Hello--I joined this forum a few days ago and I'm already very impressed with the expertise shown here regarding classic "vintage" altecs. I would really appreciate any advice I can get here as it's not easy finding people who know about these older speakers. I have two pair of Altecs that are about 40 years old and I've heard that the caps in the crossovers should always be replaced in speakers that old. My Altec Valencias are from 1969 (for my basement stereo) and I just bought a pair of 1971 Heathkit/Altec AS-101 (same drivers as the Valencias/voice of the theater) from my local craigslist (for my living room stereo). (left to right Altec Valencia with Altec model 9 on top, heathkit/Altec AS-101) Anyways, the Valencias and AS-101s both have all the original drivers in mint condition and even the original diaphragms. I have noticed that the 806A horn in one of the AS-101s is not quite as bright as the other and that motivated me to open the cabinets and look at the caps. There are 3 caps per speaker and a couple of them look like they may have leaked oil at one time--could that be the reason why one of the horns isn't quite as bright as the other? I've been looking to find replacement caps--GPA recommended I use Solen Fast Caps. I went to the Parts Express website and checked the ratings on all their different brands of caps and the closest I've found are Solen Fast Caps. The originals are rated 8 uf 50vdc, 10 uf 50 vdc, and 11 uf 50vdc. All the caps I've seen at parts express are at least 400 vdc but I've heard that the extra vdc just gives you more headroom and won't hurt the sound--what I really need to match up is the uf rating--does anyone know if that's true? The solen has an 8.2 uf cap which I'm assuming is close enought to the original 8, they have a 10 uf cap which matches the original 10, but they don't make an 11 to match the original 11--they have a 12 uf. Is that close enough considering the solens are +/- 5% and the original caps are rated +/- 10%? Also, the "copper" in these crossovers doesn't look so great. Is that anything to worry about or should I replace the caps first and see how they sound before worrying about the "copper".... Lastly, my Valencias have a sealed crossover box which is riveted shut! They sound identical to each other but they are from 1969 and I can't help wondering how much better they'd sound with brand new caps. Has anyone out there ever pried open one of these Valencia (type) crossover boxes which are riveted shut? Any advice on how to do this safely? If I ruin my Valencias I'll have to put myself in the doghouse!
P.S. I also have a pair of P.A. Voice of the Theater A7 speakers (in the huge cabinets) that I use for PA for my (rock) band and I'm considering replacing the caps in those crossovers as well--has anyone out there ever opened up the crossover box for an Altec N501-8A crossover before? The speakers/horns sound identical to each other but like my Valencias, I'm wondering how much better they'd sound with new caps......The description of the Solen Fast Caps on the Parts Express website makes them sound like the best thing since sliced bread! "The exceptional Solen line of metallized polypropylene capacitors features a high purity, polypropylene film dielectric. They exhibit outstanding high frequency characteristics, low dielectric absorption factor, high current capacity, and unrivalled handling of fast high current pulses. Designed specifically for use in loudspeaker crossover networks. All values are rated at 400 VDC, except for the 130uF, 160uF, and 200uF values which are rated at 250 VDC. 5% tolerance. "
Thanks for any help on these questions that anyone out there can give me.....
Dave