The WOW (no Signal) Fuzz.

[digi2t]

Made one for Jimi, and his Fuzziness said it was OK. Decided to make another one for my herd. This is the Spaceman WOW Signal Fuzz, but with the LFO removed. I kept the filtering side of things but a pot now controls what the LFO/Vactrol used to run. Here's the vero;



Just a couple of notes;
- R13 can be anywhere between 1K and 4.7K. It's the current limiter for the LED, so adjust to taste.
- R10 I replaced with a 50K trimmer. 5.25v is OK but depending on the Germ, this will shift. With some transistors, this voltage is too high, and it reduces (or negates) the effectiveness of the gain pot, i.e. gain sounds maxed no matter where you set it. The ideal is to reduce base voltage until the signal cuts, and then slowly come back. Sweep the gain to see if there's a decent min./max. gain differential, and you should be good to go. Set the voltage as high as possible, without overriding the gain pot.
- The Ge transistor in the original came in between 30 - 40 hFe, with leakage under 0.1mA. Feel free to experiment with different transistors here, it can really change the character of the fuzz. The Sanyo in my build comes in a shade over 100, with 0.12mA of leakage, and it sounds much crunchier than a lower gain transistor. I even tried another Sanyo (2SB322 I think), at 200 and 0 leakage, but it turned into a buzzsaw. Like I mentioned before, stick a trimmer in the R10 spot, and twiddle away.
- C7 is 82pF in the original, but there's a lot of fizz. Depending on your final choices for transistors, I found that anything between 470pF, and 1nF tends to be more comfortable on the ears. I've even gone as high as 2.2nF, but it's much darker then, and starts to cut into the effectiveness of the filter. The one that I'm building now has an 820pF, and it's just crunchy enough. I socketed all the transistors, and that cap for testing. Once the final actors were chosen, I soldered the silicons to the sockets, and the Ge and cap went direct to the board.

My build (in progress);





Jimi's build;

[thermionix]

I just watched a TV show that mentioned the Wow signal, not even an hour ago.  Weird.

[digi2t]

That's a sign man. Build it, and they will come. 

[antonis]

Is there any specific reason for using 1558 can type op-amp when a 1458 plastic DIP should also be fine for power & voltage requirements..??

[GibsonGM]

Is there any specific reason for using 1558 can type op-amp when a 1458 plastic DIP should also be fine for power & voltage requirements..??

You have to admit, the 1558 looks very cool   

[digi2t]

Is there any specific reason for using 1558 can type op-amp when a 1458 plastic DIP should also be fine for power & voltage requirements..??

I thought about using a plastic DIP, but I knew that it would get your attention if I didn't, and that Gibson would find it cool.

You see... You both fell into my web of intrigue. 

Seriously though, strictly cool factor. The plastic DIP's are so... well, plastic!

[duck_arse]

I would admit nothing about the 1558 except "!", the grey plastic-d germ, on the other hand, looks special. is it plastic or paint?

[digi2t]

I would admit nothing about the 1558 except "!", the grey plastic-d germ, on the other hand, looks special. is it plastic or paint?

It's a plastic sleeve. That germ came from a tape deck that was integrated into an old Farfisa organ that I gutted a few years back.

[Cozybuilder]

I wonder if you could Darlington pair a couple of lower gain Russky transistors to get the 250 - 900 Hfe of that 2N5087?

[digi2t]

I wonder if you could Darlington pair a couple of lower gain Russky transistors to get the 250 - 900 Hfe of that 2N5087?

Just for info's sake, I've found that matched gains of between 300 and 320 work best. Also, 2N5087's along side BC5** seem to get along best. Don't ask me why, that's just an observation attained by trying a shitload of different transistors through this circuit. The only other pair that I got decent results with are the 2N5551/2N5401 combo, or a 2N4401 in a pinch, but I couldn't get the same sustain magic as with the 5087/BC mix. As for the gain range, lower than 300, the fuzz starts to get weak. Higher, it gets fizzy real fast.

[kaycee]

Thanks for this. I built the signal version of your vero many moons ago, liked the fuzz, but not much use for the signal so never boxed it. So added this to the list of ones to build, cheers!

[digi2t]

I may have gone a bit overboard on the Filter pot and cap values. If you find that it gets too dark past half way on the pot, change the C11 cap to a 10n, and the Filter pot to a 10k. A log pot seems to give the best sweep. It acts sort of like a mids presence controls. No matter where the tone is set, this control with a 10n/10k will either beef it up, or thin it out.

[pinkjimiphoton]

jimi MORE than approves!! this thing is bloody faantastic and very versatile..

thanks agaain dino, i absolutely love it bro!!

[digi2t]

jimi MORE than approves!! this thing is bloody faantastic and very versatile..

thanks agaain dino, i absolutely love it bro!!

Glad you like it bro. I don't to stuff a 1590B very often, so it tested my skills. I hope it serves you well.