The Mjolnir 2 thread

I have the opposite experience. My Vali 2 stock tube was good and I ended up preferring it towards the end of my time with it. Unfortunately I think you just got a bum tube.
I think the consensus on the Valhalla 2, which from personal experience, I wholeheartedly agree with, is the stock tubes are fine and rolling doesn't do much but waste money that should be applied to upgrading the amp.
I asked the question about stock tubes in Mjolnir because of my previous experience with Vali 2 and Valhalla 2. I think Jason knows what he is doing in choosing the stock tubes.

 

Does it actually go "zzzoooonngggggg"? Suddenly I'm interested!

So do I, I think he knows that people will swap them anyway, so puts something cheap and cheerful in there, something new that has a reasonably low failure rate. I don't resent it one bit, FWIW- it's just pragmatic.

 

With some tubes more than with others. With some tubes it's just a "mmnnng" and a click. And with one pair I had there was silence.

 

I like the older Schiit Russian 6922 tubes that used to come with the Lyr 2 or Valhalla 2. They're actually my preferred tube for the Vallhalla 2; a bit thin sounding on the hybrid amps. The newer Canadian tubes are completely meh, unfortunately. I get why they're used by Schiit, though. And just to reiterate it here since this is the Mjo 2 thread, if you're using the Mjolnir as a pre-amp you're losing a lot of transparency in the process. (Maybe that's what you want, but for me it's no bueno.)

 

Assuming I'm using a the Mj2 as a preamp specifically to warm up the Koss ESP950 and give them some warmth, is the Mj2 still bad choice? Would a Saga and a warm tube be a better choice?

 

I haven't heard it myself; I know Marv likes the Saga before the Jot but the Schiit preamps shouldn't add coloration, since that would defeat the point. I would expect the tube stage to help more with soundstage rather than adding much warmth. All I can say for sure is the Mjo 2 preamp is not very transparent and other people here have noticed that too. Try comparing it yourself. If it sounds good to you in your setup, I wouldn't stress about it, since it sounds good!

 

thanks. I'll trying a Saga in late june, so I will have to do lots of comparisons.

 

Western Electric 396a First Impressions


Setup
Macbook AIR -> Tidal Lossless -> TDRNova Parametric Equalizer -> Modi Multibit USB -> Mjolnir 2 high-gain XLR out -> Fostex TH900 -> 20 minute warm up. Impressions are vs Stock Tubes.

PROS
Very nice smooth treble and quite a bit cleaner sounding. Their technical performance vs stock offer notable improvements. Bass tightness, micro-detail, separation/speed, stage layering, and micro-dynamics are all like 1.5x-2.5x better. They do very well with live instrumental, classical, Jazz, and Rock. Guitars sound great on them.

CONS
Vocals in the upper registers sound unpleasantly raw or harsh, at times imparting a slight nasal quality. They feel closed-in/non-airy.

Perspective Dependant
Depending on how you see things the centre imaging and vocals are either smaller and distant, or have depth. Giving the impression of shallow triangle shaped staging as opposed to a flat line. The staging extremes are wider, but most of what you hear is closer and more intimate. The centre vocal imaging is more sharply centred, which I find uncomfortable. Reminding me of how the HD800 is vs the HD650 or TH900.

They're not as warm as stock.

Alternative Ears
My fiancé who has musical background gave this setup a very brief listen, without any comparison or any other recent listening. She typically likes a V-shaped signature. She strongly and immediately disliked them. Saying it was too bright, and then commenting on the harsh sound. Concluding with “the mids have been taken away." I tried EQing everything above 6khz further down to no avail. I made no comments to her before hand.

Conclusion
Much of their technical performance improvement makes them a pretty significant upgrade and very much worth the money, particularly with genres that benefit most from speed and soundstage layering. With certain genres that do not have a lot going on in the upper mids/lower treble they may be better, but too often with most other tracks I've just had to take my headphones off due to their harsh/raw sound. Ultimately I found them to be markedly less engaging than the stock tubes.

It's possible that the upper mid rawness is really the Mjolnir 2’s true nature, and that the WE396a are simply exposing this due to their better performance. But I couldn't tell you without having heard a variety of other tubes.

EDIT: Updated after further listening and for clarity.

EDIT 2: I had a quick listen with the HD650 SBAF-mod. Everything I wrote still stands, but probably less so. Upper mid rawness/harshness less wince inducing but still there.

EDIT 3: The rawness may be highlighted around the 3.5khz area, where headphones tend to have a rise in frequency response. EQing that down on the TH900 has helped but it's still present. Quick listen of the HD800 today and the rawness/harshness was less evident, than even the HD650. More engaging with more cohesive staging over stock.


LISST Impressions for Reference
http://www.superbestaudiofriends.org/index.php?threads/the-mjolnir-2-thread.208/page-13#post-132422

 

@BenjaminBore
Thanks for posting the impressions. I agree with the lack of airiness, but I don't get the upper mid harshness, but I used the utopia. I'll try with TH900s and see if I can hear this harness. Can you recommend a song or passage that more clearly demonstrates the issue to you?

 

Going back through a few of my recently played tracks these seem to get me the closest to wincing at the upper vocal range:
Down by Xamvolo
You're the One by Kaytranada
Bring it Home by Zak Abel
EDIT: Outshined, and The Day I Tried to Live, by Soundgarden

It's possible I am not describing this correctly. But it occurs especially when I am hearing vocals in the upper registers. (EDIT: It might be better described as raw, or glare). For example the harshness could really be coming from the lower treble. If necessary I'll try out the HD650m and HD800 tomorrow.

 

Thanks! I try to check those out tonight.

 

Outshined by Soundgarden demonstrates the upper mids issue better than the others. Chris Cornell could really belt it out. (I wrote "can" at first )

I had a quick listen with the HD650 SBAF-mod. Everything I wrote still stands, but probably less so. Upper mid rawness less wince inducing but still there.

EDIT:

That may not be surprising as the Utopia, like the Elear, have that upper mids suckout.

 

Seems to be similar to my overall experience with the Mjo 2. Difficult to describe fatigue that follows some kind of noticeable pain while listening. A real shame as I can hear how good the amp is, I just can't enjoy it the way I want to.

 

Thanks for the references. I listened, but the music is so outside my listening preference, I could not detect any issues.

 

Well, I've made an odd discovery. I have a WINIX brand air purifier in my room, and it's on the same outlet (though a different power strip) as my Mjolnir 2. When the unit is on, and I'm listening on the Mjo, on many tracks I develop a "the sun's too bright" sort of upper forehead ache within moments. The kind that makes you squint a little without meaning to. When I turn the air purifier off, my head instantly relaxes and the Mjo is no longer causing me pain. It's practically silent as a fan, so there must be some kind of electric interference at play. This comes as a relief to me. Anyone know what's afoot here?

 

My experience as an MBA would lead me to conclude that purified air is incompatible with quality music.

 

Sounds like unwanted DC offset messing with tonality and headroom. Pro tip: place your Schiit amp on a power conditioner/filter. As per @Garns tip here getting a power conditioner for my Valhalla 2 resulted in less etch and fatigue among other things. I noticed it made a positive albeit more subtle effect with the Magni 2U and Vali 2 as well.

 

Another pro tip: Get an isolation transformer!

I have my audio gear plugged into a TrippLite PS model power strip (no filtering or surge suppression) and that is plugged into a Topaz 2.5kVa .0005pF isolation transformer. The idea with the power strip is that having low impedance between the devices plugged into it reduces the noise that is injected back into the AC. Because of its extremely low inter-winding capacitance, the Topaz acts as an excellent noise and surge suppressor. Besides the Yggdrasil, the Topaz has made the single biggest gain in sound quality in my setup.

 

I'm very happy that you have figured out the problem, I was disheartened to read about the pain you experienced.

To piggyback of k4rstar's suggestion about DC offset, I would also look at the Emotiva CMX-2.

 

Thank you. I'm admittedly ignorant about this topic. Does the CMX-2 do the same thing as the Furman AC-215A power conditioner I am considering getting, and thus it's one or the other, or do they have separate functions?