Directing more amperage to certain jack points

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neb

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#2249210 31-May-2019 16:42

SATTV:
What are you seeing, if you are drawing too much current the fuse / MCB would Pop.

I don't think it's the power draw, more likely excessively sensitive analog circuitry where other equipment plugged in causes interference. So the problem would be solved by filtering or... well, depending on how sensitive it is, various amounts of voodoo. First thing would be, if you can afford it or have someone you can borrow the equipment from, monitor what's on the power lines to see if any particular item is causing the issue(s). My first guess would be something with a switchmode supply injecting hash onto the mains, which can often be solved by filtering.

neb

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#2249212 31-May-2019 16:45

automaton:
1. The gear that is malfunctioning has an unusual capacitive keyboard (it responds to touch of external wiring on the outside of the unit). It requires a specific power supply for this reason, see here at 3.2.7 - the power supply "was designed specifically to provide the ground needed for the capacitive keyboard to operate properly." (see here for the manual: http://downloads.arturia.net/products/microfreak/manual/MicroFreak_Manual_1_1_2_EN.pdf ).

2. It is the capacitive keyboard (only) that is malfunctioning for me. Specifically, it malfunctions when I have another unusual device plugged into the same circuit - namely a Trogotronic M15 Higher Power power supply for a modular synthesizer - see here - https://trogotronic.com/product/m15_diy/

4. When the Trogotronic is unplugged, the problem is gone.

Ah, I should have read a bit further in the thread. That's interference from another device, not power draw, in which case you need filtering, not a separate power line. Admittedly that might possibly work by attenuating the noise somewhat over its length, but it'd be an expensive experiment to engage in.

neb

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#2249231 31-May-2019 16:49

tripper1000:
The next best solution is to filter the power to the source of noise as close as possible to the source of the noise - not at the wall end of a extension lead. Finding filters is the problem, most retail filters are rubbish/fake, so you need to go for something a bit more industrial. I ended up building my own because it was so difficult to find proper stuff. In a lot of cases, it can work out cheaper to replace the power supply than to filter it. Also, depending on the exact nature of he problem, filtering is not guaranteed to be the solution because RF noise can be transmitted through the air from cable to cable and simply bypass the filter.

For the OP, if you're in Auckland I have both a ferroresonant power conditioner and an active sinewave tracking filter you could borrow to see if that fixes it. The former is a two-person lift.

Aredwood

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#2249264 31-May-2019 18:24

automaton:

Great reply, I am leaning this way myself. Thing is the Eurorack power supply (Trogotronic) is quite well regarded - I don't think the builder would have cut corners.

I'll try a couple of ferrite RF filters :)

Since the problem goes away with the Euro rack unit unplugged, shows that this unit is causing the problem. I see that it just uses switchmode power bricks for its actual power conversion. It could be that 1 or more of those might be faulty or just cheap. Note also that those power bricks might only be producing interference on their mains input wiring. Which would mean that the Euro rack itself would otherwise work just fine. And other owners of the same device would also report that it works fine for them.

Have you tested the keyboard with the Euro rack plugged into mains power and switched on. But with no other cables plugged into the Euro rack?

RunningMan

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#2249322 31-May-2019 19:50

neb: The one annoying thing about those is that they're designed for horizontal-mount flush boxes, so if you've got a slightly older house with vertically mounted flush boxes you have to mount the four-way outlet sideways to get it to fit.

Vertical

Horizontal

Tracer

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#2249524 1-Jun-2019 11:57

Aredwood: Since the problem goes away with the Euro rack unit unplugged, shows that this unit is causing the problem.

Be careful with that, it's more often than not true, but certainly not a rule.

neb

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#2249543 1-Jun-2019 13:44

RunningMan:
neb: The one annoying thing about those is that they're designed for horizontal-mount flush boxes, so if you've got a slightly older house with vertically mounted flush boxes you have to mount the four-way outlet sideways to get it to fit.

Vertical

Horizontal

Oh, didn't know they made those, on the basis of never having seen one in-store anywhere. Looks like they're trade-only, will try some of those...

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automaton

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#2249669 1-Jun-2019 18:32

Hi all. I did extensive trouble shooting over the last day and traced the problem to interference generated from one digital Eurorack module. By connecting an audio cable between the synth that was experiencing problems, and that module, I managed to eliminate the problem.

Very strange, but now sorted!

Thanks for all the tips :)

MattR

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#2250035 2-Jun-2019 17:43

neb:
RunningMan:

neb: The one annoying thing about those is that they're designed for horizontal-mount flush boxes, so if you've got a slightly older house with vertically mounted flush boxes you have to mount the four-way outlet sideways to get it to fit.

Vertical

Horizontal

Oh, didn't know they made those, on the basis of never having seen one in-store anywhere. Looks like they're trade-only, will try some of those...

Electrical Direct have them

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