Schiit Jotunheim "R" - Direct Drive RAAL-SR1a Amplifier - Official Thread

Official AMP/DAC/DAP Model Discussion
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Schiit Audio’s “Jotunheim R” is a unique, modular, amplifier designed specifically to drive the RAAL-requisite SR1a - itself a unique, ribbon-driver, “EarField™” monitor/headphone.

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Those that are aware of the SR1a are no doubt also aware that, to date, the SR1a require the use of a proper speaker/power amplifier (100w into 8 Ω/150w into 4 Ω) and a dedicated interface box to drive (lots more detail is already available here on the main SR1a thread).

The “Jotunheim R” is a direct-drive amplifier for the SR1a.

Direct-drive means that the SR1a “Amp/Ribbon Interface” box is NOT required here. Nor is a speaker amplifier. You plug the SR1a straight into the Jotunheim R, connect a source to one of it’s inputs (or use the optional built-in source, be it phono or one of two DAC options) and off you go:

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This has the potential to open up access to the SR1a to a much broader audience, and make them much easier to integrate into existing systems.

When this thread was originally created, Jotunheim R was not yet shipping, but that has now changed (as of 01/21/20)!

So the first part of this thread deals with the pre-production (production-qualifier) unit, and coverage of the production/release version starts here.

Original Production-Qualifier Disclaimers

I should note, here, that this is not a shipping product quite yet, but interest is high enough, and Schiit & Jason have been open enough about the project, that coverage here makes sense.

In that vein:

NOTE: The unit here is what is referred to as a “production qualifier” (the last stage in R&D before a product is sent to formal production). What that means is that this unit is fully “production intent”; it is using all the same design, parts, spec, and suppliers/manufacturers as the production units will. And, unless issues or problems are found with these units, the next step is simply “Build more, just like these.”:

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(Note the “Production Qualifier” label next to the IEC socket).

If changes do occur between now and release, they’ll be identified specifically. The changeover point will also be clearly indicated (and linked) in this thread. Until then, any commentary is based on this “production qualifier” unit.

And with those caveats out of the way, this is the spot to discuss this unique device …

*This is a provisional thread, based on “production qualifier” hardware (defined above), and will lose its “provisional” designation when final product is shipping. This will be clearly noted in the thread, so it is easy to determine where commentary shifts from “production qualifier” to “shipping retail product”.

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There’s some interesting history, despite the surprisingly short gestation period, behind the “Jotunheim R”. Uncharacteristically (for me), I’m going to skip over that for a bit and talk about the unit I have in my hands first. I’ll come back to how this all came to be in a bit … but first, how it sounds.

FIRST Impressions

Note that these impressions are based on a “production qualifier” (see above) unit and, as such, while not expected to - may change with a final released product. This unit is on loan for the purposes of providing feedback and will be returned to Schiit once done.

For context, I’ve had this unit since Thursday, 10/24/19. It’s had about 100 hours of runtime on it since then - a combination of pink-noise and music, and split between actual listening and just “breaking in”. My SR1a have hundreds of hours on them at this point, across a number of different amplifiers.

Sound

Fresh Out-of-the-Box

Initially, I found that the overall sound was a little more aggressive and “bitey” than I was used to with the SR1a. To be sure, those are both innate traits of the SR1a headphones - these are not “cans” meant for passive/background-music listening. The headphones themselves have a studio-neutral response, which most unfamiliar listeners will, at first, characterize as bright.

But bass was a definite strength, with more presence and impact than a single-Vidar, maybe two, as well as the Benchmark AHB2, and some other high-dollar speaker amplifiers. Sub-bass also got a lift here, enough to make the SR1a something I think a lot broader audience will immediately enjoy vs. being something that needs a little time to understand, appreciate and adapt to.

There were occasional hints of sibilance/splashiness in the extreme upper-mids through the treble.

Beyond that, other than an apparent increase in resolution and a general sense of “damn, this sounds good, but might want a tweak”, this is the essence of my first, super-high-level thoughts.

24-48 Hours: “Burn-In” and Warm-Up

Somewhere in the first two days of listening and letting the unit run, with some spots of turning it off rather than leaving it running while not at home, three things became apparent.

  1. The added hints of sibilance, and occasional splashiness, had completely gone away and I could not reproduce them. At the time I’d compared directly to the SR1a interface fed off a Chord Étude (my normal driver for the SR1a) and an Vidar, but this was now no longer a factor - even when trying to excite the behavior.

  2. It seems that Jotunheim R benefits from a few minutes warm-up. And by few I mean about five (with the unit playing). The difference isn’t as pronounced as it can be with tube-amplifiers. Nor is it big enough to matter in normal use. But if listening to the SR1a/Jotunheim R for the very first time, it’s worth the few minutes extra anticipation.

  3. Jotunheim R -> SR1a is more resolving and nuanced than when driven with a number of (even much more expensive) speaker amps via the “Amp/Ribbon Interface”.

48 Hours-and-Beyond …

I’ll fill in more low-level details, with examples, over subsequent posts, but from this point on, and to the current mark (I’m at about 100 hours of run-time, and probably a solid 24 of listening, with another 8 in comparisons) … this is where things sit:

First, I would swear there is more detail in evidence and the micro-dynamics are more nuanced with Jotunheim R direct vs. running via either a single or dual-mono Vidar configuration, or from several other amps, via the interface box.

Bass and sub-bass level/presence seems slightly elevated over Vidar, and a bit more so vs. the Benchmark AHB2. I like this. It yields flexibility in where you put the drivers, and puts things more on a “neutral” footing vs. “studio neutral”.

Higher treble feels like it has a tad more energy than via Vidar too, whereas Jotunheim R vs. AHB2 sounds so close in the treble as to be indistinguishable to me. And the Benchmark piece sounds leaner overall where as both Vidar and Jotunheim R have more body and weight to their delivery, with Jotunheim R having the most weight (if not by much vs. Vidar).

Vidar, in single or dual configuration, has a slightly darker signature (but certainly not dark … I’m not sure it’s possible to get the SR1a into “dark” territory without EQ).

There’s a TON of headroom here …

Even with dual Vidars, fed from the XLR outputs of a Phonitor X, quality source material, with the EQ I was initially running with (bass/sub-bass lift primarily), was not leaving a lot of room on the volume dial for more spirited listening. With the Jotunheim R, even with the quietest source material, the half-way mark on the volume dial is further than I dare take things.

Resolution and dynamics are superlative. No idea if that’s because the interface box isn’t involved or if it’s just the raw performance of the Jotunheim R. It bests 1x and 2x Vidar and 2x Aegir, the Benchmark AHB2, so far, for me, and may worry other solutions as well.

More comparative listening required, but very impressive so far.

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Torq, just a quick thank-you for giving Jotunheim R a listen, and a couple of notes.

First, yes, what Torq has is production-intent, with the exception of a couple of hilarious issues–namely, the baffle compensation and preamp out switches function in reverse. We’ll get him a final version when we have the actual boards. With a bit of luck, we’ll be shipping production Jotunheim Rs before the end of this year.

Second, a few words about the “quick gestation.” I wasn’t even really aware of the Raal/Requisite headphones until late this Spring. But when I heard them (and when I saw them using Vidar stacks to drive them), I knew I wanted to do a direct drive amp for them. Direct drive into these low impedance headphones is largely a game of huge current output at low voltages–or, in other words, very efficient power transfer. Luckily, we already had a platform that was, topologically, similar to what we wanted to do (Jotunheim, a discrete differential amp), so I was able to get a prototype working literally the same afternoon I met Danny at the Schiitr. That prototype was pure crap, but it worked, and didn’t catch fire, and after a couple of huge iterations–including moving to our Nexus™ balanced topology, and baking in Raal’s baffle compensation, and a whole bunch of protection for overcurrent and over temperature conditions, here we are.

I’m sure I’ll have a chapter up for much more development detail when we launch the product, but I did want to stop in, say thanks, and leave a couple of notes.

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Hey Jason, and welcome - nice to see you here!

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I loved it enough during my short time with it, to now, I can’t wait for its release! Super excited for it!

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Welp I guess I’ll be saving up for this and a SR1a now! R.i.p any and all future planar upgrades lol MAKE ROOM FOR RAAL

But seriously @schiit thanks for getting this onto the market! An @Torq for sharing your thoughts of this unit! I’ve yet to hear the SR1A but all impressions point to it being the HD 800 upgrade I’ve been wanting

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Could you give me the projected price of this excellent product?

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Welcome Jason.

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Price? $799 as “just an amp,” (no internal DAC) or $999 with internal True Multibit™ card.

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the SR1A has taken over just about all my listening time these past couple months, off twin Vidars. Looking forward to the Jot-R!

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I know these feels! I have the same setup…and I can say for me… that I’ll be switching to the Jotunheim R, after my listening session with it, thanks to @Torq and @schiit for allowing me the opportunity, and Jason for sending it to Torq for review/demo! Such a great community we have in the audio world =)

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Given that, so far, I prefer the Jotunheim R over some well-respected amps (both single stereo amps and dual monoblock configurations) pushing north of $3,000, and that you get to take both speaker cables and the ribbon interface out of your chain here, that $799 price point is a steal!

This is an easy choice for adding the ability to use the SR1a in my office without needing either a big box, or a very expensive smaller box, to drive them.

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I’m now to the point, with enough time on the amp, that I’m starting to do proper, focused, review/audition-style listening via the Jotunheim R.

It will be very interesting to see how far it scales, in critical comparison, vs. some of the even more expensive amplifiers I have around, vs. the stuff I think it is already clearly ahead of. Removing the interface box and additional cabling seems to pay dividends beyond just the performance of the amp.

Another obvious benefit at this time is down to the thermals of the unit.

The actual operating temperature is notably lower than with the Vidar, and that’s running at rather spirited levels (you wouldn’t listen at those volumes for very long) and, of course, there’s a lot less heat* being output here vs. Vidar too. Temperature is closer to, but still lower than, twin-Vidars as well. So no worries about running a Jotunheim R in the summer!

*Temperature and heat are not the same thing - thus two different things/masses can be at the same temperature and have very different effects on their surroundings.

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Thanks Jason!

That appears to be good value.

If Rall take 500$ off without box, then SR1a and Jotunheim combo cost less than 4k$.

Thomas

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I’d like to see RAAL-requisite offer a package deal for the SR1a and Jotunheum R in that custom fit Pelican case.

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I doubt you’d see the full $500 off if they offer the SR1a without the interface.

While that’s the list price for the box separately, there’s probably some discount/bundle factor at work in the complete package, so don’t be surprised if such a reduction was more like $350.

That’d still be enough to bring the combined setup under $4,000, however.

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I agree with @allegro about offering an official bundle that will defray the costs of running the SR1a’s. $600 off for not including the box sounds pretty reasonable given what I know about costs involved - I’ll talk to Danny about this.

With the size of this amp I can see the setup as a “mostly” travel-friendly solution, and it would be nice to have two so that I can use the cans both in the office and at home.

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That’s an interesting pricing model if they can reduce the price of the bundle by more than the retail price of just the box.

I know Alex was talking about his view on bundles, and he seemed to think Danny was in favor of making everything available separately and/or other bundles.

I need to ping Danny as well, since my review is now wrapping up (I was hoping to be able to include the Jotunheim R in it - which it turns out I will be able to do - though I’ll also be doing a review dedicated to the Jotunheim R/SR1a combo).

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Volume “Bypass” & Further Listening/Comparisons

Since my primary DAC can act as a pre-amp, with high-precision, audibly-transparent, variable output, in my normal configuration I run it straight into my speaker amp and let the DAC control the output level. This avoids having an additional pre-amp or attenuator in the chain.

With the Jotunheim R, if your DAC (or whatever source) has variable output, you can bypass the attenuation and use it simply as your “power” amp too. Simply turning the volume ALL the way up effectively turns the pot into straight wire.

DO make SURE your source has variable output, and that it is turned down, before doing this!

I wanted to do this for as close a comparison with my primary SR1a setup (Blu Mk2 -> DAVE -> Etude -> Interface) as possible. And having done it, as both the systems I want to use the SR1a in have variable output sources in them, this is how I will personally be running the Jotunheim R. It’s not a big deal, but I tend to like the simplest, most direct, chains possible.

Note that the Jotunheim R will be outputting exactly the same amount of power for the same output SPL regardless of whether you use its built-in volume control, or turn it all the way up and use your source for volume control. So no concerns about “running the amp flat out” or some such.

With the Volume by-passed …

I set about comparing the Jotunheim R to the Linn AK4200 and Chord Etude power amplifiers (both of which, of course, need the “Amp/Ribbon Interface” to drive the SR1a).

The little Schiit unit still exhibited more bass and sub-bass presence vs. using the interface. The difference was a bit smaller here, but still clearly audible. Slam and impact were similar enough that I couldn’t reliably tell them apart on those grounds - but on presence favors the Jotunheim R.

Resolution/detail was either the same, or was just favoring Jotunheim R. Bass texture/detail was indistinguishable, the difference being most audible, if still very small, at higher frequencies. It’s not apparent with all tracks … very complex pieces make this easier to discern.

Both the Linn and Chord amps exhibit just a hair more speed, though interestingly with the Linn unit as I turned the volume higher that difference got even smaller (possibly as it transitions from using monolithic’s for low-power output to augmenting them/transitioning to big bi-polar power transistors).

The Linn and Chord amps are a little smoother sounding than the Jotunheim R. Which is not to say that Jotunheim doesn’t give a smooth delivery; it does. With a lot going on, and with music that has content that is discordant, is pushing levels or has a lot of natural bite, however, the Linn and the Chord amps are just a little more refined.

It’s worth noting that both of those power amps have hundreds or thousands of hours on them, and that the cables connecting them to the SR1a interface each cost more than the entire Jotunheim R. So it’s possible with more time on the Schiit unit (it’s had about 150 hours run-time at this point) that things will get even smoother. This is something I’ll pay attention to and circle back to in my full/formal review.

At some level, prior to hearing this unit, I was thinking that if it could match a single Vidar (or similar) then it’d be a good deal and a nice “entry point” for the SR1a; But Jotunheim R is no mere “entry point” … and is showing serious signs of being the preferred way to drive these cans.

I was pleasantly surprised when Jotunheim R made relatively short work of the amplifiers I tested up to about the $3,000 mark. We’re nearly double that with the Linn and Chord amps here, and the Jotunheim R is still competitive - trading blows back and forth depending on the point of evaluation - while being 1/7th the price (or less).

I don’t need more listening time to know that I will definitely be adding the Jotunheim R to my office rig to drive a set of SR1a there.

Really impressive stuff!

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amazing!

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