One Thing Audio
One Thing Audio
OTEC-T, replacement ESL 57 treble panel
The OTEC-T, replacement ESL 57 treble panel
OTEC ‘T’ panel is the latest addition to our ESL 57 range. It is a direct replacement for the treble panel employed in Quad’s ESL 57 between its introduction and final production runs in March 1984. This penultimate panel in the range owes much to our more expensive OTEC, and derives its design from the latter, so it will be no surprise to learn that it offers a very similar performance. The main saving has been on the material which forms the electrodes - in place of the OTEC’s fibreglass, a very brittle and temperature-stable PVC manufactured in Germany, which we ourselves perforate - another considerable cost-saving process. Ironically - although a fair bit cheaper with respect to materials, this version is far more labour-intensive to produce. But at the price point it occupies we cannot deny that it is (arguably) better value than our ‘flagship’ OTEC, so anyone seeking a substantial upgrade for a ‘tired’ ESL 57 at an affordable price need look no further.
Replacement type Quad ESL 57 Dimensions 19 x 65 cm Weight 2.4 Kg Electrode material HDPVC Driven areas Nickel coating Rear electrode 2mm Front electrode 1mm Terminations Captive cable Colour codes blue, brown, red Polarising voltage 1.5kV +/- 12% Diaphragm material P.E.T.P Gauge 5 microns Coating Carbon paint Freq bandwidth 600 Hz—15 kHz Colour coding Black/Dark Grey comparison table
Ron Best
One Thing Audio
September 2008