3pdt.com Electric Mistress DIY Flanger kit doesn't affect sound when on

[Mukobi]

Hi,

I bought an Electric Goddess kit from www.3pdt.com (it's their clone of the EHX Deluxe Electric Mistress), although through a seller on Reverb.com instead of their main website. I assembled it correctly (as much as the instruction book helped; it doesn't have a schematic included) and double checked everything, but when I turn on the pedal it has no effect on my guitar signal. Sound still comes out, but no flanging occurs no matter where the 3 internal trim pots or the 3 main potentiometers are; it sounds just like the true bypass sound.

Could this be the result of a faulty BBD chip, or could it be something else? I don't think I harmed any of the 6 ICs (IC1 is JRC4558, IC2 is MN3207, IC3 is LM324, IC4 is LM311N, IC5 is CD4013B, IC6 is CD4049B) because I only put them in their sockets after soldering the whole board. The LED does go on when the pedal is on, if that helps.

What I've tried so far is reflowing all sketchy solder joints, messing with the 3 internal trim pots and the 3 big external pots, and taking all the chips out and putting them back in, but nothing has changed the problem. In the instruction, they say that T2 regulates the BBD bias at IC2 MN3207 pin 3 which should be 4.9V, but I was only able to get it to about 4.84V by turning that trim pot all the way clockwise.

I'm guessing you will need some voltages too, but what should I measure? I'm pretty new to this and this is a fairly complicated board. Here are some pictures of the schematic, the PCB with and without components, and the switch board, which may help in telling me what to measure.

Thanks!

[devastone]

Re: 3pdt.com Electric Mistress DIY Flanger kit doesn't affect sound when on

I would start with checking the 3PDT switch and connections, those have been know to fail, it may be staying in bypass. If it is switching the effect in, even if it is not oscillating, there should be some change in the sound or kill the signal.

It looks like RT3 adjusts the oscillation. The ref voltage that RT2 adjusts will be dependent on Vcc which is your battery/adapter voltage, so you might start with checking that to make sure you have 9V going in, especially if you are using an older battery. RT1 adjusts the amount of output from the effect.

[Mukobi]

Re: 3pdt.com Electric Mistress DIY Flanger kit doesn't affect sound when on

I would start with checking the 3PDT switch and connections, those have been know to fail, it may be staying in bypass. If it is switching the effect in, even if it is not oscillating, there should be some change in the sound or kill the signal.

It looks like RT3 adjusts the oscillation. The ref voltage that RT2 adjusts will be dependent on Vcc which is your battery/adapter voltage, so you might start with checking that to make sure you have 9V going in, especially if you are using an older battery. RT1 adjusts the amount of output from the effect.

I've taken done all the things suggested by the DIYstompboxes.com troubleshooting guide. Here are the results:

What does it do, not do, and sound like: True bypassed the sound is unaffected, but when switched on and powered the sound is still unaffected no matter where any of the 3 knobs or 3 internal trimpots are (it should be flanging) but the light goes on. Notably, without a power source, true bypass is still the true bypass signal but switching the pedal on gives no sound and no light. Also, battery power doesn't work at all (yes, with a cable plugged into the stereo jack) and doesn't give any light or sound when switched on; I was only able to get it light up with a 9V Boss style power supply or a 9V output my BBE Supa Charger isolated power supply.

The above issue and the below voltages were with IC6 as it is oriented in my pictures. The printing on the pcb is rather unclear which side should have the notch of IC6 (as you can see in my pictures below), so I also tried flipping it around. When I did that, it still didn't have any effect on my guitar signal, but a new quiet and constant high pitch whine could be heard that was oscillating in pitch and responded to the potentiometers. It is almost as if that was the flanged frequency, except the pedal was generating that noise and flanging it rather than doing anything to my guitar. Because spontaneous noises generated by a pedal are generally wrong and because the manufacturer's picture of the circuit shows IC6 to be oriented how I originally had it, I flipped it back around.

Name of the circuit = Electric Goddess Flanger (www.3dpt.com clone of EHX Deluxe Electric Mistress)

Source of the project = http://www.3pdt.com/products/electric-goddess-flanger

Pictures of the circuit schematic and my finished (but not working) kit: http://imgur.com/a/FXPlC

Any modifications to the circuit: None

Any parts substitutions: None

Positive ground to negative ground conversion: Not that I have done, and not that I know of in the circuit.

Voltage of the battery I used not connected to anything: -9.14V

Voltage of the isolated power supply 9V output: -9.26V

Voltage at the circuit board at end of the red battery lead with battery plugged in = -3.2mV (does this mean there is a short on the board?)
Voltage at the center of stereo jack at end of the black battery lead with battery plugged in = 0V

Voltages of all major components using isolated 9v power supply. Multimeter black was attached to negative/ground and red probed the components. T2 Trim set so IC2 MN3207 pin 3 = 4.91V. T1 Trim, T3 Trim, Range, Rate, and Color pots all at noon. Filter/matrix switch is up (which I think is normal flanging mode):

Q1: 2n3904 (NPN)
E = -4.71V
B = -5.29V
C = -9.16V

Q2: 5087 (PNP)
E= -7.95V
B= -7.86V
C= -2.27V

IC1: JRC4558
P1: -4.95V
P2: -4.95V
P3: -2.46V

P4: 0V
P5: -4.47V
P6: -4.93V
P7: -4.91V
P8: -8.93V

IC2: MN3207
P1: 0V
P2: -4.57V
P3: -4.91V
P4: -8.54V
P5: -9.17V
P6: -4.57V
P7: oscillating between -5.55V and -5.65V over about 11 seconds full cycle
P8: oscillating between -5.55V and -5.64V over about 11 seconds full cycle

IC3: LM324
P1: oscillating between -2.87V and -5.23V over about 11 seconds full cycle
P2: oscillating between -4.04V and -4.13V over about 17 (!) seconds full cycle
P3: oscillating between -3.97V and -4.05V over about 11 seconds full cycle
P4: -8.93V
P5: oscillating between -2.40V and -5.75V over about 11 seconds full cycle
P6: oscillating between -3.97V and -4.05V over about 11 seconds full cycle
P7: oscillating between -0.55V and -7.64V over about 11 seconds full cycle
P8: -4.93V
P9: -4.93V
P10: -4.80V
P11: 0V
P12: oscillating between -1.02V and -1.87V over about 11 seconds full cycle
P13: oscillating between -1.05V and -1.89V over about 11 seconds full cycle
P14: oscillating between -1.08V and -2.89V over about 11 seconds full cycle

IC4: LM311N
P1: 0V
P2: oscillating between -1.06V and -2.85V over about 11 seconds full cycle
P3: oscillating between -0.91V and -2.28V over about 11 seconds full cycle
P4: 0V
P5: -9.16V
P6: -9.16V
P7: oscillating between -8.47V and -8.93V over about 11 seconds full cycle
P8: oscillating between -1.08V and -2.95V over about 11 seconds full cycle

IC5: CD4013B
P1: -4.57V
P2: -4.57V
P3: oscillating between -8.46V and -8.94V over about 11 seconds full cycle
P4: 0V
P5: -4.57V
P6: 0V
P7: 0V
P8: 0V
P9: 0V
P10: 0V
P11: 0V
P12: 0V
P13: -9.17V
P14: -9.17V

IC6: CD4049B
P1: -9.17V
P2: oscillating between -4.55V and -4.57V over about 11 seconds full cycle
P3: oscillating between -4.54V and -4.57V over about 11 seconds full cycle
P4: oscillating between -4.56V and -4.57V over about 11 seconds full cycle
P5: oscillating between -4.56V and -4.58V over about 11 seconds full cycle
P6: oscillating between -4.57V and -4.58V over about 11 seconds full cycle
P7: oscillating between -4.56V and -4.58V over about 11 seconds full cycle
P8: 0V
P9: 0V
P10: oscillating between -4.57V and -4.58V over about 11 seconds full cycle
P11: oscillating between -4.57V and -4.58V over about 11 seconds full cycle
P12: 0V
P13: oscillating between -4.56V and -4.58V over about 11 seconds full cycle
P14: oscillating between -4.56V and -4.58V over about 11 seconds full cycle
P15: oscillating between -4.56V and -4.58V over about 11 seconds full cycle
P16: oscillating between -4.56V and -4.58V over about 11 seconds full cycle

D1: 1N4001
A (anode, the non-band end) = -9.17V
K (cathode, the banded end) = -8.76V

D2: 1N4148
A = oscillating between -0.93V and -2.28V over about 11 seconds full cycle

K = oscillating between -8.43V and -8.92V over about 11 seconds full cycle

D3: RD10 10V 0.5w Zener
A = 0V
K = -9.17V

[Gearjoneser]

Re: 3pdt.com Electric Mistress DIY Flanger kit doesn't affect sound when on

Triple pole double fail.

[Darg1911]

Re: 3pdt.com Electric Mistress DIY Flanger kit doesn't affect sound when on

Didn't read the entire thread but ... Check the polarity of the indicator LED. The 3PDT clone of the Zen Drive is a nice pedal but the polarity markings for the indicator LED were/are reversed. Might not apply to Electric Mistress clone but thought it worth mentioning. Of course, would be an obvious place to look if the LED isn't lighting but though it worth mentioning anyway.

[Mukobi]

Re: 3pdt.com Electric Mistress DIY Flanger kit doesn't affect sound when on

Triple pole double fail.

Are you saying something is wrong with the switch, or the company?

[devastone]

Re: 3pdt.com Electric Mistress DIY Flanger kit doesn't affect sound when on

I just saw this thread, I'm swamped at the moment with a client that needs something ASAP (which is SOP with clients) so I can't really go through the schematic and all your voltage measuements.

The fact that when it is powered off it only passes signal in bypass mode seems to indicate that the switch is working.

I am a little confused that you have the black lead on the DMM connected to ground but are still reading negative voltages(?), something is weird there, are the leads reversed at the meter?

The "notches" for the ICs are pretty clear, the notch for IC6 is toward the top in your picture, there is a semi-circle there.

I would start by going through with a soldering iron, keeping it well tinned, and retouching all of your solder joints to make sure none of them are cold joints, some of them look suspicious. Also trim up the long leads and go over it thoroughly and make sure you don't have any solder bridging 2 pads, again, hard to tell from pictures but neatness does count in soldering.

In the picture of the bare board, at the bottom, just to the right of center, there are some weird looking pads, are those bridging?

Good luck, let us know how it goes.