Old thread I know, but I just bought one of these amps. What you are looking at are 2 main differences, the 1st, no fan on the A500, instead, the cooling fins are external, and secondly, the torroidal transformer looks to be twice the size of the KM750 torroidal. Those are 2 highly desired features.
I opted for the KM750 is based on the desired use, to replace 2 Dayton Audio SPA500 plate amps. I am only looking for the same quality of audio, reasonably priced, not something to blow the doors off their hinges. Just something to replace what I already have/had. I think this amp should fill the need nicely.
Now, my only concern is where to place it so 1] I don't hear the fans and 2] it gets enough ventilation, which is likely what killed my SPA500, or lack thereof, anyway. Real estate in my living room is at a premium as well, making it that much more difficult to place than it needs to be.
Anyone here how loud the fan is? Can you compare it with something? Can't find any videos of the fan noise.
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