I've seen the Talking Sorting Hat set:

Back of box

How are the sounds for this hat produced? Could it be used to produce other sounds?

  • 2
    Before I saw that this was about bricks I thought "What a dumb question, obviously through magic!" :-)) And in a way, it is ... Apr 4 at 15:39

1 Answer 1


This set includes a single novel element, 102723c01 Sound Brick 4 x 4 with Random Talking Sorting Hat Sounds, that does all of the hard work:

Element render

That element is integrated into the hat so that Technic elements are able to activate it by pressing its button:

Instruction page 102

This is then connected to the top of the hat to activate the sound brick along with motion of the mouth and eyebrows:

Instruction page 142

The element can be disassembled by removing two screws:

Element internals and back cover

This makes it simple enough to replace the 3 LR44 batteries. We can also remove the PCB:

PCB top

This shows the speaker attached to the PCB along with a button, a single capacitor, and an unmarked 8-pin DIP. There is nothing on the back of the PCB:

PCB bottom

Following the tracks on the PCB, the circuit seems to be as follows:

Circuit diagram

(The indentation on the DIP marks pin 1. The switch connects to one of pins 1-4 via a track underneath the DIP which is not fully visible, so pin 3 is a guess. Pins 1,2,3,4,5 and 7 are connected to pads on the PCB surface)

The inscription "OTP" on the PCB suggests a One-Time Programabble chip, and the contact pads on the PCB are most probably used to program the chip with the sounds during manufacture. The DIP pin-out and OTP characteristic suggests a Waytronic OTP voice chip, or one electrically compatible with it.

There doesn't appear to be an easy way to repurpose this part to produce any sound other than the 31 pre-programmed phrases.

It should be possible to desolder the DIP and solder a new one then program fresh sounds, but there is no (known) way of ordering a hobbyist-sized amount of compatible sound chips.

  • 3
    The fact that there's "OTP" written on the PCB suggest a One-Time Programmable sound chip (which should tell you that new sounds cannot be added). In a DIP-8 package, with pins 1-4 on contact pads (for programming) and pins 5-8 having GND/VCC and audio output, a possible candidate would be the waytronic series (waytronic.ca/otp-voice-chip). It might be possible to de-solder and solder a new one, then program fresh sounds. Apr 4 at 1:26
  • 1
    Interesting how there's a (c) 2022 on there! Does this imply that the sound bricks were already produced back then, and that the set has been in development since at least that year?
    – Tuzi
    Apr 4 at 12:37
  • 1
    More likely that's just when the PCB was designed, having no bearing on production schedules. With a circuit this simple, there was probably very little in the way of iteration on the design. However, product development and the go-to-market process can be pretty slow.
    – JakeRobb
    Apr 4 at 18:50
  • @JakeRobb under two years from PCB design to go-to-market would often be considered blindingly fast.
    – Cylindric
    Apr 5 at 10:17
  • Yep. And yet, seems feasible in this case.
    – JakeRobb
    Apr 6 at 14:11

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