So I added an LED to my FF build

[thermionix]

And it seems to have changed the sound a bit.  Not major, maybe just a slight drop in gain and higher harmonic content.  Heck, it might even be an improvement.

Has anyone else noticed this, or am I imagining things?  This pedal is battery powered by the way.  Ge transistors seem so sensitive to everyting else, maybe sharing a battery with an LED makes a noticable sonic difference too.  I think I read somewhere that adding an LED quadruples the current draw in a FF, but maybe I'm remembering that wrong.  If I had a little switch handy, I would probably add an LED defeat function, but currently I don't.

If this does sound like something that could/would happen, not just my imagination, do you think a slight bias adjustment would change it back to the no-LED sound?  I have a pot on Q2C, but it's locked down at the Small Bear recommended setting, and I haven't tried messing with it yet.

[amptramp]

Everything affects a Fuzz Face.  The power supply rejection ratio is 0 db - any variation in power goes to the output and added current for the LED may drop the collector voltages enough to affect the sound.  You will also find variations from temperature and phase of the moon.

[thermionix]

Thanks, that's what I suspected.  Now I guess I should decide whether to remove the LED, or install a switch to make it optional.

[Electric Warrior]

How many other pedals are you using at the same time? It's a fuzz - you should be able to hear if it's on.

[thermionix]

How many other pedals are you using at the same time? It's a fuzz - you should be able to hear if it's on.

Oh yes I agree the LED isn't necessary, which is why I initially built it without one.  But after some recent changes, I was looking for something to fill a hole.  So I put in the LED.  After more playing time today, I've decided I liked the no-LED sound better, so I'm just going to remove it.

[PRR]

> I added an LED to my FF

How?

The details are the devils.

[thermionix]

> I added an LED to my FF

How?

The details are the devils.

Oh, is it MS Paint time?  Yes, it's MS Paint time!



Pretty standard stuff, except that it's a positive ground pedal.  I know you usually see the resistor on the anode side of the LED, but the internet tells me it doesn't matter.

Is there a different way I should try this?

[antonis]

Depending on your battery's capacity state, 1.5mA extra current consumption COULD affect FF bias points..

[karbomusic]

I like LEDs, not only to know if it is on but to know if it has power.   Don't really have time to wonder about things at a show.

[PRR]

Hmm, that should not make any difference.

[thermionix]

Hmm, that should not make any difference.

I didn't mind the slight gain drop, as this is a pretty gainy FF, but there was a certain sizzle that was missing which left the tone quite boring.  I did remove the LED, and the sound is back to the way it was before.  Maybe a small bias tweak would have done it as well, but the extreme battery life of an LED-free FF (from what I have read) is quite appealing to me.

I did acknowledge the possibility that it was all my imagination, but I don't think so.  I could have put a switch on the LED to prove it to myself, but I didn't bother.  Now my concern is what to fill or cover this hole with, preferably something I already have on hand.  The pedal is purple, I think a piece of tortoise pickguard would look appropriately funky on there, but I don't have any.  I'll come up with something.

First world problems, as they say.

[amptramp]

The full moon is tonight - in fact it might be an eclipse.  Your Fuzz Face will sound a bit... hairier.

[duck_arse]

why not fill the hole with a led. you could wire it backwards-like, so when it's on, the pedal is bypassed. won't affect the bypassed sound.

[thermionix]

Actually I had to drop by the guitar shop today to pick up an amp repair, and Mitch (owner) had a used tortoise acoustic pickguard that he gave me for free.  It's the thin stuff, so I don't have to worry about bevelling the edges.  As long as I don't screw up cutting it out, it should work fine.  I actually have a few unused holes I can cover with it.

[LightSoundGeometry]

The full moon is tonight - in fact it might be an eclipse.  Your Fuzz Face will sound a bit... hairier.

there are 4 tides a day, so you get 4 different fuzzes a day an an occasional AM talk radio

[karbomusic]

I'd measure (collector?) voltages and see if they change with it in/out. If so you can probably 'bias' your way out of the problem and keep the LED although I don't see how, how you have it wired is going to matter in that regard other than pulling the voltage down some - You could use a resistor twice that size and that (or other LED like a super bright) would pull less on the circuit - with a super bright you could up it to 15 or 20k.