This Findus Crispies Loudhailer is a voice changer megaphone with two voice effects. The megaphone also triggers a novelty crunching noise and has six red flashing LEDs surrounding the speaker. I guess this item was originally used to promote Findus Crispy Pancakes.

I added the following controls:

- Power switch
- Switched 1/4″ input jack. Disables the inbuilt microphone when an external audio source is plugged in.
- 1/4″ output jack
- Pitch adjustment
- Gain/Distortion
- Feedback trigger
- 4 voice effects
- Sound effect pitch control and ON/OFF switch

Yamaha DD-6 audio processed by the Crispies Loudhailer

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Feedback with pitch and distortion

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Crunching sound effect pitch and distortion

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The body of the megaphone is really solid compared to some other megaphone toys. The red front piece is glued to the body. This makes it a little tricky to remove but it is possible to do without damaging the case. I tried slightly heating the rim, which I think softened the glue and made it a little easier to remove. It all screws back together without having to use glue.

The Birdseye Loudhailer features two voice effects. More are accessible by inputs marked SW1, SW2 and SW3 on the circuit board. Each input can be selected by connecting SW to ground and voice modulation is determined by selecting different high/low combinations. I used two toggle switches connected to SW2, SW3 and ground. This makes it possible to select 4 effects (including a clean passthrough). The voice modulator circuit is an unidentifiable ‘blob’ IC so I couldn’t find any useful information about this circuit.

The Loudhailer was originally powered ON by the trigger and the slide switch selected the voice effect. I rewired the slide switch to power the megaphone. The trigger activates feedback by connecting the speaker output back into the input. The feedback screech can be adjusted with the pitch control.

Pitch
I replaced this resistor (R31) with a 100k potentiometer to control the voice effect pitch.

Gain/Distortion
A simple way to boost the output volume is to connect a potentiometer and capacitor in series between pin 1 and 8 on the LM386 amplifier IC. This can also function as an overdrive effect.

Sound Effect
This resistor (R33) controls the pitch of the crunching sound effect and when disconnected the effect stops. I installed a switch and a 1M potentiometer to change the pitch and turn the effect off.

Flashing LEDs
I replaced the red flashing lights with six bright white LEDs. This was pretty nice however I realised that the flashing was interfering with the audio, creating an oscillating effect. In the end I decided to completely remove the flashing lights.

Other Possibilities
Mix between the clean input and the effect (dry/wet).
Input and output volume controls.
Body contacts for pitch modulation.
Alternative voice effect selector- rotary switch?
Vibrato adjustment? Resistor R32
Feed the crunching sound effect into the voice modulator.
Flashing LED ON/OFF selector
Or use the megaphone case to house another project