Blade/Blade SDA cable question

[madmax]

Could someone with a blade/blade SDA cable check to see if the large blade of one side connects to the small blade of the other?
Thanks!
madmax

[F1nut]

Got a problem with a cable or are you just bored at 4:15am?

[Polk65]

I'll check but only if you pull my finger first. :D




I assume you mean continuity. Large connects to large.

[madmax]

Got a problem with a cable or are you just bored at 4:15am?

I was just sitting around looking at the schematics for my SDA-SRS trying to figure out whether or not I could use a transformer for the SDA function if I made some modifications to the xover. I noticed a note about the connections which made me wonder.

Isn't this the sort of thing all polk enthusiasts do at 4:15am? :confused: :confused: :confused:

THANKS Polk65!

madmax

[dorokusai]

The wiring inside the speaker changes in the older SDA's, not the cable.

[madmax]

The wiring inside the speaker changes in the older SDA's, not the cable.

That is what the schematics seemed to show but it could have been read either way. I figured it was better to actually check one. BTW, it's looking like too much hassle to make them work with a transformer. I'm still looking though.
Thanks!
madmax

[hoosier21]

That is what the schematics seemed to show but it could have been read either way. I figured it was better to actually check one. BTW, it's looking like too much hassle to make them work with a transformer. I'm still looking though.
Thanks!
madmax

Hasn't Ken already done this? Thought I saw somebody post he modified "something" to allow the transformer to be used on BB interconnect?

[F1nut]

Hasn't Ken already done this? Thought I saw somebody post he modified "something" to allow the transformer to be used on BB interconnect?

That's what I thought, but someone recently stated that it wasn't true. Ken, care to chime in here?

[hoosier21]

http://www.polkaudio.com/forums/showthread.php?t=37150

there is the thread

[F1nut]

Yeah, I remember that one. I've spoken with Tim, nice guy, but we didn't talk about the transformer. I also remember someone posted a pic of the "Ken cable" in here, but I also recall someone else saying it wasn't true.

[Tour2ma]

I e-mailed and spoke to Ken on the phone. He told me there's no such animal for pre-tl SDA's.

[madmax]

I e-mailed and spoke to Ken on the phone. He told me there's no such animal for pre-tl SDA's.

Well that doesn't seem to make sense. Certainly you can wire up the 1.2's or SDA-SRS above S/N 5000 that way.
madmax

[madmax]

Somewhere their is a pic of the "Ken Special". It had a connection which fed the transformer with a ground from the speaker terminal and one of the SDA connections. Looking at the schematic you can see it bypasses a choke which is in series with one of the SDA lines. Here is the problem, I know there are two different schematics for the SDA-SRS. There has to be one for s/n's below 5000 and another for s/n's above 5000. I don't know which one is shown in the compenium.
madmax

[BobMcG]

Yes, I have posted pictures a number of times over the years of the custom AI-1 made by Ken for my brother's B/B 1cs. It has been working quite fine for ten years now and counting, thank you very much.

What do some of you guys think I was doing? Blowing smoke up your asses?

[dorokusai]

Yes.

[BobMcG]

Yes.

And you think it was easy?

I don't smoke so it's quite a feat!

[madmax]

Hi Bob,
Do you know the S/N of one of his 1C's?
Thanks!
madmax

[SCompRacer]

I was just sitting around looking at the schematics for my SDA-SRS trying to figure out whether or not I could use a transformer for the SDA function if I made some modifications to the xover. I noticed a note about the connections which made me wonder.


madmax

I've only seen early and late SRS 2 schematics. On the early blade/blade speaker, the wide blade, called Pin A (# 1), is connected to the positive side and the narrow blade, called Pin B, (# 2) is connected to the negative side of the dimensional tweeter/drivers. Each terminal on the blade/blade SDA interconnect cable carries a signal.

On the late pin/blade SRS 2, the pin is connected to the negative side of the dimensional drivers, and the blade is connected to the negative speaker terminal. Just the pin carries a signal in the standard pin/blade SDA interconnect. The blade terminal is not connected. On the pin/blade A1 non common ground IC, the pin and blade carry a signal through one side of the isolation transformer windings.

I don't think you would want to connect one winding of an isolation transformer to a positive and negative terminal of the blade/blade speaker. But couldn't you connect one lead of the isolation transformer winding to the narrow blade of an early speaker (narrow being the negative side of the dimensional array) and the other lead of the winding connected externally to the negative speaker terminal? I would expect to find Bob's example wired like that.

[madmax]

That is what I was thinking. There is a choke going to ground which would be bypassed by doing that, I think.
madmax

[BobMcG]

Hi Bob,
Do you know the S/N of one of his 1C's?
Thanks!
madmax

Sorry Chuck, I don't know the number off hand but I could get it if you need it. The serial numbers did fall into the accepted range as listed by Polk though as shown below. (If I remember right, and sorry for the poor upload.)

[I-SIG]

I'm watching this thread with a very keen interest...

Wes

[madmax]

The serial numbers did fall into the accepted range as listed by Polk though as shown below.
Thanks! That's what I needed to know. Mine don't and it isn't worth the hassle...
madmax