Subwoofer connection to older tube amp


I need to connect my Dominator 8 Sub to an Audio Research D-90 Amp and SP-12 Pre. The amp outputs only allow left and right bare wire speaker connections for different ohm ratings and I'll use the 8 ohm for main speakers.

Like most subs I'm afforded 2 pair of Left & Right Speaker Level inputs and 1 pair L&R Line(RCA plug) inputs and 1 pair L&R Line outputs.

Where would I hook the L/R from the amp to the sub? I want to use the set-up mostly for music but also for movies/DVD's.
jamesk58
Right, you can't use the 'tape out' connections because they're not controlled by the volume control on the preamp, meaning the volume coming from the sub wouldn't change as you adjust the volume to your main speakers.

If you do want to split the preamp output you can use one of the devices Steuspeed recommended. He suggested one from Audioquest and there's another from Monster. Click here to see what the one from Monster looks like. Both it and the Audioquest version are solid connectors, no wire involved.

You shouldn't worry about using the speaker wire connection method, though. The subwoofer amp won't be pulling any substantial power from your main amp and won't overload it at all. That connection method is the one recommended by both REL and HSU, makers of some of the better subs out there. You should definitely do what you're most comfortable with, however, it's your gear.
So if I just go with the doubling of the wires off the same 8 ohm speaker output directly from the amp I'll be fine? That would be easiest and I wouldn't have to go out and buy more connectors.
Also, do I need to run left and right wires or just a single? Right now I'm using an A/V receiver that has the single RCA Sub output and its connected to the left input on the sub. Now I want to switch back to using my Audio Reserch gear. Do I need L&R or just go with one speaker wire off the ARC amp to say the left speaker sub input?
Ok, I called Audio Research and talked with Leonard in the service department. I think he's been there forever and remember speaking with him maybe 15 years ago when I first got this equipment.

Anyway, he basically said to go ahead and hook-up the dual speakerwire set-up. He did confirm that the "Tape Out" on the pre-amp would not provide any volume. Said to double the wire L&R for both the main speakers and the sub.

There is a warning in the Sub manual saying the amp must be common grounded for this connection, but Leonard said that's fine and not an issue. So I'm going with the dual speakerwire config and let you know how it goes.
Well, everything is hooked-up as described above and no probs, sounds great.

Thanks for the input and help.