Hi Tim
I am new here and been looking back through the forum to see what you have done to upgrade your E1.
I have the E1 Plus. In the op-amp manual it recommends to change slot 2 with Muses 02.
I am thinking of trying this in slot 1 & 2 and maybe in the RCA buffer output stage.
Has anyone used Muses 02's instead of 01's? I heard they are a better op-amp, Bi-polar not FET.
What upgrades have you tried? & is that a custom op-amp in the buffer RCA output stage?
I also seen this link for a custom op-amp.
http://www.hificollective.co.uk/components/newclassdopamps.html
01 is superior for the Essence One.
I only have two MUSES02's.
Your link is down.
RCA & Headphone buffers are using two LME49710HA metal can op-amps on TO-99 to DIP8 adapters. Less bias/crosstalk/distortion than the stock LME49720. If you're too lazy doing all that, then just get a LME49720HA pre-soldered to a DIP socket. Should sound a little more "real" than the non metal version.
I've swapped most electrolytic capacitors from Nichicon KT 25V to Nichicon KA 50V.
Also swapped all film capacitors from Wima FKS 10% / FKP 5% to Wima FKP 2.5% Tolerance.
Swapped one Sanyo polymer capacitor for a Nichicon FP (which Schiit seem to also use and like), Don't believe me? Check their Bifrost and Gungnir pcb photos.
Swapped (2) RCA capacitors with Elna Silmic II as i find them to be the best performing audio capacitor (especially after 100+ hours) and close to close to film.
Changed power supply mosfet's thermal paste with Prolimatech PK-3, and Added a custom heat sink on the right side which oh boy, is very warm whenever i touch it, so its working like a charm. New paste dissapates heat very sell, i have replacement psu capacitors, exact brand/model/capacitance/voltage for whenever they give out.
All wires directly connected to or on the main pcb has been changed out, since im a hardcore believer in wires.
Last but not least, my led change from stock blues to less bright reds.
If you ever try the muses02's let us know.
Tim