Thursday, January 01, 2009

Dada Loudspeaker Protection & Delay pre-announcement


The Loudspeaker protection / Delay is available in the Dada Electronics Webshop here.

Dada Electronics and JP Engineering are proud to pre-announce:

The Dada High End Loudspeaker DC protection with delayed switch-on, fast switch-off. (this is the first pre-production version, after the first ten units, real production starts. Size 24 x 89 mm. Product specifications might be changing. )



  • No switch-on/off noises like “Plop” or “Pmp” anymore.


  • Protects your valuable speakers against DC voltage from the output of your amplifier when something is wrong. Outperforms the original 405 'Clamp' circuit. The clamp board or components on the modules can be removed. A led will be used to indcate the activation of one of the protection circuits.


  • Designed for Quad transistor amplifiers, but can be used with almost any other transistor amplifier up to 500W RMS.


  • Fixed delay: 4 a 5 seconds. Other values on request. The switch on delay in a Quad 34 or 44 is not needed anymore.


  • AC detection: Immediate switch-off when mains power is removed from the amplifier. The AC detection is done via an optic coupler so no ground loops or other related problems.


  • Runs on the DC power supply of the amplifier 35 - 90V DC. Can be used with the Quad 303 as well, as with most other power-amplifiers. No separate mains power needed.
    Less mains-power leads inside the amplifier means less induced hum.


  • Audio Grade loudspeaker relay (the only one we know of) - very low contact resistance, double contact, one heavy duty and one gold plated silver contact, the gold contact closes after the heavy duty contact and opens before the heavy duty contact.


  • DC sensing and protection must be used when you have an amplifier with symmetric power-supply. It can be switched off by removing a jumper, when you have an amplifier with output-transformers and a single power supply or output-capacitors. With this option the relay contact can switch the loudspeaker without any galvanic connection with the rest of the amplifier.


  • Mono design. The unit can be used with amplifiers which are built as four pole devices, like the Quad 520 and 606 range. Or when a 405 is fitted with our double PSU in full floating mode. For use in a Stereo amplifier you should use 2 modules.


Placement of the unit in a 405, it will fit beside the modules. Firmly connected to the bottom cover with self adhesive feet.