Function Generator. Shot in the dark

[Kipper4]

Say guys is it a stupid idea to want to have a function generator that spans the notes played on a bass and guitar but delivers periodic bursts of sound at the same amplitude as the instruments and maybe up to 2v pp?
Doable in diy or pie in the sky shot in the dark?
Thoughts please.

[duck_arse]

you mean a tone burst generator, like they used to use to test loudspeakers? you can make them yourself (the ETI124 is the one I built), and you feed it your signal, it then counts cycles of input (switch selectable) and allows output or blanks output. easy peasy.

if you wanted it to decay like a decaying signal, that's a different kettle of kippers. do-able, tho.

[sajy_ho]

I'm using my android phone as function generator and it can goes down to 20Hz that I can't hear but my voltmeter apparently can:
https://play.google.com/store/apps/details?id=com.keuwl.functiongenerator&hl=en
To get 1V p-p I would use a LM386 to amplify the headphone out.

[slacker]

There's R.G's fake guitar http://www.diystompboxes.com/smfforum/index.php?topic=85408.0 which generates single string like plucking sounds, the frequency is fixed but can be made variable by switching in different capacitor values. Or you could look at Merlin's signal generator http://www.valvewizard.co.uk/siggen.html if you ran that through a trem you'd get period bursts.

I would just use my computer though, something like Audacity [url]http://www.audacityteam.org/[/url can generate a variety of tones, if you want something portable you could just save a different sounds as mp3s and whack them on a cheap mp3 player or old smart phone. In fact you can probably get signal generator apps for smart phones and tablets.

[R.G.]

Say guys is it a stupid idea to want to have a function generator that spans the notes played on a bass and guitar but delivers periodic bursts of sound at the same amplitude as the instruments and maybe up to 2v pp?
Doable in diy or pie in the sky shot in the dark?
Thoughts please.

Works fine. Back in 2010 I posted my design for a "fake guitar' oscillator that blangs out note-ish looking signals on geofex.com.

See http://www.geofex.com/FX_images/Fake%20Guitar%20Oscillator.pdf

It's not exactly what you described, but remarkably close and used in the same way.

AAAAAND I can't type fast enough. Slacker beat me to it.   

[robthequiet]

Thanks for putting this out -- I was thinking along these lines to make a poor man's impulse response tool that could add some transients (transience?) to a guitar pick attack, by itself useless, but when combined with some reverb would add some atmospherics to mimic a room or cabinet. Or goat calls, as it were...

[Kipper4]

Thanks guys.

[vigilante397]

I bought a function generator on eBay a few months back. It was about $35 shipped if I remember right. Chinese made, pretty cheap construction, but I checked it with my oscilloscope and it's legit. Has adjustable output voltage, adjustable frequency from 1Hz to 2MHz if I recall, and does sine, triangle, and square wave.

In other words WAAAAYYYY more than I will ever need, but well worth the $35

EDIT: Just dug through my eBay history and my memory was a bit off, it was actually about $60. Whoops

[bluebunny]

It was about $35 shipped if I remember right.
:
:
:
EDIT: Just dug through my eBay history and my memory was a bit off, it was actually about $60. Whoops

You owe us all twenty-five bucks.   

[Rixen]

how about recording a wave file of the signal you wish to experiment with ? I used recordings of a couple of chords I could inject into effects..

There are a number of oscilloscope and function generator apps for smartphones too

[anotherjim]

One of these?

An older model - cheap from e-bay? Although I see they hold price pretty well. Some are going for what I paid for my 404 new about 6 years ago (I got it for am-dram sound fx)!

OK, it looks like, and marketed as a rap/DJ toy, but it's actually pretty versatile. As a test source it can hold loads of picks & strums and they can either play looped, gated (plays as longs as a pad is pressed) or one shot. You can sequence a selection of sounds with pattern function (midi like sequencer). I/O is line level on RCA phono except for an additional unbalanced 1/4" "mic" input - you would need a hi-z buffer to record guitar in.
Older models like sp-202 and sp-303 would also do the job, but they have small internal memory and obsolete memory card expansion.
The original SP-404 (CF card expansion) and the current SP-404SX (SD card expansion) have enough memory for a gigs (pun not intended) worth of backing tracks too if that's your thing.
Output is going to be low-impedance, so not like having a guitar plugged in, especially with fuzz-face type circuits so try a pickup simulator...
http://www.muzique.com/lab/pickups.htm

Older Akai MPC units may be worth looking at too.

You don't have to wear a baseball cap backwards or sideways to use one dude.

[Kipper4]

Thanks guys
All solutions will be considered,

[vigilante397]

It was about $35 shipped if I remember right.
:
:
:
EDIT: Just dug through my eBay history and my memory was a bit off, it was actually about $60. Whoops

You owe us all twenty-five bucks.   

Will you accept that in Tayda coupon codes?

[Kipper4]

Paypal might be a safer option.
Knowing how you like to miss codes. You might miss the coupons........

[cab42]

I found these two in the trash a few years ago. The top one is a Leader function generator. Does pretty much anything you would want. However I mostly use my Q&D oscillator, thanks R.G.

[Kipper4]

Thats nice Cab. I think I'll save some pennies and go to the mom pop electric shop in the summer.
meantime I'll build the RG circuit and Sam Hay circuit.
I have the RG Q&D oscillator and make good use of it but i need more power for testing some circuits.
Cheers

[tubegeek]

I found these two in the trash a few years ago.

That's pretty classy trash.