SRS2 crossover ?

stubby2

So I just acquired a pair of SRS 2 pin/blade connection. The serial numbers are below the cut off for safe use of an AI 1 interface.
What exactly is the difference between the lower serial numbers and the higher ones?
Anything I can do to mine to make them compatible with the AI 1?

Thanks!
Stubby

stubby2

Apologies. I am the same old stubby that's been here for like 20 years.

ken brydson

@KennethSwauger can help restore your old account

stubby2

That's great to know! Thanks Ken.

F1nut

stubby2 wrote: »

So I just acquired a pair of SRS 2 pin/blade connection. The serial numbers are below the cut off for safe use of an AI 1 interface.
What exactly is the difference between the lower serial numbers and the higher ones?
Anything I can do to mine to make them compatible with the AI 1?

Thanks!
Stubby

I'm not entirely sure. I suggest you compare the internal wire connections and crossover against the schematic for the later version, which is posted here.

stubby2

That will probably be my best bet, F1. I was just hoping someone from the brain trust would ring in with the info. Lazy me!

F1nut

It's likely to do with the blade connection, but there's no schematic for your speakers.

Schurkey

stubby2 wrote: »

So I just acquired a pair of SRS 2 pin/blade connection. The serial numbers are below the cut off for safe use of an AI 1 interface.

Huh?

WHAT "cut off for safe use of an AI1 interface"?

Are you thinking of the SDA-2Bs, some of which got the old blade/blade connector, and were missing about a foot of wire inside? Some SDA 1Cs also got the older connector, and were also missing about a foot of wire inside the cabinet. Far as I know, that never happened to the SRS 2 pin/blade.

In fact, the "pin/blade" part tells me you're good to go already.

stubby2 wrote: »

What exactly is the difference between the lower serial numbers and the higher ones?
Anything I can do to mine to make them compatible with the AI 1?

Far as I know, there's no reason why your SRS 2 pin/blade can't be used with the isolation transformer as-is.

If there is a problem, I want to know about it 'cause it's news to me.

F1nut

Schurkey

Well, don't I feel silly.

I've been so focused on the "note" at the bottom that I've forgotten that the CRS, SRS, and SRS 2 were included in the main part at the top.

I'm gonna have to dig my SRS 2s out, and see what the serial numbers are.

Wild Guess: They need about a foot of wire inside the cabinet.

Navy_Goat

Schurkey wrote: »

Are you thinking of the SDA-2Bs, some of which got the old blade/blade connector, and were missing about a foot of wire inside?

I don't want to hijack this thread, but I am curious about the missing foot of wire in early 2B. I have a pair of 2B with blade/blade connectors that I believe match this description. I don't have an A1 or Dreadnaught at this point so its not critical, but I'm always looking to learn more about my speakers. Is there a thread or post that you know of that goes in to more detail? Thanks!

Schurkey

https://forum.polkaudio.com/discussion/131691/2b-and-early-1c-ai-1-modifications#latest

stubby2

Here's a look at the wiring. The blade wire jumps to the positive input.
Looks the same as the wiring on an SRS 3.1 TL crossover.
The caps aren't bulging but I plan on replacing them as well as the resistors.

stubby2

Sorry, the blade jumps to a NEGATIVE input.

F1nut

I'm not seeing anything obvious that would prevent using the AI-1 or Dreadnought.

stubby2

Thanks F1, I feel pretty confident about the situation. The DOM on the passive is January 1988, if that helps.