Shit Wolf Computer

[Ben79]

I've tried to build a Wolf Computer, point to point cos I'm an idiot and I always think my pedals will work first time even though they rarely do.

I can only get very gated starved sounds out of it, it's not sounding right at all.

I've checked all my component values and they're all good.

Here's the schem....



Only changes I made are no 330 ohm resistor, a 10k resistor to Q3 from the starve pot and a 0.1 output cap.

With my starve pot at ZERO ohms and the bias pot at 13.8k I got the following

Q1 E 0
B 0.67
C 6.6

Q2 E 0
B 0.66
C 1.59

Q3 E 0.88
B 1.59
C 0.95

[crochambeau]

Q3 base voltage is higher than collector, forcing the transistor into saturation.

When you say you omitted the 330 ohm resistor, does this indicate you are pulling your output directly off the power rail?

I think that drawing is bodged, I like to pull output directly off the collector (with DC blocking cap intact) or whatever leg I've defined as being a signal provider.

[BetterOffShred]

Yeah I'd move the output cap to the collector after the 10k (you indicated it was not an 8.2k) and try that.

Eatyourguitar has a modified schematic for the wolf computer I'm sure you have seen, I would copy the volume out after Q3 from that minus the tone pot.

I built the EYG board and there are settings where it does not produce sound. Having the 100k bias pot to Q2 makes some tweaking necessary.

[Ben79]

Oh yeah, I was working with EYG's schem alongside and added the 2.2m across q1 base and collector but didn't notice that, although something deep inside me was telling me that output config was iffy.

That schem also has a 0.1uf in series before the 2.2 so I got rid of that.

Thanks guys.

[eatyourguitar]

if you ever spent time with a fuzz face, you will know that the 330R is where you connect the output. if you delete it, you will always have +9v no matter what the transistor does for current consumption. the power supply is constant voltage. it will always be +9v. the only way to get a signal there is if you can load the battery enough to make it sag under AC based on the internal resistance of the battery or power supply. we are talking about ultra extreme conditions, overloading the power supply, and only having a few millivolts of output. when you connect directly to Q3 collector you are basically increasing the 330R to the size of the collector resistor. this can give you a lot more volume than if you did take the output at the 330R. I don't have a 330R in my schematic so I don't know where you got that from or if it is accurate. the schematic I have can be reduced down to the original wolf computer by deleting all the stuff I added but I can not say with %100 confidence that it is accurate to a real wolf computer. I am going on my best guess based on what people say and what they have tried. the world may never know. I can say though that if you build something based on my design, you will have a working pedal and it will even sound and behave like a wolf computer. I would not have restocked the PCB if I did not have people telling me the beta PCB works good.

[Ben79]

I moved the output cap to the right place and it now works ok although I find the starve pot is very sensitive and only useful up to about 800ohm. Maybe I've messed something up but I can't see why he put a 10k in there. I like the weird motorboaty scrambled sub octave breakdowns but I haven't found the usable overdrive people talk about....I wonder what I've got wrong this time.

[BetterOffShred]

Mine has the 10k and 1k in series and it's useful from max to min on both. I'm no expert but maybe try a 2m between Q1 collector and base. That seems to be common with pedals that have a starve pot maybe a trimmer..

[Ben79]

I put the 2M2 in from the beginning.

I traced the source of the problems....bad power cable! Still sounds kind of gated and not as OTT splatty fuzzy as the originals but it seems to be working ok now. I'll do some more experimenting on it when I get some time. There are some nice sounds in there. Some big fat synthy tones that sound a bit like there's some chorusing and some mild pulse width modulation.

[BetterOffShred]

Great man post a final schematic when you're done? I'd love to see what you finished with. I enjoy the circuit quite a bit. I need to finish boxing mine

[Ben79]

This one is a build for a friend so it'll just be stock. I've lost interest in splatty, gating, oscillating etc. silicon fuzzes recently. Since my move to France all my pedals were in boxes and I tried something really odd, I mean really strange, I wasn't even sure it would work, but I plugged my guitar straight into my amp. It's an old Carlsbro valve PA with reverb and I started just playing my songs through that and forgot about pedals. The preamp will overdrive a bit if I hit the strings hard and the reverb is really lush and controllable. I'm playing a Hofner semi (it actually has a wah and fuzz built in but they're not working right now) and I can get feedback when I want. At the moment that's enough for me.

I guess I might build a booster just to see where else that overdrive goes....

.....and if I'm building a booster I guess it's not much more work to add another germanium gain stage for a bit of fuzzy overdrive.....

....and I might as well make that go a bit beyond into full on fuzz.....maybe add some clipping diodes.......what about an option for octave, it's only.....

.....oh fuck

[eatyourguitar]

I tried something really odd, I mean really strange, I wasn't even sure it would work, but I plugged my guitar straight into my amp.

I don't usually get a chance to have a good laugh. This made my day. But anyway I'm cool with raw dog style as well. These are all just tools to make the sound you want to express yourself with a guitar. Sometimes there is nothing you can add to a sound to make it better. You actually said something important that you have distortion when you want it by playing one note a little louder. This is probably the best way an amp can enhance the way you play instead of hiding it. With heavy fuzz, the pedal is the star and we are more like keyboard players sending note on note off messages. That's how I see it. They are worlds apart so I don't think it is fair to compare them as though they are only slightly different. The range master was a lot like an amp. That was the only time there was a blurred line.