artto Posted June 25, 2004 Share Posted June 25, 2004 My Khorns (76) and Belle (78) still have the original crossovers. Any thoughts on rebuilding these with newer capacitors? Or should the old oil & paper caps be ok after all this time? Quote Link to comment Share on other sites More sharing options...
JohnA Posted June 25, 2004 Share Posted June 25, 2004 artto, Until recently I thought the caps and inductors would remain in spec and perform as intended for decades unless there was a visible defect like a leak. However, there have been a few on the Forum that built new crossovers replicating the originals with new caps and inductors and reported nice improvements in sound quality. Some of those were Type A or AA with new oil caps, too. If I were you, I'd build a pair of new Type AAs with the caps and coils you prefer for your K-horns and see what happens. AS simple as they are, the cost would not be great. I'd use the 3916 autoformer Al Klappenberger commissioned from UTC as it is supposed to have a little more bandwidth then the T-2A. I would also substitute the resistor and polyswitch (PartsExpress.com) used in the Type AK-3 for the KLiP diodes in the Type AA. Quote Link to comment Share on other sites More sharing options...
artto Posted June 25, 2004 Author Share Posted June 25, 2004 Thanks John. Should I use oil & paper caps or is something else better nowadays? Actually, I scrapped the diode protection. And I disconnected the inductor from the woofer as Klipsch mentioned in a Dope From Hope article. Seems to produce a flatter mid bass response. Quote Link to comment Share on other sites More sharing options...
BEC Posted June 25, 2004 Share Posted June 25, 2004 artto, I think you would be fine keeping the original inductors and autotransformers. The caps, I would definately replace. In the A and AA crossovers that I rebuild for customers, the caps have almost always increased in ESR to the point that they are not working right any more. I did a set of AAs today. Big increase in the voltage to the tweeter after the caps were replaced. Right back to where it should be. Bob Quote Link to comment Share on other sites More sharing options...
djk Posted June 26, 2004 Share Posted June 26, 2004 " I'd use the 3916 autoformer Al Klappenberger commissioned from UTC as it is supposed to have a little more bandwidth then the T-2A." It feeds the midrange 400hz~6Khz. The only reason I can see to buy one would for using the 'X' tap. Quote Link to comment Share on other sites More sharing options...
JohnA Posted June 26, 2004 Share Posted June 26, 2004 djk, I wouldn't buy it for the extra tap(s), I'd buy it for the increased performance and unoxidized varnish insulation. I *think* is has a little less resistive loss. Quote Link to comment Share on other sites More sharing options...
BEC Posted June 26, 2004 Share Posted June 26, 2004 John, You are correct about the resistance. The T2A typically measures 0.575 ohms DCR. The 3619 around 0.375 ohms. So, far, in limited testing, I have not been able to see (using test equipment) or hear that difference with an actual signal. I thought at first that I would be able to see or hear that. Bob Crites Quote Link to comment Share on other sites More sharing options...
djk Posted June 26, 2004 Share Posted June 26, 2004 The attenuation is determined by the turns ratio and the impedance involved. The midrange 'looks' like 32 ohms, the fraction of an ohm DCR is moot. Varnish, that's on top of the enamel on the wire, that's a who cares? in my book. Insulation on wire early last century had high sulphur content, now that was a problem with damp storage (garages and basements) for old radios. Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted June 26, 2004 Share Posted June 26, 2004 Guys, Just a bit of history... The 3619 transfomrer came into being becasue Klipsch would not sell me the T2A. I went to Universal Transformer (who also make the T2A) and asked them to design me a "better one". The only real way to improve it was to increase the core area and bifilar wind it with thicker wire. They did it and shiped me the prototype. I measured it every way I could and compared it to the T2A. I also found that I really couldn't measure any significant difference. So, that made it acceptable for crossover networks. I have been usnig them ever since. The real big advantage is that I can get them direct from the source at a lower cost that I could get the T2A from Klipsch once thy relented and decided they WOULD sell the T2 after all! By then though, I no longer need the T2! BTW: I was asked if I would allow anybody to buy them of if they were to be sold only to me. I said they could sell them to anybody but that I would reserve the right to change my mind. So far I have only prohibited sale to a single entity. That was an outfit advertising parts kits for "the new ALK network". They had only purchased 4 of them to that point anyhow! Al K. Quote Link to comment Share on other sites More sharing options...
artto Posted June 27, 2004 Author Share Posted June 27, 2004 So should I replace the caps with oil & paper ones, or are there better alternatives? BTW AL K, your crossovers are still under consideration, but right now it looks like I'm going to have to shell out a lot more for a new SACD player than I thought. Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted June 27, 2004 Share Posted June 27, 2004 Artto, Paper and oil caps are simpy OLD technology. The just absorb power and mess up filter passband / stopband transitions. Don't use them. Use Polypropylene caps. If you have too much highs with them, just add an L pad to bring it back down from crisp to dull. With the paper caps you have the choice of dull or dull! Al K. Quote Link to comment Share on other sites More sharing options...
Deang Posted June 27, 2004 Share Posted June 27, 2004 Paper and oil caps are simpy OLD technology. So are horns -- and the two were put together to give us what we have. Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted June 27, 2004 Share Posted June 27, 2004 AK-4 Yes, horns are old technology. The difference is that something better hasn't come along yet to replace them! Al K Quote Link to comment Share on other sites More sharing options...
3dzapper Posted June 27, 2004 Share Posted June 27, 2004 Quote Link to comment Share on other sites More sharing options...
Deang Posted June 27, 2004 Share Posted June 27, 2004 Did any of you see this post in 2-channel? http://forums.klipsch.com/idealbb/view.asp?topicID=51406 2uF Jensen PIOs have an average ESR of about 37 mOhms. I maintain this "loss" is insignificant when compared to the amount of loss found in the old cans after 20 years. I think it's desireable to use capacitors of the same dielectric, which should exhibit the same electrical and sonic properties as the original cans (when new). If the original networks were built with capacitors exhibiting a bit of "loss", or internal resistance -- then this certainly contributed to the overall voicing of the speaker. I don't see how there can be anything inherently "wrong" with using the PIOs. In fact, if one wants to maintain the original voicing -- then they are the clear choice. Also, reports coming in on my side from those who have ordered my boards using these parts are all saying the same thing: cleaner and more coherent than what what they had. Finally, I still don't believe the measurements tell the whole story. I want to believe that they do -- but they don't. A Solen and a Hovland that Bob Crites measured in Little Rock on Dee's patio measured near identical in ESR -- but these caps sound very different when dropped into a crossover. Solens and MultiCaps also have similiar numbers, but hearing these two different capacitors in the same crossover will leave you shaking your head. Quote Link to comment Share on other sites More sharing options...
Royster Posted June 28, 2004 Share Posted June 28, 2004 Artto, I was at the same point you are a few months ago. My 71 khorns had the orig. AA networks. After reading many posts here I decided to invest into some new networks. Keep in mind that the orig networks sounded fine to me (guess you don't ntice a gradual dcline in performance. I sent ALK and BEC both email asking for quotes and input. I bought a pair of AA networks from (Bob) BEC. 9I would loved to have tried the ALK's but I have to this day NEVER recieved a responce to 4 emails and 2 phone calls. The result was WONDERFUL, it was like taking several blankets off the speakers! Bass was tighter, and imaging was just awsome. I still need to get my stock AA's in for rebuild. Good luck, I know it will be a good investment into your system. Roy Quote Link to comment Share on other sites More sharing options...
Deang Posted June 28, 2004 Share Posted June 28, 2004 I'm tired of hearing about this "no-response" issue with Al from you. I mean, do you have to put it in every post? I thought he said he had server problems there for a while? Here, watch this. Al, you out there? Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted June 28, 2004 Share Posted June 28, 2004 Roy, You have a private message here on the board. Ak-4, Yes, I am here. Al K. Quote Link to comment Share on other sites More sharing options...
Deang Posted June 28, 2004 Share Posted June 28, 2004 19 minutes. Not bad Al. Quote Link to comment Share on other sites More sharing options...
J.4knee Posted June 29, 2004 Share Posted June 29, 2004 I e-mailed both Al and Bob tonight I think there was about a 30 difference between their replies. Hmmm 30 seconds in the computer world is an eternity you boys are gonna have to work on this slow repsonse time. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.