Help debug a circuit.

Started by JackLondon, April 09, 2010, 06:43:52 AM

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JackLondon

Hi Guys, I'm having a bit of a problem with one of my builds. Here's the spec

1.What does it do, not do, and sound like? – Doesn't put enough signal to the output, it's very very very silent. In bypass mode there is no signal at all.
2.Name of the circuit = Agua Filter
3.Source of the circuit (URL of schematic or project) = http://www.tonepad.com/project.asp?id=4
4.Any modifications to the circuit? – Yes, Emphasis control, reverse sweep, filter range, all from the schematic

5.Any parts substitutions - No.

6.Positive ground to negative ground conversion - No

7.Voltage at the circuit board end of the red battery lead = 9.11
Voltage at the circuit board end of the black battery lead = 0.79


IC1
P1 0.34
P2 0.19
P3 0.20
P4 0.18
P5 0.14
P6 0
P7 0.79
P8 0.20
P9 0.21
P10 0.20
P11 0.21
P12 0.22
P13 0.74
P14 0.17

IC2
P1 0.56
P2 0.21
P3 0.21
P4 0.21
P5 0.70
P6 0.24
P7 0.79
P8 0.71
P9 0.23
P10 0.20
P11 0.23
P12 0.23
P13 0.75
P14 0.17

IC3
P1 0.66
P2 0.69
P3 0.70
P4 0.68
P5 0.73
P6 0.71
P7 0.79
P8 0.14
P9 0.00
P10 0.14
P11 0.47
P12 0.71
P13 0.74
P14 0.17

D1
A = 0.04
K = 0.17

D2
A = 0.10
K = 0.15


Any help kindly appreciated
Cheers
Jack

anchovie

Check your offboard wiring - something is very wrong if you get nothing in bypass as this should just create a connection straight from input to output. Your black battery lead should be 0V because it's a direct connection to ground. Pin 14 of each of the ICs should be seeing several volts, pin 7 should be zero.
Bringing you yesterday's technology tomorrow.

differo

Check that you have all jumpers installed, specially the little one in the middle.
My youtube channel:
http://www.youtube.com/user/BeToneful

Rebote2.5,MXR dist+,DrBoogie,BSIAB2,Ross Compressor&Phaser,MXR EnvFilt &Noise Gate,TS808,Condor CabSim,SansampGT2,Fraverb,Small Clone,TremLune,ValveCaster

JackLondon

I've checked all the wiring and it seems fine, this is the schem I followed for offboard wiring :



This is the pic :




There's no jumpers because the spaces are used for the dpdt switches for reverse sweep and filter range mod.

There's signal on C4 and R1 but it is very quiet, almost nothing at all.

differo

Have you tried the circuit before installing mods?
My youtube channel:
http://www.youtube.com/user/BeToneful

Rebote2.5,MXR dist+,DrBoogie,BSIAB2,Ross Compressor&Phaser,MXR EnvFilt &Noise Gate,TS808,Condor CabSim,SansampGT2,Fraverb,Small Clone,TremLune,ValveCaster

markeebee

Looks like your output jack is connected wrongly.  The output from the switch should go to tip, but instead it's connected to shield.

markeebee

Ooops, also looks like ring and shield of input are incorrect.

JackLondon

No, I haven't tried it before the mods, and I'm now thinking about the IC's because according to some build reports on tonepad the TI IC's don't work in this circuit and I believe my IC 3 is TI

markeebee


JackLondon

Quote from: markeebee on April 09, 2010, 08:38:40 AM
Really, check your jacks  :icon_wink:

Right I've checked my jacks ;) It's working when in bypass mode but still no audible signal when on :icon_rolleyes:

differo

If chips aren't fried (probably not but you never know:) ) you should hear almost bypass (clean) sound when effect is engaged even if (TI) chips are used which are not working (out of the box eh) with this circuit. Meaning, if everything else is correct, wiring, soldering, component values etc. you should be able to get signal through the circuit but no auto wah audible.
My youtube channel:
http://www.youtube.com/user/BeToneful

Rebote2.5,MXR dist+,DrBoogie,BSIAB2,Ross Compressor&Phaser,MXR EnvFilt &Noise Gate,TS808,Condor CabSim,SansampGT2,Fraverb,Small Clone,TremLune,ValveCaster

JackLondon

Right, I've changed the 4066 IC and now I get a signal (with a small volume drop) through the circuit but it's not wah wahing. Checked all the solder points etc and it seems that nothing is wrong. Any ideas where to look ? I can't change the 4069IC because the local shop didn't had them so I'll have to order some in...

differo

do a search on that volume drop, there is some resistor to be changed for that, don't recall myself, do you know the manufacturer for 4069 you have? IC2 is the one that is (sometimes) problematic.
My youtube channel:
http://www.youtube.com/user/BeToneful

Rebote2.5,MXR dist+,DrBoogie,BSIAB2,Ross Compressor&Phaser,MXR EnvFilt &Noise Gate,TS808,Condor CabSim,SansampGT2,Fraverb,Small Clone,TremLune,ValveCaster

JackLondon

I'm not sure about the manufacturer, will this pic help ? Both 4069 are the same



Cheers
Jack

differo

ok, not TI, thats good, and unbuffered also good, you don't need (I don't know this but a good guess) to fidle with it.
My youtube channel:
http://www.youtube.com/user/BeToneful

Rebote2.5,MXR dist+,DrBoogie,BSIAB2,Ross Compressor&Phaser,MXR EnvFilt &Noise Gate,TS808,Condor CabSim,SansampGT2,Fraverb,Small Clone,TremLune,ValveCaster

JackLondon

I just saw in members only are that you're in a similar boat to me :D Agua bloody filter eh?

Brymus

Have you tried E-mailing Fernando about this?
Since two of you are having similiar problems maybe its something he has already dealt with.
I'm no EE or even a tech,just a monkey with a soldering iron that can read,and follow instructions. ;D
My now defunct band http://www.facebook.com/TheZedLeppelinExperience

differo

Mine works now, but not with TI chip in pos2. I get the sound and everything but no autowah. I put a pot instead of that resistor (100K) close to ic2 as some sort of 'mod' - like that I can change the sweep range and/or starting point kinda nice. I have bunch of chips all work in all positions (besides pos2 where TI won't work) - some other guys have made this work somehow but I didn't have that luck (so far). 
My youtube channel:
http://www.youtube.com/user/BeToneful

Rebote2.5,MXR dist+,DrBoogie,BSIAB2,Ross Compressor&Phaser,MXR EnvFilt &Noise Gate,TS808,Condor CabSim,SansampGT2,Fraverb,Small Clone,TremLune,ValveCaster

JackLondon

I've ordered some new chips which should come in the next couple of days, I also had a chat with one of the boutique pedal makers and he suggested a few changes so I'll try them, in the meantime I've built rebote 2 which doesn't work either :(

Solidhex

Quote from: JackLondon on April 09, 2010, 08:56:23 AM
Quote from: markeebee on April 09, 2010, 08:38:40 AM
Really, check your jacks  :icon_wink:

Right I've checked my jacks ;) It's working when in bypass mode but still no audible signal when on :icon_rolleyes:

Did you just check them or did you rewire them? They were definitely wired wrong.

--Brad