One day we wanted to listen to a newly arrived CD. After selecting the R2R 7 as input on the preamp, there was silence. Deep silence. What could have been its cause? The interconnect perhaps. We swapped the R2R 7 for the La Rosita Beta next to the PWT. With this streamer we could play from Qobuz without a problem. So the DAC had given up on us. A short communication with the Dutch distributor resulted in a shipping voucher. Earlier they'd sent us a tool set to perform a firmware upgrade. Until then we hadn't done that yet so we returned the DAC with said tool. The day after we dropped off the boxed DAC at the post office, we had notice that the DAC had arrived at the distributor who had already found the cause of the failure and fixed it. While the DAC's cover was off, he'd also reflashed the firmware. The next day, our doorbell rang and the DAC was back. Talk about service!
With their DAC, Audio-gd ship a standard power and USB cable plus a packet of jumpers. These jumpers can fine-tune oversampling or NOS modes. Our loaner arrived with no jumpers set to 'on'. That meant it was set to x 8 oversampling with a steep -130dB stop-band attenuation. Since we wanted our DAC in NOS mode, we inserted two jumpers accordingly. Compared to the default x 8 oversampling, this in combination with the PWT's character was not ideal for Redbook CD or 24-bit/176.4kHz files.


Switching back to the default upsampling resulted in a less poignant sound. With oversampling active, the sound was more linear throughout even if the soundstage was also more confined to the loudspeakers and the space between them. In NOS mode, the stage grew wider and deeper but at a cost to tonality. Armed with this experience, we dug deeper to examine the jumper options for bypass, Dith, IPS1, IPS0, ATT0, ATT1 and PLLEN.


We had a good time playing with these possibilities. Since we could find no hints on their website as to their actions, we just followed our ears. We finally arrived at a setting which we really loved for CD playback: IPS1, IPS0, ATT1 and ATT0 to 'on', the rest to 'off'. This arrived us at NOS mode with a shallower filter setting. Playing the Drums & Bells tracks with these settings capitalized the 'live' in the live vibe of this uncompressed recording.


As Srajan mentioned in his review of it, its dynamic range is a massive 50dB. A nice detail of his review is that he too used an R2R DAC and amplifiers with ultra-fast rise times. That live-vibe aspect has a lot to do with instrumental sizing. An unspoiled recording with large dynamic range puts a true-sized instrument in the room and that's exactly what happened here with the settings mentioned.




Aside from CD, we also used our favourite Sound Galleries SGM 2015 streamer. This receives its input from the Internet by way of our Tidal subscription; or from a locally attached hard drive. At review time the Internet connection was finalized with a costly but brilliant StavEssence Eloquence Ethernet cable from Poland. From the SGM we ran an Audiomica USB cable. With Windows, every USB DAC above 96kHz needs its own driver [USB 2.0 rather than 1.0]. It took a bit of a search to find the correct one but the local distributor helped out in minutes to point us at the Combo384 ASIO v1.03 code. Once installed, we needed to make a little adjustment to the HQPlayer settings on the SGM 2015. It had been configured for the $3'995 T+A DAC8 which handles up to DSD512. The Audio-gd R2R 7 limits at DSD256.


Adjusting this setting was very easy but even though the SGM now saw the DAC, the handshake still produced no sound. We rebooted and fiddled with the startup sequence of DAC and SGM 2015 but to no effect. Again the distributor helped out. This DAC seems to be very picky about which USB cable is used. So-called audiophile cables may cause problems, hence a more generic cable is recommended. From our gear closet we picked out a higher-quality generic and bingo, we had sound. HQPlayer now took care of all sampling for PCM and PCM to DSD conversion. This resampled output is as good as it possibly gets, hence any further sampling from a DAC isn't welcome. For DSD it really is most straightforward now. The incoming DSD signal gets simply filtered by the FPGA and that's it. For PCM our favourite way is NOS. Again, no real fiddling.