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GUTB
230
Mar 4, 2016
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So....a USB-powered baby chip amp sitting on top of an unbalanced 4490? Seems useless as an amp for high-end headphones. If the 4490 implementation is good it might be useful as a no-frills DAC, but the lack of quality analog stage components fundamentally ruin it for that application. Grace likely designed the DAC portion to synergize with the baby's first class D/T circuitry.
Note that my hatred is aimed towards class D and chip amps in general. I'm sure the Grace implementation is much better than the average consumer junk.
Mar 4, 2016
CalebRoberts
56
Mar 4, 2016
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Hi GUTB, So....what are you talking about? It appears that you are implying that m9xx is a class-D amplifier. That is not the case. best wishes
Mar 4, 2016
GUTB
230
Mar 4, 2016
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How do you accomplish class A without any capacitors? Isn't this a chip amp?
Mar 4, 2016
Will
6824
Chief Product Officer
Mar 4, 2016
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Hey GUTB,
Thanks for your post! Unfortunatly, it's deeply misleading on all points.
The amplifier stage in the m9XX is based on the TI THS6012 (spec sheet here http://www.ti.com/lit/ds/symlink/ths6012.pdf ) chipset which uses a Class A-B output stage, but also carries an entirely different set of properties than almost any chipset used in headphone amplifiers available today.
The THS6012 is a current feedback, trans-impedance amplifier. Here's an analysis on the benefits of high-speed (trans-impedance) amplifiers over traditional designs in HiFi applications: http://sound.westhost.com/highspeed.htm
The m9XX also features a dual power supply, giving you the option to power via USB if that's the only option.
If you're interested in learning more about the internals of the m9XX, here's a link to a technical discussion written by Michael Grace specifically for discussion participants like yourself:
https://drive.google.com/file/d/0B6CXpQd8zuHUVm81eDlrUjUwWWM/view?usp=sharing
Mar 4, 2016
Socratease
189
Mar 4, 2016
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Mar 4, 2016
Villy
68
Mar 5, 2016
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@GUTB - Would elaborate on your personal experience with the m9xx? Not backed up by much substance if any, your comments do sound hateful and out of touch.
Mar 5, 2016
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