Exactly. That has to be it. This guy really turned those screws up. I wondered how those things held the speakers up.
Thanks,
Kffern
Glad to hear you got them going. They are nice speakers, well worth keeping alive.
Sheldon
I went and bought that $350 pair. They had the most sun-bleached grille cloth I've ever seen, and the clamp boards in both speakers were replaced, and there was the obvious signs of the previous clamp boards catching fire. There was a significant blast radius under the hood. They are all fixed up and working well now. Here they are in my shop with some Curly Maple wooden trim pieces I had made at a CNC shop.
Sheldon
Hi Sheldon,
Looks really nice.
I have to warn you. I will haunt you
as I hopefully this winter start to get my speakers up and running again after they haven't been used for years. That and the two other pairs I bought in an attempt to get a pair for spare parts but turned out to be to good to use for spare-parts. Are now attempting to buy a third pair.
Do you replace the high-voltage diodes per default or do you measure first? I'm looking at getting hold of an high-voltage probe. What do you use?
Cheers,
Mogens
Looks really nice.
I have to warn you. I will haunt you
as I hopefully this winter start to get my speakers up and running again after they haven't been used for years. That and the two other pairs I bought in an attempt to get a pair for spare parts but turned out to be to good to use for spare-parts. Are now attempting to buy a third pair. Do you replace the high-voltage diodes per default or do you measure first? I'm looking at getting hold of an high-voltage probe. What do you use?
Cheers,
Mogens
Hi Sheldon,
I have to warn you. I will haunt you
Could you spare a set of dust cover frames and the plastic plate at the base of the side bar extrusions? I will pay of course.
Here are some instructions for a HV probe.
Regards,
kffern
The wood trim on mine is pretty dull. I tried sanding a bit on the underneath but its so soft it seems to have absorbed a lot of the stain. I plan on making new hardwood tops using a pattern router bit and the old one. The bottom wood pieces have been spray painted black. Again so soft that I dare not start sanding.
I finished front dust covers for both speakers using 3.5 Um mylar. Pretty easy in the end.
kffern
I will let you know if I succeed in getting af pair in "spare-part" condition. As of now the ones I got are in way to good condition.
Thanks, I will take a look. Quad seemed to offer a meter or probe as far as I can see from the service-manual. But, I have not been able to find further information. I read somewhere (could be Sheldon) that it can be a bit difficult measuring as even the high-voltage probe is loading the supply so the measurement is not correct.
Mogens
Restoration Update
Well, I finished the second set of panels and all seemed good till I heard distortion from the tweeter panels of the second speaker. I examined the tweeter panels and noticed that a couple of the side edges weren't perfectly glued. Re-glued and re-diaphragmed and went on holday for 2 weeks. Got back and wired them up but the distortion was still there.
I then swapped out the entire set of panels to the working speaker and they play well. Checked with Rob and I opened the defective speaker clamp board. Looks like the previous owner had tried to do the same as the screws were partially undone. I had bought a pair of 1000uf/25V Panasonics from Mouser on my last order but since the caps looked fine I thought I would change them later. I have decided to change out C27 and C14 as well since its opened up.
I found one of Sheldons posts about adding an 8.2uf polyprop cap to input capacitor and have ordered a pair as well. Postage is a killer but I have no choice. Is there an affordable and practical option to 220uf input cap?
Suggestions on other possible causes for this tweeter distortion?
Regards,
kffern
Well, I finished the second set of panels and all seemed good till I heard distortion from the tweeter panels of the second speaker. I examined the tweeter panels and noticed that a couple of the side edges weren't perfectly glued. Re-glued and re-diaphragmed and went on holday for 2 weeks. Got back and wired them up but the distortion was still there.
I then swapped out the entire set of panels to the working speaker and they play well. Checked with Rob and I opened the defective speaker clamp board. Looks like the previous owner had tried to do the same as the screws were partially undone. I had bought a pair of 1000uf/25V Panasonics from Mouser on my last order but since the caps looked fine I thought I would change them later. I have decided to change out C27 and C14 as well since its opened up.
I found one of Sheldons posts about adding an 8.2uf polyprop cap to input capacitor and have ordered a pair as well. Postage is a killer but I have no choice. Is there an affordable and practical option to 220uf input cap?
Suggestions on other possible causes for this tweeter distortion?
Regards,
kffern
Check the 1.5uf cap in the clamp circuit. you can remove it and give a listen. The triac could be bad.
Swapping bases on a 63 is easy, its just unsoldering three wires and removing 8 nuts. So if anybody has a question as to whether its panels or electronics, swapping bases is a good way to quickly figure out which is the problem if it's not obvious.
Sheldon
Swapping bases on a 63 is easy, its just unsoldering three wires and removing 8 nuts. So if anybody has a question as to whether its panels or electronics, swapping bases is a good way to quickly figure out which is the problem if it's not obvious.
Sheldon
I received the dust cover frame from QUAD Musikwiedergabe while I was away. The Aussie Quad dealer supposedly asked Quad China but looks like there wasn't a response. The dealer hasn't replied to my emails either. Doesn't change my opinion of Australian hifi distributers or dealerships.
Kffern
Kffern
Didn't think of that! I did remove the base when I dismantled the first speaker. All the messy wax puts me off. Wish I had posted here before I put in the order. Hope it isn't the transistor. Should get the caps on the 20th.
Would a 2n6488 be an equivalent?
kffern
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that 1000uF capacitor can make the clamp circuit hyper-sensitive and fire all the time. It's a good thing to replace. Here in the states, the DC supply runs at about 16v across that capacitor, and it's a 16v rated cap, so it's pretty heavily stressed. I swap them out with 25V 105C long life units just as a matter of course.
The cap I was referring to above is the 1.5 uf cap (C14 in the schematic just above) which is across the input transformers. I've had two of those be bad and cause distortion at normal or slightly elevated listening volumes. It's a weird looking square guy on the clamp board.
Sheldon
The cap I was referring to above is the 1.5 uf cap (C14 in the schematic just above) which is across the input transformers. I've had two of those be bad and cause distortion at normal or slightly elevated listening volumes. It's a weird looking square guy on the clamp board.
Sheldon
I finally received the caps I ordered. I changed C14, C28 and C27. problem solved and it sounds quite a bit better than the other speaker with the originals. I didnt add the 6.8uf cap across C25 because I stupidly ordered a 460v Vishay wich is a bit big and might need some planning. Maybe a 100v or so would have been easier.
Thanks for the advice everyone.
kffern
Thanks for the advice everyone.
kffern