13 January, 2021

Terminal Block Spring Clip Adaptors

 

Talk Tweak : Use of Terminal Block as Adaptors
Letter from Shenzhen (21-4): doctorjohn on a Tweak


Some readers may not know what a Terminal Block is. As pictured, it is a plastic sleeve with enclosed copper tube with screw terminals at both ends. It comes in various sizes and in a row (about 8-10), You can cut the plastic between the sleeves for use in singles, two's or whatever.

These are typically used in electric installations, behind light switches to connect the switch with the inlaid electrical network. The screw terminals are robust as the installation electrc cables are usually thick solid-core, which are harder to screw down than stranded. In HK, one can get this at a Hardware or Lighting supply store, In the US, as mom and pop hardware stores are rare as hen's teeth, you may have to go to Home Depot or online to get it.

I only occasionally see these in audio DIY use, but I have what I think is a good tweak for you, and it's solder-less.

For those who use certain Vintage Amps (like NAD 3020) and Loudspeakers with Spring Clip Loudspeaker Terminals (like my beloved Yamaha NS-1000 and NS-10, and old TAD's like TAD-3401) and who want to use loudspeaker cables with banana's, this is a good tweak.

Just insert your favorite short strip of loudspeaker cable at one end and screw on tight (make sure the strip is centered and with good contact). At the other end, adjust the screw so your banana can glide in easily (do it gently to minimize scratching) but would not slip out. Don't over-tighten as the screw will scratch and deform your banana. Done.

It costs cents and, believe me, the copper is of good quality, better than in many audio connectors. Some may object to no-solder, but my own experience with screw-on terminals is positive. If you use spades, you're out of luck, but personally I hate spades, cumbersome and dangerous.

Of course, the block can used in other ways, to connect 2 wires or serve as an extension in a pinch (which we all have experienced). I'd think power supply would be a good place for its use.

3 comments:

  1. Nice piece of practical advise. Thanks for thinking of, and then carrying out the act, of sharing.

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  2. Thanks for sharing. I often use these connectors but never realized that they could be used with banana terminals. Great news! All the best for your travel adventures - it has been really interesting getting an inside view of things.

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  3. I too, amongst others, have the NAD 3020 Series 20 and other vintage gear with troublesome and dubious spring clip connections.
    My take on this is to use (as well) a very short strip of quality speaker cable - with bare wire one end to go into the spring clip - with the other end soldered onto a quality hollow Z-banana plug. In this instance your precious speaker cables 4mm banana plug slides into the hollow Z plug making for a tight firm connection. With the added bonuses of low mass and easy unplugging re-plugging.
    Works a treat.
    Just my 2c

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