Speak and spell

Speak And Spell 2 – Pitch Bend and Hold

Sam

Pitch Bend and HoldAfter a lot of experimentation and some frustration I feel like I am beginning to wrap my head around the Speak and Spell’s operation. This is by far the most complex toy I’ve attempted to bend and as such there has been something of a learning curve as I explored the circuit and began manipulating it. That being said because this is such a popular toy for circuit bending I’ve been able to find a wealth of information to supplement my own experimentation and give me direction as I delve into this project. Today I’ll take you through the addition of a pitch bend up knob and a hold switch to my Speak and Spell.

Pitch Bend

Speak and Spell Pitch BendFor the pitch up bend I actually used three points, I initially found and started experimenting with the pitch bend using the two points on the board above (The 2nd and 4th pins from the right on the synthesizer chip) but found I was able to get a greater range by connecting the third lug on the potentiometer through a resistor to the point shown on the smaller board on the right side. I used a 100K pot and a 15K resistor though I recommend experimenting with different values until you find what works best for you.

Hold

wp-1467656667322.jpgHold and loop functions can be some of the most fun bends on any device as the allow you to create a constant repeating noise from the device which you can modify or play with in all kinds of ways and from my research into the speak and spell I understand it has a number of these type of bends available. Above is shown the first of these bends I was able to locate. If the switch is flipped while the device is making a noise it will continue to make that noise until it is flipped back down. You can then modify the noise output using the pitch bend.

Speak And Spell Part 1 – Set-up and First Glitch

Sam

Kill Switch, Output, Glitch, Speak And Spell

Today I wanted to show you guys another circuit bending job I’ve been working on that I’m pretty exited about. I found a working Speak And Spell at a local Value Village recently and have begun exploring and cannibalizing its innards for my own amusement. If you’ve so much as googled circuit bending you are likely familiar with the speak and spell and what it’s capable of (not to mention its sister devices the Speak And Read and Speak And Math), These devices can be turned into incredibly effective electronic instruments. I have never worked with one before but I wanted to take you guys along with me for the ride and share with you my victories and mistakes as we turn this device into something awesome.

If your looking for in depth schematics and diagrams of the circuit and possible bends, Casper Electronics offers a lot of great information.

Kill Switch And Output

circuit bending

The first thing I did to prepare the device for bending was to add a kill switch along the power connection and a switched output jack from the speaker connection. As these modifications are identical to what I did on my Vtech Alphabet Apple I will not go into to much detail here. Note the Speak and Spell does feature an on board headphone jack which could be used in place of the output jack it you prefer but I like having 1/4 inch jacks on all of my devices so I added one anyway.

The First Glitch

Speak And Spell - Glitch 1

Next up was to start exploring the circuit, I began triggering sounds from the keypad while touching a pair of probes to different pins on the board. After a little bit of searching I had come up with one which spewed bits of gibberish or random tones when the points were touched. I attached two lengths of wire and experimented with a few different control methods before settling on attaching them with a button.

A Silly Mistake

Speak And Spell - Mistake

Those of you who have worked with Speak And Spells before may have already noticed it but I made rookie error with my first glitch. I am slightly embarrassed about it but wanted to share it as a cautionary tale. When choosing the location of the button I began drilling from the back thinking that I was clear of the keypad, but in my excitement I did not check to see how far clear of it I was. Sadly the hole I drilled damaged the key matrix and has stopped many of the keys on the left side of the keypad from working. Luckily, enough keys still work that I can still turn the device on and trigger lots of noises but it has interrupted normal function of the device. No more scary robot hangman for me…