Pots arent working

[MrMumbasa]

So i build a ts808, I got the board from tonepad and the parts from smallbear.
When the pedal is off the signal works perfectly but when i turn the pedal on the signal becomes very quiet and the pots aren't working. So pretty much its quited down and it seems as if the effect is not in going through at all.

Has anyone encountered this problem before?

[Jdansti]

Welcome to the forum!

It should work. It sounds like a a wiring, solder, or grounding problem. Could you please post photos of both sides of your board and of any off board components?  Also, please post the layout and bill of materials.

[MrMumbasa]

https://www.dropbox.com/s/gjrfylt0h1lw9ok/IMG_1693.JPG
https://www.dropbox.com/s/dahk2oyamzu6gtf/IMG_1694.JPG
https://www.dropbox.com/s/xjamp69gjet24cn/IMG_1695.JPG

I know the board looks pretty bad by where the pots connect but that happened cause i kept changing the pots back and forth and eventually that happened, and it was doing this same think before it looked that bad so its not it...
And i made sure that the pots are connected along the paths on the board so they should be fine.

But all the connections are correct from what i see and none of the other connections are touching so maybe its some component?

Here's the list of parts i got from Smallbear

IC RC4558P  (RC4558P)
Metal Film 6.8K To 39K <B>Individual</B>  (10K)
Metal Film 110 Ohms To 1K <B>Individual</B>  (1K)
240K to 1 Meg - Individual  (510K)
Metal Film 1.1K To 6.2K <B>Individual</B>  (4.7K)
Metal Film 43K To 220K <B>Individual</B>  (51K)
Metal Film 110 Ohms To 1K <B>Individual</B>  (220 Ohms)
Metal Film 240K To 2.2 Meg <B>Individual</B>  (2.2 Meg)
Capacitor, BC Components, 1 mf 63V  (BC Comp 1 mf 63V)
Capacitor, Topmay TCM07 5mm Box, .15 mf - .47 mf  (.22 mf)
Capacitor, Panasonic ECQ-V .01 mf. - .056 mf. <B>- Individual</B>  (.047 mf)
Capacitor, Panasonic ECQ-B (50V)/APEX (100V) 470 pf - .039 mf <B>- Individual</B>  (.0027 mF)
Capacitor, Electrolytic, Axial 16 V 1 mf. - 100 mf.  (47 mf.)
Polystyrene Capacitors, 100 pf - .01 mf  (.01 mf)
Xicon Ceramic Capacitors, 47 pf. to 820 pf.  (51 pf)
Capacitor, Electrolytic, Radial 16V 1 mf - 100 mf  (10 mf)
Alpha Single-Gang 24mm, Linear & Audio Taper, Solder Terms  (100K Linear)
Alpha Single-Gang 24mm, Linear & Audio Taper, Solder Terms  (25K Linear)
Alpha Single-Gang 24mm, Linear & Audio Taper, Solder Terms  (500K Audio)
Transistor 2N3904
Metal Film 10 Ohms To 100 Ohms <B>Individual</B>  (100 Ohms)
Diode 1N914  (1N914)


My guess is its probably the Capacitor, BC Components, 1 mf 63V  (BC Comp 1 mf 63V) I didn't think that the 63V would really matter but now that im looking at myself writing this im thinking that probably the issue... That was the only one that was 1 mf...

And here is the Tonepad page for it..
http://tonepad.com/project.asp?id=

[Jdansti]

Thanks for the pictures. The most likely reason for your problem is that you are relying on the metal box for a ground path to one of your 1/4" jacks.  The problem is your box has paint on the inside and outside which is insulating the jack, or at least giving you a poor connection to the metal box.

Attach a jumper between the ground lugs of your jacks and I'll bet your pedal works beautifully.  If not, we'll head down another path.

[MrMumbasa]

I checked with a multimeter and everything is grounded.

Also i did just add a jumper cable in between the two jacks just in case but it still does the same thing.

[Jdansti]

Ok. Here's the next step. Please check, record, and post the voltages of the transistors and IC as shown in this thread:
http://www.diystompboxes.com/smfforum/index.php?topic=91157.0

[Jdansti]

My guess is its probably the Capacitor, BC Components, 1 mf 63V  (BC Comp 1 mf 63V) I didn't think that the 63V would really matter but now that im looking at myself writing this im thinking that probably the issue... That was the only one that was 1 mf...

BTW- the voltage rating of the cap shouldn't matter as long as it is greater than the voltage that the cap sees. Since 63v is > 9v, you're ok. The rating just warns you not to exceed that voltage.

[MrMumbasa]

how do i check the voltage?


do i need to have a battery in?

and would i have to keep one of the connectors from the multimeter on ground all the time and check that way or how?

[Jdansti]

Make sure you know which leads are which on the IC and transistors. If necessary, search the web for data sheets for these parts which will show you the lead configurations.

Yes, connect the battery and make sure that the bypass switch is engaged so that the board has power. Set your meter to a range that would allow you to read 9VDC and then turn it on. Make sure you can get good readings by placing the negative probe on the negative battery terminal and the positive probe on the positive terminal. Make sure you read 8.0-9.6 VDC. If that looks good, place the negative probe on a ground point and use the positive probe to measure the voltages at the various points as shown on the DIY link I gave you.

BTW- Does the LED light up when you switch it on and turn off when you switch it off?

[MrMumbasa]

The LED lights up when i use a battery, but when i use the 9volt input the LED actually does not come on for some reason.

[MrMumbasa]

Battery voltage=8.11V
Voltage at the circuit board end of the red battery lead =8.07V
Voltage at the circuit board end of the black battery lead =0V

Q1 (2n3904)
C =8.01
B =2.80
E =2.26

Q2(2n3904)
C=8.00
B=2.81
E=2.22

IC1
P1 3.97
P2 3.94
P3 3.94
P4 0
P5 3.97
P6 3.95
P7 3.95
P8 7.98

D1
A (anode, the non-band end) =3.93
K (cathode, the banded end) =3.96

D2
A =3.96
K =3.72

D3
A =3.72
K =3.92

My battery is a little weak so that might be the reason for the low voltages.... but it seems like everything is fine right?

[Paul Marossy]

Looking at the picture of the back side of the PCB, my guess is a cold solder joint somewhere.

[Govmnt_Lacky]

After looking at your off-board wiring, here is my suggestion:

Disconnect ALL of your 3PDT, In/Out jacks, DC jack, and battery wiring.

Wire ALL of the above according to this diagram (USE DIAGRAM #5):

http://www.tonepad.com/getFile.asp?id=76

Good Luck

[MrMumbasa]

Looking at the picture of the back side of the PCB, my guess is a cold solder joint somewhere.

I just put fresh solder on all the components and still the same result.

After looking at your off-board wiring, here is my suggestion:

Disconnect ALL of your 3PDT, In/Out jacks, DC jack, and battery wiring.

Wire ALL of the above according to this diagram (USE DIAGRAM #5):

http://www.tonepad.com/getFile.asp?id=76

Good Luck

Ive tried that before and i got better results with this way of wiring, the tonepad one always gave me this sound as if its not grounded... but ill give it another shot.

[Govmnt_Lacky]

Ive tried that before and i got better results with this way of wiring, the tonepad one always gave me this sound as if its not grounded... but ill give it another shot.

That wiring method has been proven time and time again. It has been more than verified. If you wired your build EXACTLY like the link I posted and you still had problems then either you did not wire it exactly OR your problem is on the PCB somewhere.

I have used this off-board wiring dozens of times with no problems  

EDIT: Pay special attention to the wiring on the DC jack. If you do not wire that exactly as it looks in the diagram then you will have big power problems 

[Paul Marossy]

There's several places where it looks like you might have a solder bridge between pads. In other words it looks like you might have one or two places where connections are being made where they shouldn't be. A slight connection to ground on something in the audio path might almost kill your signal. Kinda sounds like what you are experiencing assuming everything else has been ruled out.

[Jdansti]

Ive tried that before and i got better results with this way of wiring, the tonepad one always gave me this sound as if its not grounded... but ill give it another shot.

That wiring method has been proven time and time again. It has been more than verified. If you wired your build EXACTLY like the link I posted and you still had problems then either you did not wire it exactly OR your problem is on the PCB somewhere.

I have used this off-board wiring dozens of times with no problems  

EDIT: Pay special attention to the wiring on the DC jack. If you do not wire that exactly as it looks in the diagram then you will have big power problems 

I agree. Something's not right if the LED doesn't light up when you just use the battery. 8v should be enough to do the job.  Were the readings above taken using the battery or PS?

Also, you might want to check for continuity between each pot lug and points on the board away from your solder joints to make sure each lug has a good connection.

+1 on the solder bridges. I use a magnifying loup to examine all of my solder joints. Watch for flux between the joints. It is shiny and looks like solder. I use alcohol and a tooth brush to clean the board and then inspect it with the loup.

[MrMumbasa]

so i rewired it to the tonepad way, same result as before. When i use the 9v input theres a horrible "ground" sound coming out of the amp.

the LED DOES work with the battery, it didnt work with the DC jack.

And it still makes the guitar signal quiet and the pots arent working... im thinking of just taking all the components off the board one more time and starting from scratch...

Hopefully this time itll work cause im losing hope pretty quickly with this pedal...

[Govmnt_Lacky]

the LED DOES work with the battery, it didnt work with the DC jack.

Are you ABSOLUTELY POSITIVE that you have the Battery snap RED wire going to the correct terminal on the DC jack? Take another look at the DC jack on the Tonepad link and verify. It sounds to me like you have your +9V hookups reversed on the DC jack.

If this is/was the case, then you may have fried some of the components on your PCB 

[Paul Marossy]

Look for solder bridges as I suggested a minute ago. That has happened to me more than once.