Quad 306 Upgrade-service & DIY Kit launch

Dada Electronics launches the Quad 306 Revision-service and the Do-It-Yourself kit. They will be available in the European, USA and Australian Ebay-shop.

The input-filter and the DC Feedback circuit are upgraded to the Quad 909 quality-level.

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Low-noise 1% Metalfilm resistors give less noise on the base of the input-transistor. The TL071 opamp in this amplifier is not replaced as it is not in the signal-line and so it has no impact on the sound quality.

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All 4 zeners in both channels are decoupled with 100 nF MKT, thus eliminating HF ripple and further improving signal/noise level of the zener's output voltage.

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The old 4700 µF Power-supply caps are replaced with new 6800 µF caps with low ESR. The higher capacitance reduces ripple and increases stability of the PSU voltage.

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Finally the input-sensitivity is adapted to modern standards. The original value was 0,375 Volt which is much to sensitive for modern preamplifiers or input-sources. As this is done by increasing the local feedback of the input stage, as Quad did also in the later 707 and 909 models, this also improves overall signal to noise ratio.

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The kit and the service are available in Dada's Ebay-shop, just click on the links in the article above.

If you want a (free) copy of the upgrade/revision manual just send an e-mail to info@dadaelectronics.com.

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Stefaan & Joost