NOZ Posted October 23, 2002 Author Share Posted October 23, 2002 Thanks Mobile, Chris and Ed, Chris, I'll take the AA's and for sure give you something for them. Would love to hear the difference. I've been listening to these La Scalas with AL's for about eight years now. I'll e-mail you to talk about this. I would then offer up my AL's the same way to anyone who wanted them, or was in need of them. Sean Quote Link to comment Share on other sites More sharing options...
John Warren Posted October 24, 2002 Share Posted October 24, 2002 Al-Reputations are not always deserved. The AL, except for the woofer inductor, is identical to the AK, which many people find quite exceptable. Quote Link to comment Share on other sites More sharing options...
jazman Posted October 24, 2002 Share Posted October 24, 2002 edwardre, Which one of the wire's should be removed? There is one from each of the two, one to red, one to black, to the tweeter. You're saying it doesn't matter which. Correct. Klipsch out. Quote Link to comment Share on other sites More sharing options...
mungkiman Posted October 24, 2002 Share Posted October 24, 2002 There are at least 3 kinds of AA networks that I am aware of, and probably more. My '73 La Scalas have 5 oil caps, 2 piggy backs and a single. They are square, flat, and labeled "John E. Fast". They sound great, but the oil cap AA's pictured within this post sound better IMHO. Chris Quote Link to comment Share on other sites More sharing options...
NOZ Posted October 26, 2002 Author Share Posted October 26, 2002 AA's with oil caps on their way coutesy of Chris Robinson. Thanks Chris for a great deal. Did you see how much some lunatic paid for just one on Ebay. $129.50.... for one!!!!!!! Quote Link to comment Share on other sites More sharing options...
JohnA Posted October 27, 2002 Share Posted October 27, 2002 The Type AL is a second order crossover from woofer to squawker at a nominal 400 Hz with what looks like some EQ built into the woofer section. The squawker bandpass section has a second order roll-off at about 6000 Hz. The squawker circuit includes a resistor intended to prevent ringing, but it is insufficient. The tweeter is initially a 3rd order high-pass but has additional elements that, after a small shelf steepen the response to, I'm guessing, about 30 dB/octave (5th order). The Type AL also includes the pair of zener diodes. I have schematics available. The voicing of the 2 networks are similar, but detectably different. The Type AL sounds thicker and caused low brass (French Horns, etc.) to blend into a cacophony of howls. At high levels, the Type ALs tend to screech. The Type AA has some of the screech, mostly traceable to the diodes, chopping off the highs to save the tweeter. I am no fan of the AL. I have a hotrodded pair of Type AAs, a pair of ALKs, and a stock pair of AAs. I vacillate between the hotrodded AAs and ALKs as the best. The ALKs measured quite flat in an anechoic chamber, but do not quite have the voicing I fell for 25 years ago. All 3 have the Type ALs beat in the clarity and natural sound arena. John Quote Link to comment Share on other sites More sharing options...
edwardre Posted October 28, 2002 Share Posted October 28, 2002 So John.....exactly how did you 'hotrod' a pair of AA's? Remove steel screw, snip diode wire, add capacitance? Or did you do something different? Quote Link to comment Share on other sites More sharing options...
JohnA Posted October 30, 2002 Share Posted October 30, 2002 So far, I've replace all of the caps with Hovland Musicaps and disconnected the tweeter diodes. I have a pair of 12 ga. inductors for the woofers, but have not installed them. I didn't like the change with the tweeter inductor screw removed. I was given a graph that showed removing it exaggerated the 6k hump in the tweeters response. I heard more brightness and didn't like it. John Quote Link to comment Share on other sites More sharing options...
Deang Posted June 15, 2004 Share Posted June 15, 2004 John, it seems Klipsch used both brass screws and steel screws. Obviously, brass would have no effect at all, and steel would raise the inductance. It sounds to me like you are saying the plots revealed the elevated inductance (with steel screw) brought down the peak. Do I have this right? Quote Link to comment Share on other sites More sharing options...
Dale W Posted June 15, 2004 Share Posted June 15, 2004 Gezz Dean !! your really digging deep into the old threads tonight Quote Link to comment Share on other sites More sharing options...
Guy Landau Posted June 15, 2004 Share Posted June 15, 2004 Tell your supplier that I want some of that stuff, too. Quote Link to comment Share on other sites More sharing options...
Deang Posted June 15, 2004 Share Posted June 15, 2004 Sorry guys, I thought this was going to pop up in the mods section. Quote Link to comment Share on other sites More sharing options...
John Warren Posted June 16, 2004 Share Posted June 16, 2004 ---------------- On 6/15/2004 10:54:15 PM AK-4 wrote: Obviously, brass would have no effect at all... Do I have this right?---------------- No, you do not have it right. Brass is paramagnetic, it will have a relative permeability a little higher than 1 (maybe 1.05?) so it "will" have "some" effect. Air has a relative permeabilty of unity. revision: added relative. Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted June 16, 2004 Share Posted June 16, 2004 Despite the antiquity of this thread (I did the same thing, recently!), I'm glad it has been brought back to life. I found the AA to sound very poor. It was dull, rolled-off, masked in the upper midrange and HF response, but bass was about the same as other networks I've used, which include the A (both with oil caps, poly caps, and a combination of the two), the AA (same as versions of the A, and with the addition of the bridging capacitor across the series caps in the high pass section, and finally lastly the AL. The A with poly caps, bridged AA, and AL sound rather similar to me, with the AA being a little darker than the other two. Another factor that comes into play, which wasn't mentioned above, is the now established fact that SET amps are rounded off at the frequency extremes. With this in mind, it might make sense that the AL sounds better in MY system, due to my use of single-ended triode amplifiers, than it (the AL network) might in a system with different amplification. I totally agree that these different networks all have slightly different personalities in general, but I think it possible that those differences may become more or less emphasized by the manner in which they interact with different source, preamp, and amplifier combinations. This is just they way I am, but when I hear of an audio device that has a so-called 'bad reputation,' I often am interested in learning more about what makes it so. In my opinion, such a reputation does not automatically qualify for a sort of knee-jerk response that results in complete avoidance. As far as the AL network goes, I feel the same way -- and in fact know there are others who also like the way they sound. The La Scalas I sold to buy the K-horns used the AL network. The person who bought them from me called to let me know that the ALs sounded much more bright in his house than they did in ours when he auditioned the speakers, and asked me what might account for the difference. For one, his house has very little wall treatment and all-tile floors. Moreover, he was using the La Scalas with solid-state-everything equipment. It's no wonder they sounded that way. However, along with the speakers, I gave Kevin (not Cut-Throat)an extra pair of AA networks, which he installed, and noticed an immediate improvement. He's now using stock AA networks. Crossover design is complex. I recently read a thread somewhere that questioned why AL's networks have become so popular as replacements. My thought on this is that AL does not simply replace one kind of capacitor or coil for another, but in fact is able to -- and has the equipment and knowledge to do so -- actually DESIGN a network. I have done a little of this when I was building my own speakers and designing crossovers for them, and learned that effective crossover design requires an understanding of impedance equalization, construction of resonant-peak filters, notch filters, etc. It's not simply throwing in a different capacitor or inductor. There's much, much more to it than that. But I'm really glad this thread came up again, because it provides some useful information that can be used to help iron out some of the questionable aspects (if that's the case)of the AL network. For example, a resonant peak filter can be created to bring about an inverse response at the frequency of the peak, which in turn can help bring about a more linear response. The same is true for notch filters. Making any of these compensation networks requires certain parameters concerning the drivers in question, as well as the frequency/ies at which the peaky response is taking place. There are then formulas that can be used to find the needed capacitance, resistance, and inductance to help correct the problem. So far, I don't have a problem with the AL network. I like it the way it is. I'm kind of hard of hearing in one ear though, and might not be able to detect changes I made in the network anyway. The only test equipment I have are sound-catchers on either side of my head, and one of those just doesn't seem to be as good at catching the fly balls anymore -- 'specially those that are really high. Quote Link to comment Share on other sites More sharing options...
BEC Posted June 16, 2004 Share Posted June 16, 2004 On 6/16/2004 4:52:10 AM John Warren wrote: ] No, you do not have it right. Brass is paramagnetic, it will have a relative permeability a little higher than 1 (maybe 1.05?) so it "will" have "some" effect. Air has a relative permeabilty of unity. revision: added relative. ---------------- John, The brass screw has no effect that I can measure on the inductance of that coil and I can measure down to a uH. A stainless screw also has no measurable effect. A steel screw changes the inductance from 245 uH to 385 uH. Bob Crites Quote Link to comment Share on other sites More sharing options...
Guy Landau Posted June 16, 2004 Share Posted June 16, 2004 ---------------- On 6/16/2004 6:42:56 AM Erik Mandaville wrote: Another factor that comes into play, which wasn't mentioned above, is the now established fact that SET amps are rounded off at the frequency extremes. ---------------- Erik, I don't know how who exactly came to this conclusion. I've heared a few SET amps and NON of them was rounded at the frequency extremes - especially parafeed designed amps. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted June 16, 2004 Share Posted June 16, 2004 I just put my Type A's with Auricaps and Hovlands in last night. My innitial impression was more clarity and maybe even warmth. I do have one question for the Xover Gods what effect does using the #3 squawker tap have compares to #4. I'm sure this has some way of skewing the caparison to my stock type A networks. Craig Quote Link to comment Share on other sites More sharing options...
BEC Posted June 16, 2004 Share Posted June 16, 2004 Using tape 3 instead of 4 will drop the squawker output 3 db. Bob Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted June 16, 2004 Share Posted June 16, 2004 "Erik, I don't know how who exactly came to this conclusion. I've heared a few SET amps and NON of them was rounded at the frequency extremes - especially parafeed designed amps." Hi, Guy: I couldn't agree with you more. I included that estimation of SET performance for the same reason I mentioned the infamous reputation of the AL network. I don't think SET amps sound rolled off, but many people do. There isn't a right or wrong -- just what works best for those involved. My whole point is that, just because something has a reputation for poor performance in certain circumstances, doesn't mean that it is necesarily true in all cases. I have built, modified, and heard all versions of the AA and A type crossovers (using the best parts I could afford at the time), and I just like what I hear in the AL better. Even if there is general consensus that the AL network is 'shabby,' I want to use what sounds best to me, not the general consensus. I think it would be unfortunate if someone felt or was made to feel obliged to follow a certain trend that may not be particularly suited to the interests, habits, or inclinations of the individual in question. Some people also think horns are hopelessly 'colored' and inaccurate. I don't, which is why have them. I think parafeed SET amps are really, really good examples of this kind of amplifier. That's was the case with JFL's Horus, and I feel the same about the changes I made and now have in my amplifiers. AND!!! I am also very, very interested in exploring higher power, PP amplification. I worked until about 11:00 on a pair of 6V6 PP monoblocks (integrated) amps I rebuilt years ago, and have them at the point where they are about ready to try. I was not happy with some of the wiring and parts replacement choices I had originally done, and made repairs and changes there. I also tried one of the finished amps in one channel, and there was a strong treble response that I couldn't cure, but noticed in the schamatic that a ceramic cap high pass filter was installed on the input level control, which could boost HF response at lower volume levels (which is how I was listening to the amplifier). I removed that from the circuit, and I'm curious to see how things sound today. It was just so bright that it bothered me. Quote Link to comment Share on other sites More sharing options...
John Warren Posted June 16, 2004 Share Posted June 16, 2004 ---------------- On 6/16/2004 8:01:54 AM BEC wrote: On 6/16/2004 4:52:10 AM John Warren wrote: ] No, you do not have it right. Brass is paramagnetic, it will have a relative permeability a little higher than 1 (maybe 1.05?) so it "will" have "some" effect. Air has a relative permeabilty of unity. revision: added relative. ---------------- John, The brass screw has no effect that I can measure on the inductance of that coil and I can measure down to a uH. A stainless screw also has no measurable effect. A steel screw changes the inductance from 245 uH to 385 uH. Bob Crites ---------------- Bob- I can't comment of the sensitivity of your tests but the point I'm getting at is that brass (and there are many types) are paramagnetic and, as such, will exhibit a relative permeability "slightly" greater than unity (i.e. air). It may only be a fraction of a percent but it is greater than 1. Dean was emphatic about his claim to the contrary which would only be true if the material had a relative permeablity equal to air (i.e unity). Ferromagnetic materials have large realtive permeabilties (>200) and, as your observations prove, their effects are easily measured. jw Quote Link to comment Share on other sites More sharing options...
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