Crossover upgrades to 2.3 Parts List

[BobMcG]

Has anyone already updated the four crossovers on their 2.3s and thus have a list of the #of and value of the caps and resistors needed or do I have to wait untill I get around to opening them up and make a list myself? I'd just as soon have the parts already in my possesion before I find the time to do the job.

Thanks.

[F1nut]

I haven't done the 2.3's, but reading the schematic, you will need the following.

Caps:
(4) 12uf
(2) 5.8uf
(2) 4.4uf
(2) 20uf
(2) 40uf
(2) 750pf (change these too as the original ones are crap)

Resistors:
(2) 22.5 ohms
(2) 6.2 ohms
(4) 33 ohms

You'll have to get the watt rating off of the ones on the crossovers, but they are probably 5 watt.

I would recommend you change the polyswitches while you are in there. In fact, talk to Ken about replacing them with ones of higher value if you're running a high end amp. Another option that Raife chose was to remove them, but then you have no tweeter pretection.

Here's interesting link on one guys capacitor test results, http://home.versatel.nl/geenius/Cap.html

A number of folks here have been using the Solen caps. I chose the Sonicaps for a CRS+ upgrade I'm doing.

Solen caps - http://www.madisound.com/chateauroux.html

Multiple cap selection - http://www.partsconnexion.com/catalo...itorsFilm.html

Sonicap - http://www.soniccraft.com/parts/capacitors.htm

Resistor list - http://www.partsconnexion.com/catalog/resistors.html
The Mills resistors are the prefered choice.

[ND13]

F1, could you replace the polyswitch with a fastburn fuse? Or would that affect SQ or power handling?

[F1nut]

I'm sure you could, but why? The polyswitch is a better choice as it resets automatically.

[BobMcG]

Thanks Jessie.

I had planned on changing out the poly-switches too. I did my 2Bs probably 12yrs ago and never had another one trip. My brother was having the same problem with his and he swapped his out then too. I've had the 2.3s about nine or ten yrs now and never had one trip untill a couple of months ago. Left channel has tripped twice. Even if the 750s were good ones when Polk put them in I'll probably replace them just due to their age.

[ND13]

Originally posted by F1nut
I'm sure you could, but why? The polyswitch is a better choice as it resets automatically.

Just wondering. I kinda like being able to switch out the fuse like the Monitors. I wouldn't do it unless I relocated the block to the terminal cap. Fuses blow but they don't wear out and make one tear apart the speaker and possibly effect the seal to repair them.
That said, it was really just curiosity. : :)

[BobMcG]

Changing over to a fuse setup would only be a cobbjob pain the neck and a step backwards in design.

The polyswiches are are small semi-conductors right on the PC board. They are out of sight out of mind and maintenance free. The stock units were ok until they were tripped. This usually set the stage for repeated tripping and usually at lower and lower settings. The replacements are a higher value than the stockers and are pretty much failsafe. They are an advancement above the older fuse setups. It would have been great if Polk had gone with the higher value conductors in the first place but I would imagine it was just one more cost consideration that goes into all designs.

[ND13]

Originally posted by BobMcG
Changing over to a fuse setup would only be a cobbjob pain the neck and a step backwards in design.

The polyswiches are are small semi-conductors right on the PC board. They are out of sight out of mind and maintenance free. The stock units were ok until they were tripped. This usually set the stage for repeated tripping and usually at lower and lower settings. The replacements are a higher value than the stockers and are pretty much failsafe. They are an advancement above the older fuse setups. It would have been great if Polk had gone with the higher value conductors in the first place but I would imagine it was just one more cost consideration that goes into all designs.

Yeah, I know it's older technology, it was just curiosity. I've never understood why Polk took shortcuts on the SDA's on such inexpensive parts. I know they could have raised the price another $25-50 per speaker or pair and most consumers wouldn't have blinked an eye. I mean what's another $50-100 on a multi thousand dollar system anyway? I've always thought that if Polk would have wanted to they could have marketed the SRS series to the wealthy and could have sold them for 5-10x what they did. I'm just thankful they didn't. I know they wouldn't have sold as many, but they wouldn't have had to either.
Throw on some exotic wood and BAM, you have yourself a $15000 pair of speakers.

[BobMcG]

1) I've found Solen to have 4.0uf & 4.7uf value caps. Should I get the 4.7s in place of the Polk 4.4s?

2) And they have 5.6s and 6.0s instead of the original Polk 5.8uf. Should I go with the 6.0s?

3) Can't find any 750pfs anywhere.

4) Mills has the 33.0 ohm 5watt resistors and 22.0 ohm 5w rather than the the stock 22.5 ohm jobbers which I take is close enough?

5) Can't locate a 6.2 ohm 5w any place.


Any input?

[F1nut]

Bob,

Parts Connexion has a Solen 4.3 which is close enough, but you could piggyback a 0.10 to it to get the 4.4. The same with the 5.8, get the 5.6 and add a 0.18.

Sonic Craft has Mills, add a 4 and a 2.2 to equal the 6.2. They have a 22, so add a 0.5. They don't show the 5 watt resistors on their site, but they do carry them.

The 750pf can be found at http://www.audience-av.com/auricap5.htm

JESSE

[BobMcG]

Thanks once again Jesse.

[BobMcG]

I see the 750pf caps are rated 600v. The 12uf caps come in 200v or 450v. Does it matter which you use. Can you use a mix of 200v, 450, and 600v caps???

[F1nut]

You know I'm not 100% about that. I don't believe it does, but it might be worth getting the opinion of someone who knows for sure. I'd call one of the companies to check on that.

I did find another 750pf at Michael Percy Audio and it's 630V. God knows what the original one is and it's such a small cap that I don't think it would matter much.

Backing up a bit. Caps are not exactly on the money as far as values. When I was talking with Sonicap about needing a 5.8 and that they only sell a 5.6 they told me they would pick though and find me two that were 5.8. You might see if Parts Connexion will do the same for you. The same goes for the resistors, a 22 instead of a 22.5 will work just fine unless you want to shoot for a exact match to Polk's specs.

[BobMcG]

I see where Sonicap has their values listed as +\- 10% and probably all the companies are similar in this regard. Madisound offers matched pairs to within 1% of each other for an additional 10% cost.

Also where as pcX lists their Solen PBs as 400v, Madisound lists the same Solens as simply 250+v. The Sonicap equivalents are listed as 220v and the Auricap equivalents are listed as 200v. Probably makes no difference which you use even if you mix. The only odd one out is the 750pf. All the companies along this value are way up in the 600v range.

[F1nut]

Actually Sonicap states, "Tolerances are typically better than 5%. Custom values and tighter tolerances are available." They will match at 1% for free.

This has gotten interesting and I had to check a few things. Most of the original caps are marked 50V, so anything above that is good. As this is a crossover and not a power supply the voltage levels are going to be low.

What is really interesting is the silver mica 750pf. I took a close look (believe me you have to look close) and the original is marked 1000pf +/- 50% and 100V. 50%!!! What crap!

Anyway, that got me searching because I am definitely replacing mine and this looks to be a good one. http://www.justradios.com/mica.html 750pf 500V with a +/- of 5%.

Edit: Just found another one, http://www.hndme.com/storesilvermica.html 750pf 500v with a +/- of 1%. Ya man!

[BobMcG]

You're right, Sonicaps and Solens are +\-5% I can't find the one that stated 10% right now. (Probably seeing things anyways.) Didn't know Sonicaps would match for free though. I like that. The silvermicas look like the ticket. I'm going for those and the 6, 22 and 33 ohm Mills resistors from Handmade Electronics. Sonicaps will be getting a call from me too. Thanks.

[F1nut]

Originally posted by BobMcG
Didn't know Sonicaps would match for free though. I like that.

For what they cost, it should be free. ;)

[BobMcG]

For what they cost, it should be free.

You gotta good point there!