Sony PR-150
A workhorse 1.0-mil polyester tape that Sony built its own decks around — and that reviewers found perfectly competent, if never the quietest reel in the box.
Overview
The PR-150 is not a machine. It's recording tape — a 1.0 mil polyester-based formulation that Sony/Superscope brought to the American market in the mid-1960s, sold on 7-, 5-, and 3⅜-inch reels carrying 1800, 900, and 300 feet respectively. That last reel is the interesting one: it was cut to fit three-pin-drive professional machines as well as ordinary home decks, which meant radio stations could buy cheap short reels for commercials and spot work without hunting down broadcast-only stock. Sony also offered a 3-inch mailer reel loaded with 300 feet for the same purpose.
The formulation itself was thoroughly conventional. Tape Recording (April 1965, p.29) described the PR-150 as similar in properties and price to the standard tapes from most American suppliers, made in Japan, and noted that Sony recommended it for general recording use — not specifically for slow-speed work. That's an honest positioning, and it matters: this was never marketed as a low-noise or high-output tape. It was the baseline Sony you bought because you owned a Sony.
Which brings up the bias question, and it's the single most useful thing to know about PR-150 today. The same held true for the common 111 formulation, which the reviewer called most similar to PR-150. For 7½ and 3¾ ips work, that reviewer recommended the Sony tape outright. The takeaway for anyone running period Sony gear: if your deck was set up at the factory for PR-150, feeding it a different formulation is how you get a response curve that looks broken when nothing is.
How does it actually sound? The period testing was blunt. In a slow-speed tape shootout, Tape Recording (April 1965) found the PR-150 showed somewhat more tape hiss than the low-noise and high-output contenders — Scotch's 201 walked away with the noise prize, with Audio, Kodak, and Ampex close behind. On low-frequency behavior, though, the Sony did real work: the same test credited PR-150 with substantial improvements in eliminating some of the boom that traditionally plagued 1⅞ ips recordings, producing a more natural bottom end. At 3¾ ips the magazine found all five brands uniformly good in the low end. On distortion at 1⅞ ips, Scotch took the easy victory with Ampex and Sony following. In listener rankings for high frequency response, PR-150 came in fifth of five — behind Ampex 536, Audio Devices B-25, Kodak 34-A, and Scotch 201. None of this is damning. It's just the profile of a tape that does its job without flattering itself.
The physical construction got a fair hearing too. That same piece noted Superscope's introductory promotion: a discount book of twelve coupons, redeemable at Superscope tape dealers for roughly 50 percent off list. Sony's own advertising of the era pushed the tape hard, with a full-page spread in HiFi-Stereo (November 1965, p.39) touting a silicone-impregnated lubricant that "cannot wear off," a proprietary slitting technique, and an extra-heavy homogenized oxide coating. Marketing copy is not a measurement, and the independent testers never confirmed any of it as a differentiator — the hiss numbers tell a more modest story.
Where does that leave the PR-150 for a collector? It's a tape, so the practical reality is that most surviving reels are either shed-riddled or already wound onto something else. The value is documentary as much as usable: it's the formulation Sony biased its own machines around, the one that shows up in period test reports as the reference against which other tapes were judged on Sony decks, and a small but genuine piece of the Superscope distribution story. Buy it sealed if you find it, but buy it knowing what it is — a solid general-purpose polyester, not a low-noise marvel.
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