Not sure if it's more elegant but you can hacksaw your ground pin off the power cord and it will sound way better than those nasty adapters...
Grimm Audio MU2 "Major Dac"
- Thread starter PaulB
- Start date
Absolutely. You can also not connect the ground wire to your receptacle. I would prefer not to go that route if I can help it. I am hoping that a ground wire from the ground lug on my amp to either the receptacle screw or MU2 chassis works.
hope that works so that you can enjoy the MU2 without noise and without more drastic workarounds because on day six (approximately 1/3 of the way there according to @owen lawlor 's observation of 200 hours total) of burn-in reveals that the MU2 is exceptional.
Thanks. I did get a chance to listen yesterday with a cheater plug in. Sounds pretty amazing already with about 20 hours in. You can tell this is going to be really special. I am also burning in a quad of Emission Labs 300B meshies that are very special. About 100 hours in on those.
I must say that I have been suffering with painfully slow Roon...buffering sometimes >1 minute and hanging up. Not sure if that is a local (MU2 CPU) thing or network thing. I was having some issues prior to the latest Roon update with drops and skips but that seemed to be fixed with my old DAC. I hope this isn't a MU2 processing issue.
Anybody having this issue?
Anybody having this issue?
no issues here. Roon working normally. One dealer told me to reboot the MU1/MU2 after a Roon update. Haven't tried that. In the past, when Roon was slow I would re-boot my modem/router/wifi unit and that would work.
I think it’s weekend traffic on the Xfinity DNS. They won’t let me change it, so I might have to get another router to connect to my current ISP router ,which uses a proprietary fiber connection, in order to change to a third party DNS. I have been told that works. I just hate to get more crap in the signal path.
I have xfinity as my ISP. It does seem to me that web traffic has been slower in the last few weeks, but it hasn't affected Roon playback, fortunately. Sometimes the slower response rate persists for a while. I assume they receive complaints and figure out the problem. Or they are upgrading and until they do, performance lags.
Agree that adding more crap in the signal path isn't desirable. Or more crap in general.
BTW…I’m at 6 days of running files and it is beginning to sound amazing. The voices are stunning, soundstage is so precise.I have xfinity as my ISP. It does seem to me that web traffic has been slower in the last few weeks, but it hasn't affected Roon playback, fortunately. Sometimes the slower response rate persists for a while. I assume they receive complaints and figure out the problem. Or they are upgrading and until they do, performance lags.
Agree that adding more crap in the signal path isn't desirable. Or more crap in general.
it seems to me that the MU2 breaks in from the midrange out to HF and LF. My previous experiences with digital has been LF are resolved first and then upwards to MF and HF. Perhaps some folks who opine about the LF and HF being somewhat different (perhaps less extension) than other digital gear are listening to an MU2 that is not fully broken in.
You may have mentioned this in another post so my apologies if so. What is the rest of your system, specifically are you feeding the inputs of a preamp, integrated or are you feeding amplifier direct? XLR or RCA?
Is there any chance you are overloading the inputs? In other words, is there a volume level for the MU2 output where the "crispiness" is absent? Into an integrated, you may need more volume on the integrated side of the equation and less volume on the MU2 side of the equation. Your Trafo probably is looking for 2-2.5v and you might be feeding it 8/10/12v?
Thanks. That is a very good observation. I have the volume level set to fixed (line level) on the MU2, so you would think that it would be okay. I will check it out and see. Also, the RCA jacks are right next to the power IEC, so there is a possibility that I might be getting some EMI on the ICs? I could try some XLRs to see if it goes away, but I love the sound of my ICs and would hate to have to switch. I am also breaking in a new set of output tubes on the amp which have about 150 hours on them. Not sure if that might be a factor as well.
What follows is pure conjecture because, (A) I am no expert, only a hobbyist like many here and, (B) I wish I could say that I've not been befuddled in the past trying to chase down a similar issue.So, here goes...
First, I wouldn't worry about the proximity of the rca jacks to the IEC. Easy enough to check though.
I would first focus on what may be a volume level mismatch. If it were me, I would change the Grimm output from fixed to variable so that you could utilize the Grimm's analog volume control, turn it down considerably and then adjust the volume on the Trafomatic to achieve a reasonable listening volume. It's highly likely the Grimm volume is more transparent anyway. Is the "crispiness" still there? While your tube breakin could have been a culprit, I would have expected them to settle in far sooner than 150 hours, so I doubt the issue is there, although swapping in some known tubes will eliminate that from your checklist. Lastly, when you say you love your interconnects, is that an in general type of observation or is that a specific to the Grimm observation?
Thanks very much for your input. The Grimm volume level is an easy way to start and I will give that a whirl. With the tubes, I would think that would be the case as well, but Emission Labs is saying that it will continue to break in out to 300 hours, so it may be a factor? I really like the way they sound in general.
I hear you on the tube breakin message from EML. Let us know if the volume duty shifting helps.
There is also the volume control on Roon. Known issue on Grimm website:
#2 Playback sounds distorted with Roon at volume ‘100’.
When using an external preamplifier and using the MU2 with fixed volume at the maximum Roon setting of ‘100’, distortion occurs on some music.
The MU2 has 8 dB of exces gain at the top of the scale. This is intended to only be used with soft sources and can cause clipping with loud sources. The display of the MU2 shows “+8 dB” when Roon is set to 100. When using the MU2 with an external preamplifier, please do not use levels above ’92’ in Roon, which equals “0 dB” on the MU2 display.
Need to take this into account as well....too many volume controls to have to deal with!
Adjusting the volume level made a difference. I learned a couple of things yesterday: The volume level of the MU2 is best controlled via Roon. Roon adjusts the gain of the unit based on the volume level on the Roon slider. I have set mine to 92 in Roon which corresponds to 0db on the MU2. For whatever reason, before I rebooted the unit I was able to have two volume levels, one on the MU2 and one in Roon. Since reboot I adjust the volume level in Roon and it automatically adjusts the gain on the unit.
Secondly I found that using the control disc to navigate to the power button on the screen does not completely turn the unit off. It puts in into standby mode. To completely turn the unit off you have to go to standby mode initially, presumably, and then use the small button on the back to turn off the unit. That is not intuitively obvious. There should be a standby symbol on the screen rather than the international symbol for on/off. My unit was running sluggishly before I rebooted and now it is running much faster. I must have cleared out the cache or something.
I think a contributing factor, or perhaps the main factor, for the crispiness may be coming from the input tubes. I also recently changed the input tubes to PsVane "Cossor" 6SN7 carbon balls. They sounded fantastic when they were installed, but they might be losing their mojo. They probably only have 100 hours on them. I think the soundstage may be narrowing and there is not the layering that I had when they were brand new. Could they be causing some sibilance?
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