SDA Wiring Questions

[Ricardo]

I spent some time today checking all the connections on the 1.2 TL's, just to make sure everything was ok; I have a couple of questions:

1.-I've read that the blade in the pin-blade connector has no function, but I saw that it is actually connected to the negative binding posts....I guess that the common ground amp requirement takes care of making sure that negatives are connected....but does it really make no difference?? I don't have the interconnect and have been using a speaker wire just connecting the pins....maybe I'll try connecting the blades also just to see if I hear any difference.

2.-Does anyone have an electronic copy of the schematics? I could not believe what I saw when checking wires for the drivers...I guess it is right because it looks original...but hearing about the importance of having the right phases I was surprised how these get mixed for the stereo and SDA drivers. I definitely need to check this is actually right ( or one of the experts please confirm this is right..); I made a sketch that shows what I found...

[george daniel]

Don't know about the 1.2's,but when I rebuilt the x-overs in my 1c's,the blade had a wire connected to the neg. post, which I eliminated,as it was there just to help secure the connection. I installed new binding posts,and used the old post for the pin connection,as another forum member had done so before me,I think it was Wm. It is my understanding that the "pin" is actually the "connection" and the blade seves no function except to help secure the cable in place, currently have about 100 hours on the rebiulds w/o problems,it early and I have not had my coffee, hope this in someway answers your question :)

[SCompRacer]

The blade on my pin/blade SRS 2's is connected to the negative binding post too. The purpose is to allow a complete circuit to flow through one of the two windings in the isolation transformer when the non-common ground amp interface cable is used. With a common ground amp, just a pin to pin conection is required.

EDIT. I added the early and late SRS 2 schematics to show the difference between the blade/blade versus pin/blade.

[Ricardo]

Thanks SCompRacer; in the late schematics I can see how there are some +/- crossings in the drivers...not exactly as what I saw (the TL's have it in both the stereo and SDA drivers), but I am not so concerned now..I'll email Ken for a copy of the right schematics.