I'm planning a setup for speaker, amp and preamp testing, and am looking for an interface that connects to a Mac's USB port and converts analog input to digital data.
Here is a list of interfaces that look like they will do the job.
Focusrite Scarlett Solo and 2i2 2nd gen:
Solo - 1 mic input w/phantom power, 1 line input
24bit/192khz sample rate
20hz - 20khz frequency response
2i2 - adds a 2nd mic pre and 2nd line input
Mackie Onyx Artist and Producer:
Artist - 1 mic input/1 line input
Producer - adds a 2nd mic pre and 2nd line input
Same sample rate and frequency response as Focusrite
Steinberg UR12/UR22:
UR12 - 1 mic input/1 line input
UR22 - adds a 2nd mic input and a 2nd line input
Same sample rate and frequency response as others
Native Instruments Komplete Audio 1/Audio 2
Audio 1 - 1 mic input/1 line input
Audio 2 - adds a 2nd mic input and a 2nd line input
Same specs as above
Behringer U-Phoria UM202HD
2 mic inputs with preamp and phantom power
2 line inputs
Same specs as above
I haven't been able to find out much about the input impedance or the dynamic range of these boxes, but they are probably all similar.
Any comments about any of these? Any one better than the others?
There's probably a lot more information about these things on this forum than I've seen so far, but any info or opinions would be appreciated.
Here is a list of interfaces that look like they will do the job.
Focusrite Scarlett Solo and 2i2 2nd gen:
Solo - 1 mic input w/phantom power, 1 line input
24bit/192khz sample rate
20hz - 20khz frequency response
2i2 - adds a 2nd mic pre and 2nd line input
Mackie Onyx Artist and Producer:
Artist - 1 mic input/1 line input
Producer - adds a 2nd mic pre and 2nd line input
Same sample rate and frequency response as Focusrite
Steinberg UR12/UR22:
UR12 - 1 mic input/1 line input
UR22 - adds a 2nd mic input and a 2nd line input
Same sample rate and frequency response as others
Native Instruments Komplete Audio 1/Audio 2
Audio 1 - 1 mic input/1 line input
Audio 2 - adds a 2nd mic input and a 2nd line input
Same specs as above
Behringer U-Phoria UM202HD
2 mic inputs with preamp and phantom power
2 line inputs
Same specs as above
I haven't been able to find out much about the input impedance or the dynamic range of these boxes, but they are probably all similar.
Any comments about any of these? Any one better than the others?
There's probably a lot more information about these things on this forum than I've seen so far, but any info or opinions would be appreciated.
The Focusrite Scarlett Solo appears to have 1 Megohm input capability.
I found that level of input impedance very useful with the EMU0404, as it allows a common scope probe to be used, ie. 10:1 and 100:1 probe interfacing. I use the 100:1 probe a lot with typical amplifier AC output testing, and low DC level circuitry probing (eg. I wouldn't typical probe above about 200Vdc).
I did have to modify the 100:1 probe compensation network (removed the 400pF fixed shunt cap) to obtain a flat response. Software then has to be used to generate a calibration file to flatten the probe response across the entire soundcard and software bandwidth (2Hz to 96kHz for the EMU0404 and REW).
I found that level of input impedance very useful with the EMU0404, as it allows a common scope probe to be used, ie. 10:1 and 100:1 probe interfacing. I use the 100:1 probe a lot with typical amplifier AC output testing, and low DC level circuitry probing (eg. I wouldn't typical probe above about 200Vdc).
I did have to modify the 100:1 probe compensation network (removed the 400pF fixed shunt cap) to obtain a flat response. Software then has to be used to generate a calibration file to flatten the probe response across the entire soundcard and software bandwidth (2Hz to 96kHz for the EMU0404 and REW).
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The specs that I have for the UMC202HD claim input impedance at 1Mohm Instrument / 3kohm Mic.
Dynamic range 110 dB, A-weighted
Frequency response 10 Hz – 43 kHz (0 / + 0.3 dB)
Data sourced from the U-PHORIA UMC404HD/UMC204HD/UMC202HD/UMC22/UM2 Quick Start Guide.
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I found some more info on some of the interfaces:
Focusrite Scarlett
Mic Input
Frequency Response – 20 Hz - 20 kHz ± 0.25dB
Dynamic Range – 106 dB (A-Weighted)
THD+N – <0.002% (minimum gain, -1dBFS input with 22Hz/22kHz bandpass filter)
Noise EIN – < -128 dBu (A-Weighted)
Maximum input level – +4 dBu
Gain Range – 50 dB
Impedance – 3k Ω
Instrument Input
Frequency Response – 20 Hz - 20 kHz ± 0.1dB
Dynamic Range – 106 dB (A-Weighted)
THD+N – <0.02% (minimum gain, -1dBFS input with 22Hz/22kHz bandpass filter)
Maximum input level – +13 dBu
Gain Range – 50 dB
Impedance – 1M Ω
Line Input
Frequency Response – 20 Hz - 20 kHz ± 0.1dB
Dynamic Range – 106 dB (A-Weighted)
THD+N – <0.003% (minimum gain, -1dBFS input with 22Hz/22kHz bandpass filter)
Maximum input level – +22 dBu
Gain Range – 50 dB
Impedance – 52k Ω
Steinberg UR12, 22
Mic Input
Frequency Response – 20 Hz - 22 kHz ± 0.3dB
Dynamic Range – 101 dB (A-Weighted)
THD+N – <0.0035% , 1 kHz, -1dBFS input with 22Hz/22kHz bandpass filter
Maximum input level - +4 dBu
Gain Range – +6dB - +60dB
Impedance – 4K Ω
Line Input (Balanced)
Maximum input level – +24dBu
Impedance – 20K Ω
Gain Range – -14dB - +40dB
Hi-Z Input (Unbalanced)
Maximum input level – +8.5dBV
Impedance – 1M Ω
Gain Range – -0.7dB - +53.3dB
Mackie Onyx
Frequency Response
At minimum gain, +4 dBu / –6 dBFS input
All inputs: ±0.5 dB, 20 Hz – 20 kHz
Noise Characteristics (RMS, 10 Hz – 22 kHz)
Mic inputs: <–100 dBFS
Line inputs: <–100 dBFS
Instrument input: <–100 dBFS
Distortion (THD)
+4 dBu / –6 dBFS, 1 kHz input, minimum gain
Mic input: <0.001%
Line input: <0.005%
Instrument input: <0.005%
Maximum Levels (0 dBFS, 1 kHz)
Mic input, gain at minimum: +11 dBu
Line input, gain at minimum: +24 dBu
Instrument input, gain at minimum: +24 dBu
Focusrite Scarlett
Mic Input
Frequency Response – 20 Hz - 20 kHz ± 0.25dB
Dynamic Range – 106 dB (A-Weighted)
THD+N – <0.002% (minimum gain, -1dBFS input with 22Hz/22kHz bandpass filter)
Noise EIN – < -128 dBu (A-Weighted)
Maximum input level – +4 dBu
Gain Range – 50 dB
Impedance – 3k Ω
Instrument Input
Frequency Response – 20 Hz - 20 kHz ± 0.1dB
Dynamic Range – 106 dB (A-Weighted)
THD+N – <0.02% (minimum gain, -1dBFS input with 22Hz/22kHz bandpass filter)
Maximum input level – +13 dBu
Gain Range – 50 dB
Impedance – 1M Ω
Line Input
Frequency Response – 20 Hz - 20 kHz ± 0.1dB
Dynamic Range – 106 dB (A-Weighted)
THD+N – <0.003% (minimum gain, -1dBFS input with 22Hz/22kHz bandpass filter)
Maximum input level – +22 dBu
Gain Range – 50 dB
Impedance – 52k Ω
Steinberg UR12, 22
Mic Input
Frequency Response – 20 Hz - 22 kHz ± 0.3dB
Dynamic Range – 101 dB (A-Weighted)
THD+N – <0.0035% , 1 kHz, -1dBFS input with 22Hz/22kHz bandpass filter
Maximum input level - +4 dBu
Gain Range – +6dB - +60dB
Impedance – 4K Ω
Line Input (Balanced)
Maximum input level – +24dBu
Impedance – 20K Ω
Gain Range – -14dB - +40dB
Hi-Z Input (Unbalanced)
Maximum input level – +8.5dBV
Impedance – 1M Ω
Gain Range – -0.7dB - +53.3dB
Mackie Onyx
Frequency Response
At minimum gain, +4 dBu / –6 dBFS input
All inputs: ±0.5 dB, 20 Hz – 20 kHz
Noise Characteristics (RMS, 10 Hz – 22 kHz)
Mic inputs: <–100 dBFS
Line inputs: <–100 dBFS
Instrument input: <–100 dBFS
Distortion (THD)
+4 dBu / –6 dBFS, 1 kHz input, minimum gain
Mic input: <0.001%
Line input: <0.005%
Instrument input: <0.005%
Maximum Levels (0 dBFS, 1 kHz)
Mic input, gain at minimum: +11 dBu
Line input, gain at minimum: +24 dBu
Instrument input, gain at minimum: +24 dBu
It's quite surprising that the overall specs of the E-MU 0404 USB are still basically unmatched after 12 years, at least in the price range below ~300 EUR.
Behringer U-Phoria quote nice SNR figures but no distortion. Also beware the very low level of their line output.
Zoom UAC-2 seems to have better dynamic range but they don't quote distortion specs (and from some anonymous - so maybe not reliable - RMAA results online they don't seem stellar).
Focusrite Scarlett Solo seems to be a good compromise, slightly better specs than the 2i2 even. No balanced output though.
Audient iD4 or iD14 seem to have good spec if we believe what they quote. iD14 has better SNR than iD4 but worse distortion.
Behringer U-Phoria quote nice SNR figures but no distortion. Also beware the very low level of their line output.
Zoom UAC-2 seems to have better dynamic range but they don't quote distortion specs (and from some anonymous - so maybe not reliable - RMAA results online they don't seem stellar).
Focusrite Scarlett Solo seems to be a good compromise, slightly better specs than the 2i2 even. No balanced output though.
Audient iD4 or iD14 seem to have good spec if we believe what they quote. iD14 has better SNR than iD4 but worse distortion.
How about DIY PCM4222, using EVM board and I2S-to-USB XMOS (as sold by DIYINHK), adding some protection.
Or, the EVGA's new PCI-E sound card seems to have good ADC and DAC chips, especially the ADC, AK5572, reaching 32/384 and -112dB noise.
Or, the EVGA's new PCI-E sound card seems to have good ADC and DAC chips, especially the ADC, AK5572, reaching 32/384 and -112dB noise.
For the next model up (204HD), this piece of intel could help fill in the blanks:
Budget DAC Review: behringer UMC204HD | Audio Science Review (ASR) Forum
Note:
1. Test was done using unbalanced inputs .. go in a couple of pages and you'll find some follow on stuff covering balanced performance
2. You're right about the output, it would appear that this bit of kit is not a front runner for headphone use
From the specs, the claimed Max. output level is + 3 dBu. So, this might relate to balanced operation.
From the above, the unit looks like a reasonable choice to use as an input for testing. I bloody well hope so, because I've got one turning up tomorrow 😱
Maybe I went through the thread too fast, but I don't see any A/D performance measurement.
Headphone output is never strong on these interfaces, is basically OK for "monitoring" but usually output impedance is high and max power is low. Most people will be fine with it, anyway.
Means 1.10 Vrms, a almost 3 dB short of standard 2-2.1 Vrms of most DACs. Shouldn't be a problem for most consumer equipment but definitely not enough to drive professional amplifier or powered monitors.
I think it can perform reasonably well but I would like to see some loopback tests.
Maybe you could load up the latest REW beta version and try some tests? There are some RMAA results scattered around the net, but looking as some spectra is in general much more informative.
Good pick up. I went too quick myself and missed that crucial point. There's ADC measurement here:
Budget DAC Review: behringer UMC204HD | Page 12 | Audio Science Review (ASR) Forum
FWIW, here's a review of the Scarlett 2i2 that includes some tech insight:
Focusrite Scarlett 2i2
All things have their limits and you get way you pay for. I'll see how I go and once I make a loop back cable, then I'll see what I get from REW or RMAA.
Should keep me busy enough until I work out where to go next.
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Unless the OP is investigating the extremes of the audio frequency range, or wants to confirm really low distortion or noise floor levels, then a 96kHz rate with reasonable noise floor and distortion such as Focusrite Scarlet solo would seem fine. Max output level would unlikely need to be high, given speaker testing would be through an amp, and preamp testing should be fine.
Even the EMU0404's left channel noise spikes don't cause me any concern for general testing, and if I somehow just had to have a clean noisefloor for showing off on a forum I can always use the right channel. So I wouldn't personally be concerned about leakage spikes, especially if your device was new and still under warranty - and given time and lots of sales, I'm sure the diy community will find a fix with easy instruction to crack the device open and implement.
Having any device is just the start of the fun to setting up a test environment where the probe (electrical or Mic) performance is verified, noise/hum (and acoustics) are managed, and the software learning curve is achieved.
Even the EMU0404's left channel noise spikes don't cause me any concern for general testing, and if I somehow just had to have a clean noisefloor for showing off on a forum I can always use the right channel. So I wouldn't personally be concerned about leakage spikes, especially if your device was new and still under warranty - and given time and lots of sales, I'm sure the diy community will find a fix with easy instruction to crack the device open and implement.
Having any device is just the start of the fun to setting up a test environment where the probe (electrical or Mic) performance is verified, noise/hum (and acoustics) are managed, and the software learning curve is achieved.
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I could agree, but commercial preamps (or pre stages in integrated amps) usually quote > 100 dB SNR and not all interfaces make it.
Let's say your interface reaches 105 dB of SNR with a 4 Vrms, measuring a DAC with a typical output of 2 Vrms @ 0 dBFS will make you lose 6 dB of ADC dynamic range.
This problem arises with the E-MU as well when operated in unbalanced mode, the loopback dynamic range drops quite a bit.
A couple of considerations:
1. in principle one could use the XLR (mic) input that provides a lower noise floor, but this comes at a cost of an input impedance as low as 1.5 kOhm. Archimago was using the E-MU with an RCA-to-XLR adapter, so I wonder how he could avoid loading excessively the output stages of the DUTs.
2. it's not possible for loopback operation, but using external inputs as long as the grounds are isolated one could drive the output into the (+/-) pair instead of (+/shield) which would be common procedure. This may help.
Things are always a bit less trivial than expected but it's a lot of fun learning about this (and to me, opens a totally new window into audio components interfacing).
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Focuswrite
Of course, the best choice would be to focus on Scarlet 2. I used a different audio interface and constantly had problems with the latency. Now I’ve been using Focus 2і2 for two years and still no problems. This audio interface has an excellent preamp, and there is no latency when I recording. Therefore, I recommend focusing it. You can also read this article Best Drum Recording Interface – A Look into the Best Recording Equipment for Excellent Sound | SimplyDrum to confirm my answer
Of course, the best choice would be to focus on Scarlet 2. I used a different audio interface and constantly had problems with the latency. Now I’ve been using Focus 2і2 for two years and still no problems. This audio interface has an excellent preamp, and there is no latency when I recording. Therefore, I recommend focusing it. You can also read this article Best Drum Recording Interface – A Look into the Best Recording Equipment for Excellent Sound | SimplyDrum to confirm my answer