Build Your Own Clone Message Board

Sorry, my bad style of writing - The 100µF capacitor goes from the power supply at pin 6 to ground, you are right - it's just a large power supply filter.

The 100nF goes from pin 7 to ground. If you can imagine a normal transistor circuit that goes power supply - resistor - transistor collector. The LM386 goes power supply - resistor - resistor - collector. Pin 7 is a connection point between the two resistors, for our purposes it provides a convenient point to attach a smaller value capacitor to take care of high frequency noise that may appear on the power supply line. I'm sure you've seen this 100µF (or 47µF) - 100nF filter combination in some other circuits.

Pin 2 goes to ground as in the original circuit.

Correct - the 10k pot is wired as you described - it reduces the amplitude of the signal going into the LM386, with culturejam's permission, I'd call this a "drive" pot as there is a 1M volume pot at the output of the LM386.

Inverted phase - there are very few circuits where phase inversion is really needed. It is usually good practice to keep the phase of the signal at the output the same as at the input, this is important if you try to mix the input and output signal together; if the phase is inverted at the output you will get either no signal or a significantly reduced signal. You will also find this a problem when using an effects loop on a guitar amplifier, if the signal going back into the amplifier is inverted, mixing it with the dry (non-inverted) signal will cause problems.

The above is not to say that you should be overly worried about phase - is it worth the cost of extra transistors and resistors (and capacitors ?) to make the output phase the same as the input? I'd say not - anyway, clever monkeys like me have a phase reversal box in case the problem arises.

For people reading this who are wondering what the hell we are talking about - look at the first photo above; the output signal goes positive (and negative) the same time as the input signal. The output is in phase with the input signal. In the last photo the output signal goes positive when the input signal goes negative and negative when the input signal goes positive. The phase of the output is inverted with respect to the input.

How to tell if the output is inverted ? (Sorry culturejam for hi-jacking)

If the output signal is taken from the collector (or drain) of a transistor, it will be inverted with respect to the input. If the signal is taken from the emitter (or source), it won't be inverted.
For an op amp, if the input signal is fed to the +ve (non-inverting) input, the signal at the output won't be inverted, and if the input is fed to the -ve (inverting) input, the signal at the output will be inverted.

Count the number of transistors where the output is taken from the collector (or drain), odd number of transistor, the signal is inverted, even number of transistors - not inverted.

Thank you for your kind words - I've read a small number of posts where I got the impression that the technical side was not wanted/desirable on this board; pehaps I'm just being a bit paranoid. I've learnt a lot and done a lot in this highly addictive hobby with much help from other people - the only way I can show my gratitude is to try and pass on some of the stuff I've learnt to others. Some people are happy just to be given the fish - that's something I can understand and is O.K. by me. Others want to go a little bit further and learn the how and why (there's nothing like catching your first fish by yourself), this is what I try to do, hopefully keeping the technical side to just enough not to cause brain-lock. I'm sure that sometimes I suceed and other times fail.

Seriously (and thank you as well) there may be some who are here just becuase it's a cool place to hang out, and to 'get a fish' so to speak - but I would be hard-pressed to name any regular around here that would shun the knowlerdge sharing. I, for one, am happy to read everything I can and absorb anything I can.

_________________
µ

Bah. It's not really my circuit. It belongs to the people now. </hippie>

_________________
==||==
Function f(x)
TightCamera - Gear Reviews

tonmann,
We are the exact opposite here. We are totally open to the hard-core "technical" side of pedal building AND we welcome the builder who just wants to build a cool pedal or two paint-by-numbers style, too. The issue sometines is that other boards don't welcome the noob who wants to stay a noob or even worse, the noob who is trying to not be a noob.
Bring the techy stuff on. Some of us will bite, some of us will ignore and some of us will not understand. But it is always welcome.

I, for one, am waiting to get setteled in my move so I can get this guy up and running. I have faith that there is a great circuit in here. I just don't have the knowledge to get it out. That's where you come in.

_________________

what a great discussion!
i posted with (cj's permission ) a schematic updated with tonmann's modification.
would be great if somebody could double check/verify it.

http://buildyourownclone.com/board/viewtopic.php?f=41&t=18054

thanks guys!

Going thru all my pcb's and came across a devnull and was wondering if any still had the layout for it?

_________________
Doh! Stupid Diode

I updated the first post to fix the images.

_________________
==||==
Function f(x)
TightCamera - Gear Reviews

Awesome dude thanks

_________________
Doh! Stupid Diode

Back from the Grave!

_________________

Only 2 1/2 years not dead just laying dormant. lol
got a few pcb's i need layouts for. was surprized to get this one so quickly

_________________
Doh! Stupid Diode