Subwoofer connection

I'm planning on adding a sub to my two channel system. I don't want to use the sub's crossover actively - feeding it with the standard pre-out outputs from my preamp and then return from the sub to my power - amp since this will require two pairs of long interconnect cables. I'm happy with the high quality short interconnects I now use between the preamp and power amp. So my intention is to simply feed the sub a dulicate of what the amps is getting - which brings me to my questions...

I can buy two Y-adapters to split each pre-out for each channel, feeding the sup with one leg and the amp with the other for each channel. But the Y-adapters will compromise the qualtiy of the high quality interconnects I use between the preamp and the power amp... won't it?

So my thought is to use a single y-adapter between the left and right tape outputs from the preamp and feed the sub with a single cable. My question is whether or not this will have any negative audible or operational impact. I could just use a pair of cables from the tape out to the sub, but if there is no problem using the Y-adapter I would prefer a single cable, since the sub will be quite a distance from the rest of my gear.

I'm not sure I understand your description perfectly but, if I do, the problem you'll encounter with using the tape-out connection to drive the subwoofer is that it is not in line with the volume control. You'll want the same, variable output going to both speakers and sub.

I haven't used these , adapters myself, but they would let you go directly from your pre-outs and avoid any extra cabling completely.
Sfar...As I understand your question, you want to run a single interconnect to the SW, instead of two. However, if you use a Y-cable to get one from two, you will have shorted together your two stereo signals, and you will enjoy mono sound, not only from the sw, but also the mains.

Run a second set of interconnects to the sw. Then, with music playing, and with the SW turned off, connect and disconnect the second set of interconnects at the preamp. You won't hear any change.
DOH! How stupid of me - yes, of course the tape outs would not be variable. Yeah, now I'm embarrased...

Thanks, Sfar, for bringing me back to reality. Actually I have seen those Monster adapters - they include one with their subwoofer cable kits. And they seem really well made. Good thought - I think that's exactly what I'll do.

Eldhartford, yeah, that's what I was thinking too but wasn't sure if that would actually be the result. Makes sense.

I think I must have been experiencing some major brain-fade the other day. This all seems so obvious to me now, I'm embarrased to have asked.

No need to be embarrassed, how do you think I knew the answer to your question?