Oggetto utilissimo, indispensabile se si vuole utilizzare due amplificatori con due coppie di diffusori, alternandoli o addirittura incrociandoli.

Di seguito foto e descrizione dal sito.

Acquistato su ebay UK, costicchia non poco, oltre 300,00 sterline inglesi più la spedizione, ma credetemi, l'oggetto vale i soldi spesi.

Adatto a chi ha amplificazioni valvolari che come è noto, si danneggiano in assenza di carico.

Con questo oggetto è possibile tenere accesi ed attivi due finali a valvole, collegati a due coppie di diffusori (o anche ad una sola) passando ad uno all'altro senza rischi e soprattutto senza perdite.

Stereo Amplifier/Loudspeaker switch box.

The difference to the multitude of A/B switch boxes available today is that this new switcher must allow Valve Amplifiers and/or Transistor Amps to be used transparently.

As you will know, if you leave a Valve Amplifier without a set of loudspeakers connected then the output stage will destroy itself causing an extensive repair bill.

Wish List:

2 x stereo Amplifiers - Valve and/or Solid State transparent

2 x sets of stereo loudspeakers

Common Earth for all negative amplifier and loudspeaker connections

Each Amplifier can drive speakers 1 or speakers 2

Each Amplifier can drive speakers 1 and speakers 2 without changing the impedance load to the amplifier

Each Amplifier has 2 x 4 Ohm dummy loads connected if it is switched out of circuit

There must be no switching noises through the loudspeakers

The switch box must be musically transparent.

The Switch Box should be capable of switching up to 10 Amps (1KW) per channel.

It should be IMPOSSIBLE to switch 2 x Amplifiers back to back!

Designing such a simple yet complex circuit has been a challenge. Free standing push button switches and toggle switches cannot safely take the power!

Relay drive is the best solution - so that the controlling switches can be miniature toggles.

A power supply to drive the relays is required but, should this fail - then the amplifiers must see the dummy loads by default.

Housed in a lovely Chinese Black Anodised Case width 226mm (9 inches) Height 70mm (2.75 inches) Depth 271mm (10.75 inches).

"Darth Vader" Black Anodised fronts or Silver Alloy as shown by the discontinued graphic CNC'd front panel in picture 7.

The MKII front etching shown on the Black fronted units in this advert (without icons) is available with Silver Alloy fronts to special order.


3 pin IEC Euro Mains Cable (kettle lead) not supplied.