The Mjolnir 2 thread

TLDR : LISST are good

I’m going to keep raising the heat in these posts. The previous one was a recap of Mjolnir and LISST. This one is my own impressions (which differ from others) and the next is speculative and experimental (where I expect significant disagreement).


How does LISST sound in an MJ2?

Like many others my initial impressions were underwhelming. Switching from tubes, the sound seems thinner. It’s missing the richness I have become used to on my main system. So LISST didn’t feel like changing tubes, but a much bigger step.

I’ve learned that with audio, first impressions should be let go. Small things like a volume change, difference in frequency response or a similar step outside the familiar can create a bad first impression. To appreciate what is possible, we need to be open to a new presentation.

So I did extended listening. And I found I really enjoyed the LISST system in the background. While less fat and heavy, it maintains the full impact of the Mjolnir 2.

Then I started to find some tracks that sound much better on LISST than tubes.

The definitive track: Alberto Balsalm
This percussion-intensive track sounds boring on tubes, I was surprised that it became toe-tappingly joyful and impactful on LISST.

Then there many examples of LISST being a joy when listening to jazz:

For example: Ballad For Bernt
The brushwork especially came to life, while it was a blur with tubes.


Transients?

I'm guessing the key benefit is how solid state handles transients. That suggests percussion and electronic music benefit most. I know Billie Eilish's Bad Guy uses truncated samples which should have an impactful front edge, so had a listen. Again, it seemed enhanced on LISST vs tubes.

I then tried a few tubes that are mentioned as being stronger on handling of transients or more like solid-state. NOS Sylvania 5670’s didn’t do anything.
@Johnny Opps and @roshambo123 mentioned the Electro-Harmonix 6922 in this thread, and these tubes do seem much closer to the LISST experience. Thanks both.


Conclusion

So after all that, my sense is that LISST, as a plug-in replacement, are great for extended listening and specific kinds of music. They're like San Pellegrino mineral water with the sharpness of intense natural carbonation. If you sip it through the day, it's a good day.

Tubes are heavier. They're a delight for the end-of-day wind down. They're warming like cocoa. Drinking cocoa all through the day is not a recipe for happiness.

I'm thrilled that MJ2 can switch between these two modes.

 

This post is speculative - it's about tubes.

One frustration with tubes is the spectacular and outlandish claims that are made about their sound, but in the absence of proposed mechanisms. Tube discussions can read like pure magical thinking - ancient artefacts obtained from dusty vaults have miraculous effects when inserted at the core of modern technology.

There are many negatives about tubes. To the extent there is hard thinking about positive aspects tubes. it mostly comes down to two things:

1) tubes are relatively linear so don't require the feedback mechanisms used with most transistor designs

2) tubes distort in a pleasing way, emphasising octaves (harmonics 2, 4, 8.. )


Neither of these explain one of the main reasons for using tubes - that tubes seem to change the spatial experience of a recording. So..

Woland's hypothesis:

Noise reduction, compression and other audio processing destroy low level audio that provide spatial cues. Tube distortion simulates the missing low level audio.

Unfortunately we seem to have big gaps between the science of audio and the engineering. Psychoacoustics studies, like most science are tentative with claims like "we tested a group of casual listener college students and none could differentiate signal A from signal B reliably at a statistically significant level". But by the time it makes its way to ASR, the claim becomes dumbed down to "no-one gets any benefit from A vs B". Applied audio engineering sits somewhere in the middle, with audio information that isn't obvious being likely to be removed.

If we want music more like how it was performed, arguably tubes will be more realistic because they replace what has been stripped away. Not an accurate replacement, but they replace what's missing with something similar. If we want a more 'fundamentalist' or literal articulation of the digital stream, solid state is the way to go.

Coming back to MJ2, I like that LISST allows bridging this gap.

 

I've drastically raised the quality of the audio coming out of the DAC using HQPlayer for upsampling, as described in another thread.

A consequence of that is using LISST more: LISST brings out the extra detail, and even the best tubes just don't compare. What tubes added seems unnecessary. Although I keep trying out tubes from my collection, I've moved to using LISST 75% of the time or more.

 

Hooly Dooly, they did it! But in a Lyr 3 chassis!

 

Lyr 3 is not the same topology as MJ2. MJ2 has that circlotron thing and uses two dual triodes. The new Lyr 3+ seems o be the same Lyr 3, but with some added features, like remote stepped attenuator volume. However, yes, it does add the SS pre on a switch…basically LISST built in.

 

After a lot of tube rolling on the Mjolnir 2 (w/ gungnir and HD 800), it looks like the 2 winners of my collection on this amp are some Siemens ECC88 and CBS 5670. The ECC88 did what I liked in some amperex bugle boys, but with a bit wider head stage.

The CBS 5670s transform the sound a fair bit, making everything sound a more spacious but a bit less impactful/visceral. I can also pick out details more easily. Its weird, at my normal listing volume individual instruments sound a little too quiet/distant, and adjusting the volume till those instruments sound normally loud leads to a almost live concert like overall presentation. Bad for hearing probably but really fun. This didn't seem to be a sound linked to the valve type, a pair of GE 5670 didn't sound much different from other so-so 6dj8 tubes I had.

 

I'd like to ask for a quick bit of advice, please. I recently picked up a Friend's Mjolnir 2 and am doing some tube rolling. I bought the adapters needed to try a pair of Western Electric 396A tubes. My concern is about the potential for the adapters to remain affixed to the amp when I remove the tubes.

I assume it would be possible to lift them out, gently, either with needle nose pliers or tweezers. Is that the case? Or would I need to open up the amp to retrieve them? Any advice would be most welcome - thanks in advance!

 

You can use a pair of pliers, but you should unplug the amp first (and to be safe wait and let the stored power drain) before attempting. Also the pliers might mar the adapters or the chassis if you’re not careful. You might want to use socket savers if you roll often.

 

To expand a bit on what joch suggested. Use non conductive pliers or rubber tipped somethings to get them out if you have to. The MJ2 doesn’t really drain its power. The thing stays charged for weeks unplugged.

i second the socket savers!

 

Thank you both for the helpful advice, I really appreciate it. I’ll do some socket saver sleuthing!

 

Anything is better than the stock tubes.

 

Yeah, I got a pair just to get a baseline and decided in short order to move on to others. So far I’m loving a pair of USA Amperex/Hewlett Packard 6922 O-Getter Gold Pins from 1972 with my HD 600. I’m on the hunt for some Dutch ones and some
6922 Gold Lions, which were kindly recommended to me by the seller.

This thread has been outstandingly helpful for tube recommendations.

 

There is about a 50% chance the adapters will stay in the amp. Get a cheap pair of 6N3P which are taller and pin compatible with 396a. Plug them into the adapters and they are tall enough that you can use them as a lever to wiggle the adapters out of the amp. It's virtually impossible to get the adapters stuck in there, eventually they will just come out on the bottom of a tube. Basically it will be fine.

 

Just sharing since I’m a proud MJ2 owner: Love LISST (which I had to purchase used), but for me the amp is at its finest with a pair of Philips SQ E88CC. Soundstage and musicality are pretty engaging.