This kit is designed to replace both dual electrolytic capacitors used in the Marantz 2385 and 2500. The 2385 uses a set of dual 6800 uF/85 V caps, while the 2500 uses a set of dual 7200 uF/100 V caps. These dual capacitors are difficult to come by, so at the request of another eBay user I created a custom mounting board that fits four modern production screw-in capacitors.

The board mounts using four screw holes that were used by the mounting brackets of the original capacitors. Wiring is done from the bottom of the unit and is made easier by the use of robust wiring turrets. Footprints are provided for installing the bleeder resistors on the circuit board, but they can also be left where they are and attached to the wiring turrets. The mounting board itself is manufactured with double-sided 2 ounce copper and large copper pours to ensure very low impedance connections to the turrets, and a 2.4 mm thick FR-4 laminate to reduce board flex.

If you have any doubts about the fitment of your choice of replacement capacitors, feel free to send me a message.

Note that due to the slight increase in capacitance with the Kemet ALS80A822DF100 capacitors compared to the original parts, you may wish to replace the original bridge rectifiers with parts capable of handling higher continuous and peak surge currents due to the increase in power-on inrush current. For reference, the Marantz 2500 schematic indicates that it uses two S5VB40 bridge rectifiers, which are rated for 6 A continuous current (when bolted to a heat sink, i.e. the chassis), 200 A peak surge forward current, and 600 V maximum reverse voltage. The 2385 uses two S5VB20, which have the same current ratings but are rated for 200 V maximum reverse voltage.

Lastly, you will need the usual tools and equipment involved in servicing stereo equipment (pliers, wire cutters, variable temperature soldering iron, multimeter, etc.) This kit requires some skill and experience to install, so if you are not thoroughly familiar with repairing electronics at the component level, please have a qualified service center install it for you.

An install guide is included with the unit, but is also briefly listed below:

- Take pictures or make diagrams of the color codes that were used to wire up the original capacitors in your unit

- Remove the original capacitors and mounting brackets. Try to save as much wire length as possible

- Install the four included threaded standoffs to the Marantz subchassis with the included hex nuts

- Place all turrets on the "Turret Side" of the board. Flip the board over and crimp them with snub nose pliers so that they are mechanically secure, then solder them in place

- If using the specified Kemet parts, place five of the included spacer boards over the mounting studs of each capacitor. Make sure the third hole on the spacers all align with the pressure relief vent

- Mount your new screw-in capacitors on the "Capacitor Side" of the board. Silkscreen references are included on the board to indicate polarity; be sure to triple check that they are installed correctly! I recommend using internal tooth lock washers under each screw to ensure a good electrical connection

- If you want to install the two bleeder resistors on the mounting board, do so at this time. Place them on the "Capacitor Side" of the board. Per the original Marantz schematic, they connect from the negative rails to ground

- Mount the assembled board in place with the four included screws

- Turn the unit upside down. All of the wiring turrets can be seen through the two round holes in the bottom of the chassis. After confirming the color codes with the diagram or pictures taken at the beginning, strip back each wire about 1/4", insert them into the center holes of their respective turrets, and solder them in place. The turrets labeled V+ on the board's silkscreen corresponds to the positive rail, V- corresponds to the negative rail, and GND corresponds to ground. If you are leaving the bleeder resistors in place rather than moving them onto the board, they can be wrapped around the V- turrets and soldered in place.

- Triple check your wiring. If you are replacing the bridge rectifiers with parts capable of handling higher continuous and peak currents, do so now. I recommend powering the unit up slowly with a dim bulb tester and variac while monitoring the supply voltages to confirm that everything is working as expected.

- Enjoy!

- One capacitor mounting board (2.4 mm thick TG150 FR-4, 2 oz. copper, matte black solder mask, ENIG immersion gold finish)

- Twelve wiring turrets

- Twenty capacitor spacer boards designed for the Kemet ALS80-A-DF family (5 per capacitor)

- Four #6-32 x 3/8" male to female threaded hex standoffs

- Four #6-32 machine screws and nuts

- Step-by-step installation guide