Hi Dave, Have a look in your driver install directory for example: C:\Program Files\XMOS\USBAudioStDriver_300D\xmosusbaudiost300D_dfuapp.exe

Hi Dave, I think the vast majority of m920 owners are primarily using the USB interface. The goal is that the PCM data in your flac is transmitted bit-perfectly from the file on the disk, through the player software, the driver, the USB interface, XMOS - all the way to the DAC IC.  I'm...

Do you remember back in 1965, Porsche had to change the name of the 901 to 911 because there was another manufacturer's project with 901 in the name...I think it was a Peugeot. I think the story goes something like this: a big audio company politely asked us to stop naming our products 801, 901...

Hi folks, Since I've been answering a few questions, I though I could boast a little too. I came across this and want to share to perhaps demonstrate the value of this product. m920 is 4th generation with the 901 being the original reference headphone amplifier. Check this out...

Hi, no problem. The m920's unbalanced outputs are also capable of driving long cables. That's no the problem with long unbalanced cables. Unbalanced (RCA terminated) cabling is going to permit ground currents (power supply leakage, noise on the ac power line, etc) to flow on the same shield...

We considered responding to your Computer Audiophile post about some of these same points - just didn't get to it so far. A practical issue is there is no way to fit a large "B" jack on the m920.  We don't understand the report of wobbly physical connection. However, I have worn-out the...

Hi AudioMan612, My perspective on v1.3 is that it doesn't add any new features over 1.2, It's a workaround for users of that small subset of the various models of mac computers. I recently took a m920 to a local computer store with v1.2 firmware and couldn't find a mac there that didn't work...

Mike just came in the office and I asked him if he had any idea what you're referring to. He said that perhaps you are referring to: once someone asked him about using the balanced line-outputs to drive headphones. While you can connect headphones to the line outputs, this is not their intended...

Yes, as long as you use firmware v1.2, this will work. I've tested this using one of Gordon Rankin's USB2 -> S/PDIF products, the AURALiC ARES as well as our m905,

Hi again, Yes, the volume setting 96.0 sets the attenuator to unity gain. Increasing the volume setting from 96 to 96.5 engages a relay that increases the gain of the output amplifier by 10dB. At the same time the attenuator gain is reduced by 9.5dB, netting the expected 0.5dB increase. While...

Hi, yes decoding DoP as received via the S/PDIF or AES3 inputs was not implemented in version 1.3 for the m920 firmware. Version 1.2 firmware was working correctly in all respects at the time we released the m920.    I made the version 1.3 firmware because Apple began producing some computers...

Hi vsky,   I'd like to offer our perspective: The rotary encoder in the m920 is the same part that we've used for over 10 years in the m902, m903, m904, m905, m906 and m802. Many of these products are used full-time in production environments. We've found this part to be the best choice...

I use m905 for my home hi-fi preamp. There are 3 stereo analog inputs. I use 2 of them: phonograph and tuner. The 4 digital inputs + USB have everything else covered. The IR remote control receiver option and Apple remote are essential for my habits. My wife has not struggled to understand how...

Hi Jeff, I don't follow some of what you wrote.   Yes, the galvanic isolation is on the USB card. It's true that you're bringing 480Mb/s into the box. We've done a good job of isolating this from the audio circuit. You can always run the interface in USB1 mode - at 12Mb/s - up to 96kHz PCM. ...

Hi Jeff, It is possible to take the USB card out. I don't think there is any practical way to make use of the interface between the USB card and the main PCB of the m920 for any other purpose. The USB interface is a slave to the master clock produced by one of the crystal oscillators on the main...

From Morten:   Yes, the SACD dbFS scale for DSD is skewed compared to the PCM dBfs, as it actually goes to +6dB. In theory an SACD signal can reach levels of +6 dB SACD, but this is prohibited as specified in the ANNEX D.3 of the SACD Audio Signal Property Specification. Converting PCM to DSD...

Morten Lindberg (2L) gave me some test files that he produced, presumably with the same flow as the other tracks that we're talking about. I have 1kHz at 0dBFS and -3dBFS in DXD, DSD and DSD128 formats. Playing these files on the m920, the DSD files are 6dB lower than DXD. This is the case even...

I shouldn't comment not knowing much about what's inside their product. It does appear that it is a different Sabre DAC. We use a 9018-2M and we run it with a synchronous MCLK. I have no idea if the different Sabre DACs have different DSD operating levels.   Right now I'm downloading some DSD...

Hi folks, The level of PCM relative to DSD is exactly as produced by the Sabre DAC. There's no alternate attenuator offset for DSD, no digital gain applied to PCM and of course there's no diddling with DSD data. You might want to double-check that your system is not applying gain to PCM.  I...

Both the m903 and m920 have a relay on the earphone outputs that protects from pops at power-up and power-down. The line outputs do not. We recommend that you power-down your power-amplifier before powering on or off your preamp. We chose not to include additional circuitry in the line-out section.

I was just letting folks know that the DFU (Device Firmware Update) app for OSX is now available. Previously we could only offer a DFU utility for Windows. The current release remains v1.2. 

I just want to let everyone know that we added the OSX DFU app to our web site last week: gracedesign.com   thanks, Caleb

Hello Folks, I work in Engineering here at Grace Design. I have been implementing the XMOS-based USB audio interfaces for our monitoring products. I thought it would be helpful to join Head-Fi so I can get useful info out as questions about our products arise. Since the release of the m920...