This question is being asked so I can advise a friend more intelligently so any info on the Firestone in particular would be appreciated.
I have a modded Benchmark DAC 1 feeding into Sennheiser HD800 headphones & the results are brilliant. However my friend is a little more dollar conscious than me. He is prepared to buy the superb Sennheisers but I'm not sure what to suggest he put with it. Note I'm keen on a DAC/head amp combo as it works so brilliantly here. The audio here is better than through amps and speakers costing over $100k!!!!