Quad 303 High-end boards: the Figures

Esmond Pitt (Dada Elecronics Australia) measured the Dada High-end boards.

Output-transistors: 4x (new) MJ15003

Equipment used: Tektronix SG505 oscillator & AA501/01 distortion analyser.

Bias-setting: 7,5mA (10 mV between pins 4 and 6)

1. Bandwidth: -3dB at 13,5 Hz and 60KHz. Ruler-flat in the passband.


2. Distortion (THD): less than 0,015% at 4V RMS 1 KHz, less than 0,04% at 10 KHz
3. Crosstalk: less than 65 dB


4. Output-power before clipping: 59 W RMS into 8 Ohm (can be limited to 45 W for use with ESL57 speakers)

It is clear that these figures are a lot better than the original 303-specs, specially the THD.

The output-power was measured by Dada Belgium with a Hameg HM8012 multimeter, Hameg HM8037 generator and a Tektronix TDS2012B scope.
The high-end boards and the MJ15003 transistors are for sale in the Dada Electronics Ebay-shop.

Stefaan