The little hole to the left of the SD card slot.

which is just visible with the stand closed.
I guess resting the tablet on a knee while seated actually is about the best configuration accoustically.

Ok... anyone know if we can plug in ditectly from an active pickup?
This would require a mini 4 pole jack with signal on 2rd ring, tip & 1st ring open circuit and 3rd ring ground.

Yes it will work, but you'll probably need to include a series resistor to prevent overloading/clipping the mic input. If I had to guess, I'd say 200K Ohm.

Get the 1/8" 4-conductor plug connector here:

http://www.mouser.com/Search/Refine.aspx?Ntt=171-7435


You want to feed the signal to #3:

C-Video out !!!???!!! What's this?

I presume that this diagram is a generic Nokia implimentation and not specific to the N810? (ie: we don't have video out - do we?)

Anyway, Thanks ST5150 for the Mouser link and confirmation. I'll try the 200k and see how it goes and plan to post back with any sucess. I imagine the value will depend upon the actual line level of the pickup output.

If anyone is interested and uses GVM I have attempted to attach a resistor calculator (which I installed on my Palm TX but have not yet tried on the N810).

Works great on my N800/diablo.

Yes the level will depend on the input line level. 100K was my first guess, but in reality even moderate-heavy clipping is okay when counting frequency, it doesn't change the frequency of the signal any as far as the N810 is concerned. Be sure to post pictures and your findings when you're done!

Instead of mouser, you can also cut up one of these:

http://www.dealextreme.com/details.dx/sku.7396 (~3 weeks to ship)

http://cgi.ebay.com/3-ft-Mini-AV-3-5...QQcmdZViewItem

http://cgi.ebay.com/3-Mini-AV-3-5mm-...QQcmdZViewItem

Thanks for the links. I like the male/male cord from eBay. It could be cut near one end to make two adapters. The long one gets a 1/4" male plug and would work where the tablet can sit close by. The short end would get a 1/4" socket soldered onto it. Then this short 'adapter' could be used with any length guitar cord to work in any situation.

Sounds good, glad I could help. Be sure to post your results when you finish this project!

This small project is to make a guitar tuner cord suitable to use with any guitar that has a pickup and the Tuner application (which now works with Diablo)

Here are the details of the cord I have made up.

I started with a 6ft A/V cable (4 conductor mini jack each end) from the same supplier as the 3ft one described in a previous post:

http://cgi.ebay.com/6-ft-Mini-AV-3-5...QQcmdZViewItem

$5.99 inc shipping.

Thanks st5150.

I cut off one end with plug (about 4") and saved for later use. I used the long piece to start with for most flexibility.

After checking for continuity I discovered that the red cable was all I needed. The cord has three individually screened wires. However note that the screen (ground) is not connected to the conventional position - ie: the fourth 'pin'. It is in fact connected to the THIRD 'pin'. The fourth 'pin' is signal in this case.

I soldered the screen and signal to a 1/4" with a 100k resistor in line on the siganl side to avoid distortion. However, this prooved to be too much reduction in my case. And actually, removing it completey gave the best result.

I prooved this by auditioning the feed through skype on another computer and determining the cleanest signal. No in line resistor was best.

Your pickup may be different and so you may or may not require a resistor. (Just make a temporary connection and try it out before finishing everything off)

So from there it was just a matter of carefully cutting back the other two screened wires (I checked all possible permutatiosn to ensure no other continuity), clamping the cable with the plug's grip and screwing the barrel onto the plug.

The shots below are during the process and the end result.

One disadvantage is that the N810 speakers are disabled when the plug is in the tablet so if you want to hear the reference tones from the keyboard, you have to unplug the cable.

While working with the setup I discovered a couple of things. I set my Ovation (which has an active pickup) to about mid volume for best results. You probably want to bypass any eq if you have that ability (mine doesn't)

Also, I found the tuner more reliable reading 12th fret harmonics. If your guitar has good intonation you can safely rely on this method but if not you should avoid harmonics and simply pick the open strings:

The following are the base frequencies (rounded to whole Hz) for each string but you may well get an even multiple as you tune. This is fine.

E2 = 82 Hz
A2 = 110 Hz
D3 = 147 Hz
G3 = 196 Hz
B3 = 247 Hz
E4 = 330 Hz

With care, I was able to tune to within 1hz for each string.

Hope this helps someone! Cheers!

Thanks for the update and the pictures. Glad it all worked out. The more I thought about it, the more I realized 100K was too big, but it shouldn't make much of a difference for counting frequency. Like I mentioned earlier, even severe clipping is fine. I'll be making a similar cable in the future.

If you want to keep the speakers working when you plug in the connector, you'll have to find a way to keep pin 1 from touching pin 6 in the picture I posted above. This can probably be done in software as well.