User Guide

PS-220 PARASITIC SUPPRESSOR KIT INSTALLATION INSTRUCTIONS

PARTS SUPPLIED WITH THIS KIT:

(2) Plate/Resistor Choke Assemblies (4) #6 Lock Washers (1 Extra)

(1) Tuning Capacitor Feed Suppressor (4) 820pF 500V Ceramic Disc Capacitors

(2) 10Ω 2W Metal Film Resistors (2) 27Ω ½W Resistors

(2) 0.01µF 1KV Ceramic Disc Capacitors

To start the installation, read these instructions very carefully. Now unplug the amplifier

and remove any input, output and control cables that may be connected to the back of the

amplifier. Place the amplifier on a book, front panel up, and remove the bottom screws holding the

feet and case in place. Lift the case up and remove it from the amplifier. Place the amplifier on the

bench with the front panel facing you. You are now ready to proceed with the installation.

( ) Remove the 15 sheet metal screws that hold the perforated cover in place and remove this

along with the top rear plate cover.

( ) Remove the tubes and remove the plate caps from the tubes.

( ) Remove and save the screw that connects the flexible braid from the HV terminal of the

plate choke to the doorknob capacitor mounted on the end plate of the tuning capacitor.

( ) Carefully unsolder and discard the braid from the HV terminal on the plate choke, as well as

the 2 “parasitic suppressors”. Clean out the outer hole in the solder lug of the HV terminal.

( ) Put the plate caps back on the tubes. Tighten securely and reinstall the tubes.

( ) Locate the peculiar wire, the one with a straight wire paralleling a coil. Slip the loop of this

wire over the screw removed from the doorknob capacitor and then put on a #6 lock

washer. Screw this assembly into the doorknob capacitor. Make sure the suppressor wire

is approximately lined up with the HV terminal of the plate choke.

( ) Fish the free end of this assembly through the outermost hole in the HV terminal of the

plate choke. Trim the lead to about 1/8” protruding.

( ) Slip the loop end of one of the parasitic choke/resistor assemblies over one of the plate cap

screws with the coil up, followed by a #6 lock washer. Install this assembly on one of the

plate caps with the assembly pointing toward the HV lug.

( ) Fish the free end of this assembly through the outer hole in the HV lug and trim the end to

about 1/8”.

( ) In a like manner, install the other parasitic choke/resistor assembly onto the other plate cap,

trimming the end to 1/8”.

( ) Now solder the 3 wires going through the HV terminal of the plate choke.

( ) Turn the amplifier upside down with the front panel facing you.

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PS-220 PARASITIC SUPPRESSOR KIT INSTALLATION INSTRUCTIONS PART S SUPPLIED WITH T HIS KIT : (2) (1) (2) (2) Plate/Resistor Choke Assemblies Tuning Capacitor Feed Suppressor 10Ω 2W Metal Film Resistors 0.01µF 1KV Ceramic Disc Capacitors (4) #6 Lock W ashers (1 Extra) (4) 820pF 500V Ceram ic Disc Capacitors (2) 27Ω ½W Resistors To start the installation, read these instructions very carefully.
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() Locate the (2) 1mH chokes going from the rear-most tube socket pin. Remove each of these chokes. Clean out the hole through which the chokes were removed. () In place of these chokes, install a 27Ω resistor paralleled with one 820pF disc capacitor (1 resistor/capacitor pair for each choke). () On the right hand tube socket, parallel the existing 200pF capacitor closest to the front panel with (1) 820pF disc capacitor. Leave all other 200pF capacitors in place.