[JohnnyCanuck]

Gjallarhorn ordered. I will pair it with my Magni Piety to drive a pair of Tangent RS4 speakers (now 50 years old).

JC

 

[tralsa]

@Jason Stoddard --

Thank you!! I can finally retire my desktop Class D amp and stop the ridicule and shaming that I keep inflicting upon myself for owning one.

Anxiously awaiting the beautiful PCB / innards shots of the 2 newest Schitty amp additions.

** And it's made in Texas -- not China!!

The A07? I feel like it is going to be a great time to grab one second hand. Nice amp for what it is.

 

[schneller]

Dynaudio stand-mount speakers like Contour 20i and Heritage Special and Special Forty are notoriously difficult to drive. They are all 4 Ohm speakers.

@Jason Stoddard I just have a hard time believing that a Rekkr or Gjallahorn would have a chance in hell of successfully driving these with any control, volume. I'd love to be wrong.

 

[Ripper2860]

The A07? I feel like it is going to be a great time to grab one second hand. Nice amp for what it is.

I agree. The A07 is a really nice amp for the $$. I even rolled the opamp for fun and took it up another notch. I'm thinking Rekkr just because it'll go nicely with my Piety amp. And it should do nicely with my Paladin radial Speakers and sub.

 

[Chicagorob]

Rekkr order just placed to Schiit, to drive my Paradigm Micro monitor desk system. I’m stoked.

 

[JohnnyCanuck]

Just got shipping information from Schiit, my Gjallarhorn has been shipped. Fedex expects delivery tomorrow by 5pm.


JC

 

[jonathan c]

To Jason Stoddard et al: are you aware that Kennerton Group (a part of Fisher Audio) makes a line of headphones with the name Gjallarhorn? I own the GH50 JM Edition Mk-II.

 

[Yethal]

Just placed an order, this is the final component my desktop stack needed

 

[ArmchairPhilosopher]

Rekkr? So ordered!

It will replace the OG Vidar that's currently in my "sacrificial chain" that I have on my lab bench. The Vidar takes up too much space and is waaay overpowered for what I need it to do, and even though it's a spare that will otherwise just collect dust in my closet, it's still a bit too "dear" to get blown up by accident. Rekkr is the perfect little amp for this.

And isn't it just SO CUTE!?!

Thanks, Jason!

 

[Paladin79]

My long term wish has come true. I am so in.

I just ran some measurements and tiny radials would do well with the GJallarhorn, as much as 8-10 watts going into four ohms is really a nice amount of power. 6 watts max is more realistic for a desktop. I hope you get that amp so you can verify my findings.

 

[ThanatosVI]

2023, Chapter 2
Less Power, More Better


And so now there’s Gjallarhorn and Rekkr, and a whole bunch of people saying, “I don’t care I can get a Class D widget with like 100,000 watts that’s the size of a matchbook for $4, why are you making these crazy low-power antique-technology things?”

Let’s start with the TL;DR:

• Because they don’t hiss like a demon cat, drilling slowly into your synapses and draining your soul.
• Because let’s face it, how much power do you need for desktop speakers?
• Because, reaaaaaally let’s face it, how do your neighbors feel about 100,000 watts if you share walls with them?
• Because these little suckers probably get a lot louder than you think.
• Because they sound really, really good.

In short: less powah. Moar better.

A new idea, yes. But maybe one you can get behind.







A Billion Years Ago

I had a compact Realistic receiver that did 10 watts per channel into 8 ohms. Together with some tiny Minimus-7 speakers, it sounded pretty darn good. And it got fairly stupidly loud, enough that my parents really regretted me getting into music.

Think about that a bit: 10 watts into 4” 2-way speakers that were probably, what, 85dB efficient at best (in other words, they don’t make much sound for the watts you put in). Bass cranked almost all the way up…loud enough to piss off your shared-wall neighbors…that 10 watts did fine.

Somehow this antique receiver and speakers burrowed its way into the back of my mind and sat there for, like, 40 years. Because I always enjoyed the way it sounded. And I tried to replicate the experience over and over again. Whether it was Infinity Modulus speakers with Sumo gear, stuffed next to a desk in my first townhouse, or later iterations with powered monitors (of both Class AB and Class D variety), to my later Schiit-era experiments with small amps and small speakers, I’ve wanted something like that back.

So why didn’t I stick with the Modulus and Sumo gear?

Simple. The Modulus speakers were huge, and the Sumo Ulysses 2 was almost the size of a Ragnarok 2. They sounded fine, but it was overkill.

So why didn’t I stick with the various Class AB and Class D powered monitors? I mean, after all, this is what people do these days. They get powered desktop monitors and call it a day. It’s the future. Hell, they’re even biamped and DSPed and crap. It should be great. It should be paradise.

Except…hisssssssssssssssssssssssssssssssssssssssssssssssssssssss…

Yeah, maybe there are some relatively quiet desktop monitors, but I haven’t found them. Either that, or I’m extraordinarily sensitive to hiss. Either way, they weren’t for me.

And that dissatisfaction, plus the dim memory of that old Realistic receiver, stayed with me. It made me wonder if we could do a desktop-sized amp at Schiit. Hell, I even did an early prototype around 2013 or so.

Aside: named Sol, ha!​

But that prototype didn’t deliver the power I thought we needed, and it would end up being more expensive than I expected anyone would want to pay for it. So it went on the back shelf for a good, long time.

How long? Until after the launch of Ragnarok 2, when I thought, “How about that desktop amp again?”


Power Mad

Here’s the thing: when I started thinking about “that desktop amp again,” I’d been brainwashed by the prevailing “wisdom,” which went something like this: a desktop amp is still gonna need a ton of power because small speakers are inefficient and hey there are desktop amps making a ton of power with Class D and desktop amps making good power with Class G and fans and stuff and so power is important and we need to make a bunch of power.

And, here’s the even crazier thing: I did this despite already having done an experiment with a Magni as a speaker amp, where it got stupidly loud and would have been just fine if it could have survived thermally. Magni ain’t designed to drive 8 ohms at several watts forever. 8 ohm headphones with 10-100x the efficiency are fine.

But, in the end, the thing was: I went into this thinking we needed a ton of power.

How much? Well, I figured we might be able to get 20-30W of Class AB power into our standard 6”x9”x2” chassis—that is, if we played a bunch of tricks like super-low bias, stacked rails for higher efficiency, and maybe a panic fan for the end game.

Aside: it turned out that estimate was pretty bonkers. Maybe with a fan. Probably with Class A. But a fanless Class AB stereo amp in that size chassis doing 20-30W? Ah, no.​

Or we could do Class D. Or rail-switching Class G.

Since I was on this power trip, I figured we’d take a look at Class D first. That was the origin of the Not Too Schiit D project, one in which we took Class D beyond the current state of the art…and decided it wasn’t for us.

Aside: please let’s not get into another Class D discussion here. Gjallarhorn and Rekkr aren’t Class D amps. There are plenty of Class D amps to choose from if you want one.​

So we moved on to Class G.

Class G, for those who are confused by all of this engineering jargon, are amplifiers that increase efficiency by switching the rails of the output stage in response to the amplifier output level. As in, they switch to a higher rail voltage (allowing more power output) only when needed. At lower power output, they stay at a lower rail voltage, making them more efficient.

When done well, Class G amps can be spectacular. Carver amps from the 1980s could do 350W into 4 ohms from a 7” cube using a linear power transformer and no heat sink except the chassis. Modern Emotiva amps using much more developed Class G schema can do much better in terms of performance…but that’s what many years of refinement and microprocessor control can get you.

However, Class G is not trivial, and has lots of engineering gotchas, both big and small. If you’re not talking well-refined algorithms implemented via microprocessor, things can get very scary, very fast. I mean, you’re talking:

• A much more complex power supply
• A much more complicated transformer
• Noise from switching rails at audio frequencies
• Managing recovery from switching rails at audio frequencies in real time
• Managing power dissipation in all devices at all rails

I knew this when I did our first Class G prototype. And, despite knowing this, I was super-surprised when it just fired up and ran.

And boy did it run! Hell, the thing went super loud!

This was great! This was exactly what we needed! I mean, hey, we were done! I mean, from the way it sounded, it had to be putting out 30W or so!

And then I measured it. It was putting out 3.5W x 2 into 8 ohms.

Yes.

Three and a half watts.

“But from Class G?” you ask. “That doesn’t sound right. You just said Class G is how you put out big power.”

Right. Except our Class G schema wasn’t really working. I was running only on the lower rails. The higher rails were never really powering up.

And yet it was still ear-bleedingly loud!

I shook my head, denied the evidence of my senses, and went on a quest for more power. The Class G wasn’t working, surely, because the tiny power transformer we were using. A small 48VA core wouldn’t do it. I’d have to go bigger—as big as we could go—to, like a 80-100VA toroid.

So I had a custom toroid done, did a new board, adjusted the Class G schema so it should work, and powered it up again.

Whomp whomp. 5W x 2.

Okay, so it wasn’t the transformer. It had to be the way we were doing Class G. I changed how we did it (going from a “nonswitching” output-powered architecture to nonswitching on the driver side) and tried again.

Boom!

I mean literally. Smoke and flames. I’d miscalculated something.

More tweaks, more smoke. More tweaks, and I had something kinda-sorta working. It got near where we wanted it, 24W x 2, but…

…it measured pretty bad (the switching artifacts, even at audio frequencies, are no joke)…

…and it didn’t sound great.

Sigh.

Aside: yeah, Emotiva’s many years of Class G experience, plus their microprocessor-controlled schema, probably are the way to go here. ​

So what did I do?

Weeeeeeeellllll…I’d already done something. I’d remembered that former low-power amp that went so loud, and started wondering, What can we do with this size of transformer and a more conventional approach?

And I’d already laid out what we’d consider a “more conventional” approach: an all-discrete, current-feedback, stacked-rail and Continuity-S amp (for highest efficiency in a Class-AB-ish environment), and I’d gotten a prototype 80VA toroid for it.

This one worked first shot, sounded great, went super loud, dead silent, and generally was what I was looking for all along.

I measured it. 10W x 2 into 8 ohms.

And suddenly I remembered: ah yeah, that Realistic receiver was only 10 watts.

**** it. There ya go. And that’s how Gjallarhorn was born—the “loud sounding horn” from Norse mythology.

But of course you can’t stop there, can you? I mean, no, you’re an electronics engineer. I mean, you have an even smaller chassis you can make an even smaller amp in. Drop the rails on that Magni to a reasonable level and it wouldn’t self-immolate into 8 or 4 ohms. All you’d need is a different wall-wart, something about 1/3 the volts, something like…

…something like the 6VAC transformers we used to use.

And that’s how I got started on Rekkr.

Now, Rekkr went thru a lot of tweaks on the way to production, including a larger transformer (6VAC still, but lots more current) and, most importantly, a “mono” switch. One that works with single-ended inputs.

“Oh holy hell Stoddard we’ve been asking for this on Vidar and Aegir and stuff for years and now you do it on some silly tiny desktop amp?” you cry. “What’s wrong with you?”

What’s wrong with me is the “Mono” switch on Rekkr is a compromise.

As in, it “bridges” the amp. It’s better to drive the amp differentially like Vidar and Aegir in order to mono-ize it, but you tell me how to put the XLR input on the back of the tiny Rekkr. As in, it ain’t gonna happen.

But if you want the cutest pair of tiny monoblocks, here you go.

If you don’t want to compromise, I guess you could rig up an XLR-to-dual-RCA cable (splitting the XLR + and – phases into separate RCAs). But that’s up to you. Or a cable manufacturer. Completely fine to do this. And Rekkr sounds completely fine when old-skool “bridged” using the switches on it bottom.

Aside: fun fact, Rekkr came from a stillborn ribbon headphone amp in a Magni-sized chassis. Nobody was interested, so we never made it. But we took the lessons we learned and made a speaker amp out of it.​

“But, wait a sec,” you say. “Can these things drive Apogee Scintillas and Magneplanars and 2 ohm speakers and can you do it in bridged mode and will they thermal out if you do?

In short: no, no, no, no, and probably still no, unless the current limiting kicks in first. Let’s be clear: both of these amps were developed for 8 and 4 ohm speakers. You know, normal stuff. Don’t be hooking them up to crazy loads. It won’t hurt them, but you won’t be listening to them for long. They’ll just go into protection and that’s the end of that.

That said, that doesn’t mean these are weak, wimpy amplifiers. Hell, I’ve been using bridged Rekkrs to drive SVS satellites for over a year. Tyler has been using his with KEF LS50s. And these are Rekkrs—2W per channel stereo, 4W mono! They go amazingly loud for what they are. Gjallarhorn has been in use in our supersecret lab (more to come) for over a year as well, in both stereo and mono applications.

Aside: you can run Gjallarhorn as monoblocks in the same way you run Aegir or Vidar—run an XLR in. Sorry, no “bridging” switch.​

And no, Gjallarhorn still isn’t gonna be running Maggies or Apogees or what-have-you-crazy-ass-speaker-load-of-the-minute deal you want to throw at it. But for nearfield…for small rooms…you get an insanely capable, dead silent amp that will do much more than you might expect.


A Surprising Use

When we came back to Cali after the recent storms, the soundbar on our utility TV (named “Internet Fart Videos,” to give you an idea of one of its uses), took a powder. Dead. Gone. Nothing happening. It was a fairly nice soundbar, not some cheapy thing, so that sucked. TV sound sucked even worse.

It was then I remembered I had some Klipsch 4” monitors and an extra Rekkr laying around. No DAC handy, so I hooked up the Rekkr to the TV analog out and ran the Rekkr into the Klipsch speakers, with them sitting horizontally under the TV like a soundbar.

How’d it work?

In short, it rekked the fancy, expensive soundbar.

With TV analog output. Yes, I know, I’m a terrible person. Eventually I’ll add a DAC. But it already sounds better than it ever did.

(And yeah, that’s just the utility TV. We have a real setup, but that’s a projector with speakers and a big Emotiva amp. Maybe we’ll swap that over to a bunch of Gjallarhorns now that they’re in full production.)


Which One (or Neither?)

So which one of these tiny amps is for you? The answer may be “neither.” Let’s start with the formal introduction to the specs and features of Rekkr and Gjallarhorn:

Rekkr

• 2W per channel into 8 ohms, 3W into 4 ohms
• 4W mono into 8 ohms
• SNR about 120dB
• Current feedback topology
• Magni sized chassis
• “Mono” switch on bottom
• External wall-wart power supply
• Special large-pin power input to prevent boominization by Magni, etc power supplies
• Internal analog protection against overcurrent and overtemperature
• Output via banana jack sockets
• $149

Gjallarhorn

• 10W per channel into 8 ohms, 15W into 4 ohms
• 30W mono into 8 ohms
• SNR about 117dB
• Current feedback topology with Continuity S output stage
• Jotunheim sized chassis
• AC plug straight into chassis, toroid transformer, linear internal power supply
• Internal analog protection against overcurrent and overtemperature
• Output via banana jack sockets
• $299

Both of these amps share an exotic fully-discrete, current-feedback, linear-power-supply topology. Both run Class AB. Neither has any switching power supplies or Class D modules. Both are insanely quiet by power amp standards—Rekkr’s signal to noise ratio is 120dB below rated output. Gjallarhorn’s is 117dB. Both will provide hiss- and hum-free performance in nearfield applications with efficient speakers.

And both of these amps have their place. For nearfield, either is competent. For small rooms, Gjallarhorn will give you much more flexibility. For efficient speakers, you can get some truly amazing results.

Aside: I’d love to beg a pair of Klipsch Jubilees and run them with 4 mono Rekkrs at a show. 4W and 110dB efficiency would be really something. (Jubilees come with an electronic crossover, you need 2 amps).​

But I’m being scattered. Let’s break this down. If you want to:

• Drive super-inefficient speakers (planars, etc): choose neither
• Drive normal speakers to ear-bleeding levels, enough so your neighbors report you to the police: choose neither
• Drive normal speakers to realistic levels in a large room: still probably neither.
• Drive normal speakers to realistic levels in a normal room: maybe Gjallarhorn? I’d still go with Vidar myself.
• Drive high efficiency speakers to realistic levels in a normal room: probably Gjallarhorn is best
• Drive normal speakers to realistic levels in a small room: Gjallarhorn is probably fine.
• Drive low efficiency, normal efficiency, and high efficiency speakers for nearfield (like on a desk): either will probably do it. Skew Gjallarhorn for low efficiency speakers.

Bonus fun applications:

• 5x Gjallarhorn for home theater
• 3x Gjallarhorn for HT, one mono (center)
• 5x Rekkr for home theater (we should do a unified power supply for this)
• 2x Rekkr on the desktop, each sitting on top of the speaker it’s driving
• 2X Gjallarhorn for a small-room system
• Rekkr or Gjallarhorn as an amp for 2-channel TV speaker system to replace soundbar

So will either produce enough volume for you? Well, if you’re worried about volume, and if you’re in a place where you aren’t gonna have unscheduled visits from law enforcement, I’d still go with Vidar. Specifically, one Vidar. Start there and see how you like it. It’s pretty much a universal amp. I use one with Maggie 1.7s. Great match. No need for monoblocks.

But…if you’re on a desk, or if you have efficient speakers, or if you have a small listening room, or if you’re talking about a desktop system…then you got Rekkr and Gjallarhorn to consider!


The Less Power, More Better Manifesto

Now, some people are still not convinced. They want more power. And that’s fine. Maybe I’ll stack two Vidar transformers in a Tyr chassis and do a 300WPC stereo amp. Probably not, because it would also require a panic fan, and I hate fans, but after last year’s ordering debacle, we got lots of Vidar transformers to play with.

But I’d say, keep an open mind. You might be surprised.

We’re sooooooo conditioned to want more, more, mooore, moaaarrr! that I think sometimes we lose perspective, like I did when I started this amp adventure. And that can quickly devolve into venerating something that can produce huge power above everything else—even if we don’t need that power.

I mean, here’s the thing. I’ve had desktop systems for ages. A lot of them used a 60W integrated amp—first the Sumo Antares prototype, then the Ragnarok, then the Rag 2. And each of them had a common denominator: I never used even a fraction of those amp’s output power.

And yeah, I’ve also had desktop systems based on powered monitors. Including ones that like to brag they have like 1000W for the woofer and 50,000W for the tweeter and that sounds like 10,000,000W and etc. (Well, maybe a bit of hyperbole there, but you know what I mean: powered monitors with a bunch of watts and claims of hitting 1XXdB at 1 meter and other silly numbers.

And each time, those mega-powered systems were used once for that circus trick of huge output—then turned down for use at regular listening levels.

Because, you know, yeah, they go loud, but Rina’s yelling at me from the other room.

And each time, those mega-powered systems didn’t last long on the desktop—their infernal hisssssssssssssssssssssss drove me bonkers, and I went back to passive.

So, yeah, something used for a party trick once (but then annoys the neighbors) with the added bonus of the unrelenting hiss of a demonic cat drilling its way into your ears…yeah, no thanks, not for me.

Aside: and yes, I know, there are pros that have legit uses for such monitors, and people who don’t have to worry about neighbors. Not dissing those. Just asking: do you really need it? Can you use it? Or is it just crazy numbers-for-sake-of-numbers, power-nervosa specsmanship?​

Sooooo…maybe it’s time to recalibrate.

To sit back, and think, “Do I really need power for the sake of power?”

Yes. I know. It’s a challenging idea.

But maybe, just maybe, it’s time for something less power, more better.

I wonder how 2 Gjallahorn monoblocks sound with Susvara/Expanse

 

[Frank Sol]

No Silver Gjallarhorn or no more Silver Gjallarhorns left ?

 

[wbass]

I wonder how 2 Gjallahorn monoblocks sound with Susvara/Expanse

Also eyeing them for the Susvara...

 

[MtnMan307]

I have a pair of Aperion 532 speakers on my desk. I think they are 8 ohm and 86 or 88 dB sensitivity. Would the Gjallarhorn be enough?

 

[pavnobi]

There’s something ridiculously satisfying about plugging your headphones into an OG Asgard and the *click* of flipping the power switch. It has that old tech feel of a sci-fi space opera like Star Wars. Makes me think of Han Solo in the cockpit of the Millennium Falcon




(I can’t remember if I already mentioned this)