it man.
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ReplyDeleteI want to substitute that non-polarized "1uF"-cap in the bottom left of the board (right under the "1nF") with an polarized electrolytic one (just because that's what I have available). Am I am assuming that the negative lead would have to face downward while the positive goes to the bias of the first transistor. Is that correct?
ReplyDeleteEven though it's my fith diy-pedal project, I am still pretty much a noob with these things and find it quite challenging to trace out these stripboard-designs.
Figured it out now (positive to base of tranny, of course). The pedal works now but somehow I'm not quite happy with it. It does sound heavy and fuzzy when fully cranked but it lacks in the wooly warmth or thickness of the low end. Haven't played much with it yet but it also seems to only sound acceptable with at least 3/4 of gain/sustain. Everything under that sounds "meh" and hollow. Wonder if there's something wrong with my build.
ReplyDeleteGuess I'll have to experiment with other trannys. Are they 2N5089s in the original, too?
that's part of the issue i have with the effect. if you take the gain up past 3/4 it starts to oscillate like a mother, and it thins out a little. the thinning out can be fixed by playing with the tone pot though.
Deletethe one from batw's does have 2n5089s. you can try other transistors, as i mentioned. different transistors doesn't do a whole lot though, just makes a few subtle changes to the tone. i'm running MPSA18s in mine.
Do you recon, something could be done with different RC-combinations in the tone stage? Specifically the low-pass filter? And where would those be on this perfboard?
ReplyDeleteI just built it and it sounds great. The rotary bass cut is very useful when I use a low tuned guitar or run into a dirty amp. I used 2n5089's and don't have any squeals or annoying oscillation at max gain - even though it's unboxed so far.
ReplyDeleteJust built this one, and I will agree it is HOT. It also is really susceptible to picking up radio signals on my practice rig vs. my basement rig (different locations). Is there anyway to help alleviate some of that RF signal with this circuit? Shielding in the box, perhaps? Any advice?
ReplyDeleteWhat's a good voltage rating to get for the caps so they fit well? 25V or so?
ReplyDeleteThat's fine. The rule of thumb is you always want the voltage rating of your parts to be higher then the voltage you're running through the effect. I don't have any caps rated below 25V since I rarely have pedals that run close to that.
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