Flat tip screwdriver
Pliers
Wire cutters
Soldering iron, minimum 40W rating
your favorite solder
you may find a desoldering tool or desoldering braid useful
2 - Bottlehead parafeed output transformers
2 - MagneQuest BCP-15 plate loading chokes
2 - 3.3uF ICW Clarity Caps
2 - 0.1uF ICW Clarity Caps
4ft. Teflon insulated wire
8" heat shrink tubing
4 - #4-40 x 3/8" screws
4 - #4-40 nuts
4 - #6-32 x 3/8 screws
4 - #6 lock washers
4 - nylon standoffs
NOTE: The TJ Mesh Matrix 2A3 tube shown in the photo above is not included in this kit. It is available separately.
NOTE: The Paramour amplifier prototype used for this assembly guide is the same prototype that is pictured in the photos that came with your Paramour amplifier kit. It has had the C4S upgrade installed and you will notice that it is somewhat shopworn after three years of development use. Note that the power transformer lead layout is different than that of the power transformer supplied with your kit. Other parts such as the optional Big Stud binding post upgrade and the power cord wires colors shown in the photos below may look slightly different than those in your Paramour. These and any other variations you may find in your kit will have no effect on this modification.
Begin by removing the tubes. Then remove the stock output transformer and the 3.3uF parafeed coupling capacitor. Be sure to keep track of the shoulder washers that fit in the transformer mounting holes and the associated lock washers. Note that one terminal strip and the output transformer core ground wire will be detached in this process.
Power supply resistor removal
Clip the lead of the 270 ohm 5W power resistor at terminal 5, and desolder the resistor lead from the lower hole of terminal 15 to remove it.
Filter choke connection
Desolder the 10H parafeed plate loading choke lead from terminal A2. Resolder the lead to the lower hole of terminal 5. The 10H choke is now connected as a 10H power supply filter choke, replacing the 270 ohm resistor for improved power supply filtration.
New parafeed output transformer mounting
The new output transformer will mount on the holes shown with shoulder washers inserted in the photo above.
Orient the new transformer so that the red and blue primary wires are near the power transformer and the black, brown, orange and yellow secondary wires are towards the outside edge of the chassis. Insert the red and blue wires through the grommeted hole. Use the #4 screws and nuts provided with the kit to mount the new transformer. Be sure to reattach the loose terminal strip on the underside to the front screw, and the transformer core drain wire on the underside to the rear screw.
Now bring the secondary wires around the back of the output transformer and insert them through the grommeted hole.
NOTE: This odd transformer mounting is done to avoid the necessity of drilling new holes in the chassis plate. The smaller #4 screws are used to give enough flexibility for the existing holes to align with the holes on the transformer frame.
New parafeed output transformer connection
Cut to length, strip back 1/4" and solder the blue primary wire to terminal 25.
Cut to length, strip back 1/4" and solder the red primary wire to one of the holes in terminal 11. We have used the lower hole of terminal 11 in this photo. You may need to carefully tip up the hum pot to gain access to this hole, as shown here. The connection to terminal 11 results in the popular "cathode connection", which is possible with the new output transformer, but not with the stock transformer because of it's voltage limitations. You could alternately connect the red wire to ground at terminal 12 or 14, as in the stock circuit. Most Bottleheads seem to prefer the cathode connection's sonics. Be sure to restore the hum pot to its original position when finished.
Cut to length, strip back 1/4" and solder the black (common) secondary wire to the lower hole of terminal 22. Choose which secondary impedance to use -
Brown = 4 ohms
Orange = 8 ohms
Yellow = 16 ohms
and cut to length, strip back 1/4" and attach the chosen wire to terminal 24. In this photo the orange 8 ohm wire has been connected to terminal 24.
Clip of the exposed wire tips of the other two unused leads. Slip a piece of heat shrink tubing over each one and shrink to fit. Bundle the wires neatly with a nylon tie.
Parafeed coupling capacitor installation
Install the 3.3uF ICW Clarity Cap by soldering the leads at terminals 21 and 25 with the capacitor oriented as shown above. Note that the capacitor supplied in your kit will have a slightly different label and different lead colors.
MagneQuest BCP-15 plate loading choke installation
Cut two 10" long pieces of Teflon insulated wire and strip back all ends 1/4". Mark both ends of one sleeve with a marker or tape. Twist the two wires together tightly, about three turns per inch. Tin the ends. Solder one marked end to the terminal on the BCP-15 identified by a black dot on the coil. Solder the unmarked wire at that end of the twisted pair to the other terminal on the BCP-15.
Remove the #6 nuts from the filter choke mounting screws and replace them with 1" nylon standoffs.
Install the MagneQuest BCP-15 plate choke on the nylon standoffs with #6 screws and lock washers. Be sure that the wired terminals are facing in towards the power transformer.
Route the twisted wire pair down to the chassis plate and then over towards the output tube socket. Be careful to cross the green driver heater supply wires at as close to 90 degrees as possible. Solder the unmarked wire end of the pair to terminal A2 and solder the marked wire end to terminal 15.
Shrink a small length of heat shrink tubing over each of the two exposed terminals of the BCP-15 and shrink to fit.
Upgrade interstage coupling capacitor installation
Clip the stock 0.1uF interstage coupling capacitor from terminals 17 and 19. Note that this picture is viewing the terminals from the input tube end of the amp.
Install the 0.1uF ICW Clarity Cap by connecting it to the lower holes of terminals 17 and 19, in the orientation shown in the picture. Note that this picture is now viewing the terminals from the output tube end of the amp. The excess lead end shown protruding through the holes here should be clipped flush.
Insert your tubes, and recheck the resistance and voltage readings against the figures in the Paramour assembly manual. The numbers should remain unchanged. Hook it up and enjoy.