Hello,   So I'm a newbie here and am about to make my first headphone amp/DAC purchase.  I have decided on the maverick tubemagic D1 plus due to the fact many reviews claim it pairs well with my brand new Sennheiser HD 650's.  My question however is how much of a difference do the upgrades...

Hi everyone,   I'm a newbie here and am about to make my first headphone amp/DAC purchase.  I plan to use this amp with my brand new sennheiser HD 650's.  My price range is pretty low right now and I don't want to go higher then USD 250.  So far I've really been looking into either the...