[Gerzom]

  I realize you are located in Europe and so you have a different wiring scheme.
 
But I would also assume that you use 3 wires to connect power to the Mojo amp and the rest of your audio gear.
Now if this isn't the case and you use only 2 wires to connect to your ac power, then this may not work.
BUT if you run a separate ground wire to a source of outside ground (like a cold water pipe etc.) this is the 'source' of the ground used in the system.
 
As a TEST try unconnecting the ground connection at the Mojo, and see if the hum goes away.
IOW you may be grounded twice, which can cause hum due to a ground loop.
 
BE AWARE that by lifting the ground on the chassis, it MAY become a source of a shock by touching the chassis.
If this happens pull the plug out and re-connect the ground.
And if you are adventurous (and feel confident to do this) you can try this on other equipment in the audio chain, but be aware the same caution applies about being a potential shock hazard.
 
Now if it makes you uncomfortable in trying this, then don't and get an electrician or somebody you know who is 'handy' with electricity to help you with this. 
 
But ground loops are usually solvable
 
Does this answer your question?
 
JJ

Ahhhh, I used a non-grounded wall socket for my Mjolnir and now it's quiet again 

 
Thanks for pointing me in the right direction!!
 
G-J

 

[Shaker]

Thanks for all the helpful info here. Trying to decide on a headamp and interested in the Mjolnir, as well as the Audio GD Master 9, and less so the Oppo HA-1.
 
As far as HP, I'm in the midst of deciding between the LCD-3 and the LCD-X (I'll only keep one).
 
As of now, I have the Oppo 105D which I plan to keep for HT/universal disc/and as a pre for my system, and the Phonitor 2 that I just received a couple weeks ago that remains unopened as I plan to sell it since it does not fit into my overall set up with our 2 channel/HT 7.1 system.
 
I was considering the Oppo HA-1, especially if I go with the LCD-X since it is easier to drive vs. the 3, but the Mjolnir and Master 9 have caught my eye based on price and reviews.
 
Has anyone paired the Mjolnir with the Oppo 105D? My thought is that I may do this at least initially to see how it sounds with the 105D DAC and to use with CDs until I have time to rip them all. If there is a significantly better DAC to pair it with as far as SQ, then I could consider picking that up at a later date. I had been looking at the Hugo given it's reviews and size, but am unsure it's worth adding a DAC to the 105D. 
 
Can anyone comment on the Mjolnir vs. Master 9 for SQ, especially with either the LCD-X or 3?
 
Any reason that I would have issues (e.g. SQ degradation, connectivity) having the Mjolnir and 105D connected via XLR and then run a pair of XLR from the Mjolnir to my monoblocks for 2 channel listening, and connect the RCAs from the 105D to my 5 ch amp for 7.1?
 
Thanks

 

[Stormfriend]

I have really bad mains quality which affects all of my kit and I'm slowly going off the grid, with just the amplifier left to go.  I'm looking at options such as RWA and Bakoon, but I'd really be interested to know if I could bypass parts of the Mojo's power circuitry and feed it directly from a 12v battery.  Does anyone know if that's feasible?
 
I'd most likely get an expert to make the changes, but there's no point starting that conversation if the circuit is inherently unsuitable.

 

[commtrd]

Why not just go to a UPS system which would supply a constant current and voltage supply at all times? Personally I would never get into modifying internal circuitry in any electronics device when a much easier and effective solution is available by utiling an uninterruptible power supply (UPS) which is widely available being used for years for computer equipment.

 

[Stormfriend]

  Why not just go to a UPS system which would supply a constant current and voltage supply at all times? Personally I would never get into modifying internal circuitry in any electronics device when a much easier and effective solution is available by utiling an uninterruptible power supply (UPS) which is widely available being used for years for computer equipment.

 
I've tried using an online UPS, which was completely consistent, but the sound quality didn't meet my needs (HD800s are rather demanding).  I've also tried filters, balanced transformers and a variety of other stuff, most of which brought significant improvements but I've never reached 100% unless it was 2am.  I do occasionally get flashes of brilliance at other times though, for example when England were playing in the World Cup, as I guess all my neighbours went to the pub to watch it instead of messing up my power supply!  Sadly, that didn't last very long... 

 

 

[BobJS]

Sorry ahead of time for asking a question that must have been asked a thousand times........
 
From Jason's Mjolnir description of Schiit's web page:
 
"You won’t find any balanced-to-single-ended conversion or vice-versa in Mjolnir. It’s balanced in and balanced out...."
 
 
or vice-versa .... implies no single-ended input.
 
I have only single-ended DAC output available, and I see single-ended RCA inputs on the back of MJ.   Will this work or not?

 

[Defiant00]

  Sorry ahead of time for asking a question that must have been asked a thousand times........
 
From Jason's Mjolnir description of Schiit's web page:
 
"You won’t find any balanced-to-single-ended conversion or vice-versa in Mjolnir. It’s balanced in and balanced out...."
 
 
or vice-versa .... implies no single-ended input.
 
I have only single-ended DAC output available, and I see single-ended RCA inputs on the back of MJ.   Will this work or not?

 
Yes, Mjolnir will accept single-ended inputs.

 

[BobJS]

   
Yes, Mjolnir will accept single-ended inputs.

Thx

 

[johnjen]

  I have really bad mains quality which affects all of my kit and I'm slowly going off the grid, with just the amplifier left to go.  I'm looking at options such as RWA and Bakoon, but I'd really be interested to know if I could bypass parts of the Mojo's power circuitry and feed it directly from a 12v battery.  Does anyone know if that's feasible?
 
I'd most likely get an expert to make the changes, but there's no point starting that conversation if the circuit is inherently unsuitable.

The Mojo amp uses very high voltage rails (90) so 'adapting' a 12 volt battery to feed this would be a major PIA.
 
So the short answer is no, unless you want to make your own battery powered ac supply circuits, which isn't an 'easy' solution.
 
JJ

 

[IndieGradoFan]

I've got a number of dimmer switches on overhead lights throughout the house that are interfering with my Mjolnir. If I have the lights on and the dimmers at full power, I can hear a slight hum in the right channel. If I reduce the power on the dimmers, the hum gets significantly worse. If I turn the lights off completely, the hum disappears.
 
Note that the light dimmers are not on the same circuit as the Mjolnir. Also, the Mjolnir is running off a Tripp Lite 500w hospital grade isolation transformer (http://www.tripplite.com/medical-grade-isolation-transformer-500w~IS500HG/). Without the isolation transformer, the right channel hum was much worse and there was clearly audible distortion on bass frequencies.
 
I don't have hum on any other amplifiers in the house, including a Lyr, a Marantz AVR, an Onkyo AVR, and a Rega Brio-R. Schiit informed me that the circlotron topology in Mjolnir is very sensitive to AC line noise.
 
I've considered installing a dedicated circuit to the Mjolnir/Gungnir/Brio-R, especially since they sit about 8 feet above my panel, separated by just one floor. However, I get the same results with the Mjolnir on various circuits throughout my house, so I don't think a direct circuit will change anything.
 
Besides removing the dimmers, which won't fly with my wife, are there any other reasonably priced options? Has anyone had luck with the wall wart style AC line filters, ala K-Works Silencers or PurePower QuietLines or PS Audio Noise Harvesters?

 

[Ultramus]

Don't know what to tell you there, I use a Furman pl8c power conditioner and it removed my ac line noise, but I had no dimmers.anywhere.

 

[johnjen]

All dimmers create plenty of spurious noise which is added to the hot and neutral legs of the ac supply.  This in turn is added to the ground wiring as well, back at the panel where the ground and neutral legs are joined.
 
Usually the ground wire is used as an internal source of ground for all of the circuits inside an amp.
Except that the mojo's Circlotron circuits are 'different' in that the amplifier is 'floating' above ground.  But the power supplies still use ground as a pseudo reference, which means if the ground has zizz, it can modulate the floating power supply and amp circuits.
 
2 things immediately spring to mind.
 
Make sure that ALL of the neutral and ground connections at the panel are tight and clean.
Then also make sure that ALL of the branch circuits connection at the circuit breakers are also tight and clean.
It requires a certain degree of knowledge on how to SAFELY perform these wire tightening checks.
 
It 'MIGHT' be helpful to try using an independent source of ground for the entire audio system instead of using the ground supplied from the breaker box.  This suggestion has the potential to be either a solution or a source of other consequential 'problems'.  But adding a power conditioner or other 'filter' might also benefit from an independent ground, instead of using the ground from the breaker box.
 
Just some things to consider.
 
JJ

 

[IndieGradoFan]

Thanks for the tips! After doing more research, I think I'm going to stick with turning the dimmers off when using Mjolnir. Of course, now that I know what to listen for, I can hear the same issue with my Lyr. Sometimes it feels like its all I can hear anymore! Need to get back to enjoying the music instead...

 

[fmzip]

Anyone try the NAD HP50 with the Mjolnir/gungnir? Love my Audeze LCD's with this setup but need a reasonably priced closed can set. Any suggestions?

 

[reddog]

Anyone try the NAD HP50 with the Mjolnir/gungnir? Love my Audeze LCD's with this setup but need a reasonably priced closed can set. Any suggestions?

I would look at MrSpeakers Alpha Dogs for a reasonably priced set of can. The Alpha dogs sound great as well as isolate you from outside distractions.