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Lascala AA - Change from polypropylene to polyester caps. First impressions.


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Back story. MY 1977, bought in 2000, used for 6 years. Everything was original, somehow they got duller and duller. At that time I had no idea about ageing capacitors. Years later I changed to polypropylene capacitors because they are the modern standard and have such good properties as everyone says. But the spark was gone. So they were mothballed again. 7 weeks ago I activated them for the first time in years. Somehow the memory of the first years was different, the sound was warmer earlier.

So much for the back story in a nutshell.I must say that I felt little pressure to optimise the Lascala because I have the Jubilees since 2008. But now I have gone through my small collection of all speakers, so much time at home since Corona...


The Lascala with AA and polypropylene (PP) caps.

I like the Lascala very much in principle. It offers such an even impulse over the frequency band that I hardly know from any other speaker. But the sound is a bit hard and edgy. The K400 sounds tinny. The 77 sounds hissy. I can clearly hear all three drivers separately. Intuitively, I listen quite softly; listening loudly to some music hurts my ears a lot. Especially rock and many instruments like in a large classical orchestra. I have avoided songs with soprano saxophone at all e.g. Some songs, on the other hand, are cream puffs. Silky, full and soft, beautiful vocals, some piano recordings. But woe betide an electric distorted guitar. I asked myself, how can it be that some kind of sound is so acceptable and other music is intolerable?


The Lascala with AA and polyester (PO) caps.

I am trying to give my subjective listening impressions because I have not yet found anything on the subject in this form that says more in detail about the polyester caps and their sound characteristics. But I think that the honest listening impression should not be neglected. It is not enough to say buy the Klipsch certified replacement capacitors which are polyester types, the same ones that are used in the current Heritage series today.
What if I do it so that everything is historically correct, but it is done because of an emotion of safety, just because it is recommended? Personally, that would be too little strength of a reason.

I would like to make an attempt here to describe these PO types as I hear them, independent of guidelines or recommendations.
How did I come up with this attempt in the first place? I have read quite a bit in the forum here, the thousand discussions about capacitors for almost 20 years...And of course there are a hundred other forums with 10,000 posts about caps. Then I noticed in some threads here this relatively new movement that there are now Klipsch certified caps. I was sceptical at first...What on earth is a Poyester cap supposed to do I thought...a design that seems to be from the day before yesterday, or that is supposedly primarily used in cheap mass loudspeakers today. Add to that the fact that I have a Tannoy Canterbury from 1993, it also has polyester caps. And Tannoy is really kicking *** that they use clarity caps (PP) in the same speaker nowadays. You can imagine that all this does not help to accept why I should go the way of polyester caps in the Lascala. Add to this that I am not technically very competent. 

I am writing this because others may feel the same way. You hear a lot, you see marketing slogans, then it's the best Teflon caps because they have the fastest impulse, then it's silver or gold foil in oil. The best in the whole world. The gold comes from the legendary Inca treasure and was saved from being plundered by the conquistadors. The oil in which this special gold floats was already part of Cleopatra's bath concoctions. The connecting wires are made of pure silver that was mined in Colorado. Aliens wind the capacitors together in a secret place under the guidance of the spirit of Nicola Tesla. I will not deny that there are other very good capacitors that fit the AA and Lascala. But the message is that the electrical values must be correct as a prerequisite before one evaluates the perhaps great properties of a capacitor detached from it.

In view of this, it is hard to believe that I should use polyester caps to make my Lascala sound original again. But there is another side, 1) because PO are quite cheap it may be worth a try, why not, 2) and that is the main reason. Chief bonehead has spoken on the subject a few times. That convinced me right away. Roy mentions that the cap must fit the Xover and of course the drivers. A supposedly "better" cap can be completely inconsistent. If the values (not the uF value but ESR e.g.) are not those that the xover needs in the interaction of all components then it goes wrong. If the overall impedance is changed, if the energies no longer reach the individual drivers in the intended way, if the phases of the individual drivers no longer work together, if the Q of the caps is too abrupt and thus the curves make the drivers sound too sharp, etc.. 


Because the original Klipsch certified caps are quite expensive with freight and duty, I tested with comparable PO, my motivation was now very high. On the market I have not been able to find the exact capacity values. Probably Klipsch has commissioned a large pile of specific values. I tried it in principle and tested with commercial values of capacity. 2.2uF for the tweeters and 2x6.8uF for the squaker. I know that again I change the ESR if I parallel 2x6.8uF, but I thought if it works well I can always order the 13uF from Klipsch's sales partner so I don't reduce the ESR. I consider the deviation of the capacitance values themselves to be relatively minor for the test, especially with the squaker because it's a 6dB circuit and I'm still in the tolerance range with 13.6uF.


How was the hearing test with the PO:
I initially changed only one speaker so that I could hear mono PP against PO.
My first song was from the CD "Riding with the King" Eric Clapton with BB King, "Three O'clock Blues". Wow! Guitars sound like guitars are supposed to sound. I've been playing guitar in bands for 45 years, still do today. I know what my ES335 sounds like, my Bassman amp or Lespaul Standard, acoustic guitar, drums, etc. If you've been making music yourself for decades, no speaker can lie to you. Back to the song from EC and BB.  With the PO caps, it was instantly fun to listen out loud again without the pain and discomfort. The annoying hiss of the K77 was gone. The guitar has punch and color. The voices are more natural, better said, they are natural now.

Next I heard Getz/Gilberto, 1964, "O grande amor." It begins with a tenor intro. Very melancholy and at the end of the intro, before vocals enter for the first time, the tenor literally screams out. With the PP it was like running away from the room, with the PO it is a strong soulful expression.


Next recording, Daniil Trifonov, "The Carnegie Recital" piano solo, life. With the PP it was so that the middle and higher piano notes always sounded a bit tinny. They stood out, the piano had no wooden body. My guess compared to the PO: It's really not just about the frequency response and equalising what makes the difference. With the PP the sound forms differently! The impulse is not even in the frequency band, some frequencies are "faster" others are lazier. Overall, one might be tempted to associate this sound with the metal horn K400 and project the "blame" on the horn. Often you can read that people want to remedy the situation by wrapping the K400 in tar paper or other measures.
With the PO it was without exaggeration a different instrument. I have a piano in my room, I know how it sounds. Trifonov's playing with PO is melodic, warm, punchy, uninhibited and yet much more powerful. One hears much more the complexity of the chord vibrations with ease.



Next, one of my favorite records. Herbie Hancock, 1975 life, "Flood" of which the title "Spank-a-Lee".  It's about the first minutes, almost only bass and drums. It's a rhythmically very complex music. The interaction between both musicians is fabulous. It's the kind of music I should never try to copy. At best you would hit the notes, but you should find your own thing, it would never have the soul to try to copy this music. Why am I telling this? Somewhat exaggerated, it's because the PP are copying this music. One is satisfied when listening if one does not know it better.
I was shocked when I heard it with the PO. Now it showed that with the PO the bass seemed much faster and lively. The interaction was stunning and lively. In a word, the Lascala have timing with PO that they didn't have with PP. With PP, the bass dragged behind (I mean the instrument, but also the frequency range).

My conclusion, the change from PP to PO is not a small nicety, it is not "nice to have". It is a dramatic improvement that turns three drivers into a whole as a musical speaker. And it  is not just an "improvement" in the sense of a new innovation but it is the rediscovery of qualities that were once a reality but which we can no longer remember after 40 years.
My best acoustic gauge: My wife coming back home when I was done soldering and listening to the music. She just casually says, "Oh, now they sound right".





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I didn't want to advertise specific brands but it's not a secret. I use Kemet and Nichicon. Both brands are described in forums as good quality. It is what I could get from Mouser in this case. I also deliberately did not use Genteq or similar (cans of oil) because I wanted to stay close to the type recommendation of Klipsch. I'm all about the principle at this stage. The orignal Klipsch certified capacitors cost me over 220€ until they are in Germany because shipping, customs and VAT are very high. That's why I wanted to try first.


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7 hours ago, KT88 said:

The original Klipsch certified capacitors cost me over 220€


$220 euros for capacitors?!  Wow!  I know there are premium capacitors which are pricey but here in the US good caps can be found for much less which still sound good.  FYI we don't have the VAT tax and shipping is minimal.  I think US citizens often take their choices for products at reasonable prices for granted.



Your summary:  Great job of describing what you hear in terms of music.  Thank you for that detailed review.  -Dave

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  You are voicing the speakers.

  The K400 in my LSII are fine with the stock caps. Could be PP, PO, or Mylar. Whatever Roy went with. 

  I did not personally like the sound of the K77. Edgy and harsh. Changed the driver and horn instead of the crossover caps to soften and extend the top end.

  Roy changed the driver and horn used in the latest version of La Scala.  No longer a K77.

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16 hours ago, KT88 said:

The orignal Klipsch certified capacitors cost me over 220€ until they are in Germany because shipping, customs and VAT are very high. That's why I wanted to try first.


By "original Klipsch certified...", do you mean the ones from JEM?

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On 5/15/2021 at 1:17 PM, DirtyErnie said:

One speaker at a time, and listening to the change is how it should be done. Good job, and enjoy the music!

The following is not a recipe or a recommendation, I am just sharing how I do it, whether it is objectively "correct" I don't know, but it helps me.


I have learned over several years that the addition of different listening scenarios works well. When I want to listen to the speakers respectively the modification, I first do it for a long time in mono, only one speaker altered. I don't switch back and forth frantically, but I listen a whole piece of music first on one loudspeaker and then on the other. Then the next one. This gives me the basis for my impressions and the descriptions as above in the first post.
I note certain points in the music pieces that are particularly noticeable, e.g. a clear metallic sharpness in one of the speakers or the gain in timing and speed in the other speaker. Then I listen to these short parts again in direct comparison.

When I'm done with everything, I'll have listened to both speakers together with a mono signal. In the case of this test, it was striking that the centre was totally lost. Instead of a defined centre, I heard a very cloudy pseudo-space that can only be explained by clear phase shifts in relation to each other.
In my interpretation, this means evidence that the phases with the new capacitors 'inside' the one loudspeaker, i.e. the three drivers in relation to each other, also run differently because the shift is not linear from low to high freq. It is more like a confusing impression.
So there is more change than just a different 'sound' of the capacitors. They do more than that re the phase shift. This is how I explain why there is more punch and attack although the speaker sounds much smoother and more pleasant at the same time when the drivers are more „in tune“ altogether.

For example, male voices have less disturbing resonances which I would have previously explained exclusively by the thin side walls of the Lascala. These are still thin and resonate, but the resonances are less disturbing because they are more time aligned.

In the end, I hear stereo for the first time after I have also fitted the second box with new capacitors. In this case, critical listening was no longer possible because the grin didn't disappear from my face.

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