Sound effects circuit

I

itolond

New Member
Hi Forum,

Need some advice on sound circuits.

i look to create sound effects for a hobby project which will be ultimately controlled by PICAXE.

basic guide of parameters:

seeking for reasonable good sound quality (will add mixer and AMP later) 16bit....stereo preferred
MicroSD card preferred
common sound file (.WAV, MP4 etc...) preferred
Small circuit footprint, low power draw

any pointer/s would be appreciated
 
J

John West

Senior Member
2 transistor, or 3?

I looked at the owner's manual for it. (The datasheet is in Chinese.) The audio sample rate looks fine for voice, but not at all impressive for higher fidelity.
 
Buzby

Buzby

Senior Member
Well, it meets most of the requirements. :)

There are plenty more choices on eBay, SFE, etc.

Maybe if the OP told us a bit more about the kind of sound effects he's after, and what kind of loudspeakers they will be played through, we could come up with a better pointer.
 
J

JoeFromOzarks

Senior Member
I was hoping this little module would do "high fidelity" but even connected to a good "stereo" and swapping out a couple of the recommended components on the PCB, never could get "VHF" (very high fidelity.) It's great for playback of voice though. All I expected it to do was "faithfully reproduce" the sound of a bell, such as found on a kids bike or a railroad crossing gate, preferably the later. Nope. Excellent little chip/module if used within its design specification. Note: best to keep supply voltage as close to 3.3VDC as possible.

English datasheet attached. Enjoy! (Let me know what you come up with.)

:) joe
 

Attachments

Steve2381

Steve2381

Senior Member
I need something similar - and the MP3 modules isn't really ideal.
They used to make a chip called ISD2560 which was excellent - it would record 60 seconds of very good audio quality (I believe there was a 30 and a 90 second one as well).
However, they appear to have evaporated except for the extortionately priced dodgy ones on Ebay.
They were great as they instantly replayed your SFX upon applying a signal.
 
Steve2381

Steve2381

Senior Member
Not even going to follow the link Jim! I know the module you are talking about. The sound quality is pretty appalling.
I have Googled but come up with nothing much.
I used a couple of ISD2560 chips and a Woolworths MP3 player in an old Nuclear alarm clock I built many years back.
I hacked the cheapy MP3 player open and simply connected the play, pause, forward and backwards to a Basic stamp using reed relays - worked like a charm. Yes, it was primitive, but there were no easily available MP3 modules back then.

http://www.youtube.com/watch?v=vCgMDY-Sg1Q

If you are interested!

I think one of these would probably be your best bet. I ordered one last week and it was here in 5 days

http://www.ebay.co.uk/itm/SD-Card-MP3-Player-Module-Board-Rx-Tx-TTL-/380672807732?pt=LH_DefaultDomain_0&hash=item58a1de1334
 
I

itolond

New Member
Hi All,

appreciate the responses, still combing through links.

To clarify as requested in one of the replies see below:

In this application (there will be others using the same solution) I would like simulate a helicopter (static model- blades moving/lights etc..)

- in simple terms the min is to play a looping sound (recorded) which is really the engine and rotors when they are spinning (controlled also by a PicAXE)

- utopian solution is more elaborate - it would consist of 3 sound files (1 startup, running loop and a shutdown sequence ( with no gap or a cross fade between sound files) the startup sequence would run and the loop would continue until a shutdown sequence was called etc...

as far as amplifiers and speakers there are a number of solution but given the space and my options are mini portable speaker by Org audio which would use the hull of the ship (heli on landing deck) as a speaker, or something like a X-mini speaker. Both of which have suitable sound capabilities, built-in amp and self powered (usb 5 v)

the benefit of the SD card is that once created the sounds can be modified (for other applications) and I can also manage from my PC.
 
Steve2381

Steve2381

Senior Member
Trouble is the MP3 module doesn't like constant looping.

http://www.ebay.co.uk/itm/ISD2560P-ISD-DIP-28-Single-Chip-Voice-Record-Playback-x-1-pc-New-/110978880442?pt=LH_DefaultDomain_0&hash=item19d6db53ba

I think these are the best bet, as they can be constantly looped without any pause. 60 seconds is pretty reasonable length of time as well.
I had one in my model tugboat a few years back that ran the diesel engine sound.

Not sure how good these are as suppliers, but you could shop around.

Data sheet with connection diagrams:
http://www.biltek.tubitak.gov.tr/gelisim/elektronik/dosyalar/6/ISD2560.pdf
 
H

Haku

Senior Member
You also could do the 3-sound-files thing with no gaps using two MDFly mp3 modules:

One has an SD card with a multi-hour looped sound of a helicopter.
The other has an SD card with the engine startup + shutdown sounds.

The output of both goes to a small amplifier with a Picaxe controlling both modules, achieving fading between the two simply by sending volume control signals to the modules.


I've seen sound modules that can do exactly what you're looking for, designed for a lightsaber it can play the specific "power-on" + "continual loop" + "power-off" wav sounds you want without gaps (plus a bunch more features that you wouldn't need), but it's 126 Euros:
http://www.plecterlabs.com/catalog/product_info.php?cPath=23&products_id=1156
 
Steve2381

Steve2381

Senior Member
With these MDfly modules - http://www.ebay.co.uk/itm/SD-Card-MP...item58a1de1334 ....

Do you reckon its OK to drive a 12v, 7w Velleman amp directly off these modules? Last time I put a pre-amp in and the noise was terrible and the pre-amp pot needed barely moving to get full volume.
I had one before that suddenly stopped working and I wondered if it was because I drew too much out of it? (shouldn't think so however - surely the signal to the amplifier is very low)

As for the helicopter sound effect... I think it will all come down to what you want to spend on it.

I just dug around through my drawers of circuit boards and found a sound recorder module with a 2590 chip in it. I think that is a 90 second sound recorder chip.
Might try and work out the connections tonight and see if it works.
 
J

John West

Senior Member
Last time I put a pre-amp in and the noise was terrible and the pre-amp pot needed barely moving to get full volume.
Click to expand...
In such a situation you are over-driving the amplifier input. A resistor divider usually takes care of that. A potentiometer of 5K Ohms or so with the output of the sound source across the outside terminals of the pot and the amplifier's inputs hooked to the ground side of the pot and its wiper often works well.
 
R

russbow

Senior Member
Have you thought of investigating the Speakjet chip. I did an introduction some time ago. Searching in the user projects threads should find it.

Easy to interface to picaxe and no extra programming required to get "event" initiated sound, except making a pin high.
 
Steve2381

Steve2381

Senior Member
I think the Speakjet chips are expensive, and also pre-programmed, so he would not be able to add the SFX of a helicopter as required
 
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