Originally Posted by cmryan821
I personally haven't but a friend of mine compared an A51 to an XPA5 and he said there was a difference but not $2000 worth of difference. He was trying to decide if he should sell the A51 which he had for a while and ultimately did sell it and kept the XPA5.
In this scenario, it really comes down to how difficult the Speakers are to drive, the size of the Room, etc.. With the A51 having almost twice as large of a Power Transformer (2.2 versus 1.2) and close to 3 times the amount of Capacitance (164,000uf versus 60,000uf), the A51 is truly in a different class in respect to current reserves. Given the difference in price, it should be.
As one can get an HCA-2205a or AT for between 900-1200 Dollars, this is the route I would go if on a tighter budget and having difficult to drive Speakers.
The 2205 is awfully close to the A51 (2.0 versus 2.2kVA Toroidal Transformer and 150,000uf vs 164,000uf of Capacitance) in specs. Both were Designed by John Curl as well. The Halo does offer XLR's and upgraded cosmetics, but given the price disparity, the 2205 is a fantastic used value.