Jump to content

alkermes

Members
  • Posts

    117
  • Joined

  • Last visited

Everything posted by alkermes

  1. It only took me 4 years to get the second speaker, but I finally finished them both. They sound pretty good, the recap seems to have perked them up a bit. I used pots as in the photo ra.ra posted above, but with the resistor only on the pots for the mids. One of the tweeters does not put out quite as much volume as the other. I see there are now new tweeter replacements being offered on eBay for many AR speakers originating from that hub of AR speaker knowledge and wisdom, the greater Albany NY area. My 2ax's have the earlier tweeter version. I'm thinking about buying the drop-ins, I assume they have the full imprimatur of the classic speaker buff here.
  2. The higher voltage caps give you a bigger safety margin, eg. 21v on the schematic vs. 25v as spec'd, using a 35v cap makes it less likely the cap's rating will be exceeded in operation. Without putting a meter on it it's hard to know for sure what the actual voltage is. You want to use what you find for values on the actual unit, maybe slightly higher for voltages. Some capacitance values are no longer commonly used, such as 2000uf, so as Kent says you then go up a bit to 2200uf as the next best choice (not less).
  3. Ouch, that's too bad. Hope you get replacements you ar4e happy with.
  4. First of all, congratulations DavidR, I am envious! Good luck with your restoration, I'm sure they will be marvellous. Glenn's tip just caught my eye, I had never thought of a cast-off cabinet as a source for veneer. Someone was showing me a pair of derelict Optimus speakers which have a beautiful veneer. Maybe there is a way to repurpose them, they are large speakers, lots of nice veneer (looked like walnut).
  5. alkermes

    ADS L520

    Congratulations, you did well! I also lucked out once, when buying some equipment a few years ago, I ended up with a nice record collection which I have enjoyed ever since. Probably the best part of what I brought home, since I don't remember what the primary object was anymore! Like Glitch, I hope as well that you'll post your further impressions about the speakers when you have a chance.
  6. alkermes

    ADS L520

    I had a pair of L520's that I really loved. However, they didn't look like these ones. They must have been a later model, they had wood veneer and metal grilles. The ones in your photo do not evoke the warm memories I have! It's possible the earlier models used foam surrounds, so make sure to check them out, and of course make sure the tweeters work also. These may be good speakers, or not, I hope you find them to your liking.
  7. An even more specifically: http://www.humanspeakers.com/genesis/gen7.htm Welcome to the Genesis Club! (hmm, does that sound kind of sketchy?) I have Genesis II's, they are good all around speakers.
  8. Yupp, 16 screws are used to attach the baffle board. Here's a closeup photo of one of the woofer screws, you can see the t-nut attachment. The previous woofer pic show the screw heads from the back side of the woofer. I don't recall now if I needed to buy new screws or not, it's been a while but I believe I had to do some hole fixin' to go back to the original woofers.
  9. I recently put my Rectilinear III's up for sale during my early Spring speaker clearance sale. But thanks to a fellow Rectilinear enthusiast, I've decided to keep them for now. I shared this story with him, and thought it would be worth posting here. Some background on these. I don't remember why, but I developed an interest in these speakers even though I had never heard of them before. I checked Craig's List from time to time and eventually found a pair in NH near Jaffrey in July 2012. I drove up there after work. They were being sold by an elderly man who looked like he was getting ready to move. At that point I didn't know anything about these speakers, or much about speakers in general. But I did recognize that they were not completely original. One of the woofers had a funny tweeter thing inside it. The other speaker's woofer had a deteriorated foam surround. I figured one of these was the correct woofer, the other not. The funny thing (especially in retrospect) is that they did sound pretty good as they were. He looked like he really needed the money so I didn't even bother bargaining with him. Well, it turned out that neither woofer was original. Rectilinear used woofers with cloth surrounds. One of the drivers was a University tri-axial speaker, such as was used in the tube days in an infinite baffle enclosure. The other was a late 50's Wharfedale woofer with an incredibly heavy magnet. And it turned out whoever did this work cut the wires in the crossovers and rearranged things so that nothing was working except the woofers. What a mess! I found some photos off the internet that matched up with the version of the crossover in my speakers (there were some different variations). Using these photos as my reference I recapped and re-wired. One of the super tweeters had a small hole in it, I found a replacement for it, then eventually was able to buy a pair of woofers that matched the versions used in this highboy. I used them for a while in my basement, then moved them upstairs to my son's bedroom, but they never got the full listening treatment, as I had during the interval found a lovely pair of Snell II's and really loved them. During my 2017 spring cleaning sale I moved the highboys into another room and had them standing side by side next to each other, and during some critical listening tests discovered that the sound was not really equal from each speaker. After playing around with them for a while, it finally dawned on me that one of the speakers was not putting out bass equivalent to the other; in fact the woofer seemed to be putting out more of a mid-range sound. So I took them off the market and went back inside the speakers, researched crossovers again, drew out the wiring patterns and compared. What I discovered was a real surprise to me; when I reassembled the speakers, I crossed the mid and woofer leads going to one of the terminal strips on the baffle board. I put these back to rights, and presto, the speaker was back in the game. This discovery resolved a mystery for me - the pot for the mid had been operating in reverse. Back then I figured I must have wired the pot in reverse, I never suspected I was using the mid as a woofer, or whatever it was that was going on inside. And there you have it, a rather long story, it took a while to get them sorted, and for me to recognize my error. So now at last they are getting put to real use and to the test. I am impressed at how smooth they sound. The bass could be a little tighter, but it may be the listening space and how they are set up in the room. So there you have it, a rather long winded story. I hope you find it interesting. NB: The odd looking dark pattern that looks like a stain is much darker in the photo than to the human eye. The grill cloth is definitely 70's!
  10. The 2ax's are coming along nicely. I finished one and am listening to the pair now. The speaker with the new caps and l-pads is definitely clearer in the mid to upper frequencies. For the crossover/l-pad rebuild I decided to solder wire extensions to the new components and tied them together to the old wires with wire nuts. The insides now look like the wiring inside a vintage British motor car (with apologies to our UK friends). It would be nice to put some knobs on the l-pads, I did some searching and didn't find any recommendations. Anyone have anything they like to use?
  11. One more question. I recall RoyC recommended not using a resistor on the l-pads for the tweeters in the 3a. Would that apply for the 2ax tweeters as well? I just finished recapping the first speaker, and the tweeter output does seem pretty low. However, that may be because of location of the only spot on the pot where I could get a signal to the tweeter.
  12. Thanks for the tip! I remember seeing those photos once upon a time, back when I restored a set of 4x's. A visual aid helps a lot.
  13. Thanks for confirming the L-pads, I will go ahead with them and the paralleled resistor.
  14. I was wondering if the recommendation for replacement of corroded pots for the 2ax is the 8-ohm l-pad with a 25 ohm resistor. I'm working on the earlier model, with the woofers with the cloth surrounds. I've seen various solutions mentioned, and it is possible that the thinking of what is the best replacement strategy may have shifted, so I thought I would ask the experts here.
  15. ... And my understanding is that the Lowboys need high current power like the 3's to sound their best. My experience with highboys is that they sound pretty good with any amp I've tried. More power is good, but they get along pretty well with whatever I've used with them.
  16. After doing a little research, I see the Model 400 dates back to 1974 or so. There are a couple early IC's in the FM section, otherwise all discrete compnents. By the early 80's a lot had changed. The 420 in comparison use several modern Sanyo IC's in the FM section, and a couple of Sanyo LA4250's for the power amp. These are rated around 6 or 7 watts. There are some nice photos here, http://www.radiomuseum.org/r/adventcorp_response_420s.html. I pulled the case off of mine, it's packed like a sausage inside the casing. I'll post some pics in another thread later so you can compare the two models. The state of the art moved fast back then.
  17. I see the label says 'made in USA', were these ever manufactured in Japan? That's a nifty heatsink!
  18. Hey, that's pretty neat you fixed it, that's always a great feeling. I would probably replace the filter cap but leave the tuner board caps alone, as you never know if that will affect the alignment, since otherwise it seems to be working fine. I have the slightly more sophisticated 420s (the 's' may mean stereo, as it came with two speakers), it came in a grey plastic casing that has held up very well. It has phono and aux inputs, perfect for the hipster generation.
  19. the video works very nicely, thanks for putting it together. That was a nifty little project.
  20. Very cool! Maybe you could put up a video on YouTube, and link it here?
  21. Here is a little Rectilinear love for you - here is a picture of my III 'highboy' cloth. I think it looks much closer to your mid-brown cloth in real life.
  22. Kent, you have helped so much in your posts here, I hope I can make a small repayment. When I started getting into audio gear restoration, I did some research on this topic. The consenus is that metal films are preferable because they are less noisy than metal oxides. In the 1/2 watt range you can buy metal films inexpensively, I think the Xicon's from Mouser are 10 for $1. For the fat 1-2 watt resistors metal oxides are fine. You are more likely to find these in the power supply section. So, it's not so much that metal oxides are bad per se, but that the metal films are better. The cost is insignificant in the common 1/2 watt size, especially compared to going in there and desoldering and replacing. You're likely to only do it once, so my feeling is that the parts cost is insignificant. If you're only replacing one resistor, will you hear a difference? If the resistor was out of spec the unit is likely to sound (or work) better no matter what you replace it with! But if you're going to replace a bunch of them, why not use the best.
  23. Regarding the resistors in your Pioneer - as always JKent gives great advice. However, unless the originals are flame proof, and are your typical carbon film type, I would use metal film (not oxide). 5.9 ohms 1% puts you well within the original spec tolerance.
  24. My highboys have the same grille cloth. I love it, reminds me of shag carpet, sideburns and bell bottoms. Thye also use a similar plastic housing for the crossover and the same pots.
×
×
  • Create New...