The Mjolnir 2 thread

Having a product the size of MJ2 that had Jot 2 and some kind of tube pre option under the same hood with shared I/O's does sound interesting. I don't know how to design amps, but I'm guessing that's quite a challenge.

 

It' pretty much the same as what's implemented MJ2 except instead of physically swapping tube for LIIST, it would have the LIIST-like circuitry internally. It seems like LIIST was a problem product because of the challenges of squeezing circuitry into a tube's wiring and space constraints.


Why would you want an MJ2+ like this?

* Ideally because the solid state sounds great and sufficiently different to tubes that you would want to use both.
* To give a reference for comparing tubes without needing two amps and cable switching. This would be awesome for tube rolling.
* To save tube life.. switch to tubes only when needed, but still be able to play music without the hassles of a second amplifier and the associated cabling. Freya+ already does this as a preamp, MJ2+ would do this as a headphone amp.

 

And that it sounded awful. Nice extension, but all the same.

 

@cameng318

I thought you'd find this discussion on topology / MJ2 interesting.. it's from Jason's Schiit Happens post for the launch of Ragnarok 2

Circlotron: actually not a gain stage. This is an output stage. You could do a Nexus circlotron (yes, I know, your head just exploded). You could also do a Supersymmetry circlotron. I include this mainly because circlotrons have become combobulated with balanced amps, and because we use a circlotron in the Mjolnir 2, coupled with a single-stage differential amplifier. Feedback, however, goes back to the grids of the tubes, so it’s a low-impedance input, which necessitates discrete buffers before the differential stage—exactly like the LME49724. Circlotrons also have the problem of no inherent SE output—to get one, you’d have to play some capacitor-coupling tricks, and also have a very low-noise power supply. To summarize:

· Pros (of the circlotron output stage): very simple actual topology
· Cons (of the circlotron output stage): very complex power supply, no easy SE output
· Pros(of the Mjolnir single-stage+circlotron topology): very simple, no N/N+1 gain relationship
· Cons (of the Mjolnir single-stage+circlotron topology): needs input buffers, no easy SE output, requires interstage capacitors

....

Aside: a tube hybrid Nexus, like we might use for a future Mjolnir, may never happen. Seriously. We tried it. Even the best-matched input tubes cause severe imbalances in the topology. Using a differential servo to try to pull everything in place is problematic, as it fights the operational point servos. You might end up with three servos and microprocessor oversight…and still end up with many unusable tubes. However, if we can address some cost issues, there may eventually be a Jotunheim Nexus, but that’s a bigger challenge than you might think—we get away with it in Ragnarok 2 due to extreme matching and some hand-trimming, and in Freya S because it’s a relatively simple, line-level implementation (which still requires insane matching). When you put together the requirements of power output and thermal stability that Jotunheim entails, it gets a lot more complicated in a hurry.

 

I think I've read it when I tried to understand my Jot 2. Jason is way too transparent about what they do, and I love the heck out of it!

If they really can't pull off tube Nexus, it might be a game changer if they could incorporate signal transformers. IMO interstage transformer is the most ideal way to do the differential job, even Nexus can't match. Edcor XS4400 seems to be the most budget choice, but I'm not sure if it's price and lead time suits Schiit products.

It might also be cool if they could get their power supply transformer supplier to make output transformers. Then they could do output stages like Susan Parker's Zeus Amplifier. It won't have power supply and SE out pain of circlotron, but again it's all up to the transformer.

Tbh traditional push pull output stage is more flexible than circlotron. Again, simpler power supply and SE out. It could achieve the same Continuity performance by burning twice the power. Biasing is a pain, but they are already using microcontroller anyway. Loosing the Crossfet badge might hurt the marketing though.

 

Mjolnir is no longer.

Spoiler

 

I loved the idea of the MJ1, all solid state balanced with no hodge podge single endedness to murk things up, but then I heard it and really didn't like it (to be fair, I didn't like any of Schiit's first gen stuff). It's too bad there's no solid state MJ3 in the works, but reading his post on HF it looks like they don't really have anything in the cards for that at the moment, and he's stated that having the balanced only was terrible for sales.

 

Here's the link

Seems like the technical discussion above, about about challenges to refine the topology, was pretty much spot on.. + a couple of realities about the cost and size of the MJ. Regarding size, I found the biggest upgrade to my MJ2 was a long headphone extension cord that let me locate it well away from my work area.

I think MJ2 really struggled because of the product strategy too - at launch it was branded as solid state AND tubes delivering balanced output -- but the solid state / LISST aspect wasn't well received. When LISST vanished, MJ2 was tube only, but the original messaging wasn't cleared up. When a raft of other balanced amps were made by Schiit, it became a very niche product.

 

Well, it's a hybrid amp so it's solid state and tubes even without LISST.

 

At the price point, I think MJ2 was always a niche product. Jason explains in a video that it's a larger form factor and more complicated amp than your typical customer is looking for.

 

In 2021, sure.

On form factor, it's large compared to modern headphone amps. But MJ was launched in 2012 when expectations were different. MJ didn't seem large as an extra component in a 2 channel or home theatre system with the Blu-ray/SACD player, tuner, Playstation 3, speaker amp and Gungnir.

On price, when MJ launched it was the flagship product from an innovative new company, designed to offer "end game” performance at a mid-level price. So I don't think it was supposed to be niche back then. In 2021, Schiit has taken a different path, and it's best know for accessible lower priced products.

 

Weird, I just went on the Schiit website and noticed the MJ2 is no longer available. Refresh incoming? Are my eyes deceiving me?

 

Jason , somewhere mentioned that are stopping production , without intending to release a newer model.

 

Yep, here's his specific post on HF that discusses some of the issues and reasons: https://www.head-fi.org/threads/sch...bable-start-up.701900/page-5012#post-16300706

 

Ah, it makes a lot of sense to do so. Sad though. I liked my MJ2 when I had it but it was the size that made me get rid of it. Thanks for the link!

 

There have been a bunch of positive SBAF comments on the Mjolnir 1 lately.

That's nudging me to get hold of some LISST tubes. According to the old LISST page "What’s inside are two depletion-mode MOSFETs, together with minimal support circuitry to protect them against static, and to set the gain necessary for our products. There’s no “triodization” or other tricks applied to make them act like tubes, or have curves like tubes. They’re just good, linear, solid-state devices…in a can. When used in Mjolnir 2, they provide essentially the same topology as the original Mjolnir [1]’s high-voltage JFETs, now simply at a much higher voltage, for even greater linearity."

Of course some of the reviews are less than sparkling..

 

I'm sure the variance in opinion is determined by the upstream and downstream gear. My negativity toward LISST is based on judgments made with G1 (warm DAC) and different 300 ohm Senns. With planars and a resolving DAC, it's possible I'd have a different opinion. I've since given away my LISST tubes so I can't say for sure.

 

I would be curious enough to try a Mjolnir2 with LISST tubes, but finding that is rather rare these days. Even though I didn't like MJ1, but hey I'm always willing to give things another try.

Weren't there two different types of LISST though? so one would also have to track down and make sure they got the right ones for the MJ2.

 

I set up an alert for LISSTs on HiFiShark, here's the link.

 

This is the first of a few posts about LISST (Linear Integrated Solid State Tubes for Schiit's hybrid amps) and solid state vs tubes generally. After a day's use, I find them interesting enough to do a writeup. This post will provide background on LISST.

To undertand more about MJ1, MJ2 and LISST it's worth reading the relevant parts of @schiit 's blog. I've summarised and snipped the key bits below, with links to the source under each.


MJ2 was a new generation of Schiit's 'cost-no-object' statement headphone amp, with LISST providing a transition from solid state to tubes.

Source

MJ2 was a lot more than a revision.

Source

LISST might have worked for the MJ-> MJ2 transition, but wasn't a sustainable product

Source

Looking at forums, there's a shift from early adopters being MJ owners (who like a solid state option) to later purchasers who are tube fans or Lyr upgraders (who don't care about solid state). That shift may have driven the sales trends above.


How do LISST sound?
Reviews use words like these.. Neutral, Precise, Clean, Detailed, Crisp, Dry, Airy, Thin, Flat, Dry
Compared to tubes in a MJ2: reduced imaging, less immersive, less natural, better bass extension


Getting LISST in 2021
In 2021, it takes a bit of patience to get noval (MJ2) LISSTs. They come up every few weeks on ebay or online forums, often unused or little used. Prices for a pair seem to vary between $50 and $150.