H9000 USB Digital Noise using Scarlet 2i2 3rd Gen

[Steve-O Rock-O]

I’m wondering if someone else has had issues like this, but allow me to explain…

We’re nuts enough to rack up an H3500, with an H9000, and an old MXR Analog Digital Delay in ANALOG. Yes…ANALOG! Using the XLR channels 1 on each Eventide, to 1/4″ Analog and using the Focusrite Scarlet 2i2 to “Push” the analog guitar instrument input, it sounds pretty good plugged into anything BUT the H9000 USB ports. When plugged into the H9000’s USB ports (ANY of them) there is an annoying digital noise injected into the Analog signal chain.

WHY YOU ASK? Well, the Focusrite 2i2 CANNOT BE USED STANDALONE! It must be hooked to a USB “Host” port. This is indicated on the front of the 2i2 when the USB LED illuminates. If we run the 2i2 plugged into any of the H9000’s USB ports (Front or Back) the digital noise is present at the amplifier. If we plug the Focusrite 2i2 into an external host USB port (Laptop) there is zero digital noise added.

It sounds as if the USB ports of the H9000 are introducing a digital noise into the Analog side of the signal chain of the Focusrite 2i2. Plug it into the Laptop, noise is gone. Now the SIMPLE ANSWER would to be to buy and use any Focusrite 6i6 or above (Since those CAN be used in a standalone mode reportedly) once they are routed using Focusrite’s software to configure those interfaces, but we’re trying to rack this stuff up for a live performance scenario. The Focusrite 2i2 is small, compact, and would fit the bill nicely, if it weren’t for the hideous digital noise introduced into it by the H9000’s USB ports.

Is this a known anomaly, or is there a simple fix? And before anybody asks, YES, WE CHECKED FOR BAD CABLES AND GROUND LOOPS!

Any help would be appreciated.

[bsfreq]

I don’t think you can add digital noise to analog signal. The noise is analog, either some grounding issue, or probably in this case a simple power delivery issue. 2i2 requires 900mA of power, and the H9000 ports seem to deliver only 500mA, so not enough to run the 2i2.

One solution might be to use a powered USB-hub in between 2i2 and the H9000.
H9000 works as a USB-midi host, but I’m not sure if the 2i2 recognizes the H9000 as an USB audio-”host”. And is this really even necessary?
Have you tried the 2i2 with a simple USB power supply (1A or more) and enabling ”direct monitoring” ?

Also, by using 2i2 as a preamp, you’re adding unnecessary AD / DA converter stages to the signal path, which is usually not a good idea. The converters in 2i2 are not as pristine as the ones in the H9000.
(2i2 doesn’t have direct analog signal path from in to out, all audio goes thru its converters)
Why not use some fully analog mic or guitar preamp boxes instead?

[Steve-O Rock-O]

So the short answers are YES, you you can add digital noise to an analog OR digital signal chain. A poorly shielded CPU clock frequency circuit for example will inject spurious noise into anything not optically isolated. So there’s that.

You HAVE to use some sort of preamp if you intend to use an analog input on the H9000 with instrument level signal. The H9000 only accepts balanced preamp level analog inputs.

According to Focusrite, the 2i2 DOES NOT WORK IN STANDALONE MODE. I just thought at after paying 7k for an effects processor, that there shouldn’t be a noisy ANYTHING on it, INCLUDING the USB Ports! I’ve tried a powered USB hub, but this does not “wake up” the 2i2 because again, it doesn’t even see any signal until it is connected to either a computer, or another host device such as an iPad, computer, or the H9000 itself.

The whole rig is church mouse quiet when the 2i2 is plugged into an outboard laptop. If you’ve ever seen the 2i2 3rd Gen Focusrite, it doesn’t even have a DC power jack on it, so it is designed to run on the 500ma MAX current of the USB Bus. Focusrite preamps and USB bridge devices don’t start running standalone mode until the 6i6 and up models.

Thanks for the suggestions, but I think I’m seeing the forest through the trees here…

[Fender17]

Have you tried powered hub that is plugged into H9000?

If audio interface requires more than 500 mA, the digital hiss might be because of that.

By the way, wouldn’t be better to use analog preamplifier or preamplifier with digital output?

[bsfreq]

Steve-O Rock-O wrote:

So the short answers are YES, you you can add digital noise to an analog OR digital signal chain. A poorly shielded CPU clock frequency circuit for example will inject spurious noise into anything not optically isolated. So there’s that.

Splitting hairs here, but regardless of the fact that the port is meant for digital data, the interference is still analog, (electricity instead of ones and zeros) and might get through due to poor shielding.

 

Steve-O Rock-O wrote:

You HAVE to use some sort of preamp if you intend to use an analog input on the H9000 with instrument level signal. The H9000 only accepts balanced preamp level analog inputs.

I fully understand this. That’s exactly why I suggested using an analog preamp. Something made for this very purpose.

 

Steve-O Rock-O wrote:

According to Focusrite, the 2i2 DOES NOT WORK IN STANDALONE MODE. I just thought at after paying 7k for an effects processor, that there shouldn’t be a noisy ANYTHING on it, INCLUDING the USB Ports! I’ve tried a powered USB hub, but this does not “wake up” the 2i2 because again, it doesn’t even see any signal until it is connected to either a computer, or another host device such as an iPad, computer, or the H9000 itself.

 

I don’t have a 2i2 myself so I just googled it, and on the Focusrite 2i2 page

https://focusrite.com/en/usb-audio-interface/scarlett/scarlett-2i2

(bottom-specifications-connectivity), they say that it requires a 900mA USB port.

Apparently they have multiple generations of 2i2’s and I obviously didn’t look into details of the older ones. Perhaps they work at lower amps then??

However if the problem is low amperage, then connecting a powered USB-hub to H9000 port and 2i2 to that hub might work. If the H9000 has a host mode, then it should work with a hub too, I think. Did you even try this, or did you simply try powering the device with a HUB only?

You must understand that you’re using the H9000’s USB-ports for something they’re not meant for. (They are meant for digital data, midi, thumb drives, wifi-dongles etc. Not for powering audio interfaces) And your whole approach sounds sketchy to me. Those focusrites are audio interfaces with AD / DA converters, meant to be connected to a computer. I already suggested a more suitable approach, but you can of course stay in your forest if it feels cosy to you.

BTW, I’m just another forum user, not related to Eventide in any way. I was just trying to help and give you some ideas to make your setup work. All the best.

[tbskoglund]

Sorry for the issues you are having. The H9000’s USB A ports are not designed to power a USB audio interface and you should use a different approach for your setup.

As the other users have mentioned, you can use a different standalone audio interface or a dedicated preamp instead of your 2i2 if you’d like to create a rig that doesn’t require a computer.

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