I'm working on the next model in the "VP" Vocal Processor series.

<img src="http://www.casperelectronics.com/images/finishedpieces/vp-01/_vp-01_02.jpg" width="300" height="225" alt="" title="" />
OLD VP
<a href="http://www.casperelectronics.com/images/finishedpieces/VP303/S3600005.JPG"><img src="http://www.casperelectronics.com/images/finishedpieces/VP303/_S3600005.JPG" width="300" height="224" alt="" title=""  /></a>
NEW VP<p>
<a href="http://www.casperelectronics.com/images/finishedpieces/VP4/S3600054.JPG"><img src="http://www.casperelectronics.com/images/finishedpieces/VP4/_S3600054.JPG" width="400" height="300" alt="" title=""  /></a>
NEWEST VP<p>
The VP303 is similar to the VP01 but is built completely from scratch.
Both models contain an echo and a voice changer. In the 01 both circuits are taken from childrens megaphones (powergear brand). <br>
The 303 uses the <a href="javascript:openreq('http://www.ortodoxism.ro/datasheets/PrincetonTechnologyCorporation/mXyzsyzt.pdf')">pt2399</a> IC (echo) and the <a href="http://www.holtek.com.tw/pdf/consumer/8950v110.pdf">HT8950</a> IC (voice changer).<br>
I also added a timer using a 555 timer IC to the 303 model which can be used to trigger the pitch up or pitch down buttons, or turn the "robot" effect on and off, creating a tremolo effect.<p>
I'll be posting pics, sounds and detailed building instructions for this piece once it's done.