Build Your Own Clone Message Board

Hey Everyone,

Just finished my first ever pedal build last night (should've started with a Fuzz, lol). It's been a while since I've soldered so maybe I have a cold joint. I have the 3007 3.0 chipset, I made sure to follow the instructions for tack soldering the 56k resistor across the pins on the back. One thing I know I went off the rails for, I installed the 4558 socket backwards (I missed the instruction on aligning the notch, luckily the other 3 chips I got in the right way). I tried for a while to desolder and reverse the socket but just couldn't get that thing out. I just went ahead and installed the 4558 chip the right way and hoped this would work. This was all before any power was applied. I'm not finding any continuity between any of the 3 legs on the 25k Bias Pot Voltage, could this be the culprit? Readings on the chips below, answers to the support post questions and links to photos follow.

3007
Pin 1: 8.4
Pin 2: 4.4
Pin 3: 3.5
Pin 4: 0.6
Pin 5: 0.0
Pin 6: 4.3
Pin 7: 4.1
Pin 8: 4.1
3101
Pin 1: 8.2 - 8.4 (smooth sweep)
Pin 2: 4.3
Pin 3: 0.0
Pin 4: 4.3
Pin 5: 2.7 - 3.7 (smooth sweep)
Pin 6: 7.1 - 7.4 (smooth sweep)
Pin 7: 2.4 - 2.8 (smooth sweep)
Pin 8: 0.5
4558
Pin 1: 4.2
Pin 2: 4.2
Pin 3: 4.2
Pin 4: 0.0
Pin 5: 4.2
Pin 6: 4.2
Pin 7: 4.2
Pin 8: 8.5
TL022
Pin 1: .6 - 7.8 (bouncing back and forth)
Pin 2: 4.1 - 4.4 (smooth sweep)
Pin 3: 1.7 - 6.6 (smooth sweep)
Pin 4: 0.0
Pin 5: 4.0 - 4.4 (smooth sweep)
Pin 6: 4.5
Pin 7: 2.0 - 6.5 (smooth sweep)
Pin 8: 8.5

1. Picture of the top side of your PCB.
https://u.cubeupload.com/solarsamurai/B ... usTopP.jpg
2. Picture of the underside of your PCB.
https://u.cubeupload.com/solarsamurai/B ... usBott.jpg
https://u.cubeupload.com/solarsamurai/2 ... usBott.jpg
3. Picture that clearly shows your footswitch/jack wiring and the wires going to the PCB
https://u.cubeupload.com/solarsamurai/B ... usTopP.jpg
4. Picture that clearly shows your wiring going from the PCB to the off board components
https://u.cubeupload.com/solarsamurai/B ... usTopP.jpg
5. Is bypass working?
Yes
6. Does the LED come on?
Yes and reacts to the rate knob.
7. If you answer yes to 5 and 6, what does the pedal do when it is "on"? Please be as specific as possible.
Pushes through clean signal with 0 noise, very clear sound.
8. Do all of the controls work properly? Just 1 or 2 not working?
No
9. Does the problem change if you switch from battery to a power supply or visa versa.
Problem persists through battery and power supply operation.

It doesn't matter if the socket is backwards as long as you put the chip in correctly. The 4558 is in charge of the dry signal, so if you're getting clean unaffected signal when the pedal is on, then the 4558 is working. The 4558 voltages look good too. In fact, all of your voltages look good which would suggest that you simply have a cold solder joint somewhere in the wet signal path. Does the rate of the LED blinking change with the speed knob?

My first suggestion would be to reflow all of the solder joints on your PCB.

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

Not surprising, unless you happened to have the trimpot turned fully CW or CCW. This bias pot functions as a voltage divider--one outer leg connects to your power source (V+) and the other outer leg to ground. If you measure the resistance between these outer legs (with power disconnected), the result should be right about 25 Kohms. The middle leg (a.k.a. the "wiper") is what then provides the bias voltage to various points in the effect circuit--more or less depending upon where you have the trimpot set in its sweep arc. As the instructions note (pg. 15), the optimal setting should be very close to the middle of the trimpot sweep, at which point half of the supply voltage is directed to the effect circuit connections and the other half to ground. You then "tweak" the setting to get the best/cleanest chorus effect.

At that midpoint setting, there should be ~12.5 Kohms resistance between the middle leg and either of the two outer legs. You will only find continuity (i.e. near-zero resistance) between the middle leg and one of the outside legs if the trimpot is set at one or the other extreme end of its travel. At such a setting, the resistance to the opposite outer leg will be the full resistance of the pot, ~25 Kohms.

Hope that helps explain what's happening with the trimpot in this circuit.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Right, the LED matches up with the speed knob adjustments. Does this mean the LFO & Clock Driver circuit is functioning correctly? (Sorry, I'm more of an electrician than an electronic tech) I'll re-flow tonight and see if I can get it up and running. Thanks for the help.

Hey thanks for this explanation!

So I reflowed the solder joints and now everything works. Thanks!

Nice! It's amazing how often this simple process solves "no effect" problems. Enjoy your new pedal!

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2