Tuning a "toy" keyboard

Professional audio recording and studio engineering, post #46,692
Author:
Date:
Subject:
 Karl Engel
 2008-07-21 11:05:44
 Tuning a "toy" keyboard
I have a little keyboard, pretty much a toy, that I sometimes use for
working out a melody or a harmony, just because it's very small,
battery-powered & much easier to grab & switch on than my MIDI connected
keyboard - which might not be connected or hooked up to a
sampler/module/softsynth/monitors/music computer at any given time.

According to my tuner it's pitch is a little sharp though, both on batteries
and AC - any realistic way to adjust this? There've been times when I've
used it to give me a pitching reference (starting note) when singing a
harmony - would be nice to know it's accurate even if I'm not! I've also
used it's cheap little 8 bit piano sound through distortion to give me a
great overdriven guitar-like sound in some projects, works better than my
"real" piano sounds for this, but I've always been aware it was a little out
of tune.

It's called a Concertmate 470, at least a decade old.
Author:
Date:
Subject:
 Richard Crowley
 2008-07-20 20:27:04
 Re: Tuning a "toy" keyboard
"Karl Engel" wrote ...
>I have a little keyboard, pretty much a toy, that I sometimes use for
>working out a melody or a harmony, just because it's very small,
>battery-powered & much easier to grab & switch on than my MIDI connected
>keyboard - which might not be connected or hooked up to a
>sampler/module/softsynth/monitors/music computer at any given time.
>
> According to my tuner it's pitch is a little sharp though, both on
> batteries and AC - any realistic way to adjust this? There've been times
> when I've used it to give me a pitching reference (starting note) when
> singing a harmony - would be nice to know it's accurate even if I'm not!
> I've also used it's cheap little 8 bit piano sound through distortion to
> give me a great overdriven guitar-like sound in some projects, works
> better than my "real" piano sounds for this, but I've always been aware it
> was a little out of tune.
>
> It's called a Concertmate 470, at least a decade old.

The only likely method would be to locate the crystal that "times"
the electronic circuits, and experiment with putting very small-value
(< 10 pF) capacitors (or a rotary trimmer capacitor) across the crystal
to "slow" it down slightly. However, I'd bet that the result wouldn't
come close to being worth the effort required.
Author:
Date:
Subject:
 Soundhaspriority
 2008-07-21 01:25:39
 Re: Tuning a "toy" keyboard
"Richard Crowley" <[email protected]> wrote in message
news:JNSdnbLWa8KRnxnVnZ2dnUVZ_hKdnZ2d@posted.pcez...
> "Karl Engel" wrote ...
>>I have a little keyboard, pretty much a toy, that I sometimes use for
>>working out a melody or a harmony, just because it's very small,
>>battery-powered & much easier to grab & switch on than my MIDI connected
>>keyboard - which might not be connected or hooked up to a
>>sampler/module/softsynth/monitors/music computer at any given time.
>>
>> According to my tuner it's pitch is a little sharp though, both on
>> batteries and AC - any realistic way to adjust this? There've been times
>> when I've used it to give me a pitching reference (starting note) when
>> singing a harmony - would be nice to know it's accurate even if I'm not!
>> I've also used it's cheap little 8 bit piano sound through distortion to
>> give me a great overdriven guitar-like sound in some projects, works
>> better than my "real" piano sounds for this, but I've always been aware
>> it was a little out of tune.
>>
>> It's called a Concertmate 470, at least a decade old.
>
> The only likely method would be to locate the crystal that "times"
> the electronic circuits, and experiment with putting very small-value
> (< 10 pF) capacitors (or a rotary trimmer capacitor) across the crystal
> to "slow" it down slightly. However, I'd bet that the result wouldn't
> come close to being worth the effort required.
I wonder if:

a. It uses a crystal at all.

Or, if it uses a crystal,

b. whether Karl is comparing it to a tempered scale.

Bob Morein
(310) 237-6511
Author:
Date:
Subject:
 Richard Crowley
 2008-07-20 23:36:31
 Re: Tuning a "toy" keyboard
"Soundhaspriority" wrote ...
> "Richard Crowley" wrote ...
>> "Karl Engel" wrote ...
>>>I have a little keyboard, pretty much a toy, that I sometimes use for
>>>working out a melody or a harmony, just because it's very small,
>>>battery-powered & much easier to grab & switch on than my MIDI connected
>>>keyboard - which might not be connected or hooked up to a
>>>sampler/module/softsynth/monitors/music computer at any given time.
>>>
>>> According to my tuner it's pitch is a little sharp though, both on
>>> batteries and AC - any realistic way to adjust this? There've been
>>> times when I've used it to give me a pitching reference (starting note)
>>> when singing a harmony - would be nice to know it's accurate even if I'm
>>> not! I've also used it's cheap little 8 bit piano sound through
>>> distortion to give me a great overdriven guitar-like sound in some
>>> projects, works better than my "real" piano sounds for this, but I've
>>> always been aware it was a little out of tune.
>>>
>>> It's called a Concertmate 470, at least a decade old.
>>
>> The only likely method would be to locate the crystal that "times"
>> the electronic circuits, and experiment with putting very small-value
>> (< 10 pF) capacitors (or a rotary trimmer capacitor) across the crystal
>> to "slow" it down slightly. However, I'd bet that the result wouldn't
>> come close to being worth the effort required.
> I wonder if:
>
> a. It uses a crystal at all.

If it doesn't use a crystal, then it uses a ceramic resonator
or an L/C resonant circuit or an R/C resonant circuit, etc.

In all cases, adding a slight amount of capacitance will
reduce the operating frequency (which presumably controls
the frequency of the various tempered scale pitches, etc.)

> Or, if it uses a crystal,
>
> b. whether Karl is comparing it to a tempered scale.

He didn't say whether all notes were uniformly sharp, or
if some notes were closer than others.

But in any case, the patient doesn't seem worthy of the
cure.
Author:
Date:
Subject:
 Soundhaspriority
 2008-07-21 03:00:10
 Re: Tuning a "toy" keyboard
"Richard Crowley" <[email protected]> wrote in message
news:Tb2dnQyOjNzssxnVnZ2dnUVZ_uudnZ2d@posted.pcez...
> "Soundhaspriority" wrote ...
>> "Richard Crowley" wrote ...
>>> "Karl Engel" wrote ...
[snip]
>
> But in any case, the patient doesn't seem worthy of the
> cure.
I hope you're not suggesting Karl should accelerate it to the speed
necessary to create the appropriate Doppler shift.

Bob Morein
(310) 237-6511