ALTEC 806-8A (1973-76) + ALTEC 811B Sectoral Horns

ALTEC 806-8A
Released in 1973 - 45,000 (1 unit, circa 1976)

Driver unit used for A7 - 8 and late Valencia etc.
Magnetic circuits are different between 806 - 8 A and 802 - 8 D.
Broadband playback is possible by combining with 511 B horn and 811 B horn
High performance is secured by aluminum alloy diaphragm and equalizer by special double slit structure of precision machining.
Model Driver unit
Frequency characteristic 500 Hz to 20 kHz
Permissible input 30 W
Impedance 8 Ω
Output sound pressure level 107 dB / W / m ||| 108 dB (New JIS, described in 1977 catalog)
Magnetic flux density 13,000 gauss
Crossover frequency 500 Hz or more
Throat diameter 25 mm
Voice coil diameter 45 mm
Suitable horn 511B, 811B
Adaptable network N501-8A, N801-8A
External dimensions Diameter 114 × depth 83 mm (described in 1974 catalog) ||| Diameter 114 × depth 71 mm (described in 1976 catalog)
weight 2.6 kg

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
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.
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 (

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


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]