Can I use a multichannel amp to bi-amp my speakers

Hello to all... 

I have a pair of Gershman Avant Garde RX-20s and want to bi-amp them:

Confused about the advantages and disadvantages, as well as the confusion about cabling - but was wondering if I could use a multichannel amp to bi-amp them?

Thoughts appreciated... Thanks.
You can use a multichannel amp but I wouldn't purchase one just to bi-amp. I noticed more improvement getting larger amps and not bi-amping. An active crossover will also help with bi-amping.
... was considering using preamp/s I have, with a vintage SimAudio Evolution W8 for sale here on Audiogon as a bi-wire (instead of bi-amp), or considering ModWright KWI200 to simplify ( and would bi-wire also). Was lead to believe that bi-amping gave better results regarding control and clarity: true?
To biamp effectively, you really need an active x-over. I don’t know how you could use that while also using a single multi-channel amp to drive the speakers.
I think the amps you are considering would work better than a multichannel amp. I also noticed more improvement in sound with a better single speaker cable than bi-wiring with a lessor cable.
... I know that Gershman uses Nordost Red Dawn as interconnects and speaker cables and I'll probably go that route as well... I am leaning more towards the ModWright and will go Bi-WIred...
I use single Kimber 4TC unterminated wire so part is spliced for lower terminals and part is for upper respectively on the speaker end.
It looks like biwiring, only I don't have to use jumpers.
A multichannel amp will only work to bi-amp if each 'amp section' has it's own input, which (as noted) requires an active xover.  In my case, I've dispensed with a pre-amp, gone to active eq, and use a matrix (actually a pair) to control inputs and how various elements interconnect.

I really don't miss a stand-alone pre-amp, BTW...
put your money into a better 2 channel amp rather than a mediocre 4 channel.
I had a nice Theta Intrepid which I used to biamp Meadowlark Audio Heron (hot rod version) and BG Corp 520DX.  I ran directly from the source, a modded Oppo BDP 83SE, using the 2 channel outs and the FR/FL to drive 4 channels of the amp.  I thought it sounded very good.  The Theta had a beautiful top end, lots of air and detail, very delicate, mids were clear and slightly warm, while the bass was decent.  It never drew attention to itself but you never felt deprived either and the BG's are intentionally rolled off early.   You could also go with a preamp with 2 pairs of outputs to run the 4 channels.  I also had a pair of Pathos Classic One MK III integrateds.  I had 2 so I could bridge them but I ran them as 2 stereo integrateds briefly for the hell of it.  It was better than a single stereo amp but bridged was way better than 2 in stereo for biamping.   The active crossover might improve things.  I have no experience with them so can't comment on how they'd improve the sound but an active crossover isn't necessary with most speakers.  I'm not familiar with the Gershmans but I've biamped the Meadowlarks, BG Corps, and a pair of DIY 6 driver Legacy Focus clones and all did well biamped.  Just make sure you get a good multi channel amp and don't skimp on the cables.  Good luck!
Single amp probably best way to go and both Sim and Modwright very good choices. Nordost now supports a single run with jumpers to the other set of posts rather than a bi wire set. When upgrading my Nordost Valkerie (sp?) to Valhalla series 1 I went this route on recommendation from dealer and nordost and have been very pleased with result
So could anyone speak on this as an option? I’m using a Denon AVP-A1HDCI, Parasound A51, and B&W 802’s. What possible differences/improvements with options of 2 monoblocks bi-wired, 2 stereo-amps bi-amped, or multi-channel bi-amped as in the review link?

In my opinion it would entirely depend on the power supplies in the amplifiers in question. When comparing an smaller amp to a larger amp, the large amp will typically have a lot more brute power and it will make the bass/midbass sound a bit heftier/thicker.

If you are trying to bi-amp with a multi-channel amp that uses a shared power supply, the results are probably not going to be earth shattering (since the different channels will drag down the same shared power supply). In your case, the Parasound A51 has a shared transformer, but completely independent power supply / capacitor banks for each channel. In this case, you will probably get better results with bi-amping versus single-amping if you are just using your A51. However, you may get better overall results by just replacing the A51 with some big monoblocks (like the JC1). Monoblocks will have very large power supplies and may also be fully differential (as opposed to single ended). This will control the speaker movement much better. Also, the B&W speakers really need a high-power high-current amp to sing.

Thanks. Being that I'm yet to take the plunge into bi-amping this brings a bit of clarity to the approach.