Nice little yaqin valve buffer for sale.
Comes with 3 sets of valves, Chinese, Russian and RTC (my favourite) and in original box.
I believe this is the CD2 model.
£50 plus £10 postage to UK.
Works well with a passive pre to give a bit more drive and a bit of body.
Note: I found you need to switch this on for a minute or so before powering up any equipment downstream like an amplifier as there can be a short pulse of DC as the valves warm up.