No idea about the transformer upgrade, but past that the cheapest/easiest thing to do would be to add a linear power supply (LHY, SBooster, Teddy Pardo) to the Node that will yield a nice performance bump. I assume you’re using the DAC in the Node, so that’d be another obvious area for a significant upgrade. If you were to add the LPS and get a good DAC I think you’d be at a much higher level. If you really wanna up your game pair one of the above power supplies with an Innuos Pulse Mini and a good DAC — not cheap but would be another level of improvement and give you a USB output. And yes, I think your P3ESRs would reward you for feeding them a much better signal. Just some thoughts FWIW, and best of luck.
TU-8900 upgrade
I have a TU-8900 in my 2nd system with a BlueSound node and a pair of Harbeth P3ESRs.
The 8900 is the standard setup and I am wondering if anyone has upgraded with the Lundahl OPTs and audiophile caps?
Does the Bluesound node source warrant the upgrade? Are the P3ESRs sufficiently resolving that I'd hear a significant difference?
Thoughts?