Considering a self-powered audio interface?

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dominicperry
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Re: Considering a self-powered audio interface?

Post by dominicperry » Wed Feb 19, 2014 2:58 pm

You have two different sets of figures here.
The MixPreD has 66dB of mic gain available. I don't know what the phrase 'Mic to Line' is meant to mean, but I know the MixPreD is 66dB of gain. I have a MixPre (without the 'D') and that has 66dB of mic gain.
The 'nominal input level' is something different. It's about what levels the preamp can handle on the input side before it clips. It does imply the ability to add 48dB of gain, but I don't think that's what it really means.

I think you also have to consider what is 'useful' gain. The MixPre will let you crank the mix gain to max and add almost no noise. So it should, it's very expensive. The Roland Duo Capture Ex is very cheap. The gain will almost certainly have a very high noise floor (lots of hiss) even at relatively low levels. I can't say for sure - the low end Focusrite boxes are cheap and I've been told they have lots of clean gain. However, my experience of cheap interfaces and mic pres is that either all of the gain range, or at least the upper eschelons, are unusable due to the huge amount of noise added.

Of course, there are other considerations too. The MixPreD doesn't have any kind of 'return' - you can't monitor the signal from the DAW (Auria) at all. It's an input only device. The 'Tape Return' will allow that, but only if it's fed from the headphone out of the iPad, which introduces latency and the MixPreD does not allow you to mix that headphone signal with the input signal. For that, you would need the Sound Devices USBPRE2.

Dominic

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mtingle
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Re: Considering a self-powered audio interface?

Post by mtingle » Wed Feb 19, 2014 4:54 pm

Dominic your last statement about the mixpre D is incorrect. I've the mixpre D and the return from the daw/auria goes back through the usb/iOS connector and back to the mixpre D and monitored through the headphone output of the mixpre D.

The mixpre D has AD/DA convertors. It's exactly the same as all the other interfaces in that respect that work with Auria.

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lkingston
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Re: Considering a self-powered audio interface?

Post by lkingston » Wed Feb 19, 2014 7:26 pm

Those two specs are measure different ways and aren't directly comparable. Here's what you need to know:

The Sound Devices Mix Pre is a location audio mixer which has USB audio as an added feature. The primary use of this device is for capturing location sound (mostly dialog, but also foley and location sound effects). Because of this the Mix Pre is built to be able to capture a wide continuous range of audio levels. The limiters in the Sound Devices mixers are spectacular. When you are doing location audio, when the cameras are rolling, an actor can go from a whisper to a scream with no warning and when that happens, these limiters are ready. There is also circuitry to switch back and forth between monitoring the mixer sound or the sound from the headphone output of a camera. When you are working with a camera you want to be able to check the sound being recorded on the camera, not just the sound you are sending to it. A soundman armed with this mixer can also send the audio to a computer, phone or tablet with stellar sound quality should the need arise. Sound Devices products are extremely durable. I have no doubt that this device would survive being run over by a truck or left out in the rain. They are designed for location work and are very tough.

What's missing then? A low Z input for guitars. MIDI in and out. The input jacks are XLR and you would need a directbox to record a guitar. Any sort of direct monitoring for zero latency monitoring when you are doing multitrack audio. Also one should be aware that while the older model Mix Pre D used a generic iPad compatible USB interface, the current model does not and will only function with a computer able to load it's 24 bit driver.

The Roland Duo Ex is designed for recording one or two channels of either mic or line level audio. There are no limiters. The input controls expect a limited range between mic and line levels. The inputs are combo XLR/quarter inch TRS jacks and there is a switch on the back to switch one channel to low Z guitar mode so you don't need a directbox. There are MIDI in and out jacks. There is a direct monitoring switch which let's you do rudimentary direct monitoring. There is a switch which will let you choose between 24 bit 44.1 and 48k modes with a PC or Mac, or a simple generic 16bit 44.1k mode for tablets. With a computer the unit will use USB bus power, but in the tablet mode you need to use either external or battery power.

It is not that one is better than the other. I do a lot of video work and the Sound Devices Mix Pre was extremely tempting to me in that it would also be awesome at recording location audio.

The Roland mix pre is more suited to music (though the Mix Pre's limiters would be very nice for music). If you play guitar and sing, and might occasionally use the USB ports for automation or playing keyboards in Garage Band or Cubasis, this is the better choice.

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lkingston
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Re: Considering a self-powered audio interface?

Post by lkingston » Wed Feb 19, 2014 10:40 pm

A couple of points here:

The Roland Duo EX sounds really clean. I don't hear any more noise from it than I would expect from any decent quality interface.

Auria does let you record from a USB interface and monitor from the iPad headphone jack. Just use the MultiRoute driver option. An iPad can't use two separate USB audio interfaces but with Auria it can address multiple audio ins and outs on a single interface along with the microphone in and headphone out that are built into the iPad.

The new Sound Devices USB Pre 2 won't work with an iPad and Auria. It needs a computer running it's custom driver.

The main advantages of the USB Pre are it's weather resistance, structural strength, and those amazing limiters. I have no doubt that the audio might be cleaner as well, but the that is mostly because it is designed to work with such an unpredictably loud variation in audio sources. This isn't something you would be able to hear even on close inspection on something like recording guitars or vocals where any noise floor in the device would be down far enough to be irrelevant. This is a device that is designed to record audio sources ranging from whispers to explosions without noise at the low end or distortion at the high end. A very cool device, but overkill for me singing with my guitar in the living room. The lack of MIDI and high Z input for my guitar are the main reasons I passed this one by.

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bash
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Re: Considering a self-powered audio interface?

Post by bash » Thu Feb 20, 2014 1:04 am

The PedalTrain Volto works great with the Roland EX as well. A little bit of velcro and they marry up quite nicely.

http://pedaltrain.com/products/power/volto.php

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mtingle
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Re: Considering a self-powered audio interface?

Post by mtingle » Thu Feb 20, 2014 5:00 am

the sound devices website stated that the new USBpre 2 is: "a class-compliant audio device".

Being class compliant is the technical requirement to working with iOS so in theory it should work. Though I've not tested it and it doesn't mention this explicitly on the website.

The USBpre 1 was iOS compatible so there is hope for the USBpre 2 to work with Auria.

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lkingston
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Re: Considering a self-powered audio interface?

Post by lkingston » Thu Feb 20, 2014 7:27 am

You are right. My mistake. The USB Pre 2 does work with an iPad so long as you use a powered hub.

http://www.sounddevices.com/notes/usbpr ... #more-1482

dominicperry
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Re: Considering a self-powered audio interface?

Post by dominicperry » Thu Feb 20, 2014 11:06 am

mtingle wrote:Dominic your last statement about the mixpre D is incorrect. I've the mixpre D and the return from the daw/auria goes back through the usb/iOS connector and back to the mixpre D and monitored through the headphone output of the mixpre D.

The mixpre D has AD/DA convertors. It's exactly the same as all the other interfaces in that respect that work with Auria.
Yup, you're right, my mistake. I misunderstood the specs.
But you still can't mix the input and output for zero latency monitoring for overdubs. You need the UsbPre2 for that.

Dominic

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