JBL 7510A
Little is documented about the JBL 7510A beyond a period advertisement campaign. It was an automatic microphone mixer. JBL called it an "advanced digital/analog mic mixer" that could activate or deactivate up to 24 input channels automatically. The tagline was "thinks before it speaks."
The ad copy ran in DB Magazine (September 1980, p.19) and other trade publications. It lists several technical features: input and output level correction that permitted hefty power gain without feedback "howling," a zero-crossing detector on turn-on, and threshold circuits that could tell program signals on one mic from ambient noise on all mics operating. Frequency response for both the input and output modules was rated at 20 Hz-20 kHz. The tolerance was ±0.5 dB in the earlier ads and ±0.2 dB in a later printing.
Beyond the advertising claims, surviving information is thin. The 7510A appears to have been aimed at installed sound and conferencing applications rather than the home consumer market, which fits JBL's professional division offerings of the era. No owner's manual, service documentation, or independent review measurements have surfaced in the archive.
Known specs (from period advertising):
- Automatic mic mixer, up to 24 input channels
- Digital/analog hybrid design
- Input module frequency response: 20 Hz–20 kHz
- Output module frequency response: 20 Hz–20 kHz
- Zero-crossing detector on turn-on
- Threshold circuits to distinguish program signal from ambient noise
eBay Listings
As an eBay Partner, we earn from qualifying purchases. This helps support our independent vintage technology research.