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DIY Stompboxes => Building your own stompbox => Topic started by: geir_helgi on February 18, 2011, 02:26:10 PM

Title: SHX123C Recording Chip (Lofi Looper candidate?)
Post by: geir_helgi on February 18, 2011, 02:26:10 PM
Hey gang,
I found a little record-your-voice pen today for a mere ca. $5.5.

It's got a tiny double sided PCB with SMD's and a black "blob" instead of an IC
Its' called "SHX123C" (anybody know about this one?) and it's connected to a small mic and a speaker.
The size is 2 cm x 0.8 cm, which is tiny!

It takes 3x LR44/AG13 Button Cell batteries.
It's got two push-buttons (bridging the PCB "gap"-type, not two solder points, if you know what I mean)

Record time is ca. 10 secs.

I really can't judge the quality of the chip because of the speaker,
how would I go around replacing it with a proper output?

I was just wondering if this wouldn't be great to use for a looper?

ps. if someone's interested I can buy a couple of these pens and ship out the chips. :icon_lol:

Thanks!

-Geir Helgi
Title: Re: SHX123C Recording Chip (Lofi Looper candidate?)
Post by: geir_helgi on February 18, 2011, 02:32:42 PM
Similar to this,
just smaller and more rectangular.

(http://wb6.itrademarket.com/pdimage/62/s_2020862_untitled-1copy.jpg)
Title: Re: SHX123C Recording Chip (Lofi Looper candidate?)
Post by: Taylor on February 18, 2011, 02:53:48 PM
I think using a real ISD chip makes more sense.

For one thing, with this you have no access to many parts of the chip that are needed to do the logic and creating looping. It might not be possible to get this thing looping, since you need some kind of logic signal signifying "end of recording" coming out of the chip to retrigger play.

10 seconds is pretty low for this kind of thing.

Small Bear has the ISD1000 chip for $10, and the newer ISD1700 is available in some places and The Tone God's about to release his Payback 2.0 that uses it.

So, you probably could make it happen, but the question is whether it's worth all the hassle of designing a new circuit with fewer features, just to save about 5 dollars.
Title: Re: SHX123C Recording Chip (Lofi Looper candidate?)
Post by: geir_helgi on February 18, 2011, 02:58:58 PM
Quote from: Taylor on February 18, 2011, 02:53:48 PM
I think using a real ISD chip makes more sense.

For one thing, with this you have no access to many parts of the chip that are needed to do the logic and creating looping. It might not be possible to get this thing looping, since you need some kind of logic signal signifying "end of recording" coming out of the chip to retrigger play.

10 seconds is pretty low for this kind of thing.

Small Bear has the ISD1000 chip for $10, and the newer ISD1700 is available in some places and The Tone God's about to release his Payback 2.0 that uses it.

So, you probably could make it happen, but the question is whether it's worth all the hassle of designing a new circuit with fewer features, just to save about 5 dollars.

Ok, ok :)
Thanks for the reply.

Yeah, I thought so..
Anyways, just wanted to post this just to be sure..
You never know, right?

I'm just gonna feed some samples and stuff into this and resample :)
Can I hook up an input+output onto this, instead of the mic+speaker?
Title: Re: SHX123C Recording Chip (Lofi Looper candidate?)
Post by: Taylor on February 18, 2011, 03:00:20 PM
tech.thetonegod.com

Check out Andrew's Payback 1.0 - uses a chip that's meant to drive a speaker, so it shows how you can use this type of chip with guitar level signals.
Title: Re: SHX123C Recording Chip (Lofi Looper candidate?)
Post by: Top Top on February 18, 2011, 03:51:39 PM
I built a mini sampler out of something similar:

(http://oi55.tinypic.com/2z5sx9h.jpg)

I relocated the mic to plug in externally, but it wouldn't be too hard to make a little preamp circuit and make it into a normal mic/line type of thing. The speaker output I just put a cap (probably not needed) and 220k resistor in line to keep the level more tame and compatible with other line level devices.

I used a 4017 decade counter and 4016 CMOS switch so that it can automatically record/play according to the sequence set up on the dip piano switches. I take the clock from an external source.

You can hear it in a couple experiments, with me sampling my "singing" and other things:
http://www.youtube.com/watch?v=9qPN_BEM9Ug (used for that zither glissando)
http://www.youtube.com/watch?v=gf39MOs8JSc (used throughout sampling a little chunk of voice at the beginning of each bar)
http://www.youtube.com/watch?v=wBnupUqm69U (it doesn't come in until about 1:48, singing harmony with my sampled voice)

(The other sounds are all DIY electronics too)