QX / QXD / QXHD: the quarter-inch four-channel
What it is↑ TOP
The QX is the first generation's quarter-inch four-channel machine. It is on the panel photo of Otari's September 1975 tri-fold brochure, whose S/N table quotes it beside the two-channel machines (1975 brochure), and Audio's October 1976 directory lists its drive motor as DC servo alone where the two-channel machine lists both (Audio, October 1976). By 1978 the line-up ad calls it the QXHD, and the Mark II's maintenance manual title groups the QXD with the MKII-2, MKII-4 and 8SD — the four first-generation machines that shared a service book.
How to identify one↑ TOP
- Quarter-inch tape with a four-channel head block.
- The rear plate, not the faceplate: "QX", "QXD" or "QXHD". See the face badge.
- A DC-servo capstan — the 1976 directory lists no AC option for the QX.
Specifications↑ TOP
Not yet compiled beyond the drive-motor entry above. The 1975 brochure's specification page quotes the QX in its S/N table; read it on the brochure edition rather than trusting a figure copied here without its conditions.
Documents
Service training binder
Wanted
QXD maintenance manual (shared with the Mark II)
The QXD is the third machine in the shared "MKII-2, QXD, MKII-4 AND 8SD" book. Nothing else on the QX line has surfaced — a brochure, a spec sheet or a rear-plate photo would each be a first.
Have one? Here is how to contribute.
In the period press
- db, January 1978 — Otari's whole line on one page — and the proof that the MARK II shipped alongside the silver-face MX-5050-2S, with DC servo standard while the 2S still listed it as an option.
Sources↑ TOP
- Sales brochure, September 1975 — the QX on the panel photo and in the S/N table.
- Audio, October 1976 — the directory's drive-motor column.
- db, January 1978 — the QXHD in the line-up ad.
- The wider family — the shared maintenance manual title.
Have one, or paper for it?↑ TOP
This is the thinnest page on the site by design. A QX/QXD/QXHD owner with a rear plate, a head-block photo, or the shared maintenance manual would fill most of it. See how to contribute.