Sansui AU-717 AU-517 speaker binding post adapters by bloblob

Last crawled date: 3 years, 3 months ago

These parts are used to convert a vintage Sansui AU-717 or AU-517 integrated amplifier to use speaker binding posts instead of the original bare wire spring clips. With binding posts you can still use bare stranded wire, but also 4mm banana plugs (recommended), spade terminals, etc.
You will need to buy binding posts (4x red, 4x black) to do this conversion. I used these: https://www.amazon.es/gp/product/B01FQXOYV6, but you may find other compatible options depending on where you live. The binding posts should be the type with a solder tab/ring that detaches from the binding post. This will make it FAR easier to do the soldering, since there isn't much slack in the existing wires.
There is no hardware required to install these, nor drilling/modification of the rear panel. The outer part has a 'key' that locates it in the existing opening. The inner and outer parts are clamped together by the binding posts, and are held firmly (no movement) to the panel.
The inner part has 'partitions' to prevent adjacent wires from touching even if the nut on the binding post came loose. The inner part also has rectangular recesses that keep the solder tabs oriented in specific directions so they won't rotate under strain.
Instructions:
Take pictures of the existing connections before disassembly. It is very important to remember which wire connects to which terminal when assembling later!
Cut the existing wires as close as possible to the terminals of the old speaker clips.
Remove the spring clip terminals. There are spring tabs at either end of each terminal block that must be (very firmly) squeezed together, which will allow them to be pushed out. It might be worth saving these for another project, or to sell on eBay, for example. If it is too much trouble, you can try breaking off the spring tabs at either end.
Strip the wires (18 AWG), leaving about 8mm of bare wire exposed. I started with the lower terminal's wires (labeled System-B on the rear panel). Bend all of the solder tabs to 90 degrees.
The two outer wires (red and yellow in my case) were folded through the eyelets of two of the solder tabs, and soldered. For the two inner wires (black and white), you need to solder the amp wires to the tabs, as well as jumper wires that will connect to the inner tabs of the upper System-A terminal. I found it easier to solder the wires perpendicular to the tabs, from opposite sides (see 3rd photo).
Fit the inner and outer pieces to the lower panel hole, and insert the four binding post threaded shafts (having removed nuts, broken washers, and solder tabs). The outer two are red, the inner two are black. Fit the solder tabs over the shafts, and install the broken washers and nuts loosely. Orient the tabs as shown, and seat them in the rectangular depressions before tightening the nuts. The inner two tabs are turned 90 degrees to allow for the two connections (amp and jumper to upper terminals). It is recommended to use thread locker to prevent the nuts from coming loose, especially if using bare wire or spade terminals.
Repeat the process for the upper terminals.