One Thing Audio
One Thing Audio
OTA ESL 63 EQ, the Widget
OTA ESL 63 EQ
Introducing: the “Widget”
The most cost-effective upgrade yet devised for this truly classic loudspeaker?
At the time of writing, what is arguably Peter Walker’s finest creation is about to celebrate the 27th birthday of its introduction. Like the ESL 57 which preceded it, it is slowly but surely acquiring “classic” status, possibly due to the fact that, working properly, it is probably the most accurate sound reproducer on the planet (which even the very dedicated Quad team themselves have only been able to ‘top’ with a long-term programme of expensive refinements). . . . and is occasionally available on the second-hand market for silly money.
Over the years we have compiled a dossier of “improvements” to the ESL 63, the total number of which we have lost count - but the remainder worthy of note currently stands at 13 (unlucky for. . .well, it won’t be long before another one will be added to it so there is no cause for panic). Some are (in our humble opinion) cheap to incorporate but of questionable value; others are slightly cranky; some are downright dangerous; some show intelligence, and a good knowledge of engineering, and will undoubtedly be moderately effective but are too difficult for the average owner to even contemplate. Others hale from over the pond, and are usually incredibly expensive, but produce an audible difference rather than an improvement in any generally accepted sense - and some of the mods are just plain daft or aimed at the gullible with more money than sense. We believe we can make these statements with some authority, as we have at least tried to put most of them into effect (not all, as some were so pointless and arbitrary that we - rightly or wrongly - considered them a total waste of our valuable time). In audio, common sense and nonsense predominates in a ratio of two-to-one. And perhaps the latter category drive the biggest cars (a cheap quip - and maybe it’s untrue - but we are unrepentant!)
Anyway - to get back to the nitty-gritty - one small and undeniably effective mod to the ESL 63 has usually proved very worthwhile and cost-effective, and seriously investigated by many serious audiophiles including the late lamented Robertson-Aikman. This concerns the simple ‘equalisation’ network placed in the ‘live’ wire of the 63 input, and all current derivates of that loudspeaker. Mr R.A. considered this network important enough to substitute a cluster of high-quality capacitors the size of cocoa tins, which were allowed to ‘dangle’ at the back of the speaker adjacent to the input terminal. In parallel with the capacitor network is a high-wattage resistor . The latter is not critical in terms of quality, but should be pretty temperature-stable, and many unnecessarily expensive devices have been nominated for this fairly mundane function.
In place of Quad’s non-polarised electrolytic (not bad quality, at that) and adequate series resistor, many “audiophile” substitutes have been propounded. For many years we ourselves supplied an “upgrade” package consisting of a thick-film plate resistor and Black Gate cap. After many hours of listening we came to the conclusion that the “modification” was worthwhile, but perhaps a bit expensive in terms of the perceived improvement. Then the price of Black Gate caps went through the roof, and competing products were being pushed aggressively into the commercial spotlight - the costs creeping up and up. Make no mistake, all these components were better than the originals which Quad (for understandable commercial reasons) were obliged to use, but were more expensive (in one case, over 130 times more expensive!)
We decided a fresh approach was called for, and building on the research carried out for our incredibly well-received ESL 57 EQ (the “Widget”) we began work on our EQ 63 version. It took many months of painstaking trials and research to arrive at a circuit which sounded and measured to our complete satisfaction, and feedback from ESL 63 owners and a veritable army of golden-eared friends and critics appears to have justified our efforts. The finished product is far removed from the simple ‘R&C’ network of the originals, but has a better power rating, is affordable, and superior to anything we know of offered as an “upgrade” to the original, irrespective of the cost of components employed. The EQ 63 has been made to fit in the smallest package we could devise, so it can be easily accommodated in the base of the loudspeaker in place of the original components. Easy-to-follow instructions are supplied. [See EQ 63 on our current price list].
August, 2008
