On the schematic you will find one chanel of this amplifier so basically you need second one to have a stereo sound in your headphone.

Each tube have to identical section inside so you need basicaly one ECC88 (V1) and one 6H13C(V2).

Input stage I used quite good quality Alps 100KAX2 potenciometer with good compromise quality/price.

At this moment I've rebuild little bit filament for tubes and power supply for filament is 6.3VAC directly from the transformer.