I'm happy you've found an amp that let's you get the best from your Golds. I must say that my Ref1s (as I run them-in my sig) have nary a trace of harshness or edge and have wonderful depth and tremendous imaging and fine detail within a wide, deep, noiseless and vertically expansive soundstage. And that's with a Mimby and Magni 3, linked with ultra silent pure silver ICs. Almost always with the QP1R as source. Female vocals such as Lorde and Ricki Lee Jones are 3D organic flesh and blood, so natural that any thought of 'hifi' never enters my mind. The only way my Ref1s show any edge and vocal thinness is with truly horrible recordings - which isn't their fault and even then it's easy to hear that it was caused by electronic means, their essential humanity remains - or I go back to using them with the stock steel cables .... very VERY briefly! ... and just as a sample of how far they have come with pleather pads, correct inners and Mogami cable. As a whole, edgy, sharp and thin has no place with them. At 600 ohms they are easy to drive even from my recently restored 40 year old Akai AM-2600 amplifier, much easier than the 22 ohm HE400S! No edge or sharpness there either from the Ref1s, just their innate organic and fantastically tuneful aliveness, as always. I seem to have found the perfect match of cable, pads and inner foams with them, musically adept gems.
I even tried the Magni with some much cheaper, though still well made, cables the other night and although a touch of smear and grain was introduced, along with less inter-spacial silence, there was still no thin edginess, I wondered if there might be. The Magni 3 needs a good DAC in front of it, I think, not so much to smooth it out, as I find it to be a generally very even amplifier in my experience, but to let it shine as it is so capable of being.
Still, that's really neither here or there for you now
You have your wonderful match in the Liquid Spark.