Topping MX3s, DX3Pro+, PA3s Mount Kit

A complete kit to mount the Topping MX3s Amp+DAC, Remote and Power Supply neatly on the underside of your desk, or anywhere else you'd like to put it!


Other Topping Amps / DACs

These parts were designed for the MX3s.
However, some parts should be compatible with the DX3 Pro+ and PA3s, so you can print only the relevant parts you need:

Thanks for @nole120_3468223 for confirming DX3 Pro+ compatibility (link). ❤

* PA3s compatibility is untested at this stage and is assumed. I think the MX3s and PA3s use the same power supply, but I cannot confirm. The MX3s power supply dimensions are approx. 61mm (W) * 32mm (H). If someone is able to check or test and let me know, I'll update the above table.


Kit Details

Kit consists of:

- 1x Rear Bracket
- 1x Front Bracket
- 1x Remote Holder
- 2x Power Supply brackets.

Print only the bits you need, or all of them.

The kit is designed to use 8 Gauge (8G) Pan Head screws. I use the sheet metal kind when mounting into wood/chipboard, 8Gx18mm, works great - rock solid.

The mounts are designed to space the amp body 10mm away from the mounting surface. This spacing helps make it more comfortable to turn the control knob.

The front mount can be used anywhere along the amps length, so you can place it wherever you like. Alternatively, you could also use two of the Front mounts (rather than one front, one rear), however the amp might slide when you try to handle it, especially when pressing on the control knob.

The Remote Holder can happily be mounted horizontally or upside down. It is a clip design, so you can snap the remote into it. The remote can also be clipped in either direction (Face side towards, or away from, the holder). However if you wanted to mount it in a vertical orientation, the remote could slide out, so some slight modification might be necessary in that instance - perhaps just add a small 5mm foot on one end for the remote to rest on.

The power supply mounts just slide onto the PSU body from either end, with holes for the cords to pass through.

The only limitation of this design is that it likely will not accommodate speaker cables when using bare wires into the terminals. This design assumes / requires your speaker cables have banana plugs.

For an easy and solid print, I configured the slicer to use 6 Perimeters with a 0.4mm Nozzle. I used PETG, just for it's higher heat tolerance, as these little amps can get warm sometimes, but PLA would probably be OK too. I also used support material with 0.8mm interface spacing for the screw holes, though this may not be necessary.


Drill guide

Due to the hidden screw design, drilling the holes in the desired locations can be tricky.

The mounting holes are 87.4mm apart on centre, and the 4 screw holes need to be properly aligned. If they are crooked, the amp won't slide into the mounts properly. 

The front mount can be mounted as close or as far from the rear mount as you like. However, if you want the front mount as close to the front of the amp as possible, the maximum distance from the front to rear drill holes would be ~124mm.

A Drill Template PDF is available under “Other Files”. Ensure printing is at 1:1 (no scaling). PDF Paper size is A4. Verify dimensions before use.

Using the drill guide is not necessary. Here's what I did:

• Determine where you want the amp to sit. Where the rear bracket will be placed, through the first hole closest to a reference surface, make a mark on the mounting surface, and drill a single 3mm hole (assuming 8G screws).
• Mount the rear bracket with a single screw in the hole you just drilled. Tighten it all the way, but a little loose enough so the mount can still pivot on the screw.
• Get the orientation right, e.g. with a builder's square against a reference surface, rotating the mount as needed. Use a 4.5mm drill bit through the other open hole to make a mark.
• Remove the mount, locate the mark, drill another 3mm hole.
• Mount the front backet here temporarily. Slide the amp in backwards, with the rear of the amp facing the front of the desk.
• Place the rear mount on the amp, just slightly. Don't push it on all the way, just a little bit so the holes are exposed, but is aligned straight. Position the amp + mount to where you want the front mount to be. Use the 4.5mm drill bit and insert it between the amp and mount on the side with the USB port, through the hole, making a mark. Don't worry about the other side for now - the antenna attachment gets in the way.
• Remove the amp. Drill the 3mm hole on the mark you just made.
• Screw either the front or rear mount onto the 3rd hole.
• Use the builders square or other reference tool again to ensure the mount is parallel to a reference surface and/or parallel to the other mount (when affixed). Use the 4.5mm bit through the final open hole to make your final mark.
• Move / pivot the mount out of the way and drill a final 3mm hole.
• Done! Move the mounts to their correct positions, and then slide the amp in from the front of your desk.

The Power Supply and Remote mounts are obvious enough to do without instruction. The Remote holder can be mounted with a single centre screw (which will allow it to pivot) or two opposing screws.