3
Figure 1 Tube and Deck Layout
INSTALLING THE STEREO 90 INTO YOUR SYSTEM
Connecting the Stereo 90 to the Loudspeakers:
The Stereo 90 provides options for either 4 or 8 ohm speakers. The impedance
selected will depend on the speakers used. Consult either the owner’s manual for
your speaker or your local dealer to determine the correct choice. The amplifier is
factory set to 8 ohm.
To switch impedance setting:
1)
Using a ½” wrench remove the outermost nut from the positive (red) binding
post.
2)
Remove the 8 ohm tap (green wire marked 8) from the binding post. Be
careful to leave the black wire with heat shrink on the post.
3)
Remove the polyurethane tubing from the unused 4 ohm wire (yellow) and
lug.
4)
Place the 4 ohm wire onto the binding post and replace the outer nut.
5)
Place the polyurethane tubing on the 8 ohm wire and lug.
V1
Left Binding Post
Right Binding Post
Bias Meter
Rotary Bias
Switch
Potentiometers
V1
V2
V4
V3
12AX7
6SN7
Bias Tool
