Filter / Wah (Optical Bass Wah (light sensor))
The Tech 21 Killer Blue Wail is an analog optical Bass Wah (light sensor) pedal based on the Optical (light-sensor) bass wah filter, with Treadle sweep (light-sensor filter varies frequency and Q) controls, made in USA.
| Category | Filter / Wah (Optical Bass Wah (light sensor)) |
| Circuit / based on | Optical (light-sensor) bass wah filter |
| Signal | Analog |
| Controls | Treadle sweep (light-sensor filter varies frequency and Q) |
| Footswitches | treadle |
| Bypass | spring-loaded rocker (auto-returns to bypass) |
| I/O | 1/4" input, 1/4" output |
| Power | 9V DC (Tech 21 #DC9) or 9V battery |
| Battery power | Yes |
| Dimensions | 3.375" x 8.0" x 1.75" |
| Weight | 24 oz |
| Country of manufacture | USA |
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