One Thing Audio
One Thing Audio
Original refurbished ESL 57 treble panel
Original refurbished ESL 57 treble panel
For Quad “traditionalists” we offer the original Quad panel as used in the majority of ESL 57s since their introduction. But we have made improvements in certain critical performance areas: for instance, the original panel had poor power handling. Frequent “burn-ups” were not uncommon. Intensive research on our OTEC panels has proved the wisdom of working with relatively low-impedance diaphragms with carbon particle paint as the conductive medium, but increasing diaphragm excursion by 10% (more significant than it sounds) with no loss of sensitivity over an original brand-new Quad panel (no comparison can be drawn for an aging Quad panel, as these could lose as much as 20% of their output over the years). We also re-dope the front electrode for better insulation properties. Some owners have commented that our ‘Standard’ Quad panel sounds a fair bit ‘brighter’ than the original—this is not true. If you were able to listen to an original Quad panel a few weeks or months after it had come out of the factory, we assure you its tonal balance would be virtually indistinguishable to that of our current Standard rebuild (we have spent many hundreds of hours researching this!) Here then, perhaps the most affordable “upgrade” of the lot!
Replacement type Quad ESL 57 Dimensions 19 x 65 cm Weight 2.9 Kg Electrode material Thermoplastics Driven areas Silver paint Rear electrode 2 mm Front electrode 2 mm Terminations Captive cable Colour codes blue, brown, red Polarising voltage 1.5 kV +/- 7% Diaphragm material P.E.T.P Gauge 6 microns Coating Carbon paint Freq bandwidth 600 Hz—15 kHz Colour coding Grey comparison table
Ron Best
One Thing Audio
September 2008