Tonepad Envelope Filter

[bilo01]

Hi, I'm a Noob here. I recently have build a rangemaster which came out great. I simply love this pedal.
Now i have been working on tonepads envelope filter. I have etched the pcb myself and after putting everything together i can get no sound at all. I really need some help debugging this.
Can anyone help me? Don't know where to start.

[bilo01]

I'll include some more info after reading the How to Debug post.
Here's the link to the Tonepad lay-out: http://www.tonepad.com/getFile.asp?id=113

and here a pic of the soldered PCB[http://i325.photobucket.com/albums/k397/philby01/PCBMXR-EF_zpsc8cfe768.jpg]
It's the third PCB i made for this project. Others didn't work ( I think because of solder bridges ) so i started all over.

I used all the mods. For the IC's i asked specificly to not give me TI's after reading about that problem. And i trusted the guy in the shop  ...
When i found that out I changed the 4069's in Philips HEF4069UBP and the 4066 in Motorola MC14066BCP.

Other changes I have made are R13 ( 240K ) into 270K because not available.
Reading earlier posts on tonepad i changed R1 (3K6) into 1K, R2 (200K) into 100K, R14 (62K) into 100K, C4 (0.1uF) into 0.047uF, and C2 (0.05uF) into 1uF.
According to the mods I changed R19 (200K) into 47K, added Ca1 and Ca2 (470pF) and changed C6 and C7 (0.001uF) into 560pF.

For the Pots I used 470K LIN instead of the described 500K Lin Pots.

When i plug it in on the adapter it gives no sound at all. With the reverse switch turned off it buzzes like a busy bee. Bypass works though when switching off.
On the (rechargeable ) battery - only 2,33 V when fully loaded, it gives a clean tone with severe volume drop, but no effects on the tone. To hear someting I have to turn the volume of my Kustom amp up to 3 oçlock.

I wired the pots according to the earlier posted scheme http://www.diystompboxes.com/smfforum/index.php?topic=103316.msg919930#msg919930

I will measure the values this afternoon when i get a new battery and post them. Don't know how to describe each pin of the resistors though.

Any help would be appreciated.
Thanx

[StephenGiles]

Number 1 - check that there are no solder bridges before you do anything.

[bilo01]

After looking very closely ... again.... there might be a bridge between D1 and D2 at the top end. The circuit combines the two so i thought it wouldn´t be that much of an issue. I´ll try to desolder and do it again. Thnx for making me look closer

[StephenGiles]

On the (rechargeable ) battery - only 2,33 V when fully loaded, it gives a clean tone with severe volume drop, but no effects on the tone. To hear someting I have to turn the volume of my Kustom amp up to 3 oçlock.

That may could be that the PWM signal applied to pins 6 & 12 of the 4066 is not what it wants to see for proper switching operation.

[duck_arse]

your soldering looks pretty good, you might need to clean your board a little more before you start though. steel wool will do, scotchbrite or similar, so it is bright shiny clean, the solder will take and flow quicker then. you must clip all the long leads off close to the board, they serve no purpose as they are. this will make seeing shorts a litle easier. if you have to cut through solder, you probably have too much on the joint.

can we see shots of the top of board as well?

[bilo01]

Thnx for the compliment on the soldering. It´s my 4th PCB and soldering ever lol.
I keep the cleaning in mind for the next project which i´m sure it will come, because i like this very much.

Here is the pic of the top:
[http://i325.photobucket.com/albums/k397/philby01/topPCBMXR-EF_zps20543789.jpg]

[bilo01]

I've redone the soldering of D1 and D2, put in a brand new battery. Result: no sound at all lol. Bypass still works

[PRR]

> Others didn't work ( I think because of solder bridges

Soldering can be like gitar-picking. Learn to play the first 124 notes of Smoke On the Stairway or other classic lick, *perfectly*. If you flub three times, the forth time may be better but there's probably some mis-fire in there. It probably takes a beginner dozens of practices to play a 124 note run.

This project has 124 solder points. And unlike a drunken audience, the electrons demand that EVERY joint be perfect or it will not work as expected.

> no sound at all. With the reverse switch turned off it buzzes

That's actually a MAJOR clue. BUt I don't understand it.

Let's check some basics.

Voltages at pins 14 and 7 of all three chips.

Voltage at IC1 pin 3.

[bilo01]

I totally agree PRR. That's how i learned to play anyway. Restarting after every mistake i made. Really don't pretend that i can solder.

And here are the points of the Dutch Jury 

IC1:
Pin 3 - 2.80 V
Pin 7 - 0 V
Pin 14 - 5,10 V

IC2:
Pin 7 - 0 V
Pin 14 - 5.06 V

IC3:
Pin 7 - 0V
Pin 14 - 5.05 V

Thanks for support
Will

[bilo01]

I totally agree PRR. That's how i learned to play anyway. Restarting after every mistake i made. Really don't pretend that i can solder.

And here are the points of the Dutch Jury 

IC1:
Pin 3 - 2.80 V
Pin 7 - 0 V
Pin 14 - 5,10 V

IC2:
Pin 7 - 0 V
Pin 14 - 5.06 V

IC3:
Pin 7 - 0V
Pin 14 - 5.05 V

Thanks for support
Will

[PRR]

> Pin 14 - 5,10 V

ALL-- has someone else built this thing?

We might expect pin 14 at battery voltage. But there is a 3K resistor between batt and all the supply pins. And CMOS in linear mode sucks current. I'm wondering if 5V is in the ballpark.

If the chip has 5V on 14 we might expect "half" at the signal-pin (pin 3). In fact CMOS center-point runs high. So 2.8V under 5V is probably peachy.

This may come down to signal-tracing. Even a 'scope, because there's a lot of hyper-sonic action.

[bilo01]

I guess you know the wright questions PRR. This is chinese to me. I'll calmly sit and wait.
Thanks again

[bilo01]

Waiting for more info i decided to measure the whole thing. It leaves me puzzled though. Too many 0V values.
I might do the notation wrong but here it is:

A=0
B=0
C=0
D=4.65 and counting down
E=0
F=0
G=0
H=0
I=0
J=0

So this part can't be right anyway

R1=0/0
R2=0/0
R3=1.20/0.34
R4=8.79/4.95
R5=2.82/2.77
R6=1.71/2.76
R7=2.55/2.78
R8=1.69/2.55
R9=0.38/3.67
R10=1.74/1.72
R11=2.79/2.76
R12=4.94/2.79
R13=2.79/2.79
R14=4.84/2.46
R15=0.61/1.74
R16=2.50/0
R17=2.47/4.91
R18=2.84/2.80
R19=2.73/2.84
R20=2.50/0
R21=0/0
R22=4.97/2.50
R23=4.48/4.51
R24=2.44/0.62
R25=0/0
R26=4.61/0

R27(Attack)
L=1.76 M=1.76 R=1.23
R28(Treshold)
L=2.80 M=2.80 R=2.80
9V=8.89

C1=4.52/1.20
C2=4.86/0
C3=2.52/0
C4=0/0
C5=2.75/2.32
C6=4.94/0
C7=4.05/0
C8=5.03/0
C9=2.49/4.92
C10=4.90/4.61
C11=0/4.91

Ground=0
In=0
Out=0

Ca1=4.94/0
Ca2=4.95/0

D1=2.32/4.92
D2=2.31/2.47

IC1:
1=0
2=4.90
3=2.78
4=2.81
5=0
6=2.76
7=0
8=4.93
9=0
10=2.76
11=2.75
12=2.73
13=1.68
14=4.91

IC2
1=2.46
2=4.75
3=4.75
4=0
5=0
6=4.89
7=0
8=0
9=4.61
10=4.55
11=0.34
12=1.73
13=0.61
14=4.87

IC3:
1=0
2=0
3=0
4=0
5=0
6=0
7=0
8=0
9=4.98
10=0
11=2.86
12=0
13=0
14=4.99

I'm not much of a wizzard but can tell something is seriously wrong.. but don't know what 
Maybe someone can enlighten me.

[duck_arse]

IC3 is a quad switch, only half being used. when the control is high, the switch is on, and whatever is at the left will appear at the right. as pin12 and pin6 are both low (0V, gnd), the switches are off, and left can be different from right. so don't worry about lots of nothing, sometimes it's right.

it seems yr ic1 and ic2 are doing vaugely what would be expected of them, but I'd need to breadboard the circuit before I had the slightest idea of what it does.

can we have slightly better, clearer pics of the topside, so we can read component values etc? and why the heatshrink on the wires at the board end?

[bilo01]

Thnx Duck,

I've tried to get some better pics.
Here they are:
[http://i325.photobucket.com/albums/k397/philby01/photo6_zpsc3697aa5.jpg]
[http://i325.photobucket.com/albums/k397/philby01/photo1_zps758da9eb.jpg]
[http://rs325.pbsrc.com/albums/k397/philby01/photo4_zps080a72a3.jpg~c100]
[http://i325.photobucket.com/albums/k397/philby01/photo2_zps7c0821dc.jpg]

If you have questions about what's on the caps let me know.
About the heathshrink on the board side: I've read somewhere it would be better, don't know where though.

Will

[bilo01]

Anyone has any idea?

[duck_arse]

I'll tyr and breadboard this tomorrow, see what is. those 22M resistors are a worry, though.

[Blitz Krieg]

I don't know if this has been suggested already, but you need a Solder Pump (solder sucker) or some Solder Wick.  But you don't really need to get solder wick, you can just use some stranded hookup wire.

The pads on your board should not have those big spikes.  The flux has burned off. 

Do not 'wipe' solder over the connections.  The solder should not come into 'direct' contact with the iron.  Place the iron on one side of the pad and the solder on the other.  The solder flows where there is sufficient heat.

Post some sound clips when you get it fixed.

[bilo01]

Thnx for the info Blitz. I do have and use the pump and desolder wire.
I soldered like you described by putting the iron between the pad and the pin on one side and the solder on the other touching pad and pin and then circling it halfway round, not touching the iron. I need to get experience however by keeping busy lol.

What is the best way for cutting the pins? After soldering or before? I did it after but maybe next time it's better to cut them first at 2 mill from the board