I'm so lucky to have met some lovely people over the years and got to know many customers on a personal level. One of them is Alex Simler. Alex is... well, kind of a bit geeky, eccentric, loves old gear and recently commissioned me to build a power supply for the Elektron MachineDrum Mk1.
Being a simple 6V ac supply, this wasn't a particularly challenging or even difficult project. Alex lent me his MachineDrum Mk1 as he was off to New Zealand for a couple of weeks and this would be an opportunity for me to knock something together. After a couple of days and in-between my regular stuff, I WhatsApped Alex a picture of the finished product.
Yeah, okay, it's a bit more fancy than your average wall-wart but that's just me. While the power cable is integral, the low-voltage cable is detachable. Hey let's face it, these cables get mashed, right? Having a detachable cable means that when your cable does get müllered, you can just buy another one or even just have some spares. It's a standard 5.5mm x 2.5mm DC cable and available for a couple of quid, bucks, Euros or whatever from Amazon.
The MachineDrum Mk1 pulls about 1.6A from a 6V a.c. supply. This means that the current supplied from the mains into the primary of the transformer is about 42mA when used on a 230V supply. Here's how you work that out:
Supply Voltage = 230V
Secondary Voltage = 6V
Voltage Ratio = 6/230 = 0.026
Secondary Current = 1.6A
Primary Current = (Voltage Ratio \times Secondary Current)A
Primary Current = 0.026 \times 1.6A = 0.042A
So with a current consumption of 42mA from a 230V supply, a standard value 63mA slo-blo fuse should be fine. WRONG! You need to cater for transients on the mains supply and I would normally double this without compromising safety. Hence the internal fuse is rated at 120mA.
Since power is the product of voltage and current, if the supply voltage is halved from 230V to 115V, you have to double the current to maintain the same power. Hence the fuse rating on a 115V supply, is 250mA (kind of 2 x 120mA). Hope that all makes sense.
My power supply for the Elektron MachineDrum Mk1 is rated at 15VA. That's 56% more than what I measured (1.6A x 6V = 9.6VA) so it won't get hot! 🙂
This power supply for the Elektron MachineDrum Mk1 is offered with either
- a 3-pin UK plug with the PSU configured to operate on 230V.
- a 2-pin European plug with the PSU configured to operate on 230V.
- a 2-pin US plug with the PSU configured to operate on 115V.
Anyway, the main thing was that Alex returned from his New Zealand adventures and loved his new power supply!
Incidentally, this power supply for the Elektron MachineDrum Mk1 which I've christened 'PSU-MDMK1' (well I had to call it something), can also be used on the Elektron MonoMachine Mk1.
You can buy this power supply here...
If you need help with any Elektron products, the Elektronauts forum is a great resource. Please do check it out.
THIS POWER SUPPLY IS NOT COMPATIBLE WITH THE
ELEKTRON MACHINEDRUM MK2
UPDATE - 18th January 2023
I recently got a MachineDrum Mk1 in that had been damaged in the post. The display cover was cracked and the display itself was intermittently failing to come on. Read how I installed a replacement display here.
UPDATE - 20th January 2024
Displays arrived this morning so two machines will be going back to happy customers (one in Germany) soon! 🙂