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DIY Stompboxes => Building your own stompbox => Topic started by: rbrenne on July 21, 2011, 02:15:36 AM

Title: Ruby Debugging Problem
Post by: rbrenne on July 21, 2011, 02:15:36 AM
Hi everyone.

I posted this somewhere else by mistake, and I'm sure this has been asked hundreds of times but I'm not sure what else to do...

I'm having a major problem debugging my Ruby amp I made using the ROG diagram.  I've been looking at the other topics, but can't seem to find a solution.  With everything connected I get a loud vibrating buzz from the speaker with no guitar signal coming through at all.  I've tripled checked the connections, looked for solder bridges, swapped my 100 cap with a 470, disconnected my LED thinking I may be overloading it. Nothing has been getting rid of the buzz and the volume and gain pots seem to control it.

Any other things I can try? I can't figure out why there is no guitar sound coming through at all. This is my first DIY so I'm pretty new to electronics.

Not sure if these pics will help, but hopefully an expert could catch a mistake somewhere.


<img "https://lh4.googleusercontent.com/-gv4HXN0qtEg/Tiet60dd81I/AAAAAAAAAEw/tklVCSJc4U8/s640/IMG_20110721_001733.jpg" /img>

<img "https://lh5.googleusercontent.com/-AppltjaZoYE/TiezAnOLCCI/AAAAAAAAAFI/9kAAvgA2rUY/s512/IMG_20110721_001745.jpg" /img>

<img "https://lh4.googleusercontent.com/-wKpTADf82K0/TiezYf-zJaI/AAAAAAAAAFY/UuIkBUjFXV8/s640/IMG_20110721_001754.jpg" /img>

<img "https://lh4.googleusercontent.com/-mj9BTtzsnjA/Tiezs_DlrtI/AAAAAAAAAFo/j5AuSN88z1g/s640/IMG_20110721_001810.jpg" /img>

<img "https://lh3.googleusercontent.com/-odPo2xBCPPQ/Tiez9Rxq7zI/AAAAAAAAAF4/xvq2_H2_8SY/s640/IMG_20110721_001917.jpg" /img>

Thanks!
Title: Re: Ruby Debugging Problem
Post by: petemoore on July 21, 2011, 08:35:14 AM
  Hum? what is the power supply?
   'Only Hum's ? Sounds like the circuit isn't yet working, debugging: What to do when it doesn't work thread illustrates the necessary debugging 'content', without voltages and reference information, debugging is either a quick-big hit :icon_smile:, or a miss that may hide any useful clues.
Title: Re: Ruby Debugging Problem
Post by: rbrenne on July 21, 2011, 02:07:00 PM
I'm using a 9 volt for the power. The hum is really loud, and I'm getting no guitar sound. The pots control the hum as well.
Title: Re: Ruby Debugging Problem
Post by: PRR on July 23, 2011, 12:22:21 AM
You have an un-connected ground somewhere.
Title: Re: Ruby Debugging Problem
Post by: askwho69 on July 23, 2011, 02:23:56 AM
Quote from: PRR on July 23, 2011, 12:22:21 AM
You have an un-connected ground somewhere.

+10000
Title: Re: Ruby Debugging Problem
Post by: rbrenne on July 23, 2011, 02:28:35 AM
I tried reworking it. Now I have no buzzing, but I can't get any output from the guitar.  All of my voltages seem to be correct when I checked with the multimeter, and when I turn the volume all the way up I can hear the light static of the speaker.

Does this still sound like a ground issue?

Thanks for the replies!
Title: Re: Ruby Debugging Problem
Post by: rbrenne on July 23, 2011, 04:36:36 PM
Did some more troubleshooting today and didn't get much change.  Does it sound like I have something incorrect with my input jack? Not sure why voltages would be correct and pots work speaker white noise, but no guitar signal at all.
Title: Re: Ruby Debugging Problem
Post by: Govmnt_Lacky on July 23, 2011, 04:44:15 PM
IC, transistor, polarized cap orientation?

Sounds like a problem I had with my ruby and discovered that I put the IC in backwards  :icon_redface:
Title: Re: Ruby Debugging Problem
Post by: PRR on October 06, 2011, 06:35:34 PM
> why voltages would be correct and pots work speaker white noise, but no guitar signal at all.

Signal is not getting from guitar to chip. Either not-connected somewhere or shorted-out somewhere.

Imagine you are an electron, coming off the end of the guitar cord. Is there a plausible complete path to the chip? Is there an easier path to ground, such as solder-wisp?

It can also be seen as rain from the roof to a rain-barrel. If the downspout is clogged, or broken, rain won't run to the barrel.