Version 1.32
12
The EL34 valve bases need connecting to the PCB’s. The valve base pins are
numbered 1 to 8.
Warning
: be sure to read the numbering correctly as it is easy to
make a mistake. Pin 1 must be linked to pin 8 on all four of the EL34 valve bases, and
extended to points X1 and X4 on the respective valve bases. For PP mode connect
points X13 and X3, to pin 5 on the respective valve bases, although for PSE mode
connect X2 instead of X13 so that X2 and X3 are connected to pin 5. The 105R
resistors (R53) must be soldered between pins 4 and 6 on each EL34 valve base. See
picture above
Before the volume pot can be fitted, the paint must be scratched away from the inside
of the larger hole in the front panel to enable it to be grounded properly. For volume
pot pin numbering please refer to figure 3 below. Connect pins 1 and 4 to ground on
the closest PCB (not both) at point X10. The PCB’s will be referred to as left and
right when looking from the front so that the left PCB drives the left channel, and
vice-versa. Terminal 2 on the volume pot connects to point X9 on the right PCB, and
terminal 5 connects to point X9 on the left PCB. Connect terminal 3 to input switch
S2 terminal 4, and finally connect terminal 6 on the volume pot to input switch S2
terminal 3. The volume knob can now be fitted using a small flat bladed screwdriver.
Figure 3. Volume pot numbering
The switches can now be fitted in the two smaller holes in the front panel, although
they will be connected up later.
Complete Assembly:
The side panels are fixed to the bottom rear chassis using six M3 screws, but first
scratch the paint on the hidden edge to make a continuous earth between all panels.
The front chassis is now ready to be fitted to the chassis using six M3 screws.
For PP mode connect point X18 on the power supply board, to points X5 on each of
the audio PCBs. If configuring for PSE mode with one power supply board, then wire
it for the PP configuration as above. However, if you are configuring for PSE mode
with the extra power supply board, then connect points X18 on each power supply
board to points X6 on the respective audio PCB.
The ground terminals X12 on the audio PCB’s connect to each of the output
transformers terminals B1; the ground connection for the speakers. The output
