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Projects => Tech Help - Projects Page => Topic started by: cab_eleven on April 29, 2011, 01:17:01 PM

Title: New version Snarkdoodle: no od/fuzz
Post by: cab_eleven on April 29, 2011, 01:17:01 PM
As it stands now, it is not jumpered and I get bypass, LED lights up but no sweet tubey fuzzy sound engaged. I have tried 3 ICs, one which was socketed in a working build and 2 new ones. I haven't had the chance to really troubleshoot it yet, I am just sitting at work board and obsessing about it until 5. So, I thought i would post and see if it was a simple jumper, which I doubt. Thanks for any help in advance.
Title: Re: New version snarkdoodle, jumper r7 if doing llama specs?
Post by: madbean on April 29, 2011, 01:43:51 PM
For the Red Llama you need to jumper two pads since you are not using a switch. The are pads 2 and 1 of the boost switch which are the middle and right pads. The left-most one remains unconnected.

Sorry, I forgot to mention this in the build doc.
Title: Re: New version snarkdoodle, jumper r7 if doing llama specs?
Post by: cab_eleven on April 29, 2011, 01:55:48 PM
Awesome. I was hoping for that, thanks for the speedy reply.
Title: Re: New version snarkdoodle, jumper r7 if doing llama specs?
Post by: cab_eleven on May 01, 2011, 09:09:03 PM
(http://i20.photobucket.com/albums/b204/cab_eleven/IMAG0066.jpg)
(http://i20.photobucket.com/albums/b204/cab_eleven/IMAG0065.jpg)
(http://i20.photobucket.com/albums/b204/cab_eleven/IMAG0067.jpg)
(http://i20.photobucket.com/albums/b204/cab_eleven/IMAG0068.jpg)

These are the best pics I can get at the moment.

I have sound now that the jumpers are in place, volume knob works, but there is little to no gain. Gain knob does nothing, have tried several ICs, same with all. I also tried another gain pot.

Title: Re: New version Snarkdoodle: no od/fuzz
Post by: cab_eleven on May 02, 2011, 02:03:37 AM
Ok, I noticed that I had a 1k in r5 instead of a 100r. Swapped that out and now I just get an oscillation that sounds kinda like an old 8bit Nintendo machine gun. Gain pot will change the pitch.
Title: Re: New version Snarkdoodle: no od/fuzz
Post by: jkokura on May 02, 2011, 03:41:14 AM
I think it was supposed to be a 1K according to the docs.

Jacob
Title: Re: New version Snarkdoodle: no od/fuzz
Post by: jkokura on May 02, 2011, 03:46:40 AM
Also, I think you need to back up and get some power readings for us, which will help us debug with you.

What's your voltage at your power source?
What's your voltage at the 9V in on the board?
What's your voltage at the GND on the board?
What's the voltage on each of the pins of the IC?

Also, it's hard to read - are you SURE you've got the right IC?

Jacob
Title: Re: New version Snarkdoodle: no od/fuzz
Post by: cab_eleven on May 03, 2011, 12:29:15 AM
The chip is a cd4049ube, I replaced the resistor back to the correct 1k, the voltages are:
Source, 9.47
9v @ board, 9.47
Grnd, 0
P1, 6.5
P2, 3.5
P3, 2.8
P4, 2.2
P5, 3.5
P6, 6.5
P7, 0
P8, 0
P9, .8
P10, OL
P11, 0
P12, .9
P13, OL
P14, 0
P15, OL
P16, 0

Those look odd to me, but I have no idea what they should look like.