ProCo Rat not working

[dgargett95]

Hi,
This is my first post on this forum. I'm having a problem (A BIG ONE) with my 'ProCo Rat w/ mods' circuit.

This is the layout I followed: http://www.sabrotone.com/wp-content/uploads/2010/04/ProCo-Rat-vero.gif
I copied it exactly and the only substitutions made were with D1 which I changed from 1N4001 to 1N4004. Also there was one capacitor that I had to make slightly higher (because there was none of that value) but I forget which one.

The problem is that it makes a tick tick tick noise and a slightly synthy sound when in a certain position on the distortion knob. The filter knob doesn't change anything, the volume works. The pedal doesn't actually do anything to the guitar, except when the strings are hit hard, but it isn't a good sound. Bypass works great though...

I also made sure the LM308 and transistors were all facing the right way.

All is shown in this short video I made:

I also just attempted measuring the voltages of some of the parts. I don't know if I did it right, because it was my first time. Here they are (the knob on the multimeter was set to '20')

Q1(2n5458)
D: 5.1
S: 1.49
G: 0

Q2(IRF520)
S: 0
D: 0
G: 0

Q3(IRF520)
S: 0
D: 0
G: 0

IC1(LM308)
1: 4.1
2: 2.39
3: 0.61
4: 0
5: 0
6: 2.35
7: 4.72
8: 2.44

D1(1N4004)
A=0
K=4.7

D2(1N914)
A=0
K= Changes for every turn of mod switch

D3(1N914)
A= Changes for every turn of the mod switch
K=-0.8

D6(1N34A)
A=0
K= -0.08

D7(1N34A)
A= Starts on -0.14 and continues going up.
K= Keeps changing

D4(LED)
Positive= 0
Negative= Keeps changing.

D5(LED)
Positive= 0.18
Negative= 0

If I did it right, all the zeroes don't look good!!!

I also tried to take some close-ups as well if it helps.

Thank you for your help, I hope I can get it working because it's for an electronics assignment at school

Cheers,
Daniel

[dgargett95]

I don't think the close-ups are working
Here they are:

[lopsided]

Hey,

i am no expert in debugging. But at first glance your supply voltage seems to be very low. Q1 drain should go directly to 9+ and yours has only 5V, supply pin 7 for the opamp is also too low to work fine.
When you measure your battery disconnected does it give you normal or low voltage?
If low - change the battery. If normal look for shorts or cold joints around the supply strips.

Also, you do not happen to have the schematic with the mods? It is a lot of easier to figure out what is going on on a schematic then on a vero layout.

[lopsided]

Also, on more general level. The first think I do, when my vero build doesn't work the way it is supposed to, is take a scalpel and cut between all the strips, and re-cut all the cuts on the layout to make sure there are no accidental shorts.

[twabelljr]

A picture of the bottom of the board will help also.

[dgargett95]

Unfortunately, there was no schematic on the website 
And I tried cutting all the traces and it still doesn't work.
Battery I used measured 8.18v.
Here's the bottom of the board:



Hopefully somebody will know a solution.
Thanks

[lopsided]

Unfortunately I don't know
from what you have posted do not worry much  about the voltages on Q2 and Q3 they are there just as a clipping option, when you have the switch on position 3.
Something is clearly loading down you're supply voltage so the opamp can not operate right. A short somewhere is still a biggest suspect, but I can not give a tip , where to look for it.
Hopefully somebody can.

[stringsthings]

This is my first post on this forum. I'm having a problem (A BIG ONE) with my 'ProCo Rat w/ mods' circuit ...


... Thank you for your help, I hope I can get it working because it's for an electronics assignment at school

welcome to the forum ... is this your first circuit build?  ... and when is your assignment due?

[Scruffie]

I'd definitley reccomend reflowing the joints on that board for a start...

[Govmnt_Lacky]

I cannot get to the link for the schematic/layout but....

What is the deal with the two TO-220 transistors 

I have never seen a "signal" transistor used for pedal building purposes in a TO-220 package.

[Scruffie]

I cannot get to the link for the schematic/layout but....

What is the deal with the two TO-220 transistors 

I have never seen a "signal" transistor used for pedal building purposes in a TO-220 package.

They're MOSFETs being used as clipping diodes I presume.

[LucifersTrip]

I cannot get to the link for the schematic/layout but....

What is the deal with the two TO-220 transistors 

I have never seen a "signal" transistor used for pedal building purposes in a TO-220 package.

I've used em in Fuzz Faces...#84
http://www.luciferstrip.com/fuzz/sale6.jpg

[dgargett95]

Thanks for the replies 

Stringsthings- Thanks, no it isn't my first circuit, but it is my most complex yet. So far, I've built a BSIABII from a GGG kit, 2 bazz fuss', a ruby 9v amp and a stratoblaster boost. My electronics teacher is pretty cruisy and says to just hand in projects for marking whenever you finish them. More projects completed = more marks.

Scruffie- Thanks for the suggestion, reflowing just means to heat up the solder again, doesn't it?   

Thanks

[Scruffie]

Thanks for the replies 

Stringsthings- Thanks, no it isn't my first circuit, but it is my most complex yet. So far, I've built a BSIABII from a GGG kit, 2 bazz fuss', a ruby 9v amp and a stratoblaster boost. My electronics teacher is pretty cruisy and says to just hand in projects for marking whenever you finish them. More projects completed = more marks.

Scruffie- Thanks for the suggestion, reflowing just means to heat up the solder again, doesn't it?   

Thanks

Heat it up, let the solder melt and flow around the joints, add more solder if necessary to get a good, clean, shiny joint on each pin

[dgargett95]

Ok, I'll give that a go.
Cheers 

[dgargett95]

I just tried the reflowing, and it's still doing the same thing 
Nothing has changed. Maybe one of the parts aren't working or something???

Any other suggestions?

[lopsided]

I am pretty much clueless, but still think that something is pulling down your supply voltage.
One more think I have noticed: I can not tell from the photo, have you socketed the IC?
I am not hundred percent sure but if not, the jumpers underneath it could maybe cause problems.
I would advise to check one more time your circuit against the layout, make sure all the values are correct.
If this does not help, I would unsolder the IC and solder an IC socket in. This way you isolate the jumpers from the chip and also make it easy to swap between chips to check one is not defect (which is rather unlikely).
If this doesn't help also maybe check the voltage of pin 7 on the socket with the chip out and send if it differs from when the chip is in.

[dgargett95]

I am pretty much clueless, but still think that something is pulling down your supply voltage.
One more think I have noticed: I can not tell from the photo, have you socketed the IC?
I am not hundred percent sure but if not, the jumpers underneath it could maybe cause problems.
I would advise to check one more time your circuit against the layout, make sure all the values are correct.
If this does not help, I would unsolder the IC and solder an IC socket in. This way you isolate the jumpers from the chip and also make it easy to swap between chips to check one is not defect (which is rather unlikely).
If this doesn't help also maybe check the voltage of pin 7 on the socket with the chip out and send if it differs from when the chip is in.

No the chip is not socketed, so I'll try that. Thanks

[thedefog]

Check your resistor values again. Make sure that R8 isn't like 4k7 or 470R instead of 47R. Trace the path of the 9+ supply and see if you can isolate where it is dipping down.

[dgargett95]

Found a socket from an old organ and desoldered it from there. Then I desoldered the ic chip from the rat. After I put the socket in and attached the ic chip again, it still does the same thing 

The resistor values are right, but how do you trace the +9v to see if it dips down?

Thanks for any further suggestions...