Dual Cassette Delay + Oscillator

Introduction: Dual Cassette Delay + Oscillator

Inspired by dmark2's project: Microcassette tape delay

Step 1: Materials


For "Platform":

*1 2x2x3 - Any wood will work, I used some spare 2x2 I found in my classroom.

*4 1" Wood Screws

*1 1/4in x 2ft x 4 ft Plywood

*4 7/8 in. Rubber Screw-On Bumpers

*1 Electric drill

For Cassette Delay:

*2 Cassettes - The Cassettes I used were the "RCA RP3503". Any Cassettes will work provided that they are able to: Read, Write, and Erase. I found it easiest to use normal sized Cassettes and Tapes because they had more room to work with, however it is completely possible to complete this instructable with a microcassette player and tape.

*2 Standoffs & screws

*1 Protoboard

*1 10ft 24AWG Stranded Hookup Wire

*1 SPDT On/On Switch

*1 5mm LED - Any color will work.

*1 AA Battery holder

*2 Small Screw & matching nut - I was unable to find similar screws and nuts to what I used. Provided it isn't large you should be able to avoid touching any internal components.

*4 AA Batteries

*1 Electric Tape - Any type and color should work.

*2 Cassette Tape - Any type should work provided that it is the same type as your recorders, ie: Normal with Normal and Micro with Micro.


*1 Precision screw kit - Any type will work.

For Oscillator:

*1 10ft 24AWG Stranded Hookup Wire

*1 B10k Potentiometer

*2 3.5mm Stereo Jacks

*2 Standoffs & screws

*1 Protoboard

*1 IC Holder

*1 Texas Instruments CD40106BE IC

*1 1uf Capacitor

*1 9v Battery connector

*1 9v Battery

*1 3.5mm Mono Jack

*1 5mm LED - Any color will work.

NOTE: Not all part listings are the best price or best value. Some parts can most likely be replaced with minimal variation to the end result.

Step 2: Making the Platform

- Take the 1/4in x 2ft x 4 ft Plywood and cut 18.5" by 13", making sure that you sand each side to get rid of the sharp edges and deformations. ( The saw I used was a bandsaw )

- Take the 2x2x3 and cut it into 2 13" pieces. ( The saw I used was a handsaw, but a chop saw would probably work better )

- Drill 1" holes making sure to drill through the 2x2x3 and plywood. ( I drilled holes at 2.75", 8.25", and 10.25" in, photo above ) Line the edge of the 2x2x3 up with the edge of the plywood. Do this on both sides.

- Screw 1" screws in the pilot holes you just drilled.

You should now have a completed base.

Step 3: Making the Cassette Delay

- Open both cassettes ( making sure to first remove all batteries ). Check to see using one cassette how many batteries it uses and if it runs in parallel or in series. Both cassettes should run on the equivalent of one cassette power supply ( you can test this by running one cassette work of batteries in its respective parallel or series, splitting the negative output and positive output in half, and attaching each respective lead to the respective terminal ).

- Provided that the previous step worked, now you can solder 1 wire to each terminal on each cassette.

- I drilled two holes in the battery cover and plywood, one near the terminals, the other in the excess room. Make sure to read all the way through before you drill holes because these holes will dictate where you mount the cassettes.

- Take your previously make battery holder ( parallel or series ) and take the positive wire and solder that to the middle leg on the on/on switch. Then solder two outputs from either leg on the on/on switch. Solder a 1k resistor to one on the outputs then solder the negative leg of your LED to that. Finally, connect the positive leg of your LED to any negative lead.

** Stop, make sure you have the following. 1 LED connected to 1 positive output from the on/on switch. 3 positive outputs from the on/on switch ( including the LED ), 3 negative outputs from the batteries ( including the LED ), and 4 total leads, 1 soldered to each terminal on the cassettes. **

- Solder 1 positive lead from the on/on switch to each positive terminal on the cassettes, and the same for negative for each cassette from the batteries.

- Finally, click the play button on each cassette and flip the switch, both should now turn on and spin at the same speed at the same time.

** Turn off the switch to make sure not to waste battery life. **

Step 4: Making the Oscillator

Before we get started on this, let's look at the pins on the cd40106be. Pin 14 is the +9v input, pin 7 is the -9v input, and we will be using pins 1 & 2.

- Solder +9v in onto pin 14 on the ic holder.

- Solder -9v in onto pin 7 on the ic holder.

- Solder 2 wires on pin 1 and 2 wires on pin 2.

- Take 1 wire from pin 1 and 1 from pin 2 and solder a 3.5mm audio jack onto it.

- Take 1 wire from pin 1 and 1 from pin 2 and solder a B10k potentiometer onto it.

- Insert your cd40106be making sure that the chip orientation matches the areas you soldered.

Step 5: Mounting It All

How you do this step is up to you, I personally made sure ( and you should too ) that my cassettes were able to link and weren't overlapping the 2x2, that way the holes I drilled for the nut and bolt that hold the cassettes in place and the wires connected to the terminals could pass through the plywood without interfering with the 2x2. All the components should be able to be fastened down with the included hardware and if not **cough** **cough** hot glue **cough** **cough**.

Step 6: Making the Loop

I don't have footage of me assembling my loop but I have found some useful videos ( NOT MADE BY ME ) that might be some help.

How To Make an 8-Second Tape Loop By: Ezra Fike

Step 7: Final Touches

Make sure that on the cassette that you are recording on had tape ( clear tape or really any thin tape will do ) is covering the recording head, the recording head varies in placement but should be easy to find. I will most likely add a "jam session" once I get mine back up and working.

Step 8: Gotta Give Credit Where Credit Is Due



Tape loop video:

Ezra fike

My Weebly:


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    4 years ago on Step 8

    This looks like a super fun project to make! Well done. I can't wait for the final version to be uploaded!