No remote control on that model.
You actually have to get up out of your chair to change the volume
As others on other forums have mentioned, it is rather hard and expensive to make a good sounding, remote controlled, volume pot.
Radii does make a four input, remote controlled, transformer based preamp, but it is only 16 steps.

Bill, I am still trying to work out better shipping terms.
Right now the HAP-05 would have to sell for $500.00 including shipping from Hong Kong.

It is OTL and OPT. It uses JJ ECC-88s for outputs and 6DJ8 for a driver