Can Power mono amps be too close to the speaker

My cables are 2' and I keep my monos away by 1/2' since they have an output and power transformers that can inflict additional vibrations if fully attached onto the speaker.
Bryston Powerpack 250 for example, is designed to be attached right onto the speaker. In this case you won't even need any speaker cables -- just buy any good quality conductor and connect then directly.

how can you get them so close too the speakers? Do you have any special stands for the amps? I would realy like to see, how you conect them. I have Cary Audio with very big trafo's and I put them about 0.75m away, one friend of mine told me he could hear some noise from the trafo´s in the speakers, maybe he isn't right!!!!!! I have ProAc studio 250 speakers and the conectors behind is in a hight of 0,7m.
Yanomami

I'm not sure about electrical matters, but be sure to address the vibrational effects of having tube amps so close to the speakers, particularly if you've got a full range speaker. I've gotten by with 1/2 meter speaker cables from an ARC Classic 150 to my old Duntechs (the amps were backed right up to the speakers), but I noticed a substantial improvement when I used good isolation devices under the amps.

Try this, it has worked well for me. Get your ears down to floor level while music is playing and listen for the least loud or boomy area near the spkrs. I have found that the shortest cable length will require that the amps are placed in too noisy an area. With 4 feet I can place them in a null area between the speakers, but not at center, because it is louder there. Actually, the best spot in my room is outside of each speaker, but, then the amps are in the way of foot traffic.