New Centaur Minor owner

[Vansloneker]

Thanks for the quick reply, JarreYuri. With a magnet it's simple to test, the ones in the bigger coils as on the image are magnetic. The bolts I used on the smaller coil -no image- are not, but the rings are, so I will remove those.

[Vansloneker]

The speakers are playing. This has been an unpleasant job. Removing the coils from the back plate was difficult mostly because of the way they were soldered. Apogee didn't save on solder and the wires were bended two or three times. While attempting to get the wires off, the wriggling caused a lead from a capacitor to get off



Since unsoldering the wires was to dangerous I jut cut off the other connections.
I was going to replace a few capacitors, but I wanted to do that after the potting, to be able to determine what each change would do to the sound. Now I had to replace the damaged cap, and the other speakers' equivalent cap with temporary caps while Clarity Caps ESA caps are being ordered. Or do without my Apogees for even more days.
I've also replaced the 1.5 Ohms resistors in the high section.

Putting back the potted coils also was hard work. The smaller coil would not fit in it's original location so I had to move that to another spot on the back plate. To make it fit, the unused High contour switch went out, and a corner of the epoxy (without wiring of course) had to be sawed off. Soldering the ends of the wires that were cut, was again very difficult. I don't know what is used on the coil wires for insulation but it wouldn't come off the normal way. I ended up with scraping it off with a knife, and even then it was reluctant to be soldered.

My work isn't going to win any beauty contests, that's for sure. In future, when I maybe able to replace more caps, I may move the entire X/O external and make a clean layout with silver wire and new solder joints.

So far I did not pot the big coil that is attached in the inside of the speaker. It looks like it's treated with something and I had enough troubles on my way with the smaller coils. EldRick used about three different kinds of epoxy as he wrote in his topic. I did it with industrial epoxy I got straight from the factory. It pours well and there is plenty of time for that. For use the way Eldrick did just a little waiting for it to get viscous would do.
After the cast, evil vapours came off that even made me vomit and I quickly moved the moulds into a storage room.


I literally had to eat my way through these 'moulds':



right click, view image

[JarreYuri]

Good work!

I am in the work of building an airtight container for my potting.
I have already bought a vacuum pump so that I can draw out all the air from the coil.
My potting compound is black though.
Looks nice with clear Epoxy!

I hope it will sound great for You!

Cheers!

[Vansloneker]

I am confused.

After putting in the potted coils and replacing the damaged 10 mfd cap and it's undamaged counterpart and the 1.5 Ohms resistors I listened mostly pop music for a few nights. On most music I experienced a magical separation of tones and voices, like I almost never heard before. Every voice and every instrument could be located spot on. I understood lyrics I never really understood. Part-song was unraveled to the point where individual voices were heard and located. I heard tones never heard before and they were all in the exact right spot. I couldn't stop listening!
I credited the potted coils for this, after all, what could a humble PWA cap not even broken in and a resistor really contribute to the sound?

Then the ESA caps arrived and I was curious what would happen next. Well, after I fitted the two 10 mfd ESA caps in each X/O, the magic was gone. Perhaps I wasn't in the right mood, maybe my ears were having a bad day, the ESAs need breaking in etc. Next day, same story.

I had replaced the 10 mfd caps in the high capacitor banks and the 10 mfd going from the high capacitor bank to the ribbon with ESAs. Temporarily I had just replaced the 10 mfd from the banks to the ribbons with sort of ordinary Clarity Caps PWA caps. Could this be the source of the magic? So I disconnected the latter two ESAs and put the PWAs back in. And hear, part of the magic was back.
I tried back and forth a couple of times and I can't help finding that with the PWA the sound is just more clear and the music is more interesting and drawing my attention. It's not that the ESAs are not good, they just seem to do to much. With the bypass ESAs I experienced some breaking in but they sounded right from the first moment and I cannot really believe the current experience will change much during breaking in. I even feel tempted to replace the other two ESAs for the old caps...

I had no doubt about the ESAs after putting in the two bypass caps and hearing what they did, and what motivated me to do more work on the X/O. But what I experience now is the least I expected and that's why I am confused.

[apogee_admin]

Some of these changes are a balancing act, but I know for sure that the ESA's are better as they are much more neutral/detailed/spacious than the PX range which is slightly better than the PWA's.

I think it's a combination effect of the original caps which are ok, but probably not as good as the PWA's.

I do have some run-in 10uF PX's if you want to try them, would only want about 2 euros each.

Jon

[EldRick]

Air core simply refers to a coil without an iron core, which increases the inductance considerably without resulting in a larger coil. Non-magnetic material like epoxy does not affect the magnetic field enough to worry about.

A non-magnetic bolt would be a good idea - keep the magnetic stuff out of the core.

And perhaps you got a bad cap with internal shorts or leakage.

[Vansloneker]

Jon, I'm really curious. I'll take the PXs. I have no doubt about your opinion about the ESAs. Maybe a bad match somewhere indeed. The old caps really are old. One more died when after removing I just wanted to bend the lead: it just fell off. Would replacing the other caps with perhaps PXs or a mixture of lesser and better caps maybe cure the problem? Anyway I'll allow the ESAs some more run in.

EldRick, they are with non magnetic bolts now.
And I have no idea how to test them for deficiencies.

[apogee_admin]

Send me a pm with how many you need and your address and I will find out what the postage is.

Best not to have any type of metal at all near the coils, silicone sealant sticks them down amazingly well and you can still get them off if you need to.

Potting the coils definitely helps, but the copper foil ones are in another league sonically as they let so much more information through, I am sure it is down to the fact that they are a perfect coil rather than a slightly "randomised" version with many overlapping layers of wire. I was amazed at how much difference changing even the tiny value coils Apogee used in the mid/tweeter section makes.

[Vansloneker]

Last night listened to Jazz with the ESAs back on and I have to say, they do have the finer touch when it comes to e.g cymbals.

[Vansloneker]

Here's an update on my capacitor work. This started when on the forum Jon recommended using bypass caps to get better sound from your Apogees. I applied 0.1 mfd Clarity Cap ESA on both the high and the low Apogee stock filter of my Centaur. This was an improvement that made me want more.

I did some thinking and reading and had a suggestion from Eldrick and decided to pot the coils and change a few caps and the resistors. The idea is, by changing a cap in a capacitor bank, you get most of the good from the new cap and lift the quality of the x/o with a smaller investment as when replacing all.

The Centaur x/o has a low filter, a high filter, and the high filter is connected to the ribbon via a resistor and a parallel cap. I wanted to replace that cap with an ESA, and change one cap in the high-bank for an ESA.
While working on removing the coils one ribbon connecting cap got damaged and as a temporary solution I changed those for a Clarity Cap PWA. I was stunned and astonished by the result of this. A huge improvement was made in the placing and separation of tones and voices. They could be located exactly, sometimes even scratching at the holographic thing. Vocals much clearer, I often would look up lyrics and then had to make believe this was what was sung, now I could hear it.
The overall sound was good but a bit sturdy, not as refined as in the previous situation. But the PWA is just a basic cap in the line-up. So with the upcoming ESA taking the place things should be even better, as this setup already had the ESA bypasses an they provided miracles.

Well, it didn't. After replacing one cap in the high-bank with an ESA and the cap connecting to the ribbon with an ESA the precious spacial information was mostly gone. Not that that there wasn't, just not like that. After some breaking in and getting used to the overall sound however benefited from the ESA's which I find play instruments like cymbals and vibes and similar just wonderful.

Here's where Jon offered me some Clarity Cap PX's. They are next in the line-up from the PWA. After a while the batch had arrived and I started with replacing all caps with PX's, no bypasses. I'd say they give a fair performance. They are sort of laid back and unobtrusive. While playing random jazz several times I had this "hey what's this" and had to look at the playlist to see what was playing. I could listen for hours to anything even MP3's doing things but it wasn't really inviting me to go sit in the listening seat. That extra bit of ESA clearly was missing and after a couple of days I changed the ribbon connecting cap for an ESA. What an improvement! Here the goodies came in and the speakers really started to sing. I listened to albums like "Days of the Future Passed" (Moody Blues), Innervisions (Stevie Wonder), Nina Hagen Band and The Wall (Pink Floyd). These are all albums known to be extensively produced and they sounded great. Tones and voices were located spot-on and voices sounded natural to me. No frills and fancy stuff. The setup liked to have some volume fed to shine. Sometimes they talk about music coming from a dark or black background and that description sort of comes close. I was happy with it but still would like a bit more ESA.

So again one cap in the high-bank replaced and well, just like before the magic was gone. It got definitely more ESA sound but again most of the spacial information was gone. Apparently tonal quality and spacial quality are different quantities and they don't have to go hand in hand.
I tried all these configurations for mostly a couple of days, sometimes changing back and forth, these are not just first minute impressions, I really tried.

Well cap changed back and tried with the bypass. This was sort of same experience. For whatever reasons, the ESA does not match with the PX in that situation. Apart from listening I did some reading and thinking and apparently some combinations can give a phase-shift. To me it sounds like the sound gets a bit smeared, it all sounded rather contrived. It's not much, but an Apogee ribbon will let you know. It's been said before, an Apogee is like no other speaker. With an ordinary speaker you replace parts, it works and you're happy. With an Apogee that is only the beginning of things and it's a challenge to find the right parts in the right spot.

On the internet there's a lot to be found about capacitors. Interesting to read, there are some good clues to be found. It is maybe a bit equal to the art of "tube-rolling". It comes down to mix and match and trial and error.

By now I was having my doubts about bypassing. But I wanted to go to the bottom of things and do a final try with a different brand. An internet shop I had come across had a sale and I scored the last pair of Mundorf Supreme 0.1 mfd bypass caps. They made up for the rebate in the shipping costs by the way.
Anyway they arrived yesterday and after a busy day I soldered them in right away and held tight for the inevitable, this would not work and I had wasted the money.

First impression: hadn't I soldered them in myself I wouldn't have known, they blend in perfectly with the PX's! Today went to listen again before making dinner. Well my glass got empty, I got cold and hungry but I had problems getting away from the listening seat. I can understand why people appreciate the Mundorf Supreme, and also why people maybe dislike them. There is detail, detail, detail, gobs of detail, even after my recent experience incredible amounts of details I never heard before. Separation and placement of tones and voices very good. This has no black background, there is no background at all, it's that transparent. On a live recording a presence of audience I never heard like that before, individuals screaming or singing, wonderful clapping. Strings, Louis Armstrong and Ella Fitzgerald very convincing. Even with a reasonable volume a pleasure to listen to, and fade out was audible longer then ever before.

In this situation and set-up, and at this moment, they are like driving a luxury car. Your drive is excellent, effortless, no roar or noise. But also not that exciting. Not the fun of steering your sports-car pin-sharp through a roundabout and put the tailgater behind. There is an emotional distance, I got little or no goose-skin. Nina Hagen her voice sounded way to polished. While horizontal placing is very good, not a hint of three dimensional placing. Cymbals do not stand out like with the ESA bypass. I really would like a bit of ESA on this, I think I'll try the ESA bypass on the ribbon connecting cap although I don't expect much of it. But I have been wrong before, nothing but trying out gives the answer. But hey it's only two days actually about 26 hours with this setup, the Supremes maybe need breaking in and will get better.

Still I had another good time discovering and enjoying my music. I can honestly say I heard much of my music in a way I have never heard it before, and that is what high-end is all about for me. And it's great to lift the in the Apogee world unloved Centaur to new levels of fidelity.

[Vansloneker]

I still enjoy the Mundorf caps mostly with pop music. They are also very good on classical music, but I find jazz a bit less interesting with them. I think because I'm spoiled by the ESA's. But the Mundorfs are very musical to me, really.

Really enjoying the Mundorfs is very limited to the sweet spot for me. At first nothing special, after a little you begin to notice things and enjoy the details that are unveiled and the placing of tones and voices. I've always liked "Excerpt from a teenage opera" by Keith West. Hearing it through the Mundorfs gave new dimensions to it. The children singing as if they are standing in front of you, with individual voices clearly noticed, it's miraculous . It caused me to investigate what this song actually was about. Such a wonderful song about such sad thing, just like "Don't fear the reaper" from the Blue Oyster Cult.

The soundstage with the Mundorfs could be a bit wider though.

Now I tried the ESA bypass alongside the Mundorfs. The ESA bypass next to the ESA 10mfd connecting to the ribbon eats up all the Mundorf brings. No gain here.
The ESA bypass alongside the Mundorfs in the high capacitor bank brings back that ESA sparkle, without being that aggressive. But at the cost of spatial information. The exact spot of the tones and voices is just more washed out.
Jazz sounds great though, the ESA is wonderful on jazz percussion. I am also enjoying this very much while e.g. working in the kitchen or sitting at the dining table.
I feel it's very similar to but I can't tell if this setup is actually better then the situation of the stock caps with the ESA bypasses, one get's used to improvements quickly. (On second thought, I think it is.)

The Mundorf is very good at handling complex signals, as pop music can be and symphony orchestras are. Jazz is less complex, usually a handful of artists in a fixed location. The jazz recordings usually are very good and already have good spatial information. Therefore the ESA's can make the music shine and don't get lost in unraffling locations and sounds. Just a thought.

There is a psychological factor in changing caps -or tube rolling, or changing cartridges- that just the different sound makes it interesting and appear as better.
Anyway I do find it astonishing how a single cap can totally alter the signature of a speaker.

I don't know yet where to go from here. I am seriously considering making the bypasses switchable even when it feels like a sin. I loved the pure sound of the PX's, and I love the Mundorf bypass and the jazzy ESA.

Considering the result of the PX's I do feel it's best to have one bank of capacitors made from one type of capacitors. The bypass trick really is a trick, can come a very long way but it's not the real thing. A different cap on a different location in the filter is ok though.
Well all Mundorf is out of the question, just can't afford that. All ESA I'm afraid this may be a to aggressive sound.
All those doubts, live isn't easy for an Apogee owner!

Finally, in case it's not obvious, I wan't to express how much I appreciate Jon sharing his knowledge about and his caps.

[Zardoz]

I've really enjoyed reading of your experiences with the different caps. I redid the crossovers for my DIva's with all ESA's and a Mundorf for the bypass. Using all ESA was a revelation compared to the stock caps. I never tried mine without the Mundorf bypass, so I don't really know how much that helps, but I must say that they sound outstanding compared to the stock caps. Have you thought about trying all ESA instead of the mixture you have?

Good listening,
Z

[Vansloneker]

Thanks for the positive feedback Zardoz.
I sure did and do consider all ESA. I think you have made an excellent choice.

Right now I am assessing these baby's:

[Scinemaniac]

Avoid magnetic nut also.

----

I used large size brass wood-screws.

Drill a 1mm tapping hole into the mdf backboard, find a steel screw of equivalent size to the brass one, screw the steel screw into the hole almost as far as you will need to anchor the coil, then remove the steel screw.

This has prepared the hole ready for the brass screw.
Then insert and tighten the brass screw.

Why this procedure:

brass is very soft, and it is possible snap the thread when tightening into a stiff material like mdf.
the 1mm initial hole is needed to guide the steel screw.
If the steel screw does not go far enough before it gets stiff to turn, drill a slightly larger tapping hole with a larger drill bit.

[Scinemaniac]

cf. photo in June
with steel nut holding the coil

[Vansloneker]

This review inspired me to try the AmpOhm caps. That and the fact I found them local at a discount price. Unfortunately, the AmpOhm company went into receivership in 2009. So I scored a pair of New Old Stock Caps!
According to this Eric they are a better Mundorf Supreme. I scored one pair, connected them as bypass on the 70mfd high filter bank and had a great weekend listening to them. Then I scored the last available pair of 0.1mfd's and had those fitted as a bypass on the 10mfd ribbon connecting cap.
The sound had completely changed. I had made the mistake of having the Mundorfs as bypass on the 10mfd ribbon connecting cap, which I had changed back from ESA to PX. Turned out I had been listening to the Mundorfs mostly.
I never heard the Mundorfs silver and gold Eric compared the AmpOhms with, but the AmpOhms do have imho a very different character from the Supremes, and the silver and gold ones can't be that different I suppose?
I found they sounded more like the ESA as like the Mundorf. Like the ESA they are more up front, but not as aggressive. I found them sounding a bit dry. Also I found the sound very similar to the Apogee sound with stock caps, just much better. The AmpOhm caps are loved by musicians. I did not listen very much really and have to give them an other go later. They really are different from the other caps and deserve more attention.

It is fun to order a pair of caps, put them in the X/O and enjoy your 'new' pair of speakers. But cap testing is not my goal. People like to test caps and write about it, there's plenty to be found on the internet. Most of these test are performed on amplifiers and the results on speaker X/O's can be different. Here's another interesting one. One single Audio Note cap costs as much as I have spent so far!

I was curious about the Jantzen caps but could not get my hands on them easily. Since I enjoyed the Mundorfs so much, I decided to get a couple more of them for the other parts of the X/O. This decision was helped by the fact that I could get these at a discount. But it is my final purchase! I gotta make do with what I have now!
NorthCreek once wrote about bypassing and suggested to use 0.5 to 1% of the value of the main cap. With that in mind I picked a 0.33mfd for the 40 mfd low filter, 0.68mfd for the 70mfd high filter and moved the 0.1mfd I already had to the 10mfd ribbon connecting ESA.
I find, that with breaking in, the Mundorfs had opened up on the higher frequencies.

Sadly, then I had to learn about the passing of one very good friend and grief keeps me from getting excited about it. It is a special mood and effort -at least for me- to evaluate the caps in the X/O and right now I just can't do it.
Things sound alright though and I had these few special moments.

Things will change and music will get more fun. I will keep the setup with the Mundorf bypasses for sure. I'll try what mixing with the AmpOhms and ESA's bring and either add these, leave them out, or make them switchable. I think the last, for the jazz.

[Vansloneker]

11 past 10 pm, just finished dinner. Kinda late but I allowed myself a brief listening after a busy day before making dinner. So the brief lasted a bit longer, a good sign.

I feel I made a good move with the 0.5-1.0% Mundurf bypasses. I've also added the 0.1mfd AmpOhm to the high capacitor bank as a bypass, side by side with the Mundorfs. I feel they sort of compensate for the Mundorfs deficiencies and add to the listening experience. They are a bit hard to interpret but so far I am having the impression they are very subtle. Where they Mundorfs have -to exaggerate things- this demanding hear what I can do attitude, the AmpOhm is just doing it's job, unobtrusive, effortless but with distinction. You can enjoy them but just as easy relax and not pay to much attention. They bring a soft touch to the music, not by softening things but by revealing things. But they really do have a very delicate touch.
Also I feel that voices become crystal-clear. On the con site, any mixing trickery is also revealed.

My best experience last week was with a Grant Green track, "It Ain't Necessarily So". The guitar on the left, often the lefts will sort of stick to the speaker, here the guitar was just next to the speaker, totally free, as the other instruments were. It was as if the speakers were transducers of a a different time and place. A very good recording, and Grant really could play his guitar.

Curiously, adding the other pair of AmpOhms to bypass the connecting cap between the high bank and the ribbon does not advance things. The touch is maybe even softer, but it is almost as if it is subtracting rather then adding. Could it be that the effect of the cap applied on two sections of the x/o has sort of reverse cascading effect? I had similar experiences with the ESAs and Mundorfs before.
And then suddenly it hit me: this part of the crossover actually is a subtracting part! The high switch on the position 'high' does bypass this section of the x/o. The high switch to normal let the signal go through this cap and resistor, and is in reality attenuating the signal, that apparently otherwise would be to strong.
I now have defeated the switch, but whenever I tried it, in the past and still with the stock caps, I experienced it as if the sound was out of phase, rather then the highs upped.
Anyway this discovery has to make me rethink also the current Mundorf bypass on the ribbon connecting cap. An extra gain there maybe could be made only by a better cap, as I actually experienced when I replaced the PX with the ESA. But those upmarket 10mfd caps really cost big bucks!

[christoph]

Hi Vans

Thank you for your very interesting caps-experiments.
After all, ribbons are very transparent and show very clearly what is done in front of them.

Cheers, Christoph

[Vansloneker]

Thank you christoph!

I've been focusing on the ribbon-connecting cap and I do find that the differences of bypassing these are really very, very small. At least in conjunction with the ESA. The differences of changing caps in the high filter bank are more obvious. I have a slight preference for the Mundorf as it makes the sound stage a very little wider. The AmpOhm has a special sound I still fail to properly name. One website talks about a vintage sound. When I am at the back of the speaker, changing a wire to connect the AmpOhm I think to hear the volume is marginally lower. I have to concentrate very hard to notice all this. If then the dog starts to move and puff, the moment is gone...
Weird is, I once bypassed the cap-connecting cap, as the switch does, and I heard no difference. My hearing can't be that bad?

I decided I'll have another with the PX as the cap-connecting cap, with the Mundorfs, with the AmpOhms and them joined. Keeps one off the street ... I just want to compare some things I thought I heard or not.

[christoph]

Hi Vans

Please carry on your tests and let us know your findings.
I think this is very helpful for anyone contemplating on a x-over rebuild or mod.

Cheers, Christoph

[Vansloneker]

Thanks again for your encouragement, Christoph.
It is of course, what I experience, with my ears, with my taste in music, with my audio system and in my room. Other people may come to different results.
Basically I think, if funds are limited that for an upgrade from the stock crossover you can use any good caps for the basic crossover, be it Clarity Caps, Mundorf, Jantzen or whatever. With the addition of better but more expensive bypassing caps you add extra fidelity.

I haven't fully done with the matter of bypassing the ribbon connecting cap. So far I learned, by direct comparison the Mundorf Supreme sounds a little bit harsh when changing directly from the AmpOhm. More about that later.

You all know North Creek Music Systems has designed a crossover upgrade for the Apogee Stage. Which crossover is very similar to that of the Centaur. By the images it looks to me they retained and bypassed the ribbon connecting cap.

About the high filter they write to have bypassed it using their cascading technology. Cascading is, and I quote Richard from the old forum "With cascading you break up a single capacitor into capacitors with increasingly lower values in parallel (e.g. 10uF becomes 6uF+3uF+1uF), with bypassing you use a capacitor with a very small value parallel to the original cap thereby not changing the total value significantly (e.g. 10uF+0.1uF)".
This is from an interesting topic about caps on the old forum read it here: http://www.apogeeacoustics.com/oldforum/001371.html

Also North Creek writes to have set the value of 67.1 mfd for the high filter. This is a little lower then 70mfd stock Stage and the Centaur has. I understand by this the ribbon would go slightly lower in frequency. North Creek says to be using measured and matched caps so the true value would be close to that.
My Clarity Cap PX has a 5% tolerance so it could be as low as that 67mfd or as high as 73mfd. I do not have the equipment to measure my caps, alas. The Supreme has 2% and my AmpOhm 10% by the way.

Anyway I am tempted and considering slightly lowering the high filter as North Creek did. I did find some AmpOhm polypropylene caps available that could make a nice step or cascade from the PX to the Supreme and the AmpOhm PIO. This would also reflect a bit the cascading technology with the limitation that my PX's are all 10mfd. But changing one PX for a 6.8mfd, the Supreme has 0.68mfd and the AmpOhm PIO is rated at 0.1mfd would bring the value to 67.58
But this might not work because the woofer filter is not changed. North Creek says they changed the low section a lot more but won't publish their values. However they say they lowered the crossover frequency, so lower mid/high has to go with lower woofer. So that's the end of my dreams as far as lowering the mid/high frequency goes.
An extra 2.2mfd step in the high would give a cascaded 69.78mfd value which is reasonably close to the stock 70mfd. Just some thoughts.

Speaking of woofers, I'd say the bass has improved with the addition of the Supreme as a bypass. Sometimes I even feel it. But on recordings with an obtrusive bass it's often to much for me. But this has always been the case. I am no bass fetishist and I have neighbors. And, it's still conventional bass, that's nothing like good foil bass.


Changing the ribbon connecting cap back from ESA to PX has opened up things a lot, for me. I tried the 0.68mfd Supreme and the 0.1mfd AmpOhm on the high filter. By direct comparison I found with switching from the AmpOhm to Mundorf I was missing something. But, the Mundorf Supreme has the best spatial experience, and the AmpOhm can't exactly do that. Particularly on High-Resolution music this was apparent to me. With the Supreme, there is more then just left, center and right, it is one wide sound-stage where an instrument can appear at any spot. This experience is crucial to me. Of course, the recording has got to have it, there are plenty of pretty straight forward left-center-right recordings around.
I find that combining the Mundorf and the AmpOhm adds the AmpOhm sound with marginal or no affect to the Supreme spatiality.

The sound of the AmpOhm. Sometimes razor-sharp but also silky smooth. To me they give the music that extra glow, or warmth, or naturality. This could be due to being a paper-in-oil cap. There's a lot to be found on the internet about PIO caps and they are loved by guitar players. And the usual voices who say there is no proof and audiophiles just think to hear differences. Oh well...
We live with our audio-systems day by day and that makes us hear any difference. Someone who is not a little bit skilled listener will probably not detect those minimal changes. You have to point them to the details they can hear, the decay of a tone, how different instruments are separated. And music reproduction is a about microseconds and micro-details. They make the difference in placing, spatiality and realism of the music.
If Ferrari or Porsche changes the suspension setup a little so the car will round the Nürburg ring a tenth of a second faster nobody will say they only think it and it's of no use. Fact is, it is of no use for most people as only the skilled drivers can experience the difference and exploit it. For any regular driver it's of no meaning at all.

Anyway I come to think that adding a small value PIO or another higher grade cap next to a 0.5-1% bypass of better caps to an upgraded crossover is not a bad thing, if it serves a purpose.

[Vansloneker]

While I was listening to Bach's Mass in B minor the 'Gloria in excelsis Deo' inspired me to have another test at the ribbon connecting cap. The male and female choir provide all you need to test the spatial environment of the speakers. Again I found the differences between no bypass, the Supreme and the AmpOhm PIO very marginal and I still have no winner. But I did experience the AmpOhm bypass as, well, luscious. Just great sound.
I do find it really hard to play the same track over and over again just to try to find the differences. It's a beautiful track I enjoy a second, maybe a third time but playing it like ten times makes it hard to keep concentrating on the task.

Earlier I had tried fully bypassing the ribbon connecting cap as the 'high' switch on the back of the speaker does and heard for whatever reason no differences.
Well, I tried again and with this particular track definitely did hear differences. It sounded more open, and the sound-stage was deeper, spatiality and placement better. But after a little while I also found it to bright. But this is a good comparison for the cap and how much it takes away from the ambiance.

[Vansloneker]

Semi final capital on the ribbon-connecting-cap -pun intended.

Been busy with many things what distracts from the ribbon-connecting-cap issue.
One of those things is having setup a Linux system to run the Logitech Media Server software. I had performed a test on a simple Pentium 4 computer which worked out pretty good against the X64 Windows computer I was running. That system has a quadcore cpu and 4 times as much memory but it took at least 4 times longer to boot and have the LMS up. P4 have a reputation for being power hungry but once it's running LMS is serving the FLAC's on idle, no stress and no need for the quadcore system. Only large playlists take slightly longer to load. The P4 system I am using has the benefit of being very silent, I've put in a brand new Western Digital Green hard disk which is barely audible and produces no heat.

Listening with a fresh mind reveals me the Ampohm bypass over the Mundorf bypass makes position of the music very little, really marginal less rock solid. I guess, unless pointed to it or study hard on it you wouldn't notice. But in return the Ampohms add so much sweet sound I just don't want to do without it. So I'll stick with the Supremes and Ampohm bypasses on the ribbon-connecting-cap.
Case not entirely closed however, I want to put Mundorf Supremes on the location of the ribbon connecting cap, and retain the Ampohm bypass. But this at a moment when it suits me or when I can get discounted 10uF Supremes.

I spotted discounted Mundorf Supreme silver/oil, silver/gold and silver/gold/oil capacitors but even then the cost is massive for a poor guy but I am curious about those caps and it keeps on my mind I would want to try them.

What I did do was order a third pair of oil-tin-foil Ampohms and they will be bypassing the low filter next to the Mundorfs. What is good for high and for ribbon-connecting-cap should also be good for low.

[Vansloneker]

Two months since my last post I finally had the courage to rebuild the crossovers. It was a terrible job, taking everything apart, wiring and soldering 18 caps -per speaker- and the other parts. Because of the quantity of the parts I had to make a new topology. The position of the parts has changed, but the electrical connections remain the same. I worked one full day on each crossover. Today I finished the left crossover with a dramatic and glorious ending. Just as I was soldering the last caps, the radio played Paradisi Gloria from Stabat Mater by Karl Jenkins.

After fitting the crossover into the speaker I listened for a while. When I had done the right crossover, I found that it sounded livelier. At this moment my hearing isn't optimal because of a nose cold. But I heard differences and things I did not hear before. The clarity I find has once again improved. This must be due to the job and to the silver internal wiring. To be honest by first impression I also missed the copper wire I had used for my tests. I liked the sound of it. Actually I had started the job of rebuilding using copper wire but it proved impossible to handle therefore I purchased the silver wire what is a lot better to process. More compromises were made but I can't really complain about the result, some very nice speakers for a poor guy.

I still have the Vishay caps to test. I will do this at the suitable time using clips and they are not hard to put in the crossover if I want to keep them.

Below is an image of the left crossover not attached to the speaker. Blue are the Clarity PX caps, black the Mundorf Supreme bypasses and the 'tins' with black label are the Ampohm super-bypasses. It's interesting that the high-end caps are much larger in size. The two Ampohms about in the middle of the image have 1% of the capacity of the blue Clarity caps but they are slightly larger!



(right click/view image)

[Vansloneker]

Currently I'm testing the Vishay caps. So far I have the idea they make the leading instrument a little more outlined, but also make the sound less rich. The differences, if any, are small. But I have come to think these caps make no sense since I already have hi-end caps in my cross-over.


Vishay cap

[Scinemaniac]

Photo shows metal bolts and nuts anchoring the air coils.
Perhaps these are only temporary - in use only until the silicone has hardened [silicone alone being sufficient to hold the coil in place - as originally done by Apogee].

Or perhaps both the bolt and the nut are made of brass, suitably non-magnetic material.

However if ferrous material (eg. steel) are located within 2 diameters distance from a coil, then these coils no longer function as 'air' coils. The nominal value of the coil (measured in milliHenry) will have increased. Magnetic flux is particularly focused at the centre of each coil. Ferrous metal provides a channel for magnetic flux to flow more freely and more concentrated than in free air, increasing the density of flux which alters the operating frequency of crossover.

Also the coil will begin to exhibit hysteresis (non-linearity) so degrading sound reproduction.

[Vansloneker]

These are non-magnetic bolts and nuts as it is discussed in this topic.

[Vansloneker]

I decided to fix the coils with silicone anyway and removed the bolts. Thanks.

[Odysseyss]

Can anyone give me any tips on Apogee Minor speakers? My room is 10x12 ft. How far apart is best, Tou in, a little a lot. I am 7 feet from speakers in a treated room. Using Odyssey Khartargo Upgraded Mono Blocks and a VTL 5.5 tube pre with Cardas Twinlink speaker cable. Thanks for any info.

[BobM]

Just a suggestion on using bypass caps in crossovers. I've found they do indeed have a place on the tweeter, but adding a small value bypass on the woofer is counter intuitive to what a woofer crossover does. The bypass enhances high frequencies while the woofer crossover is trying to cut off and limit high frequencies. Using a small bypass on the woofer circuit is going to mess with your crossover point and likely not sound as good as without one.