mobbaddict
Headphoneus Supremus
Maybe try to hear some Stax if you've never heard any, you never know I would say a good Senny (or maybe Focal) or a Stax are your best bets at that point.The improvement will be hugh.
Proper amplification is a must have for the most planars. The quad isn't an exception.
But it plays well with lower sources also.
Will heading to a shop in munich next week to try out some new stuff with the R28 on hand.
The journey never ends.
But it has to be reasonable, imo.