MXR Micro Amp, from General Guitar Gadgets.

[arma61]

Have you tried to figure out how the signal flows through the switch ? I'd do that before soldering it.

something like this



Ciao

[markbee]

everthing looks okay in Position 1 - the wire from number 5 goes through the board and then through the wire to the input jack so it shall be grounded? everything seems to be wired well although it still lookes like a grounding problem.

[markbee]

ITS ALIVE! its finally working! ) but the led doesnt shine and the boosting seems to be stuffed in the last quarter of the potentiometer turning, well it boosts from the middle but its very slight and then really sudden volume gain ... any idea how to fix that?

[arma61]

ITS ALIVE! its finally working!

hey man, you did it!!! well done!!

but the led doesnt shine

Stupid answers
have you tested it's working with a battery + resistor (4.7k to be on the safe side) ?
have you checked polarity of the LED ?

the boosting seems to be stuffed in the last quarter of the potentiometer turning, well it boosts from the middle but its very slight and then really sudden volume gain ... any idea how to fix that?

is the pot the right one, so a 500k Reverse Log ?

may be now that you got it working you could post voltages as per that thread I've pointed some time ago.

Again, well done m8, what was the problem at the end


Ciao

[markbee]

I must have forgotten to check the LED, i probably wired it the wrong way
I have used the exact same potentiometer as was written in the bill of materials,
I tried to measure the voltages and almost all of it seems wrong to me, i probably dont know how to measure it properly :-|

IC1
P1 43 mV
P2 4,4 V
P3 2,3 V
P4 keeps giving me 0 for some reason
P5 265 mV
P6 8,86 V
P7 4,41 V
P8 43 mV

Well the problem was in grounding, i noticed that the one part of the output jack is touching the enclosure so i put a little tape underneath it and it started to work

[arma61]

Hi (sorry if all this sound a little bit boring... )

first of all use a fresh new batter to check your DMM is working good....

now let's talk about the same pins

looking at the IC name/mark/stamp, make sure you have the notch on the top and/or a dot on the top/left corner

the pin on the left of the notch is pin 1, the one on the right is 8, so measure the pins like this

1 8
2 7
3 6
4 5

you should have readings almost like these

1 - 0
2 - 4.2v
3 - 2.4v
4 - 0
5 - 0
6 - 4.4v
7 - 8.8v
8 - 0v


Ciao

[twabelljr]

 

[markbee]

thanks, i measured it once again and it is correct what shall be causing that gain coming in the second half of pot rotation? wrong pot is the first thing that occured to me but i ordered the exact one from US to have everything right )