hmmm. my LED stays on even with no power connected. and the pedal is hissy.

[jamiefbolton]

This is very interesting. I built a GGG Red Llama today. Its all wired up and in the enclosure. First off, I built using my own perf layout, so that could be the source of all my issues. But anyway, there seems to be a little bit of hiss. Kinda reminiscent of a vintage Big Muff but not quite that noisy. The hiss comes from the volume knob and not the gain. With the gain maxed and the volume about 9 oclock, the pedal is almost useable. But with less gain and more volume knob the hiss it too much. Bad pot perhaps? IDK.

The other thing it that 4 min after unplugging the pedal from the 9v adapter, the LED still has some glow. Has that happened to anybody before? Could this be linked to the hiss in some way?

Like I said, this is my layout and could probably be improved. I can draw it out and provide a picture if this would help you guys diagnose the problem. I'll work on that anyway. If you can shed some light please do. Also,  I have a thread about my ROG peppermill if you will take a look there too.

[mth5044]

You are going to need an old priest and a young priest. 

[Scruffie]

Just a shot in the dark that'd need someone more experienced here to confirm but could it not be a bad electrolytic, it'd cause hiss and if it was leaking I suppose it could power an LED for a short period of time... check there orientations.

Or this 

You are going to need an old priest and a young priest. 

[Skruffyhound]

Can only be a cap powering the LED, so look there. Hiss can be attributed to lots of things but unlikely to be a bad pot IMHO. If you've got dc on your pot it'll crackle, but hiss is coming from somewhere else. Post some more details, esp. layout for more help. I'm no expert but there are some around here 

[jamiefbolton]

ok. i'll replace the elec cap on the power and see if that fixes things. if not, i'll draw up the layout and post.

thanks guys

[Pakaloabob]

I built a Red Llama on a PCB that I etched using the Tonepad layout. I too have experienced a dim LED light even when cable is unplugged.
In addition, my ROG Mr. EQ exhibits the same behavior. Both include a 4049 IC. Coincidence?....
Anyway, I never really troubleshooted too much. The circuits seemed to work fine, so I could deal with that minor incovenience.
But if anyone has any ideas where to start, I wouldn't mind doing a little debugging.

[slacker]

The LED probably stays on for a while because the Red Llama has that big ass 330uF cap in there.
When the pedal is on it will charge up and then when you pull the power it will slowly drain, keeping the LED lit up for a bit.
Probably has nothing to do with the hiss though.

[deadastronaut]

yep ive got a little amp with  a big cap in it...led takes ages to dim...n off...definately...

[jamiefbolton]

Ok that makes sense. I don't have a 330+ so I put a 420+ in it. I'll change to a 220+ maybe, but i'm more concerned about the hiss than anything else. It'll be a while before I can get a layout posted. I'm crazy busy lately but maybe I can get it done soon. We'll see.

[jamiefbolton]

Here is a layout I made of the Red Llama. I used the General Guitar Gadgets schematic (but not the PCB). Here is the link to the documentation: http://www.generalguitargadgets.com/pdf/ggg_whrl_sc.pdf
Hosted on Fotki
In my actual build, I put the 9v power to the right of 1.5M resistor in the space left open. Is that a problem? Or is the noise possibly coming from the IC?