To whom this may concern,
I am presently involved in a solo project to design a tuning device for a musical instrument such as a chromatic tuner for all 12 notes! There is a slight urgency for the completion of this project which i must have complete by 12th March. Can you help? Could you give me a design for a simple tuning device? I need to know what IC's to use and it’s specifications! I am aware I need Band pass filters to match the Frequency comparator and a oscillating crystal as a reference for the frequency comparator. Can you help in the design of it?
Best regards

__________________
P A U L .

 

How accurate do you have to be? A 567 PLL IC can be set for narrow bandwidth and with 12 selectable capacitors, each tone can be measured.

__________________
see my website: www.geocities.com/russlk

 

There was such a device described in one of the electronices magazines a year or three ago. It may have been the Australian Silicon Chip.

See their web site www.siliconchip.com.au if you find the reference, send me a PM and I will see if I have it (I have at least 2 years of them in my collection plus some Electronics Worlds and some EPEs). If so, I'll scan it for you

Len

 

didn't epe do one as well?

 

Yes they did, it used a PIC!.

Obviously this is for a school project, so cost isn't an issue, but commercial ones are really cheap - I've just bought my daughter a new one for her bass guitar, a Seiko that cost about £20 - her old one wouldn't tune to 'drop D', whatever that is?. The old one came free with the bass, but they only cost about £10.

 

just for the interest value

the best tuners i have come accross are the Korg (synthesizer manfs.) models - bout £12-£20 - full chromatic tuner, 4 octaves - with built in mic and guitar input (am i sounding like a tv ad?)

N.B. - I use mine for tuning my trumpet, and couldn't do without the LCD 'needle' display (the 'needle' moves one way or the other, to indicate flat or sharp, and by how much, similar to the display on an analogue ammeter). I find that the how much part is indispensible - i don't know if you might want to consider including something along those lines?

just a thought

Tim

 

They all seem to use an LCD needle, but (being nosey) how do you tune a trumpet? - I didn't realise they had tuning adjustments (mind you, I've never played one!).

 

well, on one of several bendy bit of 'pipe' (!) on a trumpet, there is a slide, which can be pulled in or out, to make the overall length of tube in the trumpet longer or shorter - the longer the tube, the lower the note

just to confuse things, each of the three valves has its own tuning slide, so that individual valves can be tuned whilst playing (certain notes are naturally out of tune) :?

Tim

Attached Thumbnails

 

 

Cool :lol:

You learn something new every day :!:

 

Thanks for the replies from everyone ,
but i was hoping for more of a intricit analysis of the electronic components and parts required, and their functions, for this device . eg. i know i have a condenser mic that transforms the sound into a a.c. output which is amplified and filtered through a band-pass filter (actice filter maybe, i'm not entirely sure!) this then goes into a PLL IC (probably a 565 (linear) PLL!) to give a d.c. output the reference signal, which seems to have a quartz crystal oscillator going in as well but the reference frequency from the crystal needs to be say concert A=440Hz and quartz crystals generally vibrate at 20MHz so how do i use that? i think i need a frequency comparator a frequency synthesizer so maybe TWO PLL's then the output drives a dial (analog as i don't want digital programming to complicate the overall design!) indicating the pitch being sharp or flat and LED's indicating the note (it's for a violin so there are only the four notes G=? , D=? , A=440Hz and E=? )! :?:
Best regards,

__________________
P A U L .

 

hi

don't really know the answers, but -

any note will not be one frequency - there will be many other frequencies in there aswell (called harmonics)

frequencys are divided by 2 octave-wise. e.g. concert A=440Hz, 'A' one octave below that=220Hz, 'A' one octave above=880Hz - best to look on the net for the exact frequencies - i don't think they are spot on whole numbers, but i'm not sure.

again, i'm not really sure about any of this, but it may give you something to think about :?

Tim

 

Tim,
thank you but i already know this, which is why i have placed a band pass filter at the output of the external mic whch acts to delete the harmonics from the sound then the PLL fixes on the one frequency/the main one!

__________________
P A U L .