Need a quality Y-adapter for bi-amping

Any Y-adapter will always add extra reactance from itself + extra reactive loads from each amplifier into one output of your preamp. The result will be extraneous harmonic distortions Algthough you will win in dynamics if you feel you havn't enough.
The best Y-adapter for me is no Y-adapter at all. There are preamps designed to work with two amplifiers for example using tape monitoring function along with tape output. For this you only need to plug in your source into the tape input and you'll automatically get output signal from two pairs of output sockets - main and tape...

quick note to Marakanetz's post about using the "main" and "tape" outputs. DO NOT do this unless your preamp specifically mentions this ability, because the "tape out" on most preamps is NOT volume controlled. The tape out of most preamps will drive most amplifiers to FULL volume. I have not heard of many preamps that offer volume control at the tape output, but maybe there are some out there.

The least # of connections & cables the signal routes through the better (but you knew that). It would be better if you had a preamp with dual output jacks, or a power amp with a pass-thru line-out connector. Maybe you could add some extra jacks to one or the other device, or replace one of them with a unit containing that feature. Otherwise a new interconnect (built into a shotgun configuration as mentioned) would be better than the soild Y, and similarly a solid Y would be better than an add-on separate Y-cable , whcih presents the largest # of extra connectors & cables to degrade your signal path.

Contact BOB at the Cable Co. He can custom make you one out of your favorite cable.

I get great results using Comprehensive Video (www.compvideo.com, 800-431-6000, South Hackensack, NJ)Female XLR to 2 male XLRs Y-adaptor cables (part number XLRJ-2XLRP) at the amp end of my 8-meter Cello XLR-to-XLR cables from preamp to amp. This Comprehensive Video cable is very low in capacitance. The legs of the Y are about one foot long, allowing direct connection of the legs of the Y to stacked monoblocks for biamping.

Yes, you have more connections in the signal path this way, but your preamp is not loaded by a lot of extra cable capacitance from an extra set of interconnects and the Y-adaptors are much cheaper than an extra set of equal-quality interconnects. The extra capacitance of another set of interconnects can cause audible degradation since the amp input impedence seen by the preamp is halved when you use Y-adaptors. Two of these Y-adaptors cost about $50, so you don't have much to lose trying this method. I use ProGold spray on all connections. Comprehensive Video also makes single ended Y-adaptors of the same type.