Burning in hi-pass capacitors

[Herman Trivilino]

Re: Burning in hi-pass capacitors

I don't think we can get a truly silent switch, but that can be dealt with I suppose.

Why do you want a silent switch? The listeners need to know when the switch is made from one cap to another. It's like an eye exam. The examiner keeps asking which one looks (sounds) better. A or B? And you can have him switch back and forth as many times as you like. You then decide which one you like better, and that's it. You record the result: Test 5, Preference A. And continue. After a predetermined number of times, you stop and compare the results. Either you were able to consistently tell the difference between cooked and uncooked, or you weren't.

[LSV8]

Re: Burning in hi-pass capacitors

I'm definitely reading your posts and everyone else's.

That was directed towards Herman, actually... sorry for the confusion. Either way... it was more of a "just kidding" comment than anything. :D

Funny....my 20yr old son is a guitarist-- he has 4 guitars, including a Strat and a Gibson....nice switches on both...very quiet, but NOT silent. I don't think we can get a truly silent switch, but that can be dealt with I suppose.

A "fresh" 5 way on a higher-end Strat is nearly silent. You should hear absolutely no electrical scratch/fuzz/etc... and the mechanical noise is almost nonexistent. EASILY covered up by music at even a mild listening level.

I have trouble visualizing how the cap switching circuit could look with anything other than a DPDT-type switch, since I have to be able to fully isolate each cap. For the brand vs. brand test, I simply must have a stereo signal and I won't even bother doing the test if it can't be that way, so that complicates matters more.

My take on the matter is that you are perhaps assuming that both leads of the capacitors have to be removed from the circuit? Am I correct? Sorry this is so confusing when typed out without visuals...

The 5-way switch I mentioned, and posted a picture of, IS a DP switch. Specifically, a DPTT switch. (Tripple Throw). If you look again at the picture, blue is one pole and red is the other... "Double Pole". "A" and "B" are your common terminals for each idependant pole.

Then, "1" "2" and "3" of each color are your 3 selectable terminals for each pole.

I'll attach a (very crude) schematic using a diagram of a DPTT switch and the actual Monitor 40 XO schematic you posted earlier.
You can see in the drawing, all 3 caps CAN be connected to a common point... they do NOT need to be completely removed from the XO. Once one lead is open, having the other lead connected will make absolutely no difference.
-However, if this really bothers you for some reason... and you want the caps completely gone... there are 4 pole version of this switch available too! If you're searching for one, guitar lingo would be: 5-way Split Coil selector switch. This gives you 4 poles, 3 throws, and 5 positions. Just imagine the drawing having another pole with it's corresponding terminals between the other sides of the caps, and the resistor in your schematic.

When using this 5 way switch, position 1 would give you cap 1, position 3 would give you cap 2, and position 5 would give you cap 3. Positions 2 & 4 would be a "half way" transition point for you... allowing the "make before break" scenario. In other words, position 2 would have caps 1 & 2 in parallel... but only for the quick duration in which you move the switch from position 1 to 3. The same rules apply to position 4, only caps 2 & 3 would be parallel.

I guess the best way to picture it would be to ask your son to let you feel the switch on his Strat (assuming it is infact a classic 3 pickup Strat with a 5 way swtich).

Lastly, the drawing is only for one speaker. Notice in the drawing that only HALF of the terminals are used on the switch diagram. You would apply the same wiring to the other speaker on this second pole of the switch. This would give you your stereo switching, between 3 caps, with a quiet make before break operation, all in one unit.

EDIT: Gotta love google! Found a great diagram to help you understand each position on a DPTT 5-way. Just imagine one half being for the left speaker, and the other half for the right speaker. http://3.bp.blogspot.com/_8pKbeWMtBC...600/5waySW.png

[bkeane1259]

Re: Burning in hi-pass capacitors

My take on the matter is that you are perhaps assuming that both leads of the capacitors have to be removed from the circuit? Am I correct? Sorry this is so confusing when typed out without visuals...

Yup -- that's exactly what I was thinking.

However, if we all agree that stringing one lead of multiple caps together will not have an adverse effect, then I'm all for it!! Your schematic touch-up is very helpful. Thanks for taking the time to do it.

I'm thinking I could wire several caps up on one side and then take measurements of each individual cap and as long as those capacitance measurements are the same as my initial measurements, we're all good??

[bkeane1259]

Re: Burning in hi-pass capacitors

Nevertheless, it's meaningful to continue to observe and investigate. bkeane is doing this, and shouldn't be derided for attempting to either confirm or deny what some other person might already believe.

Herman, you must be an honors stats teacher. You....you're good.

[bkeane1259]

Re: Burning in hi-pass capacitors

But when listening to cap differences, I focus on the imaging cues. Grit for instance is easily heard in close mic'd dynamic female vocals, Norah Jones is a perfect example. If a cap has what's typically described as grit, her vocal image will become unstable - it will move forward and back in space along with her dynamic range. A good cap and even Norah Jones' voice will remain rock solid in place. You also listen to the edges, how far out was that triangle, how far back is the Cello, do things seem to come from outside the edges of the speakers and do they wrap around the room. If so, you make mental notes of exactly where the notes come from at very specific points in a recording ... and when swapping caps compare the image localization for those specific points.

I also find it helps to listen with eyes closed when doing cap comparisons. That makes the job of focusing on space easier, since the picture of space is wholly created by your ears/brain at that point instead of being 'polluted' by data from your eyes as well.

100% valid points!! Critical music listeners are going to do this automatically. I find myself closing eyes often to focus and sometimes even replaying passages when I think I heard something new. I'm always looking for that nuance that I didn't pick-up in the past. My sons are musicians and their ears are tuned differently I believe, but they are sharp none-the-less. I am going to get both of them in on this test.

[carlspeak]

Re: Burning in hi-pass capacitors

I would be interested in seeing this done. I have more caps in the mail as we speak, but they are Daytons -- not boutiques. None-the-less, I'd not mind cooking one and sending you the pair for your analysis. I will mark them so only I know which is which.

I'll be glad to help in any way I can. PM me for my address.

[gp4Jesus]

Re: Burning in hi-pass capacitors

Install a double throw switch that will allow you to switch back and forth between the two caps. Have a friend flip the switch as you listen, and see if you can tell the difference. Set it up, though, as a double-blind test. Your friend has to first assign letters A and B to the two switch positions, without knowing which position is the new cap or which is the old. And not tell you which position is which, and the switch needs to be hidden from your view. Moreover, he has to have the ability to start the test in either position, chosen at random, without your knowledge.

Makes sense to me.

You two should get together. Look...

http://www.polkaudio.com/forums/showthread.php?t=61727&highlight=capacitor+shootout

I support part break-in.
cheers tony

[bkeane1259]

Re: Burning in hi-pass capacitors -update

Gonna be a small delay on the burn-in test.

I wanted to make a proper switching jig that I could use for both tests (the burn-in test and the brand vs. brand test), so I needed some additional parts from PE, which I ordered on Friday. Well that shipment was supposed to be here yesterday, but for some strange reason was diverted from Chicago to New Berlin Wisconsin - THANKS FED EX!!

Anyway, I'm off to meet some DIY gurus at InDIYana on Friday, so the initial testing will likely happen the weekend of May 6th. I will post pics of the switching jig next week - many thanks to LSV8 for a quick education on switching

[LSV8]

Re: Burning in hi-pass capacitors -update

Gonna be a small delay on the burn-in test.

Well that shipment was supposed to be here yesterday, but for some strange reason was diverted from Chicago to New Berlin Wisconsin - THANKS FED EX!!

Did you get PE's "free shipping"? PE uses fedex Smart Post for their free shipping... which hardly ever has a direct route to it's destination. (This applies mostly to light packages.)

For example: I live in Maumee, OH (Toledo)... PE is in Springsboro, OH (Dayton)... So PE is approx 2.5-3hrs south of me. However, anytime I place an order and use PE's "free shipping", my package will track from Springsboro Ohio, to somewhere in Northern Kentucky, to somewhere in Southern Michigan, then finally to Maumee. Fedex will also sometimes give the package to USPS to be delivered with your mail... you wont even see a fedex truck :eek:

If I choose to pay for ground shipping... I get the package the very next day!

(Def not PE's fault, BTW... just how fedex chooses to do their economy shipping. I'm sure there's money saving logic of some sort in the way the package is handled.)

[bkeane1259]

Re: Burning in hi-pass capacitors -update

(Def not PE's fault, BTW... just how fedex chooses to do their economy shipping. I'm sure there's money saving logic of some sort in the way the package is handled.)

Yup - it was free shipping. I have never had a problem with Fed Ex economy shipping in the past. In fact, I usually get my deliveries from PE in 2 days!!

What's strange, is that this particular shipment WAS here in Chicago (I live in the city) and then it took a trip up north to Wisconsin and is now headed back. I'm thinking somebody loaded a parcel of deliveries on to the wrong truck :rolleyes:

[LSV8]

Re: Burning in hi-pass capacitors -update

Yup - it was free shipping. I have never had a problem with Fed Ex economy shipping in the past. In fact, I usually get my deliveries from PE in 2 days!!

What's strange, is that this particular shipment WAS here in Chicago (I live in the city) and then it took a trip up north to Wisconsin and is now headed back. I'm thinking somebody loaded a parcel of deliveries on to the wrong truck :rolleyes:

I think there must be a difference between the standard economy ground shipping and whatever PE uses for free shipping. I too have always had great luck with PE's "base" economy shipping (when I've paid for it that is). You're probably right about the wrong truck deal. Especially if it was already in Chicago!!!


On the tracking info page, under "Service", it says "SMART_POST" for the delivery type. I think that differs from "GROUND_HOME_DELIVERY". (Which is what I see when I pay for Fed Ex economy shipping). Who knows... I'm just speculating from what I've experienced in the past.

Either way, hope you get your stuff soon so you can continue! :D

EDIT: I attached a screen shot of the tracking page on a small-ish $60 order where I paid for Economy Fed Ex shipping. The cheapest shipping offered. I have a few orders that were free shipping "SMART_POST"... but of course the tracking numbers are expired, so I can't show you their crazy US tour, lol. :rolleyes:

[bkeane1259]

Re: Burning in hi-pass capacitors

Got my PE order today - nice surprise

So I'm cooking more caps - lower values than the last batch and I noticed something interesting. These puppies are much noisier than the larger value caps that I cooked a couple weeks ago.

I can definitely hear the test signals, sweeps, pink noise and the music is more apparent when I dig out the stethoscope, especially on those dinky 0.1uF Daytons. The music sounds muddy and like it's on a reverb box, but it's definitely noticeable at high volumes. The larger Jantzens in that bunch are quieter and clearer!! Very interesting stuff. It might not mean diddly, but it's interesting. I'm wondering if (physical and value) size does matter.

The values of the current batch are:

4.7uF, 2.0uF, 0.1uF (Daytons) and 0.1 uF (Jantzens)

[bkeane1259]

Cap Switching Jig Done

Had some time to knock out the switching jig for the caps. I kept it simple, since I'm not very bright when it comes to this stuff.

It will allow me to switch between two pair of caps and maintain a stereo signal (for the brand A vs. brand B comparison).

It can also switch between two caps on the same crossover (for the new cap vs. burnt cap comparison).

Some pics:









Tested to make sure I did the wiring correctly. The switch points towards the ACTIVE pair of caps. I measured capacitance at the outputs and flipped the switch.

The Clarity caps measure 8.4uF



The Sonicaps measure 8.2uF The wiring is correct - YAY. :D



I put my cooked Jantzens in the jig and flipped back and forth between them on one XO to see if the switch is noisy at all...... it's surprisingly quiet with no noticeable interruption in the music. It will be perfect for both tests.

[bkeane1259]

Re: Burning in hi-pass capacitors

BTW - I had the spousal unit label the three sets of caps I'm going to use for the new vs. burnt in cap comparison. They are randomly labeled A & B and only she knows which are the cooked caps and which are the new caps.

I should get this test done this weekend.

[bkeane1259]

Re: Burning in hi-pass capacitors

I have some friends coming over tonight to participate in the first round of cap listening tests. FINALLY, I am going to get this going.!! :D The first test will be to see if listeners can tell ANY difference between a cooked cap and a brand new cap of the same brand and value.

Now at the risk of totally getting flamed........

While I was setting things up today, just for yuks I dug into my last PE order. I had ordered replacement caps to replicate what came with my Polks originally (like an idiot, I tossed the old caps) -- An 8.0uF NPE bypassed with a 0.22uF mylar, was the OEM high-pass filter. I wanted to do a quickie comparison against the Jantzens I have been running since the beginning of the year. The NPE+bypass measured 9uF….so I had to parallel my Jantzen to get the value to match.



I noticed a difference immediately. :eek: Now don’t hit me back with the DBT argument either….I know, I know, but this isn’t part of the formal tests anyway - it was purely for my edification. At any rate, Norah never sounded more nasal and cymbal slaps were just plain irritating on a 96/24 drum test track I have. The clincher was The Persuasions “In the Ghetto” (also 96/24) – I had my 17yr old son listen….he had no clue why he was listening. He immediately noted the difference, pointing to the speaker with the Jantzen high-pass filter. The difference is plainly evident in vocals. I also noticed in the Talking Heads "Psycho Killer" that bass string plucks sounded weird thru the NPE....sort of muffled instead of tight/taut. I would devote more time to this, but it's just not necessary.

Folks, I know this isn’t a fair comparison, but I truly believe NPE’s are not suitable for inline use in high-pass filters. For shunts, maybe – when cost is a factor. I can’t believe I was listening to this particular set of speakers with those original components.

Anyone sparking up the flame throwers right now??