Issues with Proco Rat build

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Issues with Proco Rat build

Young Gun
Hi all,

This is my 1st (well 2nd) attempt at building a DIY stomp box so please bear with me :)

I am having issues with this build http://tagboardeffects.blogspot.co.za/2012/01/proco-rat.html. As I mentioned, its the 2nd time i've built it both with the same result, no audio whatsoever. Here are the top and bottom pics:







I live in South Africa so getting the recommended transistor (2N5458) is not easy however I replaced it with 2N5459 which after some reading I discovered it wouldn't be the same but should still work. I can order them but it'll take about a month to arrive. For the original build I used polyester caps but decided to try ceramics to see if I would have any better luck. Turns out no :D

I build and design studios for a living so I am  no newbie when it comes to a soldering iron however this is my 1st foray into electronics so I am learning. Its why I decided to try out this hobby :)


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Re: Issues with Proco Rat build

PMowdes

Your Ic voltages are all wrong, you should have 9v at pin 8, and around 4.5v at the others except pin 4 (gnd)

I'll have a proper look when I get to my laptop
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Re: Issues with Proco Rat build

Young Gun
Yeah something's not right 😕 Thanks for taking the tome
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Re: Issues with Proco Rat build

PMowdes
Here's the schematic, this is usually a good place to start when debugging

Looks like you should have 9v at pin 7 (not pin 8 like i previously said) and pin 4 is  gnd

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Re: Issues with Proco Rat build

ξεναγος νεκροπολης
i believe that this is not the right ic....!!!
this is a lm3080!!!you need a lm308...!!!
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Re: Issues with Proco Rat build

ξεναγος νεκροπολης
other than that, i can't see anything wrong...your soldering is great!
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Re: Issues with Proco Rat build

PMowdes
In reply to this post by ξεναγος νεκροπολης

Missed that!

you could try substituting for something else

Here's a good article about all of the different IC options

http://tonereport.com/blogs/tone-tips/the-great-rat-race-a-study-in-sound-on-the-pro-co-rat
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Re: Issues with Proco Rat build

Young Gun
Thanks guys! :)
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Re: Issues with Proco Rat build

Young Gun
In reply to this post by PMowdes
Been away working so I can only finally get back to this now! Thanks for the article (very interesting!) and taking the time to check the circuit! I'll need to order one that works as per the article! What are the odds of buying one that's numbering is almost the exact same but just doesn't work? 😂

Anyways, I'll start maybe working on a Big Muff while I'm waiting for the IC's to arrive! I'll keep you updated!
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Re: Issues with Proco Rat build

heuermh
> What are the odds of buying one that's numbering is almost the exact same but just doesn't work?

Ah, but what if with the wrong IC you stumbled upon the greatest sound ever?  Could happen
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Re: Issues with Proco Rat build

Ciaran Haslett
In reply to this post by Young Gun
On the upside...if you ever decide to build an old skool compressor..you're sorted
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Re: Issues with Proco Rat build

Young Gun
In reply to this post by PMowdes
Well this came in more handy than I thought! Living in South Africa, some components are just hard to get and the LM308 falls into that category. I can import it but it has to be in bulk

So For a quarter of the price I purchased the rest of the IC's
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Re: Issues with Proco Rat build

Young Gun
Well it's up and running :) thanks all for the help!

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