Showing 1 of 1091 conversations about:
View Full Discussion
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.
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
How do you accomplish class A without any capacitors? Isn't this a chip amp?
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:
@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.