50 Watt Amplifier

Vortexion 50 Watt Amplifier

The company was under the direction of the UK government during WW2 to produce amplifiers for Air Raid Precaution and the company claimed many hundreds of this 50W amplifier chassis were in use.

A pair of matched 6L6s with 10% negative feedback is fitted in the output stage, and the separate HT supplies to the anode and screen have better than 4% regulation, while a separate regulator provides bias.
The 6L6s are driven by a 6F6 triode connected through a driver transformer incorporating feedback. This is preceded by a 6N7, electronic mixing for pick-up and microphone.
The additional 6F5 operating as the first stage on microphone only is suitable for any microphone.
Tone control is fitted, and the large eight-section output transformer is available in three types;

1. 2, 8, 15 & 30 Ω
2. 4, 15, 30 & 60 Ω
3. 15, 60, 125 & 250 Ω

These output lines can be matched using all sections of windings and will deliver the full response (40-18,000 c/s) to the loudspeakers with extremely low overall harmonic distortion.

Chassis with valves and plugs £17/10/-

Or complete in black leatherette cabinet with Collaro turntable, Piezo P.U. and shielded Mike transformer for £22/10/-.
Wireless World Jan 1941 Page 27

Ed: I think the 6F6(Pentode) & 6N7(Duo Triode) are swapped in the description in the above text.

In questo link sono elencati 23 modelli, di cui 20 con immagini e 1 con schemi.
Elenco delle radio e altri apparecchi della Vortexion Ltd.; Wimbledon