Telefunken 85-KL
Six watts of push-pull valve output, two oval speakers, and a certificate of frequency response signed for every single machine that left the factory.
Overview
The 85-KL is the top of Telefunken's 85 series, and it is the version collectors actually chase. The 85T was a table model meant to feed a radio receiver. The 85K was a portable with a single-ended ECL82 output stage driving two speakers for about 3W into a 4-5 ohm load. The KL steps up to a push-pull pair of EL95 valves driven by an ECC83 double triode, still feeding two inbuilt loudspeakers, now at 5W output. Telefunken's own advertising of the period quoted the figure as a six-watt push-pull stage. The service description and the ad copy don't agree, and owners learn to live with that.
The output stage is the reason to care. The KL also carries a switch for killing the audio output, ganged with the main volume control rather than the recording-level control. The earphone signal is tapped off ahead of the ordinary volume pot, so you can monitor at a fixed level. On the push-pull version that isolating switch sits in the common return of the grid circuits, protected by a half-amp fuse. The table model does it differently, by pulling HT off the output transformer primary.
The frequency response is the headline claim, and Telefunken was unusually confident about it: 30-20,000 c.p.s. at 7½ i.p.s. and 30-15,000 c.p.s. at 3½ i.p.s., with each machine shipped with its own certificate of response to ±3 dB. Studio Sound (February 1959, p.8) reproduced that guarantee in Telefunken's advertising, and the same figures turn up again in the November 1959 listings. Telefunken's copy also made a point of the D.C.-heated pre-amplifier valves, claiming the DC heating eliminated hum and background noise.
The KL is a busy machine. Around the back and across the top plate you get two oval speakers with bass and treble controls, three separate input controls, and five push buttons, including the "trick" button for superimposing recordings. A magic-eye level indicator handles recording level, and there's an external speaker socket. Play time is quoted at over four hours on a full spool.
Price was 79 guineas, microphone excluded, and it held there for years. The same 79gn figure appears in the 1959 ads, in dealer hire-purchase tables through 1960, 1961 and 1962, and in the 1963 price list. That put the 85KL well above the 75/15 (quoted at 47gn in some listings and 52gn in others) and the four-track 76 (quoted at 57gn and 64gn across sources), and just under the Ferrograph 4A/N at 81gn.
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