Polk SDA SRS 1.2 with Marantz AMP-10 question

dirino · October 8

dirino · October 8

Could use some help here for I get conflicting answers while searching the web: I realize the Polk SDA SRA 1.2's need common ground amplifier(s). That being said, can I connect the Polk SDA SRS 1.2's to the Marantz AMP 10 (which is not a common ground amp) WITH the interconnecting cable between speakers CONNECTED..IF I use he BI-Amp modes on the Marantz AMP 10 without destroying either the speaker, the amp or both while still being able to listen to the SDA SRS 1.2's as they were designed to be listened to? I believe I can connect the SDA SRS's to an uncommon grounded amp IF I do NOT use the interconnect cable and they would simply become regular floor standing speakers. That defeats the entire purpose of the SDA SRS's. Any help would be greatly appreciated. Again, I'm getting "there is no way it could be done without using te specific adapter (unavailable) or make one...which, of course, I can't do. To: "Yes , you can safely do it if you place the AMP 10 switch in the rear in the bi-Amp mode" Thanks in advance!!

michaeljhsda2 · October 8

Correct, you can use a non-common ground amp as long as the IC cable is not connected. Just curious whether the interconnect socket is pin/blade or blade/blade.

SeleniumFalcon · October 9

The design of the Marantz Amp 10 would not allow it to be used with a common ground speaker (SDA) cable connected either in standard or bi-amp mode. Depending on the model SRS 1.2 you have you might be able to use a cable with an isolation transformer (Dreadnaught).

dirino · October 9

Thank you! The socket is blade/blade. Thanks for your answers. I'm just not going to even attemp it because in searching I come across stuff like this:
An Alternative Option: Bi-Amping
"Instead of running the AMP 10 in BTL (Bridge) mode, consider utilizing its BI-AMP mode. [1, 2]
Because the Marantz AMP 10 features 16 channels of amplification, you have plenty of channels to spare. The Polk SDA SRS 1.2 terminal plate supports bi-amplification. If you use the AMP 10's built-in Bi-Amp configuration to run independent 200W channels to the high-frequency and low-frequency inputs of each tower, the negative terminals remain safely at common ground. This configuration allows you to safely keep the SDA interconnect cable plugged in, giving you the massive power benefits of multiple amp channels without sacrificing the legendary acoustic matrix."
On top of that, I asked a very popular on line retailer the same question ....I was told if bi-amped, it could be done. My gut tells me, no it can't. Thank you for your input.

SeleniumFalcon · October 9

You should probably ask Marantz directly, explaining that you want to be able to use a speaker that ties the left and right speaker grounds together.

michaeljhsda2 · October 9

You have the 1st generation SRS, not 1.2's. Only the 1.2 and 1.2 TL'S have pin blade sockets and there's no option for your speakers to use the isolation transformer to use monoblocks.

dirino · October 9

michaeljhsda2 ....My bad, I was trying to go on memory. The speakers have been boxed up for two years (move from NJ to FL) and they are still the original boxes .They are SDA SRS 1.2's.

dirino · October 9

1.2's

michaeljhsda2 · October 9

Since you have the 1.2's now for some possible bad news, but nothing that can't be fixed. What is the position of the red and black binding posts nuts on the back of your speakers? If red is on the right, that's not where it should be. The red nut (positive) is supposed to be on the left and the black nut (negative) on the right for the 1.2 and 1.2 TL versions. To confirm, remove the binding post cup and see if the black (positive) wire is on the left when looking it at it from the front of the cup. If the black wire is on the left that's where it's supposed to be. Reinstall the binding post cup. Now it's just a matter of unscrewing the binding post nuts and moving the red to the left and the black to the right. Connect positive speaker wire from your amp to the red nut and negative to the black nut. Now your speakers will be in correct phase and you'll notice a huge improvement in bass response.

The reason I'm telling you all of this is because Polk was notorious about using the leftover label (big sticker on the back of the speaker) from the SDA SRS (1st edition) where the positive red nut is on the right and black on the left (where they're supposed to be). The inside wiring is correct for that speaker. However, the above-described debacle has been noted on every pair of 1.2's that I have encountered from people that have the 1.2's here on this forum.

dirino · October 9

michaeljhsda2. Wow. You have got me curious so I unpacked one of the 1.2's and took a look. Here's what I've got: Pin/Blade. From the outside: Red posts are on the right. Black posts are on the left.
Took the cup off and looking from the front of the cup down from the top:
On the top two posts: Red wire is on the right post, Yellow wire is on the left post.
On the bottom 2 posts: Black wire is on the right post, white wires are on the left post.

michaeljhsda2 · October 9

That's good news there's nothing to change. If you want to convert them to 1.2 TL's you have that option. You can use the AI-1 interconnect (dreadnaught) if you want to monoblock them as they are currently.

michaeljhsda2 · October 9

What does the large sticker on the back of your speaker show, a blade/blade illustration or a pin/blade?

dirino · October 9

michaeljhsda2 The illustration shows a blade/blade. The actual connection is a pin/blade.

SeleniumFalcon · October 9

In reading the Marantz owner's manual, using the bi-amp mode merely sends the same audio input signal to two amplifier channels. This is done so a separate high frequency connection and a low frequency connection can be connected to the upper and lower set of speaker terminals on the speaker. It does nothing to reconfigure the amplifier's topology. People may be confusing this with operating a two channel amplifier in a bridged mode (Marantz labels this the BTL mode).
Do you have a volt/ohm meter available?

michaeljhsda2 · October 9

dirino wrote: »

michaeljhsda2 The illustration shows a blade/blade. The actual connection is a pin/blade.

That's pretty typical as Polk was known to use parts leftover from other models. Fortunately in your case somebody wired the speaker correctly.

dirino · October 9

I do not but I believe now that you need a AI-1 interconnect (dreadnaught) . Can't get a Polk AI-1 and I'm not buying a dreadnaught for $850.00 (e-bay). I became attached to these speakers from the day I bought them and never thought I'd let them go. It's time to let them go. OR, I can just skip the interconnect and use them as regular speakers...defeating the entire purpose of the design. It is what it is. Like me..these speakers are old. Time to move on and get with today's speaker technology. Thanks.

dirino · October 9

A big thank you to all that chimed in on this dilemma of mine. It is greatly appreciated....and I learned things. As in, FACTUAL things.

SeleniumFalcon · October 9

Before you lower the lifeboats you may want to give a call to Marantz, since Marantz and Polk are under the same corporate umbrella they should have a very good sense of your "common" dilemma.

michaeljhsda2 · October 9

dirino wrote: »

I'm not buying a dreadnaught for $850.00 (e-bay)

. If you're interested in building your own it's not difficult, no way it's expensive as that. Reach out to Avel-Lindberg and get a price for the 800V version. Part number - Y236906. https://avellindberg.com/contact.htm

Polk SDA SRS 1.2 with Marantz AMP-10 question

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