SDA 2Bs Cable Problem

[marly421]

I got the SDA 2B's from here:

http://www.shopgoodwill.com/viewItem.asp?ItemID=2142884

Link was still good as of 10/17/06.

They sound very good but didn't come with the interconnect cable. Yesterday I was able to get a cable, locally (pin/blade) and holy-cow this really sucks the enjoyment out of the music.

The amp I was using is a vintage Pioneer A-717 (Reference Stereo Amplifier) rated at 140 watts with a 4 Ohm load. It's supposed to be a common ground amp that can drive low current loads; been happy with amp until I installed this cable.

At any volume level you wish, the sound from the speakers will shutter every 3 or 4 seconds and at the same time you can hear (inside the amp) a clicking sound.

Remove the cable and the sound returns to normal and the amp stops the clicking sound.

My partner in crime used a digital Ohms meter and found both pin and blade has connectivity but that's all we know.

I did hook up a Kenwood KA-8006; it's supposed to be able to drive a 4 Ohm load and got similar action as the Pioneer. Any ideas?


Edit: My partner did a little more work with the Kenwood: the 8006 has been sitting for a while and I guess we were hearing scratchy controls and such. The Kenwood and the cable are actually happy together!

The Pioneer is/may not be common ground? What can I do..is there anything I can do with Pioneer?


Marly421

[BlueMDPicker]

Use your ohm meter to prove/disprove the common ground assumption of the amp(s). Holding a lead to both channel grounds (left and right) should produce a reading of 0 for common ground. Report back. :D

[marly421]

Use your ohm meter to prove/disprove the common ground assumption of the amp(s). Holding a lead to both channel grounds (left and right) should produce a reading of 0 for common ground. Report back.

- - - - - - - - - - - -
Ok...just checked and I do get a reading .03 on the 'ol digital dial. So the Pioneer is actually NOT a common ground?

Thanks Blue...is there something I can do to work around this or just keep the Pioneer away from SDA speakers.

Marly421

[BlueMDPicker]

You're welcome.

You can use the Polk non-common ground amplifier interface (AI-1) on 2Bs with left channel serial #14115 or greater and right channel serial #14124 or greater. It's probably going to cost you nearly as much as you paid for the speakers to buy one (if you can find one for sale), or to build one yourself. I'd invest the money in a separate, common ground, amp.

[marly421]

I'll look up the AI-1 business then. The serial numbers are 20275 and 20280 on these rascals so I'll take a look.

Do you know if this interface will degrade the sound in any particular way? You know I even asked before I got the Pioneer if it was a common ground as I knew I wanted to use one of our SDA speakers. EBay sellers can sometimes lead you down a rose pedaled road. Thanks a bunch Blue....

Marly421

[F1nut]

Couple of things....


The amp I was using is a vintage Pioneer A-717 (Reference Stereo Amplifier) rated at 140 watts with a 4 Ohm load. It's supposed to be a common ground amp that can drive low current loads; been happy with amp until I installed this cable.

That would make your amp 70 wpc at 8 ohms and maybe 105 at 6 ohms, which the 2B's are. Not exactly in the high current zone. However, I don't think that's your problem.




My partner in crime used a digital Ohms meter and found both pin and blade has connectivity but that's all we know.

Only the pin should have connectivity, the blade is used for support only. You might want to check that again.


Bottom line, I agree with Blue, seems as though the Pioneer isn't a common ground amp.