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Analogue Section Reference Voltages
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Analogue Section Reference Voltages

by quango on Sun Aug 30, 2009 8:07 am


As I'm trying to troubleshoot my 2nd x0x i thought i would map out the voltages on my other working x0x as a reference. I've done this as a new layer in the Freeware Eagle Layout 5.6 software over the ladyada Eagle mainboard layout.

Here's the modified file to load into Eagle layout
(62.9 KiB) Downloaded 1258 times

As I'm a total novice myself someone may want to go over this file to OK it but hopefully its fairly accurate. I set every working x0x dial to 0 except for Cutoff which was at about the 2o'clock position.

If you spot any glaring errors please pm me or post here.

I've noticed depending if you hit keyboard buttons when testing voltages this can alter volts drastically in the vco IC's and therefore other parts of the VCO. I believe I had my x0x in keyboard and pressed C to get 2.0V
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Re: Analogue Section Reference Voltages

by reedlaw on Tue Sep 08, 2009 11:19 pm

Wow, this is awesome. It will help me a lot. I'm working on my 2nd x0x as well and I need this to troubleshoot. Thanks for the great work! :D
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Re: Analogue Section Reference Voltages

by mome rath on Thu Oct 08, 2009 8:39 pm


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My Xoxbox with Noisy Output

by Gorx on Mon Mar 01, 2010 5:47 pm

I have done some measuring of volts starting from J4 working my way up and found out that my xoxbox has 0 Volts at D25. Is there a switch I didn't turn right?

I suspected Q24, Q25, Q8 or Q27 could be faulty(?) but that's not the case, I changed Q24 and Q25, and swapped Q8 and Q27... nothing improved.

D25 @ 0Volts anyone...???
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Re: Analogue Section Reference Voltages

by MartinDidymus on Sun Oct 31, 2010 7:24 pm

I have uploaded a png file for anyone without Eagle software.

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Re: Analogue Section Reference Voltages

by ClockLoop on Thu Feb 03, 2011 7:22 am


VERY useful, thank you.

(this helped me find a 1 meg resistor that was swapped with another resistor of incorrect value.)


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Re: Analogue Section Reference Voltages

by rarara on Wed Feb 27, 2013 1:03 pm

is anyone able to flip the .brd supplied above??? i am following the doc and testing my voltages but doing it from the faceplate side for ease. would be much better if the board was flipped, but can't seem to do it with the (freeware) version of Eagle.

anyone help?? :(
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Re: Analogue Section Reference Voltages

by mattittam on Thu Feb 20, 2014 1:19 pm

thank you so much!!!
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Re: Analogue Section Reference Voltages

by Chris72160 on Wed Dec 16, 2015 7:37 am

Thank you. Great!

Are anywhere the reference voltages for the io-board available, too?

Greetz Chris
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Please be positive and constructive with your questions and comments.