Don't go mad on me, please

Hi everyone, it’s a shame that I have to make an entrance on this forum with a thread about this but I’m just an insecure person when it comes to these things.

I moved to London and I will be here for around 6 months. I miss my little studio back in my country so I went to the internet to see if I could find a simple synth that I could make some noise with, and hopefully put out some tunes with the stuff that I brought with me.

The result couldn’t be better. I found about mutable-instruments and this great community within it.
Unfortunately, I still don’t have any soldering skills, nor circuitry ones. Hopefully, when I get back to my country, I’ll just buy my first soldering equipment and start the DIY part of my life.

Lucky me, I found a local pre-assembled shruthi-1 seller and I bought one with a 4-Pole Mission filter, which apparently turns out to be a little beast of an instrument and not a simple one like I said before.

Well, enough talk.

I’ll grab it tomorrow morning at the post-office and bought some DC adaptors yesterday. I bought a regulated 9V, switchable polarity, 600mA - - and an unregulated, 6 output voltages, switchable polarity - - which now seems like the dumbest purchase ever. Both are from Maplin.

Should I really be concerned about the regulated 9V outputting more than 9V ?

The reason I bought the unregulated one, was to use it at 7.5V (it says 7.5V 2A on the back) if the other one was not to be trusted as a “really regulated” one. Am I paranoid ?

Also, both come with 8 power tips, I’ll just try to fit them into the Shruthi and only the 2.1mm will enter, or there’s any other way I can make sure it’s the 2.1mm ? They all have different colours.

Sorry for the newbie questions,


Welcome to the forum!

The unregulated PSU will output more volts when it’s unloaded - not driving the Shruthi. If you measure it with a multimeter this is no cause for concern. Yet.

However, if you take the Shruthi apart and run it foe a while using the unregulated you should try to measure what it outputs into the Shruthi- if it’s too much the regulators will get very hot.

I would suggest you try the 7.5V version first. If everything works well with that there’s no use inputting more voltage that only heats your Shruthi.

I think both adapters will be fine… Make sure you get the polarity right. Centre tip positive.
Don’t worry there shouldn’t be anything wrong about it. Just make sure you don’t use anything above 12V…

Well I bought these 2 to make sure I can keep it under 12V. Only thing is I don’t have a multimeter and wouldn’t even know how to use it.

That’s why I wasn’t really confident with either one of them…

Try the 7.5v one, it should be fine, I use a cheapish eco changeable volt one, and it works perfectly at 7,5volts :slight_smile:

The PSU does not have to regulated, the Shruthi regulates the voltages internally. But as the others have said, if the Voltage goes up to high, the components could overheat and burn out.
Well afaik it should be able to handle 12V just fine, 9V is to be safe (because it could output a higher voltage) and 7.5V is like double safe.
But still, I’d say too that if the 7.5V adapter works, then go for that one.
The only thing to make sure about the different tips is that you don’t get the one with the bigger “hole”. It will fit it will not be stable and moving the cable could make the current “jump”.
Take the one that fits tightest. These universal PSUs usually have a marking and a little drawing on them like the one that should be on the Shruthi case
Something like this:

the Shruthi needs the + to be in the center, so make sure you attach the tip the right way around

Thank you very much for all the replies ! I’m a lot more relaxed now…

The tip positive thing I already managed to learn at the store, I think I can’t go wrong with it.

So I’ll go for the 7.5V first then, it’s not a problem that it outputs 2000mA, cause the Shruthi will only draw 300mA right ?

Also, couldn’t it output more than the 9V because it is unregulated ?

All your posts are very clear, don’t get me wrong. Just want to make sure I learn this for life.

Thanks !

Welcome to the forum ogait.

Hope you enjoy London as much as I do whenever I am there.

Merry tunes!

No problem with the 2000mA, the shruthi will indeed like you said only draw 300 of them :slight_smile:
You can even chain several shruthii together with that much power, just use a splitter cable :slight_smile:
(Once the bug bites you and all that)

Thanks Varthdader, really enjoying it so far !

Alright guys thanks for everything ! I bought the regulated thinking it was the best and the unregulated just in case, now I’m gonna use the unregulated !

V`cent, I’m sure it will bite but the next one will have to be assembled by me. I really need to develop some skills in this area.

Can’t wait to grab that Shruthi ! :wink:

This unregulated one is making an hiss… is it normal ?

Power supplies should never make a sound. A hum is about all that would be considered “normal”, but that would be the sign of a poor transformer?

Ahum, just to be sure.
Is the adapter itself making a hiss or is the shruthi making a hiss in the sound with this adapter?

Just the adapter ! The shruthi is fine despite the fact that I’m not yet sure which one is the 2.1mm tip.

@ogait enjoy your stay in London- it’s a great place!

a|x (London resident for the past 16+ years)

Thanks bro !