KT88 Posted October 31, 2022 Share Posted October 31, 2022 1.5 years ago I described how pleased I am with polyester caps I traded in for sonicaps. It was only a test and I used standard values which did not exactly match the Klipsch requirements. I thought 10% tolerance was ok. I used 2x6.8 uF instead of the required 13uF. And for the tweeter of the AA crossover 2 caps each 2.2 uF instead of the required 2 uF per cap. I thought I was not that wrong, but somewhere Roy Delgado described that the uF values should be followed as closely as possible because the intended range of use of the 2 uF caps in series depends on the accuracy of the 13 uF. In the meantime, I have learned that the total ESR of caps in parallel is pretty much the same as the ESR of a single cap with the total capacitance. So I tried it out, for 13uF I took 6.8 4.7 and 1.5 uF. For 2 uF I took 2x1 uF. I was able to match these polyester caps with each other so that I actually get 13.04 uF for both channels. I wouldn't have considered this change worth mentioning if it hadn't had such a positive effect. Ok, at the same time I removed some unnecessary connectors from the xover, of course the circuit remained the same, but these connectors are not responsible for the positive effect of the correct uF values. The result is that the LaScala sounds very "right" now. I couldn't get out of my chair because of the listening pleasure, although I just wanted to check that it works after soldering. The loud and sensitive horns register every small change for the better with great effect. Squaker and tweeter discolour much less and the added transparency and punch almost scared me. Basically, this post is a plea for using JEM original Heritage vintage replacement caps. Only because of the high cost of shipping to Germany, customs and import VAT I did not order them from JEM. I can highly recommend it to every vintage Heritage owner to use JEM caps because only there the uF values are exactly matched to the Klipsch speakers and you will make the same positive experience. Below is a picture from today, I am not a master solderer but it works. Don't believe anyone who says that polyester caps are not transparent or that violin strings sound like paper or any other nonsense. They are the caps that exactly fit the vintage Heritage models and Klipsch still use them today, as do other well-known manufacturers, e.g. my Stirling Broadcast LS 3/6 and LS 3/5a use the same type of caps. It's not about buying cheap parts but about the "right" cap in the context of its circuit and it's not about the "best" cap in its own 3 Quote Link to comment Share on other sites More sharing options...
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