Pepper Spray diodes

[miter53]

I just got my Pepper Spray together enough to try it out, and I love the germ diode mode, but the 1N914 not so much. What have other people tried in this spot?

Mike

[midwayfair]

What are you going for in that position? The 1N914s make it more of an overdrive than a fuzz due to the significantly higher Fv. Note that there's also no series resistor to make it asymmetrical.

If you want more fuzz, you're going to need to lower the Fv. 1N400x will be closer to .53v. You can put two Scotkeys (BAT41, 43, 85, 5817, etc.) in series for ~.5v or less. 1N34A is about the top of the germanium Fv range, so they might be good if you didn't use them in the standard slot. (1N695 clips around .25v, whereas 1N34A is more like .35v). Finally, you can try a MOSFET for a very different character and a Fv of ~.55v

My favorite diode period in this circuit was OA126 in the symmetric position. It has a very high Fv (~.65v) for a germanium diode.

However, simply changing the composition or type of diode at the same Fv won't necessarily alter the fundamental character of that position. It could be that you prefer the lower clipping threshold, it could be that you need to find the sweet spot on the Harm control, or it could be that you miss having the asymmetric distortion and a mix of germanium and silicon in that position is in order.

[JakeFuzz]

My two favorites have been an orange 3mm LED in parallel with a BAT46 in the symmetric section and parallel OA126's in the Ge positions. The LED and BAT46 are the first sounds on this demo.
[soundcloud]
http://soundcloud.com/jakefuzz/pepperspray[/soundcloud]

[miter53]

Thanks for the advice. I'm pretty new at this so it helps. I have 1n695s in the Ge position, and I found that the other position with two 1n914s was somewhat muted and lacked complexity.

Questions:
Why are two BAT41 in series (for a total of 4?) another suggested option? Why not just a pair? Or is it just a pair wired in series rather than parallel?

Does the color of an LED really effect the tone?

I have a couple of BAT41s. Would one of them (or both in series paired with an OA126) be a viable option?

How about LED + OA126 for the suggested mix of germanium and silicon?

Thanks again,
Mike

[midwayfair]

Thanks for the advice. I'm pretty new at this so it helps. I have 1n695s in the Ge position, and I found that the other position with two 1n914s was somewhat muted and lacked complexity.

Questions:
Why are two BAT41 in series (for a total of 4?) another suggested option? Why not just a pair? Or is it just a pair wired in series rather than parallel?

Does the color of an LED really effect the tone?

I have a couple of BAT41s. Would one of them (or both in series paired with an OA126) be a viable option?

How about LED + OA126 for the suggested mix of germanium and silicon?

Thanks again,
Mike

BAT41s clip about the same as a 1N695. It would be way too similar to really be worth the cost of a switch. (They ARE different, but only very subtley.) Using two in series on each side means that you can get about double the clipping of the 1N695 side, making it a much larger difference in both volume and distortion. Putting one in parallel with one of your 1N914s might be fun. You should try it. Using 1N34A instead might be worth the switch, and it would be closer but different. You should try it.

Different color LEDs affect the tone "a little." They have slightly different clipping thresholds; some LEDs don't meaningfully clip at all (blue and white ...). LEDs will be extremely loud in this circuit and not much different from a diode lift. However, you should try it!

The "muted" sound you're hearing is not necessarily the diodes. They definitely sound chunkier, octaving is less apparent, the tone is less scooped, and there's far less distortion, which makes it sound less complex. IMO if you don't like the basic sound, a different diode is going to be a cure. For instance, I don't particularly care for the 1N695 side in mine. I tried a lot of normal germanium and schotkey diodes there and ended up using the originals JUST so I had a way to show what it was supposed to sound like vs. my prefered choice of 1N695. If I were to build another, I'd probably skip the stock settings. However, you should try various diodes there. Doesn't have to be NOW -- just grab a couple fun things to play with each time you order parts. Look up the datasheets or read forum posts that talk about the sound of certain diodes or just the circuit in general (http://www.diystompboxes.com/smfforum/index.php?topic=99596.0 and ahem http://www.madbeanpedals.com/forum/index.php?topic=5399.0) to know what to grab. Building a collection of parts to experiment with is fun, and it's going to be much more instructive than listening to me prattle on about my preferences, especially because we've established here that we're probably going to disagree on the final results. "Tone" is like that, and that's why we build things for ourselves, right?

I wouldn't discourage anyone from experimenting, but my gut feeling is that you're going to be happier playing with the 1N695 slot with other germanium and schotkey diodes and saving the $1 or so you'd spend on the switch.

[miter53]

An update. In fact, it was the 1n695s that sounded muted, and that was largely due to the attenuation on that position. Adjust the balance and it sounds a lot better. Duh!

In the other position, I've tried many different combinations, including 1n914, OA126, OA1160, 2n7000 MOSFETs, 1s1588, BAT41, and BAT85. I'm waiting on some orange LEDs. Two OA126s sound great, but for the time being, I like an OA126 and a 1s1588 a little better.

Thanks for the advice. And btw, this pedal is awesome!

Mike