Sorry I feel so stupid - how do I power my Shruthi?

Ive looked as far as I can - I;m about to start my build - have the kit and case, got my soldering tools up - how the hell do I power this thing up to test? Im assuming its a wallwart - I live in Australia so 240v 50 hz. Im sorry for the noob question. I love this place. So glad I found Olivers instruments… - cheers, Matt

Wallwart or equivalent, 2.1mm, tip positive (centre positive), 7.5V-12V DC.

Thank you. Its written on the enclosure:). Its says 300MA DC - so ask for that specific output or is there a allowable tolerance?

Sorry I meant the output - it says 300ma dc. I usually stay away from walwarts so I’ve no clue. I’m wondering if it says like 800ma ans 9v tip positive (old phone charger) would be OK

9V, 800mA tip positive is OK.

The limit on wall warts is the maximum amount of current that can be drawn by something before the wart heats up and starts to smell, and worse. At 800 mA, that wart is fine (centre pin + !) as the Shruthi will only draw 300 mA. If you had one at 250 , it would not cut the mustard. But the Voltage should never be exceeded or you will potentially damage chips ( there are IC’s on board to regulate the voltage, but they can only do so much, the more you put in the hotter they get ). Which leads to this One Spot .It is rated 9V at 1700mA so with polarity reversers ( which cost a little extra, it is designed for guitar stomp boxes , which are mostly centre negative, so you have to reverse the polarity for MI kit) you can hang quite a few Shruthis (and the likelyhood is you will own more than one) , Anushris, etc off one wart. But not Ambikas, they run on AC.

I would not use a 12v PSU except if it is a good, regulated one. Go for 7,5 or 9v and you’re on the safe side, even if it’s not regulated.

I heartily agree , hence my endorsement of the One Spot at 9V.


btw. does the One Spot also come with euro plug? Looks like a really nice solution… though, you can also just get a standard universal 1500mA PSU and make yourself the cable for it (or buy it for 5 euro on the nets)

Maybe the documentation should be altered then:

“2.1mm DC power jack. The Shruthi-1 can be powered with a 7.5V-12V unregulated supply, or with a 9V battery adapter. Make sure that the connector has a center pin (or tip) positive / outer collar (or sleeve) negative pin polarity. Most universal power supplies allows the polarity to be selected — the polarity being often represented by a diagram like this: – (o , or by the indication tip:. The power supply has a reverse polarity protection and can handle voltages up to 15V. Note that VCF/VCA boards distributed by third parties might not follow these specifications and have different power supply requirements.”

I don’t really know what to do about this. The objective information is that the Shruthi will work with a 12V power supply - and people with a good 12V power supply would have no problem using it. The problem is that the voltage rating of the unregulated PSU is not to be trusted…

yep that’s why I was pointing out that 9v is a safer solution. of course you can use a 12v PSU, but if it’s unregulated, you don’t know if voltage may peak over 15v, and that might be a problem.

re the one spot it depends where you buy it I assume, mine came with 3 pins , but I have seen 2 pin …

The One Spot looks intriguing. I use these from Amazon. When putting in the plug, check the polarity.

1-spot is the bees knees. Nevereverever an issue running multiple shruthi’s and a midipal off of 1.

I run a MicroKorg XL simultaneously with 2 Shruthi , A GorF ,Anushri and my SH-101. More to be added.