mungkiman Posted October 12, 2002 Share Posted October 12, 2002 I have some project speakers I've been working on. The AA networks were borrowed from '73 La Scalas until I recently purchased another pair of AA's. The seller said these were from '79 Khorns. I'm hearing a lot more deep clean bass than I do with the '73 networks, and I'm wondering what the differences between the networks would be. My project speakers are: Speakerlab clone Klipschorn bass bin with '73 K-33-P woofers, Altec 511B horns with University SA-HF drivers, and University 4401 tweeters. Currently I am using the '79 networks and really like the sound better than before. I think the woofers went to K-33-E before '79, and I assume the network was tweaked at the same time. Am I in danger of damaging the '73 woofers with a later network, both AA's? If so, I would rather put them back into my '73 La Scalas, completing them again, and order some new K-33-E's for my project. Any advice would be appreciated. The Speakerlab bass bins came with a driver that looked identical to the P, had the same DCR, and sounded great. What other tests can I perform to see if it is a close match for the K-33-P, K-33-E, or neither? Thanks for any help. Chris Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted October 12, 2002 Share Posted October 12, 2002 mungkiman, An "AA" netwrok is an "AA" is and "AA"! It has a single inductor in series with the woofer. Both sets should sound identical on bass unless one set has a higher quality inductor in it than the other. Compare the iron core components that have only two wires coming out of them to see if they are different (the transforme looks similar but has several connection points). Al K. Quote Link to comment Share on other sites More sharing options...
mungkiman Posted October 12, 2002 Author Share Posted October 12, 2002 Al, Forgive my ignorance. Each AA has a similiar configuration. There are three metal containers, a spool, and two items that look like rolls of tape held by square collars. The metal containers are different between the vintages, while the other parts are verysimiliar. One of the rolls is on a vertical axis, the other is horizontal. One has 6 taps coming out with wires attached at 6,5,&4. Is the other roll the inductor? If so, the square collars are stamped with #: 2133 on both vintages. Chris Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted October 12, 2002 Share Posted October 12, 2002 mungkiman, The one marked 2133 is the woofer inductor. The other, with the 6 terminals is the autotransformer. I doubt if there is any difference in the woofer inductors between the two vintage networks. The only other thing that might make the bass seem higher is if the squawker was running at a lower level. That could be caused by a bad 13 uFd capacitor (the aluminum cans marked 2 uFd and 13 uFd on the older set). Check the connections to the autotransformer too. They all should have connections to terminal number 4. If somebody moved that wire to some other terminal, moved it back! Al K. Quote Link to comment Share on other sites More sharing options...
mungkiman Posted October 12, 2002 Author Share Posted October 12, 2002 Al, The only differences in the woofer inductors are in the stamping. Ink stamped for the '73, and stamped into the metal on the '79's. The capacitors are the same between the '79 pair, but the capacitors on the two from '73 are different from one board to the other. The '73 networks are from consecutive La Scalas and appear to be original. This difference may be partly to blame, however. All networks are connected to terminal 4. Chris Quote Link to comment Share on other sites More sharing options...
Guy Landau Posted October 13, 2002 Share Posted October 13, 2002 mungkiman, try to remove the screw that hold the plastic cap of the top left inductor.It is the tweeter inductor but it really opens the sound. Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted October 13, 2002 Share Posted October 13, 2002 Guy is right. The tweeter inductor is mounted with a steel screw on early "AA" netwroks. That louses up both the Q and the inductance. If it's got a brass screw that's not as bad, but remove it anyhow. If the coil falls off, but it probably will NOT, just glue it back on with silicone goop. That's not going to do anything for your bass problem though. That has me stumped! Al K. Quote Link to comment Share on other sites More sharing options...
HDBRbuilder Posted October 13, 2002 Share Posted October 13, 2002 Sometimes the simplest solution to a problem is the last one tried. We all have gotten so caught up in things that we sometimes overlook the obvious. I am assuming you have already done so, but if not....Have you checked to make sure the screw connections are clean, bright and shiny where the screws hold the wiring down at the terminal connections??...sometimes glop gets on them over the years, corrosion, etc. Clean up those connections if you haven't done so already and then see if they sound the same. Clean the connectors on the wires that go to the terminal connections, too. Also check for a "cold solder" on the soldered connections. Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted October 13, 2002 Share Posted October 13, 2002 builder, Did you ever hear any talk about that steel screw in the tweeter filter of the AA network while you were at Klipsch? Maybe a discussion about the use of a steel versus brass screw? Al K. Quote Link to comment Share on other sites More sharing options...
HDBRbuilder Posted October 13, 2002 Share Posted October 13, 2002 AL, If I did, I don't remember it. Back in those days, I was just a peon speaker builder...still am. I picked up alot from the engineers when sitting around shooting the bull, but I was, and still am, a neophyte in the electrical end of things on speakers. Hell, I don't know a triode from a diode!! LOL! But I figure that I can and will be learning, pretty soon...considering I plan to attempt to build a tube amp in the future!!...LOL! I understand how to wire a house, if that will help me any...LOL! I've had to do that a few times!! LOL! It seems to me that if a brass screw is better than a steel one, then a copper screw should be better than brass, though(or at least copper plating on it), provided the copper is coated with di-electric grease ...but what the hell do I know? Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted October 13, 2002 Share Posted October 13, 2002 Builder, Ok.. I just thought you might have heard something about the screw. The best screw to use is no screw at all! Steel is a conductor and a poor one. It acts like a short circuited turn like a transformer secondary winding. Current goes around inside the screw and gets lost. To make matters worse, it acts like a "core" to raise the inductance. Brass has a negative effect and lower the inductancs, but not as much as steel raises it. Becasue brass is partly copper, it has less loss to the circulating (eddy) currents and contrinutes less loss to the coil. As to a copper screw, I have neer seen a copper screw! I never thought about that possibility! Why bother anyhow? Just glue the coil down or use plastic cable ties like I use to mount my inductors! Al K. Quote Link to comment Share on other sites More sharing options...
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