 AudioGD is world renowned within a small group of audio connoisseurs. Its regenerative power supply in FPGA-corrected R2R DAC, capable of both native PCM and native DSD, makes it stand out. And then there is its giant cabinet and its weight of over 17 kilos. Initially I got lost in the R2R models offered by AudioGD. But once explained to me I now see it's rather simple. There are two classes of electronics. The R8 series being the standard version with SMD components on a single PCB. And the R7 series that has a more sophisticated DSP board, almost only Vima capacitors and Dell resistors, a heavier chassis, a 10 MHz external clock input and class A power supplies instead of standard voltage regulators. Both series are also available in the HE version, that instead of three main transformers for digital left channel and right channel, has a regenerative power supply to almost eliminate any negative influence coming from the grid. The review sample is the R7 HE, so the deluxe version with the regenerative power supply. The 2020 extension indicates it's the current version. The distributor Magna Audio then upgraded it somewhat more by replacing some components in the digital circuit plus silver cabling at a modest extra charge. Hence the addition Magna. The AudioGD is a digital to analog converter that must have its analog outputs connected to the amplifier. Both single and RCA imbalanced XLR outputs are available, as are special ACSS outputs on mini XLR. These are compatible with Krelcast and thus relevant for Krel users. If you use your computer or laptop as a music source, you connect it over USB, SPDIF or TOSLink to the DAC. USB often gives the best result with computers. You can also connect a CD player over SPDIF, TOSLink or, in some cases, I2S. The latter uses an HDMI cable but is not compatible with video equipment. See if your digital source has an HDMI socket labeled I2S according to the de-factor PS Audio standard, it is suited for this DAC. If you use a streamer or network bridge, as digital source, it is to be connected to one of the inputs. SPDIF and USB are the most popular, AES-EBU is used too, I2S is less used but is a very good interface. The streamer or network bridge is then connected over the network to your router for internet sources and over the router to your computer for locally stored music. Usually streamers are controlled over tablets or smartphones. Network bridges need a suitable program to run on the computer. The Audio GD is huge and heavy. It is an aluminium cabinet that measures 430 x 488 x 125 mm and weighs 17.4 kg. Especially the depth is something to take into account. When we look at the front we see the power button and three smaller buttons. Settings let you select the setting you want to change. Select left lets you go back in a menu and select right lets you step forward. When not in the setting mode you use the select left and right for input choice. The display appears to show quasi-random characters but together with the manual they let you set for instance oversampling, PLL chasing, display dimming and so on. It's an archaic system but it works and most people will not change settings after initial choices are set. Remote control is optional. In the middle we find the IEC mains entry with above it the digital inputs. That starts with a menu USB for updating the firmware. Next with the AES-EBU input on XLR, the SPDIF input on RCA, a 10 MHz clock input on B&C, an optical digital input on Toslink, the I2S input on HDMI and the USB B connector according to the USB Audio Class 2 standard. On request other input configurations are possible. If you want two SPDIF inputs on RCA and no AES-EBU that can be arranged. Want B&Cs instead of RCA is no problem either. There are three kinds of analog outputs. Single-ended on RCA, balanced on XLR and Craylcast compatible ACSS or Minidin. As you can see no space is left unused. It might be a very big DAC but the space was needed. On the left you see an R-Core transformer that size wise would not be misplaced in an amplifier. The R-Core type of transformers is getting more popular by the day for audio applications. They can be wound more evenly than toroidal transformers. This transformer feeds a balanced class A power supply that, instead of 50 Hz, generates a clean 400 Hz AC current. This higher frequency is chosen since it is more efficient and the end result has to be converted to direct current anyway. This AC current is then sent to three separate R-Core transformers that feed individual class A power supplies, one for the digital circuitry and one for each analog channel. The circuit board in the middle contains all digital interfacing and processing. In the middle we see the Altera Cyclone 4 FPGA which is a microprocessor that is programmed by AudioGD. I presume to do the upsampling, digital filtering and the like. Two silent FPGAs closer to the inputs are probably used for interfacing. Furthermore two costly AcuSilicon precision crystal oscillators. One for 44.1 kHz and one for 48 kHz based sampling frequencies. To both sides of the digital board we see the analog circuitry. I remove the metal shielding of the bottom one so you can see the SMD resistor banks that form the digital to analog converters. There are two banks for each channel to generate two balanced outputs. A silent FPGA per bank switches the resistors in parallel rather than in series as is usual with ladder converters. This way of working makes it possible to work around resistor tolerances and achieve a higher resolution. Below the DAC board the analog audio is situated. As mentioned no SMD components here, only through-hole components of the best quality. Basic use is quite simple. Press the power button, wait for the unit to start up and then select the required input. Although not needed you can then play with all kinds of settings, for instance the face lock loop catch range. If you use a very high quality source the catch range can be limited to reduce jitter. Oversampling can be set to off or two times four times or eight times. You can even upload other software to get TDA 1541 like behaviour. The TDA 1541 was a very popular DAC chip by Philips that combined a ladder converter and oversampling. The maximum sample rate varies per the input. I2S does PCM up to 384 kHz 32-bit and DSD up to DSD 512. USB does PCM 384 kHz 32-bit and DSD 256, while SPDIF, ASEBU and TOSLINK do PCM up to 192 kHz 24-bit and DSD 64. I have been playing around with the settings to conclude that the non-oversampling mode was the best to my taste. In this setting it has the same character as the Holo Audio May DAC I reviewed two videos ago. Which means it sounds very natural and relaxed yet dynamic and powerful. It's very clean on voices and has a fantastic way of reproducing strings, especially double bass and piano. The stereo image is not big or small, it's just natural. This is a very fine sounding DAC that never fatigues and plays anything with ease, from 60s jazz folk rock by the pentangle to Rossini chamber music, from Wagner to Imagine Dragons and from Muddy Waters to Duke Ellington. I auditioned the Audio GD in my setup 1, now using the uptone Ethered Regen to feed the Uralic Ares G2. DACs of this level should be fed a quality signal like this of course. Judging on the sound quality, the Audio GD R7HE Magna is well priced. With the Magna options installed, the price is just under € 3800, clearly cheaper than the aforementioned Holo Audio May. That might sound yet a bit better, although I can't say to what degrees precisely since I couldn't do a direct comparison. The Holo Audio has a more mature user interface while the Audio GD is a bit rough on the edges. For some operations you need to mute the amp to avoid plops, which is no problem unless you have the family operated as well. If you can live with that, you really buy a very good sounding DAC with lots of tweaking options for an attractive price. That brings us to the end of this video. There will be a new video as always at Friday, 5pm Central European time. If you don't want to miss that, subscribe to this channel or follow me on the social media so you will be informed when new videos are out. If you liked this video, give it a thumbs up. Many thanks to all viewers that support this channel financially, it keeps me independent and thus trustworthy. If that makes you feel like supporting my work too, the links are in the comments below this video on YouTube. I am Hans Beekhuyzen, thank you for watching and see you in the next show or on theHBproject.com and whatever you do, enjoy the music.