Apple Omni-Directional Microphone (1990)
The Apple Omni-Directional Microphone is the small round microphone from the Macintosh LC and IIsi period. Apple documented an electret microphone and holder with both computers in an article created on 16 October 1990. That year dates the documentation, not a proven first separate retail sale.


Original labelled schematic, not a photograph or scale drawing.
Specs
| Documented year | 1990 |
| Format | Wired |
| Element | Electret |
| Pickup pattern | Omnidirectional |
| Signal level | Mic level |
| Connector | 3.5 mm |
| Signal | Mono |
| Control | Recording software |
| Own switch | No |
| Mount | Adhesive holder |
| Placement | Display, keyboard or desk |
| Documented computers | Macintosh LC / IIsi |
History and documentation
The Apple Omni-Directional Microphone is the small round microphone from the Macintosh LC and IIsi period. Apple documented an electret microphone and holder with both computers in an article created on 16 October 1990. That year dates the documentation, not a proven first separate retail sale.
Design and specifications
The LC manual allows placement beside the display, on the keyboard or on the desk. Its adhesive holder attaches to a clean surface; the manual also describes a shirt clip holder. There is no on/off switch: sound-recording software controls the microphone.
Use and context
It is an analog mic-level microphone, distinct from the later line-level PlainTalk. Apple explains that both need voltage but receive it through different contacts. Similar-looking connectors do not make the microphones interchangeable.
Notes and image
Apple warns against using the Omni on computers requiring PlainTalk because its signal is too low. The 20 mV and 600 ohms in the LC/IIsi document describe the computer input, not a measured microphone output specification. Check the Mac model, cable and holder before connecting it.
Sources
- Apple · Macintosh LC and Macintosh IIsi: Sound Input · TIL6170 · created 16 October 1990
- Apple · Setting Up Your Macintosh LC · 1990 · pp.7-8
- Apple · PlainTalk Microphone: Specifications · TIL15884 · updated 30 August 1995
- Apple · PlainTalk Audio Port Microphone Support · TIL15699 · updated 30 August 1995
- dimensionapple.com · Original schematic illustration