Elma A47 Switch Update

A quick update regarding the popular Elma A47 Switches. Find the links to them all here

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AI-generated video transcript

Hi, Nick from Hi-Fi Collective here.

Just a quick video to talk about the Elma A47 switches. We’ve sold these for many, many years, but we’ve recently had notification that production is going to stop. Until the end of the year we can still place orders, but after that these switches will no longer be available, so just be aware of that.

I’m going to quickly go through the different types.

This is the jumbo switch, which is designed for building a shunt stepped attenuator. This particular version can accommodate 1 watt resistors. We offer these in different forms — either as separate parts so you can build your own, or we can build them for you.

That’s the stereo version. We also do a smaller version built on a compact board like this. With this one you get a much smaller profile, so it’s ideal where space is limited. These will accommodate quarter watt and half watt resistors. Like the jumbo version, it’s also a shunt attenuator design.

For this series of switches we also offer all the various impedance boards. Let me just grab one here.

These are series attenuator boards. This particular one is 100k. Basically, you have a whole chain of resistors in line and the switch moves through them. Here we’ve got SMD resistors already fitted to the board, all soldered up and ready to go.

We have a full assembly process for these. When we receive an order we keep all the component parts in stock and build the switches to order. We recently had an order for 10 of these going off to Japan, so I’m building those up now.

You can see all the drawers behind me with the part numbers labelled. I’ll quickly show you how one of these is assembled.

You start off with the switch body and clamp it in the vice to keep it fixed in place. I don’t know if you can see, but the positions are numbered all the way around. You start with position one pointing towards you.

Then you fit the centre shaft. This is the stereo version, so it’s quite long. There’s also a mono version, which is shorter.

You line that up and push it into place. Then the covers fit into the grooves on top. They’re deliberately quite tight. One of the great things about these switches is that they’re enclosed, so the contacts aren’t exposed to dust.

Next you have the former. This is where the spring and contact mechanism fit, and that goes facing towards you. Then the washer goes over the top.

This piece here is what actually makes the contact. After that comes the spring. I believe these are 1.5 Newton springs, which controls how much torque is required to turn the switch. This is the lightest torque option.

Then we fit the gold-flash contact. As it rotates around the board it joins the outer connection track. You can see the continuous circular connection there.

The board itself is raised slightly using these spacers on the connection side. You can press those down either with pliers or against the bench.

Then another washer goes over the top. I’ve built hundreds of these over the years, but everything still has to line up perfectly. It’s quite a precisely engineered product, so if anything is out of place the connections won’t work properly.

There’s also a plastic retaining ring that fits underneath. You lift the inner washer slightly and slide it into place.

After that you just repeat the same process for each layer.

We always supply these fully assembled in whatever configuration you want, but we can also provide them without resistors fitted if you prefer to build them yourself.

I think the main thing to take away from this video is that these switches are not going to be around forever. We’ll be doing a large final buy before the end of the year because they are still very popular.

It’s a shame, but it seems to be the way things are going now. The high-end audio market is relatively small, and if manufacturers don’t sell enough of a product they eventually discontinue it. We’ve seen the same thing happen with various capacitor manufacturers over the years.

Anyway, that’s the switch assembled. You can see the gold contact strip there, and how it sweeps around the board making the connections.

I’ve already got 10 of these completed and ready to ship off to Japan.

So, if you’re thinking about using one of these switches, now is probably the time to do it rather than waiting until later.

Before I sign off, I just want to say a big thank you for watching our videos. Please like, subscribe, and follow us on all our social media platforms.

See you later.