Annotated BOM
| Designator | Designation | Quantity | Marking | Usage |
|---|---|---|---|---|
| BT1 | 3.6v-4.5v | 1 | n/a | Power; wires to 3*AAA battery pack |
| C1,C5 | 220uF | 2 | n/a | Big bypass cap, Amp output |
| C3 | 1uF | 1 | n/a | Amp gain |
| C2,C4,C6 | .1uF | 3 | 104 | Bypass caps, RESET pin cap (C4) |
| D1 | LED_CRGB | 1 | n/a | On/off+playing indicators |
| J1 | AudioJack2_SwitchT | 1 | n/a | Line out headphone jack |
| J2 | Conn_01x06_Male | 1 | n/a | Programming header |
| LS1 | Speaker, AZ40R 40mm x 5mm | 1 | n/a | Wires to output speaker |
| R1,R2 | 220 | 2 | Red Red Brown | LED current limiters |
| R3,R5 | 10k | 2 | Brown Black Orange | Brings volume closer to ear-safe level for line out, "pull up" resistor for RESET pin |
| R4 | 1m | 1 | Brown Black Green | Drops volume even more before amp |
| RV1 | 10k Log, RV09AF-40-20K-A10K | 1 | n/a | Volume control |
| SW1 | SPDT, OS102011MA1QN1 | 1 | n/a | On/off power switch |
| SW2-SW18 | SPST, 6mm tall | 17 | n/a | Key buttons |
| U1 | ATmega328P-PU with bootloader | 1 | n/a | Microcontroller chip |
| U2 | LM386 | 1 | n/a | Amplifier chip |
| Y1 | 16.00MHz | 1 | n/a | Ceramic oscillator for microcontroller |
Also:
- 2 2-wire ribbon cables (or similar small gauge, stranded wire)
- 1 7" for BT1
- 1 3" for LS1
- 4 battery terminal contacts for BT1
- 2 dual spring+button wire contacts (Keystone 181)
- 1 tabbed spring contact (Keystone 5204)
- 1 tabbed button contact (Keystone 5226)
- 2 DIP sockets
- 1 28 pin for U1
- 1 8 pin for U2
- 4 nuts and bolts
- 2 4/40 square nuts
- 2 4/40 3/4" machine screws
Alternate speakers for the AZ40R:
- PSR-40N08A05-JQ
- AS04008MR-21-R
- CMS-4051-058SP
Any circular 8ohm speaker that matches the dimensions will probably work, thought you may find you need a bit of hot glue to hold it in place.