Personally I'd give both of them a miss and splash out on the new 650, which from the look of the blurb on the website, actually has a volume control that works properly.
tractorboy:Personally I'd give both of them a miss and splash out on the new 650, which from the look of the blurb on the website, actually has a volume control that works properly.
Yes, the volume pot should be better on the 650A. However, the 640A that I had here didn't suffer from the dreaded channel in-balance even at very low volumes.