Review MOON 680D (V2)

The 680d is playing for almost 6 weeks now. So it should be burned in for at least 95%. The first impression, I mean the very first hours were really great. Unfortunately just like any other component in my system the 680 sounded worse over time. I now know why!

For about 27months ago we went into a new house. We installed a new system and the problems started. At first the sound was great and a few day’s later the sound went pretty dark. The high frequencies became dull. At first I thought, this won’t be a problem. It will be solved in the next few weeks. I bought some new powercords and immediately the sound cleared up. Unfortunatly after 3 days the sound was dull again. I switched out a Pink Faun powerblock for a Furutech NCF, after this I started to change powersupply’s and again and again the problem was solved…. for 3 day’s, Another powerline 3 day’s, BiWiring loudspeaker cables 5 day’s. This went on for 27 months. I realy changed everything I could think of. Think about at least 100 things. Because I also went inside the equipment. For example I changed capacitors of powersupply’s at least 15 attempts, the internal wiring of a modified NAD M12, clock position, powersupply’s. I changed the ethernet card of the streamer, the clocks, I bought an AES/EBU card with a Pink Faun ultra clock. I changed the main bord several times. I replaced the wall socket’s. For example I switched 4 orange Senergistic Research for purples and the sound was at ultra high levels for one week.

Earlier this year I bought two Farads Super 10 with QSA red fuses and a new Dac streamer Moon 390 to compare it with the NAD M12. With the new gear the sound was good for weeks, but after that it became dark and dull again. I was almost done with the hobby, because I was analysing instead of listening to music for years now. Still I wanted to try something else, because we have a second audio system in the livingroom, which never sounded dark. This system Arcam SA10 with bluesound and B&W 805D3. So I bought the Moon 680D and moved the moon 390 to the livingroom. We bought an NAD C298 poweramp. So the system in the livingroom was upgraded with the moon 390 and the C298. This system was only getting better and better. While the Moon 680D in the audioroom became dark and dull. So I had to look further again.

So I looked into the powersystem again…. I had already done this for at least 5 times, with al sorts of measurement devices, but now I was planning to replace 15 ground leakage circuit breakers just for a test. For the audiosystem we already had special fuse breakers without ground leakage circuit breakers. It seemed we had a TN-C powersystem, which means the ground conductor and the neutral conductor are one and the same and they are divided at the main powerbord. From there the ground and neutral conductor are divided. I decided to place a grounding spike and drilled it 7.5 meters into the ground. I changed the powersystem into a TT-System for a test (I’m an electrical engineer). In a TT-System the ground connection is made by ground spikes there’s no copper connection. This also didn’t solve the problem. It did help but was not the solution, because there were still connections left with the TN-C system, because the water and gas was still connected to the systems in the neighborhood. So I changed it back and connected the grounding spike directly to the audio system. This did help big time, but the system was only for 80% where it belonged to be. I bought a Doupke ground leakage switch, because the audio system was now on a TT-System and should be protected. I bought some extra meters ground spikes and isolated them. I connected them on top of the earlier drilled spikes and drilled it another 3 meters deeper. This helped even more. After this I measured al 18 power circuits in our home for isolation problems of the wiring. Normally one should measure at 1000 volts, but because on every circuit things (lamps, television etc) were still connected. I only measured at 250 volt. It seemed that most of the circuits were above 200Mega ohm, but a few were around 3 to 6Mega ohm. Still this is good enough and there’s no need to be replaced. But when these few circuits were switched of the sound SQ clearly increased. Today the sound is great for almost 20 Days. So I think the problems are solved. Why the system in the living room does not had the same issues is still a mystery, but I guess it’s because on the lenght of the wiring from the main powerbord. 20 meters vs 7 meters for the audioroom. Ground and Neutral was only 7 meters from the system connected with each other. This means the noise from the neutral conductor is directly connected with the audio system ground. Even the noise of neighbors will have it’s influence on the ground of the audio system.

This week I compared the Moon 390 with the Moon 680D and the modified NAD M12. In the past I replaced a PS Audio Directstream for the NAD M12. The M12 was clearly better to my ears and some friends were with me on that. I guess the Moon 390 will come close to a NAD M12, but I ain’t sure which will be better. I guess the NAD will sound a little bit better. Both are great devices and I like the Moon 390 for it’s solid build. Realy great!
The Moon 390 compared with the 680D is a big step. The 680 is far more refined and low frequencies are so much more precise. Still the NAD M12 modified with two Pink Faun clocks. One Ultra on the audiobord and one Connor and Winfield on the BluOs. The NAD is Fed by a 5V Farad Super 10 with QSA red fuse and a 24V Farad super 3 with also a QSA red fuse. Is on another level. The sound stage of the NAD is so incredibly solid, analog, acoustics and voices are breathtaking. The downside of the sound of the NAD is that the soundstage is to wide for my liking. This is where the Moon 680D suits my room better. The 680 has a deeper soundstage, which is easier to listen to. So I decided to stay with the 680D because in the basic it’s already on a higher level than a NAD M12. In the future I will upgrade the 680 with an external powersupply. The 680 is prepared for that. With the 680 my system really rocks!

Best regards,
Wijnand