Tube rolling for EAR 912

With regards tube rolling the EAR 88PB. I recently bought one from new and opened it up and was surprised to find the ECC88 type of tubes in it! All I've read in previous forums has been that it uses the higher heater voltage type of valve (PCC88). Tried some Mullard PCC88 in it which work very nicely. Will ring up EAR to find out why they changed to ECC88 (?).
Mark

Wow that's odd.  My late 2017 88pb came from EAR with 4x dP PCC88.

When I talked to Tim at the Anaheim Show in 2015, he told me his favorite tube brand was Mullard. The old ones, of course. Isn't is surprising how few audiophiles own, or have even heard, EAR electronics? Small number of dealers and pro reviews, no advertising, no frequent and regular model "updates" (Mk.2, Mk.2SE, Mk.3, Mk.3SE). 

I have an EAR 912 preamp and 890 power amp, as well as the HP4 headphone amp and the EAR Dac 4 (although I generally use my Chord DAVE instead). As soon as I got the preamp I started tube rolling. I tried Telefunken, Phillips and a bunch of other NOS 7DJ8s.  Then I tried some new JJ gold pin 6DJ8s. They all sounded awful.

I emailed EAR to ask why and Tim replied that he found it amusing that audiophiles thought they knew better than he did and tried to improve on his design by trying different tubes. I reinstalled the stock tubes - which I believe are re-branded Sovtek. You know what, it sounded amazing, much better than any of the NOS tubes I tried.

It may be that EAR carefully select the tubes they put their own brand onto. But it did teach me that sometimes it is best to listen to the person who designed the equipment.

Anyone want to buy a big box of preamp tubes?

FWIW this is my experience exactly on my EAR 912 - tried Telefunkens, tried Teslas, went back to the standard tubes.