I've had my Taboo III for several months now and loving it. I was using it primarilly as a speaker amp with my Omega 3Es. I, disconnected the speakers and, temporarilly, switched it to a headphones only amp (LCD-2.1). Without speakers connected I seem to have a very slight mv drop on both meters ( from 28mv per side down to about 26mv).

Rectifier tube: NOS Philips 5R4GYS
Input tube: changed from 6N1P-EV to NOS Telefunken E88CC
Driver tubes: 6P15P-EB.

The manual says 30mv is optimal, but anything between 20-40mv is acceptable and useable.  I'm wondering what other owners have for meter readings (preferrably without speakers connected, although I don't know if that should make any difference) and whether, and how much, the sound might change from an optimal 30mv to 26mv.

I have the feeling I may be nit picking here.

26 both sides; headphones only...

28 both sides, headphones only with stock tubes.