Mylar caps in RTA 11T

heiney9

danger boy wrote: »

why are today's caps so much bigger than they used to be?

So they can charge more! .

george daniel

heiney9 wrote: »

Those are 5A's with the peerless, correct? When Jockos or one of the others did their later 5b's (with poly switches) I believe all the components were vertical. Who knows though, Polk was always changing things on the fly so there probably isn't one difinitive answer. Just look at all the differences in the SDA lines and models

Correctamundo 5A's with the peerless, sweet,sweet speaks,especially when powered by tubes.

billbillw

george daniel wrote: »

Correctamundo 5A's with the peerless, sweet,sweet speaks,especially when powered by tubes.

Are those my previous 5A peerless? If so, I'm glad to hear you're enjoying them. I find myself missing them more often than I would have thought. The Mirage have them beat in most ways, but the 5A were just so much fun.

george daniel

yes they are,,and they sound great with the asl mono's,,I intentionly set them on top of the 11t's,and it's amazing how many people think that it's the 11t's playing,,, and find out it's the 5's instead..

Disc Jockey

Nice job George, I'm sure you'll enjoy it. I didn't realize there were any differences in orientation of the caps between the 11t and the 11tl. The ones on my 11tl were all horizontal - sure made the job a lot easier!

WilliamM2

danger boy wrote: »

why are today's caps so much bigger than they used to be?

Actually, caps today are smaller than they used to be, especially electrolytics.

The reason they are bigger than the original Polk caps is because these are 400v caps, most the originals are 50v or less.

F1nut

That's partly true. However, film and foil caps are larger by nature even if they and an electrolytic are of the same voltage value.

heiney9

heiney9 wrote: »

So they can charge more! .

PUN INTENDED

Jockos

I'm in luck, just pulled out my x-overs and all the components are lying horizontal, should be much easier! Just ordered from parts connection.
Jockos

Jockos

Just finished my x-over upgrade. Interesting note on the original is how the 12uf cap is placed over the resistor for space. I've included some pics on before and after. All caps were replaced with solens and resistors with mills 12w. The original tweeter cap was not electrolytic, I believe mylar. Intial listening session with upgrades is that the soundstage has moved forward. The highs seem dull and lifeless not crisp. The midrange sounds hollow at times. I do have the RDO tweeters. Will let the parts break in. If I still don't like the sound I have some BP electrolytics in the mail. Will keep the Solen for the mylar replacement. Maybe Polk used electrolytics for a certain voicing of the speaker not just cost.

Jockos

engtaz

Good work Congrats

Jockos

Does anyone know where to get those yellow mylar caps? Also does anyone have experience with the dayton caps or who makes them. The more I listen to the solens my speakers sound nasal.

heiney9

Jockos wrote: »

Just finished my x-over upgrade. Interesting note on the original is how the 12uf cap is placed over the resistor for space. I've included some pics on before and after. All caps were replaced with solens and resistors with mills 12w. The original tweeter cap was not electrolytic, I believe mylar. Intial listening session with upgrades is that the soundstage has moved forward. The highs seem dull and lifeless not crisp. The midrange sounds hollow at times. I do have the RDO tweeters. Will let the parts break in. If I still don't like the sound I have some BP electrolytics in the mail. Will keep the Solen for the mylar replacement. Maybe Polk used electrolytics for a certain voicing of the speaker not just cost.

Jockos

Break in will do wonders. Give them about 30-40 hours. I was initially disappointed when I did my 5b's, now they are maaaaaahhhhhvalous.

H9

Jockos

Thanks, if in 40 hours it still sounds funny I'm going to try the Daytons(bennics), alot of people seem to like these. Ive been comparing the high's to my 5'Bs and they seem much clearer, even my wife likes the sound of the 5'Bs better. But I'm going to wait and see. Question: is the first 12uf elec.(Polks specs.) with 2.0 resistor being used as a bypass cap to the mylar?

F1nut

Dayton/Bennic caps are crap made in China.

Yes, the stock yellow cap is mylar and no, it's not film and foil.

You have to let the new caps burn in for at least 50 to 100 hours. Put something on repeat, walk away and don't listen until you rack up enough hours. You can't judge the sound until then.

Maybe Polk used electrolytics for a certain voicing of the speaker not just cost.

Polk used electrolytics because they are cheap and available in mass quantities not because of how they sound.

Question: is the first 12uf elec.(Polks specs.) with 2.0 resistor being used as a bypass cap to the mylar?

NO!

heiney9

Also if your RD0's are new they need about the same amount of break in. I was always on the fence as far if break in was a myth or not. After using new parts and new tweeters it's very true.

Be patient and you will be rewarded.

H9

Jockos

Well I've had my stereo on for 3 days now and the speakers still don't sound right. To forward and kind of edgy. I will give it a few more days.
My question is if I decide to try a different cap what 12uf would make the most difference. The electrolytic with 2.0 ohm resistor or the mylar one. Looking at the original schematic it seems as though the mylar is the last filter before hitting the tweeter. I would like to just change 1 first and see how it sounds. Thinking of Dayton's and Clarity Caps.

Jockos

heiney9

Jockos wrote: »

Well I've had my stereo on for 3 days now and the speakers still don't sound right. To forward and kind of edgy. I will give it a few more days.
My question is if I decide to try a different cap what 12uf would make the most difference. The electrolytic with 2.0 ohm resistor or the mylar one. Looking at the original schematic it seems as though the mylar is the last filter before hitting the tweeter. I would like to just change 1 first and see how it sounds. Thinking of Dayton's and Clarity Caps.

Jockos

I'll be blunt you need more break in time. I forget are you using the RD0's or the sl2000? Dayton's are pretty crappy and not worth the time and effort. Give it some time. If you do still have the sl2000 that's where the problem is.

Jockos

I will give it a few more days. I have had the RDO's for almost a year now.

Jockos

heiney9

Jockos wrote: »

I will give it a few more days. I have had the RDO's for almost a year now.

Jockos

Sorry then, I am at a loss. They should sound really good. Yes, give it a few more days. The Solens are very nice parts compared to the standard stuff so I'm just not sure where to go from here.

george daniel

Jockos wrote: »

Well I've had my stereo on for 3 days now and the speakers still don't sound right. To forward and kind of edgy. I will give it a few more days.
My question is if I decide to try a different cap what 12uf would make the most difference. The electrolytic with 2.0 ohm resistor or the mylar one. Looking at the original schematic it seems as though the mylar is the last filter before hitting the tweeter. I would like to just change 1 first and see how it sounds. Thinking of Dayton's and Clarity Caps.

Jockos

I just did mine (11t's) with the exact same parts that you used,they sound fine,rdo's as well,, did you check the connections on the board that originate from the binding post ,as I had a minor issue with them(had to resolder) Good luck

Jockos

I just redid my crossovers with all Dayton 12uf caps.I kept the 33uf solen.
I did run into a small problem. I tried using my heat gun to soften all that hot glue I used to mount the Solen's. Upon doing so I accidently melted some of the black tape off my 33uf Solen exposing what looked to be coils of wrapped wire. The area is about the size of a 2mm oval. I put electrical tape on the area and even sealed the area of tape with glue. Is this O.K.? I believe the black tape is just used to insulate the cap? The 12 uf cap also had a small area melted off but since I replaced this I was not too concerned. I did measure the 12uf and it seemed fine.
How does it sound: Well after firing my system up my RTA 11's sounded like thespeaker I fell in love with; with more definition and clarity. Gone is the nasal and edgy sound. The tone with piano music was awesome. I'm extremely pleased with the results! Just hope I didn't damage the 33uf cap . Any info on capacitor construction would be appreciated.
By the way if anyone would like my 4 12uf solens and 2 mills 2.0 resistors give me a pm. Some of the leads are a little short and there is glue still on them.

Jockos

ben62670

PM sent

F1nut

Hmmm...different strokes for different folks, but how you can tell what new caps sound like right off the bat is a mystery to me.

Anyway, enjoy!

Jockos

Any advice or knowledge if the 33uf fix was sufficient? I figure if the original black tape was just tape then electrical tape would be ok. I don't think the tape affects the performance of the capacitor............

heiney9

Whatever works for you. They still need break in (the new caps). If it sounds fine then I would say you didn't damage the cap. DIY sure is fun isn't it.

H9

Jockos

Thanks, I tried to measure the cap in circuit but I get no reading. To my knowledge I don't think you can measure in circuit? For my knowledge does the 33uf block frequencies going to the bass drivers? I always thought the inductors did that. If I have to I'll just get another new one from PE, thinking of getting daytons for my 5B's too. Boy this hobby gets to be a real money pit, but it sure is fun!




Jockos

Jockos

Took out the crossover and measured the solen 33uf out of circuit, checked out great, that sure was alot of work.whew!

PoweredByDodge

re - caps.

metal film caps are typically some of the nicest products that you can buy. while they're not as 'uber cool' as aero-gel or others, they're spot on accurate to their spec, and non polarized. there's not a whole lot more you can ask of a piece of a purely immobile material. with the price difference between metal film and its supposed 'competitors' it makes no sense to opt for higher-grade parts unless you have a specific use (aircraft guidance systems, etc. would qualify as a 'specific use' -- environments of grossly high heat, or any other military spec project). given even the hottest house in florida or the coldest one in alaska, metal film will perform the same as anything else in a home or pro audio application.

edit... p.s. mtbf on most quality caps will be somewhere in the 100k hours or greater range. at 10 hours per day listening (assuming a worst case), that would be 27 years before you would be at the 100k hour mark.

ben62670

Thanks Jockos I received them already!
Ben