Io1 and SUT?

About 3 months ago I acquired an iO1 packaged together with a SUT that I know nothing about and a P10.
Overall they sound good together, however no matter where I place the SUT I get hum. Some places worse than others, not managed to get it quiet yet.
I’ve tried the io straight into my Paradise and it sounds great I just turn up the volume a bit. But I would like to get The best out of SUT. Any advice on how I might get it to be quiet?

Sell it


Suspect due to the labelling the transformers themselves are these AN ones.
3 & 12 Ohm – 100 KOhm, copper wired High Quality, MC matching, standard mumetal core

Have you tried swapping the phono leads around as some connect any shielding at one end only. Also keep it well away from anything with a transformer in such as the turntable power supply, pre amp or phono stage. You might have to try some long cables to take it well away and see if that works. If so its then a matter of how you arrange your kit to keep the SUT socially distanced. :slight_smile:

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You could try earthing your tonearm on the earth terminal of your phonostage and then earthing the SUT to something else.

My ANJS6c hummed a bit so it gets earthed to the earth terminal on MC side of my phono stage. The tonearm is earthed to the MM earth terminal of the Allnic. Dunno why it works, but it works. My curiosity as to why this works can get to feck.

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Brilliant @flapland
Just identifying the transformers used is a step forward.

I always try to work towards the front. First check that the P10 is quiet when nothing is attached to it’s input. Once you’re happy that it is, connect the SUT with your chosen (and properly screened) cables. Then, without attaching the tonearm leads, experiment with the position of the SUT to find the quietest location for it that you can. Also experiment with having a wire between the earth terminal on the SUT and the terminal on the P10. See if you can get that arrangement satisfactorily quiet. If you can’t it’ll be necessary to see how the SUT is wired internally. Sometimes people seek to achieve full isolation by not linking the primary winding to the secondary but such an arrangement can result in hum. If you can get the connected SUT quiet, then try attaching the tonearm leads and again experiment with whether the tonearm’s earth wire needs to be connected. It’s also instructive to take a separate wire and try holding one end to the earth terminal on the phono stage or the SUT and try touching the other end to the TT spindle or chassis. Report back.


I’m starting to regret the path I’m going down with turntables.

Thanks @murrayjohnson I’ll follow that and report back. :+1:

The Io is ‘special needs’. You don’t have to go that far.


I already have. I got the one from HiFi Hangar a while back and still not got it sorted. My whole hi-fi is just bits and pieces waiting for other bits for it to all fit together. My choices are horrifying (special needs doesn’t come close) and the IO I blame on the people here, actually I think it was a post you wrote (great piece by the way) on the Wam lol

Pretty much sums up most of the members here :rofl:


I learned from the best lol

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I only started this whole thing looking for surround sound speakers.



You boarded the wrong bus mate, here be dragons.

I realised quickly I didn’t give a shit about surround sound and joined the Wam only for it to shut down just after.

It’s been a long road since of me spending my full budget on each separate piece of equipment :joy:

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Er wait, some of us actually had something working once, by the time @Pan has something to listen too, this place will be some sort of virtual ossuary. :grin:


You’re nearly there, but you have to exceed your budget on each piece of equipment, then you’re on the road to being a complete nutcase.

Ossuary, but yeah, we’re pretty much there now :stuck_out_tongue_winking_eye:

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We’ll probably have music sent direct to the brain and I’ll never hear what I’ve assembled.

It’s late… :disappointed:

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Sometimes you have to know the cut off point on your journey

Have you tried kondo yet?

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