Burning in hi-pass capacitors

[bkeane1259]

Re: Burning in hi-pass capacitors

Can't find an 'insert image' button. I found a 'manage attachments' button. When I paste in the flickr URL it doesn't recognize it.

When you post, you should have a toolbar above the writing window that has several functions - one of which allows you to "INSERT IMAGE"

[bkeane1259]

Re: Burning in hi-pass capacitors

Also, make sure the picture album from which you are pasting the URL's is a "PUBLIC ALBUM". If you have privacy set on the album, then this function won't work for you.

[carlspeak]

Re: Burning in hi-pass capacitors

When I do what you instructed, all I get is a red X in a box back in post #151. So, I modified my post to provide the link address viewers can click on to view the images at my Flickr site.

Boy, and I thought I was a bit savvy with this stuff!

Sorry everybody for going OT!

[bkeane1259]

Re: Burning in hi-pass capacitors

TREMENDOUSLY INTERESTING!! Please no flaming.....

I have been cooking my caps for 15 hours straight. I have had the spousal unit check a few times to make sure everything was running smoothly as I was at work most of the day and night. She reported that the dummy load resistor got hot at times but then cooled down, only to heat back up....seemingly at random times. Fine. That only seems normal.

Now I'm home and I'm sitting right next to the cooking rig and I can hear the caps either charging or actually emanating the frequency sweeps I have on the program!! It only happens when The 20Hz-20kHz sweeps play, and I can hear the high end of the sweep coming out of the caps. Am I crazy? .....I even plugged in my cans to make sure of what I was hearing and sure enough, it is towards the end of the sweep that I'm hearing - thru the caps. Is it the plates in the caps resonating, shrinking/expanding??

Also, the dummy load resistor for sure heats up when it is presented with the periods of frequency sweeps, and white and pink noise. Very interesting. Is this simply because it has to process the whole frequency spectrum at once?? This is where I'd love to get the scientist's opinions.

[jbruner]

Re: Burning in hi-pass capacitors

TREMENDOUSLY INTERESTING!! Please no flaming.....

I have been cooking my caps for 15 hours straight. I have had the spousal unit check a few times to make sure everything was running smoothly as I was at work most of the day and night. She reported that the dummy load resistor got hot at times but then cooled down, only to heat back up....seemingly at random times. Fine. That only seems normal.

Now I'm home and I'm sitting right next to the cooking rig and I can hear the caps either charging or actually emanating the frequency sweeps I have on the program!! It only happens when The 20Hz-20kHz sweeps play, and I can hear the high end of the sweep coming out of the caps. Am I crazy? .....I even plugged in my cans to make sure of what I was hearing and sure enough, it is towards the end of the sweep that I'm hearing - thru the caps. Is it the plates in the caps resonating, shrinking/expanding??

Also, the dummy load resistor for sure heats up when it is presented with the periods of frequency sweeps, and white and pink noise. Very interesting. Is this simply because it has to process the whole frequency spectrum at once?? This is where I'd love to get the scientist's opinions.

Actually, if you turn it up enough, you can hear the music too.

Now, see if you can pick out which cap is louder.

Which cap sounds better/quieter/less distorted?

Does the cap's sound quality/distortion level as a transducer correlate with it's sound quality in a loudspeaker circuit?

[carlspeak]

Re: Burning in hi-pass capacitors

With regard to the burning in process, the power resistor's heating and cooling reflect varying levels of energy transfered much like you'd have with normal music and the speaker playing louder and softer at times. The resistor is giving up the energy as heat.

The cap sounds are indeed interesting. Keep us posted.

[carlspeak]

Re: Burning in hi-pass capacitors

Here are some measurements that may shed some quantitative light on the Cross-Cap vs Superior Z-Cap discussion.

Luckily, I had a 4.7 uF Jantzen MKP 400 V Cross-Cap and a 3.9 uF Jantzen 800 V Superior Z-Cap to test. I ran some special tests with my WT2. Not a megabuck test instrument, but a very effective one just the same. The test methodology is the subject of a forthcoming article in audioXpress magazine.

BTW, I can now confirm that audioXpress has published the cap measurement article in the May issue.

[bkeane1259]

Test Crossovers

I drilled my boards and did some preliminary layout work on the crossovers. Gonna solder 'em up later tonight.

Component layout:



Boards drilled - they will fit inside the Monitor-40's thru a woofer hole, but if I mount these back inside, I'm gonna make them a bit smaller. For the tests, I'm leaving them as is (external).



Everything, sans the tweeter cap. It will sit between the binding posts on the left hand side of the XO. All the parts are new except for the tweeter shunt coil, which was salvaged from the old XO.



What it looks like with the largest tweeter cap -- The Jantzen Superior Z.



With a Clarity ESA.



Time for dinner :D

[bkeane1259]

NEW vs. OLD crossover

The rebuild and the OEM Polk XO

Not gonna miss the NPE's ;)

[dantheman]

Re: Burning in hi-pass capacitors

Great job man! Nice.

Dan

[bkeane1259]

First XO board test

All good after doing the component connections and initial testing. Dare I say the Monitor-40's sound a bit more solid in the low end with the woofer air coil?? Is it possible?? :rolleyes:

Off to do the other XO and hopefully we get some burn-in testing done tomorrow, but I'm going to the Sox game so.......

[dantheman]

Re: Burning in hi-pass capacitors

Is that Dynamat and Sorbothane?

Dan

[bkeane1259]

Re: Burning in hi-pass capacitors

Is that Dynamat and Sorbothane?

Dan

Yes and sort of. Yes, it's Dynamat.

The feet are Vibrapods -- I love em. I use them on my near fields (the Monitor-40's) and on a couple subs I have. I live in a town home in downtown Chicago and the neighbors are not very forgiving of bass. The Vibrapods work....I'll leave it at that.

[bkeane1259]

Crossovers ready to rock

Both are wired up, tested and ready to run.

I used temporary connections so that I can dismantle everything after the tests. I'm either going to spiffy up the boards and keep the XO's external or cut them down a bit and mount them back inside the Polks.

Here's a shot of both sides

[jcandy]

Re: Crossovers ready to rock

Both are wired up, tested and ready to run.

I used temporary connections so that I can dismantle everything after the tests. I'm either going to spiffy up the boards and keep the XO's external or cut them down a bit and mount them back inside the Polks.

Here's a shot of both sides

LOL. You used wire nuts!

On a more serious note, you should rotate the small inductor 90 degrees to reduce the flux coupling:

http://www.troelsgravesen.dk/coils.htm

How do the DCR of the original and present large inductors differ?