OT-ish: I'm in the market for a bit more lateral thinking

Only to say that musical instrument tuning is in itself almost a degree subject. Pianos tend to be tuned in an even (or is it equal ?) temperament meaning they are pretty evenly out of tune in all keys. However some instruments of the orchestra are fated to be tuned to a key.

I have forgotten more than I can remember :(

Ah - you mean equi-tempered vs diatonic. Yes, I know all about that - but that isn't the issue here. The digital piano uses equi-tempered tuning anyway - so that each octave is divided into 12 equal geometric steps of the 12th root of 2 and so that, for example, A# and Bb are the same note, but wouldn't be with diatonic tuning. There's nothing I can do about that - even if I wanted to.

In its default state, when you go up by an octave, the frequency doubles. But that isn't how *real* pianos are tuned - they are stretched at the ends in order to sound right. The digital piano has the option of simulating this stretching. That's what I want to measure in order to check whether it's actually doing anything.

So *all*(!) I need to do is to convert an electrical signal into a mechanical vibration with enough amplitude to trigger my tuning device.

Get a (free) app for your PC or smartphone - much easier than what you're proposing. Google is your friend.

One possibility is something like daqarta which will more or less do what you want out of the tin. Feed your electronic line out signal into the PCs sound line in or just use its microphone and you are away!

I have used it for various lectures involving sound and music.

The realtime display of the harmonic content is also fun if the instrument will do a large range of different voices.

The Martin Guitar tuner for Android is quite well thought of and is fun if you are a guitarist.

Now there's a useful bit of lateral thinking - thanks! I don't *have* to use my tuning device if an app on my phone will do instead.

Sure, I can Google for apps - but do you have any particular recommendations for something which will run on an Android phone or tablet?

Thanks - looks interesting.

Am I misunderstanding it, though, because it says that the displayed frequency range is from about 1000 Hz to 2500 Hz. That's nothing like enough to cover all the notes on a piano - particularly the ones at the extreme ends, which are the ones I'm interested in.

The tuner that I use (Korg) has a mono 1/4" jack input.

I have "gstrings" loaded on my Android Tablet. It give a frequency reading as well as showing what note is involved.

Dunno. I suspect that is what it happens to be set to in that example. I have never used that feature. It is new since I last used it.

I think it will do any frequency from 0.1Hz to around 20kHz limited by the input stage of the PC or microphone. Others have suggested an App for an Android - be interested in any recommendations there myself.

You need to register it after 30 days if you like it and want to keep on using it but it does a signal generator free and in perpetuity.

DaTunerLite and PitchLabPro are both excellent.

If its the same as mine its got a microphone too.

I discovered that I can "whistle" a pretty good sine wave at about 440Hz and its damn annoying to others. It was a challenge when someone with a scope said you couldn't whistle a sine wave and I did.

To drag this briefly back to DIY, I used gstrings to look for wall battens. Give the wall a thump, it shows the frequency spectrum, use that to try to work out if that's near to a batten or not. Listening alone couldn't spot a difference.

It kind of worked - a capacitive detector found them in 30 seconds, but it was vaguely useful while waiting a week for that to arrive.

Theo

Mine's only a cheap affair, costing a couple of quid on Ebay from the Far East. There's no electrical input - only mechanical vibration.

Thanks for the suggestion. I've installed it, but haven't yet managed to work out how it's supposed to work. In any event, it seems to be aimed mainly at guitars.

Thanks. I've installed DaTunerLite and it seems pretty good.

You need a loudspeaker big enough to support your device on its cone.

But I'd still need a sounding board - or something excited by the speaker - to which to clip the device. I tried clipping it onto the edge of a speaker so that part of the clip was in contact with the cone, but that didn't work.

In the event, I've more or less abandoned the idea of using the tuning device, in favour of phone apps. I'm currently trying out a couple of apps - DaTuner Lite and Piano Tuner - which are looking promising.