Qed tape switching unit 3 way, made in England

Conn StroboTuner ST-5 (ST-6) Piano Tuning Organ Vocals instrumental vintage, 195¿, made in USA




Year: 1950 ? 
Category: Miscellaneous (Other, Various) - see notes
Valves / Tubes 6: 12AU7 6AQ5 6AQ5 5879 12AT7 6X4
Wave bands - without
Details
Power type and voltage Alternating Current supply (AC) / 60 cycles AC 105 - 120 Volt
Loudspeaker - - No sound reproduction output.
Power out
Model: Conn Strobotuner ST-6 - Conn, C.G. Instruments Ltd
Material Metal case
Shape Tablemodel, with any shape - general.
Notes
The Conn Strobotuner model ST-6 uses tubes and two neon lamps NE2H. It has a microphone with a cable inside the lid including the power cable. The pentode 5879 was introduced in 1950. Schematic and technical picture by courtesy of Terry Smythe (mts.net).

The first Strobotuner was invented by Conn and called Ctroboconn and came on the market in 1936. On YouTube you find this very well done explanation about the principle of strobe tuners including a more modern Conn Strobotuner - like the Strobotuner ST-12 (or ST-11).

Joseph Plateau of Belgium is generally credited with the invention of the stroboscope in 1831 (1932), when he used a disc with radial slits which he turned while viewing images on a separate rotating wheel. Plateau called his device the "Phenakistoscope". There was a simultaneous and independent invention of the device by the Austrian Simon von Stampfer, which he named the "Stroboscope"




Evans Super Echo EE-3, 197¿, made in Japan


Linkestecho





Symetrix A-220 Stereo Amplifier, 1981-1994, made in USA


The Model A-220 Stereo Amplifier is a compact, high performance power amplifier configured for use in professional and commercial audio systems. The A-220 may be operated as a two channel amplifier with 20 watts per-channel, or as a single channel amplifier capable of 40 watts (in bridged mode). The amplifier is intended for use with near field monitors, small speakers used for 'radio reference', audio or video, and with headphones. In stereo mode the minimum load is 4-ohms, in mono-bridged mode the minimum load is 8-ohms.
For convenience, the A-220 is equipped with both 1/4' and XLR-3 input connectors, which will accept either balanced or imbalanced input signals. Full power output can be produced with an unbalanced .5 volt (-6dBv) input signal, or 1 volt (0dBv) balanced input signal. Since the A-220 can be used as a true stereo amplifier, as a 2-channel amplifier, or as a single-channel mono-bridged amplifier, the input level control configuration may be switched to reflect the usage. For stereo, use the DUAL TRACKING position, for 2-channel use the INDEPENDENT position.



Model: A-220
Manufacturer: Symetrix, Inc.
Type: Power Amplifier - Pro
Year: 1981-1994
# of Channels 2 (Stereo)
RMS Power (Watts Per Channel) 20 x 2 @ 4
Amplifier Features Bridgeable
I/O Interfaces 1/4", TRS
Weight (lb) 9


Link: symetrix [Operating Manual, PDF]