User guide
6
Installation
Installation of Vacuum Tubes
Before operating the SP20...
This unit has been shipped with the vacuum tubes installed in protective 
foam  in  a  separate  box  packed  inside  the  shipping  carton.  Remove  the 
tubes carefully from the protective foam. Using a phillips-head screwdriver 
to loosen the fastening screws, remove the top cover and set aside. 
After removing the top cover and the vacuum tubes packed in protective 
foam, see the accompanying illustrated sheet for instructions on installing 
the tubes for your SP20 in their proper locations in the power supply and 
audio chassis. Note that the numbers written on each tube correspond to 
a ‘V’ number printed on the circuit board next to each tube socket. Insert 
each  tube  rmly,  carefully  aligning  the  tube  pins  with  the  corresponding 
socket holes.
Line
Stage
Phono
Stage
V1
V3
V2
V4
CHANNEL
R L










