Living with Dolby B (continued)
It seems, in fact, that the first generation of Dolby B processors weren't all they could have been, and nor were the machines they were fitted into. Since I'm assured that Dolby Laboratories take great pains to produce excellent technical advice for the manufacturers I can only assume that somewhere along the line people tried to cut corners.
("What's that, Walt?"1
"It's my design for a new low-noise input circuit."
"Forget it, will ya? We'll shove a Dolby in wiv the old one.")
Anyway, the "Which?" article certainly made me stop and think. Did I really want my cassette deck to incorporate, somewhere within its depths, a Dolby circuit that I couldn't get at? Why not use a separate Dolby processor? It'll mean I've got complete control over the calibration and, (who knows?), Dolby FM may yet happen over here.
So, having carefully perused a review of four such processors I rushed out and bought a Phoenix-Videosonic (or, as I presume it's now called, Uher) PD2B. This is a two-processor unit which means I can either record or playback in stereo, but not both at once. And since my present employers are for their sins a bona-fide Hitachi dealer I also bought what seemed a logical choice: the most expensive non-Dolby deck that Hitachi make, the TRQ 2030D.
They arrived more-or-less together in February 1975 but, alas, they soon parted company. The Hitachi could only handle virgin cassettes (there's probably a word for that but I don't want to know it). It didn't fully erase the old material when re-recording. And Hitachi were busy changing the address of their service department, so I had to stare at the gleaming new PD2B for six weeks.
Those of you still awake may remember, however, that I still had a stereo Sony FM radio-recorder and you might even wonder why I didn't make do with this hooked up to the PD2B while the Hitachi was hors de combat. Well I tried, honestly I did! But it wouldn't let me. The Sony has an automatic recording level control (plus a distinct lack of VU meters) that defeated me before I could get the calibration tape out of its library case.
You see, setting up the PD2B isn't simply a question of slotting it between the cassette deck and the amplifier. Dolby units, as a breed, come complete with calibration2 tapes. These are tapes that have recorded on them a signal at what's known as Dolby level. Precisely what this level is seems to depend on who does the measuring, and how. But whatever it is, it's too much for Sony's automatic recording level, and (inevitably) there's no way for me to switch to manual control on my model.