Got a pair of Polk Audio SDA CRS

cortico

Could you guys let me know what is the biding post thread size, one of the plastic nuts is not griping well, I may replace it with a metal nuts until I redo the xcovers and upgrade the biding posts.

Thanks!

cortico

I hope everybody is doing great, came back to this project and will finally recap this speakers found a pretty good deal on the Clarity ESAs.

I have been away for a while and a few issues came up as I am placing the order. The closest to 20uF in the 250V version is 18uf or 22uf. The 20uf is only available in 600v, they are bit bigger and a bit more expensive.

-Can you please remind me what happens to the frequencies if i go to far low or highs in capacitance on the LF filter?

-Whats is the function of that yellow .5uf cap in parallel with the resistor on the stereo crossover?

Thank so much!

Stereo crossover:


Dimensional crossover:

westmassguy

The 18uf caps will be fine, the slope of the cutoff will not be as steep, but should not be noticeable. Your other two options, are two 10ufs stacked in parallel, or Clarity PXs. The 20ufs are in the low-pass shunt, not in series with the driver.
The .5uf in parallel with the 5.6 ohm resistor, is a contour circuit, I explained it earlier in this thread. Since you're not using the dimensional tweeters, all you need to replace on the dimensional section is the 29?uf shunt cap.

cortico

Thanks Westmassguy,

I am doing excatly what you have mentioned, will replace all caps and resistors on stereo array. Since I will not be using the dimensional tweeter, I will only replace dimensional LF shunt, is this a 29uf cap? I thought this was 20uf, the schematic is not very clear.

Thanks

westmassguy

Always check what's actually on the crossovers before you order anything. Polk made on the fly changes, and the schematics are sometimes hard to read.
I've seen quite a few oddball crossovers. Wrong value caps and resistors, inductors mounted in the wrong place, even recently, an SRS-2 with the wrong sub-bass drive inductors.

cortico

Yeah, I wasn't sure and checked. my dimensional module has 20uf woofer shunt caps.

I have no idea of what the impact to the sound would be going 2uf higher or lower in capacitance, so I followed one of your tips and ended up selecting 18uf. The other options would take to much real state insede the cabinet...

cortico

Got all caps ordered, was able to find all values except the 27uf, opted to stack a 12uf and a 15uf, all will be in spec with correct tolerances as it should be.

Pretty good deal on parts conexicon, 40% off on ESA and 20% off Mills, there's quite a few caps to replace, huge savings!

I was told that there a new improved Clarity series to come out, the CSA. In any event I really like the ESA, they sound beautifuly with my 70's Marantz!

cortico

Have received part of the order. Exciting, started coupling the resitor and small cap of contour circuits and a 12uf with 15uf as a sub for the 27uf electrolytic. Still waiting for the 20uf low pass filters.... I have saved the cap's lead insulation and used it on the resistor ledas, I thought it woukd look neat.

txcoastal1

Nice clean work sir

cortico

could you recommend me good source for gold or nickel plated spade connectors for internal wiring?

I believe tweeter used .11" and the woofer .187", correct?

Just planing redo all internal wire and connections, while I am at it.

Thank you

cortico

By the way, what is the original gauge of internal wiring?
Thanks for any direction

leftwinger57

You went w/ an updated style of the blade /blade interconnect matching your speaker cable and looks good. I used that also until I let Dave do up my terminal cups and use the Neutrik/Speakon connectors.Yes they stick out a few inches but for 2Bs you need even more room off the front wall and secondary to that I don't know of anyone who looks behind speakers. Most no matter what brand or type of speakers are not in the middle of your living/ listening room.

cortico

Hi leftwinger thank you for chiming in!

Those speakon connectors do look great, I was about to install it but opted out because I like to preserve the period correct look on vintage audio gear. Would use it for sure If I was building something new.

Also, performance wise, I tend to believe that the speakon conectors would had very little to the improvement already achieved with the new canare star quad external wiring, the improvement was huge! I can't overstate how good and underrated this wire is, seriously. Almost the same quantum leap as when I introduced my Parasound 1100 DAC on my system

Next step after new caps/resistors are in is replacing all internal wiring like I did on my 5b:



Although, this time I would take a more simple approach, I think the 5b's internal wiring is a bit overdone.

I was also researching for replacement bidding posts, avoiding again something too modern looking or oversized. Rather prefer smaller low mass post, preferably insulated plated solid brass or copper posts. I found this, very ordinary but it fits my bill:



There's time to digest the ideas, I have this CRS speakers for almost an year, only changed the tweeters and cableIing, I am very familiar with their sound it would be easy for me to evaluate any other improvements. In any event there's room for improve the, I believe the caps have drift enough over the years and they are not at their best....

[Deleted User]

Nice work!

cortico

TForan wrote: »

Nice work!

Thank you!

cortico

I find this speaker connectors by Electra very interesting:
http://www.electracable.com/tubeconnector.htm

cortico

ah, noticed ordered the wrong resistor value for the contour circuit, got 2.7K ohms instead 2.7 ohms... silly mistake from my part, good thing I always check with multimeter...

cortico

Got some spare time to work on this today, finally had a chance to read the value on the original Installed component on my croosovers.

This clarified a few issues I had on values and resitor locations I wrongly mentioned on previous post, I got all sorted out.

As advised I had replaced all resistors, capacitors and polyswitch on the stereo module and on the dimensional module just replaced the LF filter cap. As expected older electrolytics and resistors had drifted a bit from design values. It was a little bit of a challenging fitting all parts on the board but I managed by transplanting a couple resistors to the onsite side.

I will probably do the dimentional tweeter as well as original design intent. It may sound better with upgraded caps and tweeters... I might like it.

[Deleted User]

Really nice work!

cortico

TForan wrote: »

Really nice work!

Thanks man! It's sounding pretty good right out the gate...
I will give it some time before I redo internal wiring and biding posts.

cortico

There is about 100 hours on the recapped crossovers.

The improvements were obvious, but I got the sense that high freq was set a bit on the hot side. Westmassguy recommended to replace use .5ohm instead .27ohm resistor as a polyswitch replacement. I was skeptical, but must admit that, if I haven't tried myself I wouldn't believe the wonders that such a small value difference do ... thanks for that!

The soundstage feels more balanced now and wider than pre recap, vocals and instruments are more real and pleasant to hear.

My main rig has a Parasound 1500 cd changer, Parasound 1100hd DAC and a Marantz 2270 and a turntable. Lately I have been mainly listening Compact Disks and have been curious about tube a buffers and got a Grant fidelity B283 MKII. The plan is connecting it between the DAC and amplifier, this specific buffer was designed to soften things a bit and allegedly increases the soundstage a bit... maybe this is subject to a different discussion...

westmassguy

It's all about balance and voicing. Some people wouldn't notice, but I get listening fatigue if the tweeters are too bright. Glad it worked out for you.

tat

Wow that was some impressive Jinga stacking of those caps! Impressive spacial reasoning lol. Looks like you even repainted the bolts for the passive's cover! That is admirable attn. to detail. Great thread man...just what I am starting on 1 year later almost to the day. Love the pic of the kid with the Ramones album...looks like a downtown flat too, though those days are long gone.
Just moved down South from other side of tunnel myself.

Where did you get the new Canare interconnect (or spade plugs more precisely)? Guess Ill try Canare cables have been watching those but never used them.

Im gonna have a bit more challenge with mounting the tweeters than you bc mine have the routing for the smaller SL000 hence dont drop right in usually. Im hoping I can get away with new screw holes. I do have a Dremel in case but it always a risk when I start freehanding

cortico

Thanks for you kind words Tat!

You're right good old New York, charming pre war apt but very little space for your buck! I have to make the move myself, it getting tight... my older kid has great hears and refined musical taste.

I have built the interconect cable myself, I have found NOS 2 blade connectors on the bay, it doesn't offer the most secure connection but serves the purpose.

Good luck with routing, don't go free and, can you do some kind of metal wood template do serve as guide?

cortico

here a few picture of the cable assembling:

agfrost

Nice work!

Looks like you used the same Techflex as I did on my interconnects.

cortico

Looks great! I love it, I started using it on my guitar stuff, now goes on everything, looks pretty classic.