Vacuum HE1 SE (Single-ended)
Vacuum HE1 XLR (Balanced)

Built in regenerative power supply
8 unit vacuum valves in Vacuum HE1 SE
10 unit vacuum valves in Vacuum HE1 XLR
Applied vacuum rectifier ,Without silicon elements on signal and tube power circuits
All power caps built with SOLEN film caps
All vacuum valve filaments power supply by AC
Remote function

Option 1 ：Custom order output delay , price is USD15 (Only available for Vacuum 1 SE).
         For avoid the sound quality degrade, the unit has not built the output delay design.
         After power on the unit, the display will blinking around 30 second, we are recommend power on the power amp after the display stop blink .
         If you feel bother of this operate , you can custom order the delay output while place the order .

Option 2 ：Buy the spare matched vacuum tubes.
                  6H2N-EB cost price USD15/pc, total 4 pcs for Vacuum 1SE or total 6 pcs for Vacuum 1 XLR.
                  6U4N-EB cost price USD15/pc, total 4 pcs for Vacuum 1 SE or Vacuum 1 XLR.
          For avoid the sound quality degrade, we are recommend replace the new vacuum valves after 5000 hours, (Every day 3 hours, it is around 5 years) . After replace the new vacuum valves, it need around 150 hours burn in.

Option 3 ：Custom order blue display.
         Extra 3 workdays leadtime and free.

Option 4 ：Custom order ACSS -XLR cable, the ACSS and XLR signal impedance un-match cause the sound more warmer..
         Price is USD45 /pair , 1 meter .