Conrad Buzztone and Volume Expander

[heuermh]

Great, thanks for the reply!

I've built a Fuzzrite-ish clone from a kit PCB and enjoy that sound.  I am looking forward to experimenting with this layout and a bunch of different odd transistors I've recently collected.

Oh and an Atlas DCA55 is on its way to help.  :)

[Beaker]

Just finishing boxing mine up. Here's a few pictures. I've "borrowed Bjorn's insulation method - wrapped the board in mountain bike inner tube.

Outside:




Inside:



Circuit Board.

[anders]

Cool! What is the extra footswitch and the toogle for?. Oscillation and diode selector? You made me inspired, I think I have to build another one with your mods. And I really dig the enclosure, it really captures the nature of this thing. Great job!

[Beaker]

"What is the extra footswitch and the toogle for?. Oscillation and diode selector?"

Correct.

I have no artistic talent whatsoever, so plain enclosures and Brother label maker is about my limit!

[adapt]

hi guys, i tend to draw my own layouts when i want to build stuff, that said i've drawn a layout for this, incorporating the diode switch onboard as well as the oscillation switch, and it turned out pretty small. thought maybe you guys would like it if you plan on building this.

http://i.imgur.com/EY1gGjj.png

[rocket88]

awesome. nice job buddy.

[Beaker]

That's great Adapt, really neat. Mine got it's first live outing last night, when my son used it at his new bands debut gig. It got a lot of compliments as did his band!

Just one thing though - don't use this after a buffered pedal as the oscillator barely works.

[heuermh]

Hello adapt, I finally got around to building this and I used your layout, thanks!

I have 2N2222A at 100 hFE in Q1, MP38A at 80 hFE in Q2, and D311 as diodes.  With the osc switch down I get insane oscillation as I would expect and the diode switch changes the tone significantly.

With the osc switch up I get plenty of volume increase but no clipping, certainly not "pure, utter, velcro ripping filth" :)  And the diode switch doesn't have any effect.

Maybe I'm missing a jumper?  The legend says 3 and I only see two in the layout.

[Beaker]

Only had a quick look, and I'm not sure on this, but try adding a link to the last column (column K),
between rows 3 and 6 (next to sw1 and sw2). There is a handy space for this.

See what happens, and report back.

[heuermh]

Thanks!

Now with the osc switch up I get no signal.  Osc switch down gives oscillation + clipped guitar mayhem.

[Beaker]

Crap. I'll see if I can have another look later, but hopefully Adapt will be able to sort it out.

BTW the oscillator switch should be a momentary footswitch for best effect. That way, you don't have to bend down to operate it.

[Beaker]

Looking at my build I've realised that I dropped a clanger. The diode switch should be on/off/on, not on/on/on as I stated earlier in the thread. I'm not sue if this will sort your problem out, but it's worth mentioning.

 Also you want to use two different diodes, so replace one of your D311 with something else, or you will get the same sound from both "on" positions. You could use something like a D9 for example, or use a silicon like a D321 or a KD521 - it's up to you what you think sounds best.

I hope this helps.

[heuermh]

That might explain it!  Will give it a try, thanks.

[heuermh]

Worked great, thank you, Beaker!

Thinking I might be able to balance the volume of with vs. without oscillation, I socketed a resistor to ground between the momentary osc switch and the volume pot.  That didn't do what I expected (decrease the volume of oscillation compared to without) but acted more like a starve pot, making the fuzz break up in unpredictable ways.

I ended with 1M; it might be useful to throw a 1M or higher pot in there for tweaking.