Eliminate electrical noise when doing measurements

[tomp]

When doing measurements of speakers, amps, etc. using my laptop and a Scarlett 2i2 as an interface between the USB and audio connections, I had some background noise. I just got a Topping HS01 high speed USB2 isolator which I put between the USB port on the laptop and the USB port on the Scarlett. The noise went away and it did not interfere with the test signals in either direction. Handy device.

[David McGown]

Tom,

That is interesting to know. I have a Intona USB isolator that I am not using, and I bet it would help between my Picoscope hardware and the computer running the software. I always get low level noise on the trace. The Intona isolator was designed for this kind of use, and was only “discovered” as useful for audio. I will give it try.

David

[tomp]

David:

Should work fine. Looks like a much more advanced unit than the Topping.

Tom

[HAL]

When I had laptop USB power noise, I took a USB2 cable and cut the +5VDC power supply and ground lines and connected an external regulated linear PS. At 0.5A, an LT1085 TO220 regulator setup for +5VDC is very quiet and an LDO style. Works well here as a DIY alternative. Just attach both grounds together for signal and power as you need a reference for the USB data.

Any DC power supply at least 7VDC would work well with an linear LDO regulator for 5VDC. Just use low ESR electrolytics and film caps with the regulator for the filters and bypass.

[tomp]

The Topping has an external power input if the connected device needs extra power. For some reason they suggest not using a linear supply, but rather a phone charger or other USB type supply.

[SoundMods]

The Topping has an external power input if the connected device needs extra power. For some reason they suggest not using a linear supply, but rather a phone charger or other USB type supply.

That's strange. I would think a linear supply would be perfect for an audio piece of kit.

[tomp]

Here is what they say. BTW, it supported the Scarlett fine with no need for external power.

Attachments

Topping HS01 external power.pdf

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Topping HS01 external power.pdf

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