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HiAnyone please tell me what size of screw is that for mounting audio transformers to speakers wooden base and where to buy them( So. California) . My speakers missing couple of them
Thanks
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Hi Gary/Sandro,
I would surely like to know about the story behind the selection of screws.
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Those transformer screws are approx. 1/8" wide x 1.25" long but I think the easiest way to match up the thread is to take one of your remaining screws to a decent hardware store & let them screw it into their screw matcher plate. Maybe others have a better solution.Sandro Boccara
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...Sandro. We could have told the story about the highly specialised bolts that Quad used to obtain just the right resonance when tensioned correctly into the transformer through the timber base.Now you've gone and ruined the whole thing :))
Mea Culpa, Gary & AJ. Somehow in the scramble I forgot to mention the resonance controlling micro-tensioning which must be applied to each CNC'd 10-32/1.25" hardened steel bolt, & which can only be accomplished by a fully programmable specially designed Quad tool (read medium flat blade screwdriver). I must have er, slipped a cog. Apologies all around.Sandro
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QUAD came out with a Service Bulletin in 1968 that explained the instruments needed and the procedure for installing the screws. Haven't you seen it? I have a copy somewhere but I cannot remember where, of course.The screws are probably BA thread and so may be impossible to get in the US. Notwithstanding the previous paragraph, one could always tap the existing hole with a machine screw thread or a metric thread and then visit your local hardware store.
Boy, now you really have me in a pickle! Please e-mail QUAD's unsevice bulletin if & when it turns up. And I thought I had all of 'em...Sandro
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Thanks everyone for your info.The bolts are not 10-32 not M4 or M5, I have difficulty finding one that fit,
Bill: What is BA thread ? something unique ? I am reluctant to re-thread, afraid that i will damage them permanently
Anyone know if I can buy these from Europe?
Thanks
I think I understand the problem. The original screws were hand formed by diaphanous Grecian nymphs and imported into Great Britain during the earlier part of this century under heavy cover. They have interesting resonant properties that uniquely conform to the (formerly) SAE thread orifice presented by the female mounting stub located at the four most folded corners of the laminated steel transformer shell. This explains your struggle.Seriously, I have three pairs of ESls and 3 spare output transformers. I went to the extent of removing an original screw and used an ordinary 10-32 thread and it works...additionally, took the original screw and spun on an ordinary 10-32 nut and it works fabulously. Sooo you might have an odd ball or sometimes aligning the screw is a real pain: loosen the two that you have in there so that the tranformer almost flops and put a little silicone grease on the end of a 10-32 screw and it should work.. The studs the screws fit into are brazed on they may have been deformed in the original process or could have been damaged by a previous owner??? Try a brass screw as this is softer and will "conform" without doing further damage if you have to....I need to get a life...Good luck with it hope this helps!
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In truth, we've had a little fun at your expense but I know you are frustrated with the flippant answers to your very legit question. If it's any consolation, I have had to tap out several Quad audio transformer housings over the years. Customers would bring in speakers for repair & make no mention of one or more missing screws. In the very old days English Quad could supply "Screw 2BA 1.25 ch. steel" (Part No. TB220DA) but I'm afraid that era is long over. Still, you could write to Quad's service dept. & maybe get lucky. I'd love to hear from you if you can find the real McCoy.Sandro
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Wow very boring talking about screw size ! 10-32 thread at 1 1/4" should do it. Sandro's advice works... AJ
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