That mystery cable

hoosier21

dorokusai wrote:

Big deal it won't fit? It might be a big deal if it doesn't fit what you own, and you bought it under the assumption that it would eh? The Ebay advertisement doesn't specify a model and is at the very least, misleading. The associated model(s) are ancient and if they haven't made it to the graveyard or dump, it's borderline amazing.

The linked historical thread and pictures were all but forgotten until now.

I agree, it won't fit 99% of the SDA speakers out there,

Polk65 wrote:

I started this thread hoping to learn if this was a genuine cable and it appears that it was used prior to the blade/blade cable.

Thats how I read it from the beginng, my comments on this thread have nothing to do with that auction or how MANY speakers this type of cable will fit.

F1nut

Validate what Russ? That you keep attacking anything I say? That you act like a spoiled little child? I don't have to validate any of that, you do a fine job all by yourself.

ohskigod

I guess the next mixed martial arts match is set for polkfest

dorokusai

Crouching Coif, Hidden Vomit

BobMcG

Thanks Steve for the great info and photos on a missing SDA link. Never knew about it to be sure.

steveinaz

dorokusai wrote:

Crouching Coif, Hidden Vomit

ROTFLMAO!!!!!!!

Polk65

Polk65 wrote:

Who can spot what else is different with the later version?

Here is the difference I am curious about. Was there a pair of ports underneath the tweeters in the earlier model?

DarqueKnight

The SDA 1 manual says the four midrange drivers operate as a "fourth-order vented system".

A fourth-order (vented) enclosure is a sealed enclosure with the additon of a port tuned to a specific frequency. The purpose of the two small ports is to extend the low frequency response of the sealed enclosure in order to provide a lower cut-off frequency. The trade-off is that some transient response is sacrificed to achieve bass extension.

ESavinon

Isn't it great that we have raife and ken to sort these things out for us? I sure do think so!

DarqueKnight

It's even better when you can catch a word or two from Matthew Polk. Here is what he had to say:

"In the original SDA-1's there were 4 drivers. Two of these were dedicated to producing bass and driving the passive radiator. The other two drivers, one for producing the stereo signal and one for producing the SDA Dimensional signal, had their own enclosures which isolated them from each other and from the bass drivers. The small vents did help blending to the bass drivers but did not really "tune" the mid-band drivers. They were really more of a pressure vent to prevent buckling of the mid-range driver cones when driven hard.
-msp"

Toka78

Missed this thread the first time 'round somehow, but wanted to add that my SDA 2's have the same 'mystery' interconnect (as well as dual SL-1000's). I bought them from the original owner, who was 'pretty sure' he bought them 'in 1984 I think'. Take that for what you will, but it does look like they made it onto more than one line.

Gary Batson

My SDA1's have the same interconnect cable in question. It's a pin pin connector with a plastic socket that locks in place when its plugged in. Mine appears to me to be a better quality connector than ALL the other connectors. How's that for ego?

Boywonder

For future reference, if anyone stumbles across this post in need of one of these IC cables, the plugs and crimp contacts to build an IC cable for these early SDA-1's (or for the HF tweeter module for an RTA-12) are AMP parts and are available from Jameco.

The connector is called an AMP snap-lock circular plastic (CPC) connector, also known as an AMP econoseal connector. The plugs are $6.49/ea at Jameco Electronics. You also need to order crimp socket contacts, and have a crimp tool for these connectors. The crimp contacts can be ordered individually. They should be quite inexpensive, even gold plated (if that's an option). Nickel plated contacts are 30 cents each and gold plated contacts are 99 cents each.

The Jameco P/N is 839017 and the AMP P/N is 207567

According to Jameco, compatible contacts are 66100-6; 66101-1; 66580-2; 66590-1; 51565-2 These various P/N's probably represent different plating, wire gauge, and whether they are for manual crimping or machine crimping.


The max wire insulation size for these connectors is .100" according to the drawings, but if you pop out the rubber sealing booties, much larger wire insulation will fit.

Face

Bad link Boywonder.

Boywonder

Sorry about the bad link...I just modified the post to include the Jameco and AMP P/N's instead.

ShinAce

Didn't read all replies, but I did see Boywonder's:

Yes, that is a military connector. Amphenol makes them(expect to pay $ 10 a piece for the 3 pin).

There are different diameters of connector available. That seems to be the larger diameter(maybe 1 inch) with only 3 pins. The 3 pins we used to sell were smaller(maybe 5/8" inch).

peppoman

Does anyone have the schematic (or PDF) for the cross connection inside the cabinet ?
I can make a cable with the right gauge wire, but my knucklehead brother pulled off
the terminations for the +, - and G_ on each speaker.

Thanks

peppoman

Oops, the question about the crossconnect above is to SDA-1's

schwarcw

Welcome to the Club Polk Forums pepoman!

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