Bi-Amping

You are facing the following 3 scenarios:

1. Two identical amps is ideal and can be used without electronic crossover. There are amps that will have line level output terminals (XLR or RCA) that make things easier by connecting them one to another otherwise you'll have to use Y-conector at your preamp output. Preamp might as well have more than one output set which will make it suitable for bi-amplification

2. Two different amps with different gains and output power. In this case if you just connect them to the speaker binding posts, you'll get overloaded or undefined bass depending which side the more powerful amp is connected to. For common sense sake we can assume that more powerful amp is connected to the low binding posts. The necessity of either electronic crossover or volume control is necessary. If volume control is used on larger poweramp, you simply will have a constant problem of tonal balance and instead of adjusting preamp volume control, you'll always have to adjust your bottom amp 'by ear' that will never be precise.

3. Opt out of biamping and get more powerful amp. THAT's my choice after trying out both above.

I have a friend who ran a tube amp on the high post and solid state for the low. Something didn't click so he sold both amps and purchased a more powerful and slightly more expensive solid state amp and used a very good jumper. In the end this worked out much better than the two dissimilar amps.

I agree with all the responses. But why are you starting off with 2 amps? Do you have a large room to fill or is the biamping for less noise/distortion reasons?
There is also horizontal and vertical biamping to the speakers. Please explain what you are attempting to achieve.

Apparently my prev conception of Biamping was incorrect. My hope was to hook up a Sansui 2000x & a Denon 395 to the same speakers at the same time for comparison. r

I thought that was your question, rather than biamping which is using two amps at once. You cant just hook up two amps to one speaker, as the signal from one amp will feed into the other amp through the combined speaker terminal connection. If you are trying to compare two amps, you need some sort of switching box to isolate one from the other so only one is hooked up to the speaker at a time.