Thank you Mert. The mono would be ideal to quatruple the power to woofer section but my idea was to take advantage of VR speakers designed specifically to be bi-amped by powering the midrange and tweeter section by one amp and woofer section by another. Ideally, I should use A-30 for M/T and A-60 for woofer but sensitivities/gains are different. Bi-amping with different amps A vesrus AB, neddless to say with difefrent brands or SS versus tubes, it would only aggreviate the compatibility. Any other advantages of using these amps in MONO configuration, besides for greater amplification?