budget analog mixers, any measurements of their effect ?

[SuperValue]

Howdy all,

Long time listening, first time caller. I'm a fan and have read many of the reviews here, this is my go to page for audio stuff, along with other objective based audio sites like Audioholics, Hydrogen Audio, Solderdude's site etc etc.

So here's my question. I route my audio through a Yamaha MG10XU. Has anyone ever measured what something like this or another low cost mixer does to the sound?

 

[AnalogSteph]

I have done some testing on a lowly Behringer Q1002USB, which should give you an idea about the kinds of quirks and features you can expect:
Care and Feeding of an Inexpensive Mixer
As well as some comparisons with the one that succeeded it here:
Portable Mixer Shootout: Mackie 402 VLZ4 vs. Behringer Q1002USB

Note that the equipment I used is actually quite modest, so basically anyone should be able to conduct similar tests of their own without breaking the bank. (I guess having a decent multimeter for level calibration would help.) Probably not a bad idea for figuring out the actual tone control midpoints alone. From what I've seen I'd say tone controls are a common limit on noise and distortion (especially when preamps are good), and output stages tend to be a weak point in terms of distortion as well. Stuff around the mix bus generally tend to be OK, although noise levels may still vary.

THD specs of the MG10XU seem to suggest that the unit may have some less-than-great high frequency distortion, so I'd do some poking around in that regard.

 

[SuperValue]

Very interesting writeup there. I'll have to read through both. The Behringer Q1002USB or Q1202USB was my other choice. Without any hard measurements, I was basically hoping the Yamaha name would be good enough.

What really would be interesting would be how the internal DAC measures. I have my computer hooked up via USB. The headphone power out seems to be garbage. But then again, pro headphone outs always historically have had high impedance.

 

[AnalogSteph]

I never actually even tried the USB audio codec in the Q1002USB based on its reputation of not being very much to write home about... I'd guess it's the same Coolaudio V2902 (PCM2902 ripoff) found in newer UCA202s and UM2/UMC22 and the like. (This is literally better than nothing but you're generally better off if you have the mixer use your PC's onboard audio.) Your MG10XU should contain something substantially better, based on price and features alone.

High headphone output impedance wouldn't surprise me one bit, the Steinberg interfaces from the same stable tend to be negative outliers with about 90 ohms. Yeah, it even says 110 ohms right in the specs - just like in the olden days. Behringers have always been lowish-impedance... the old Eurorack UB802 would only be giving you a measly 4580 opamp, but 22 ohms it was. (The posher UB1204FX would give you two 4580s in an "apheared-47" type amp instead.) Their interfaces tend to be at 10 ohms these days.

 

[SuperValue]

Ah interesting, did you teardown one of those devices? Not sure how easy it would be to do that with the Yamaha, also not much free time these days with young kids.

The specs state 24/192khz so definitely some other chip. I didn't know unified USB/DAC chips like that existed but that does make it cheap and easy for them to use. I'm sure its a dollar/euro/pound or 2 at best. I would not be surprised if this device uses something similar. I have not did any testing against my better DAC devices but it doesn't sound too bad for listening while working.