My first correct audio setup, discounting the GE Wildcat file participant I had as a child:

was a JVC PC-11 transportable stereo system (thank goodness for Google Picture Search to refresh my reminiscence!), an instance of which my (Catholic) highschool chaplain owned, performed (George Winston tapes, to be exact) within the background throughout weekly confession classes, and acted as inspiration for my very own subsequent acquisition, which made it by way of most of school:

Fairly slick setup: this was the pre-CD period, however the JVC PC-11 included an AM/FM tuner, five-band equalizer, cassette participant, all (plus the audio system) removable, and turntable inputs:

And for the needs of at this time’s dialogue, take a look at these modest specs:

• Output energy: 2 x 15 W max.
  • DC fluctuation: < 0.05 % WRMS
• Speaker chassis diameter: 120 mm “Excessive Ceramic” cone
  • Impedance: 6 Ohm
  • Effectivity: 90 dB / W / m

However, it may fill my dorm-later-fraternity room with tunes discernible even over no matter get together may need been happening on the time. Distorted? Mebbe. However discernible nonetheless.

Historic precedents

Extra right here.

Much more “correct” was a Kenwood KA-4002 built-in amplifier (albeit with switch-selectable separate preamp outputs and essential amp inputs, plus a separate mono output, no much less!), apparently manufactured from 1970-1973, that I acquired at round that very same time. I vaguely recall that my dad may need purchased it for me used from a co-worker of his? The JVC PC-11 ultimately died: I vaguely recall—once more—that the cassette deck locked up, plus the pressboard-construction speaker enclosures have been getting beat up from my back-and-forth strikes between the college campus in West Lafayette and my co-op classes at Magnavox in Fort Wayne.

At that time, I pressed the KA-4002 into service, together with audio system and different discretes whose identities I not recall (although I bear in mind a 10-band equalizer with a bouncing pink multi-LED show!). It will definitely additionally met its demise, full with an acrid “magic smoke” launch if I recall accurately, however solely after serving me faithfully for a remarkably very long time, together with, on the finish, performing as an influence amplifier for a passive subwoofer. Once more, take a look at the modest specs:

• Steady energy (at THD)
  • 8 Ohm: 2×18 W (RMS, 20Hz…20Khz, 0.05% THD), 2x 24W (8 Ohm, 1Khz)
  • 4 Ohm: 2×33 W

A contemporary (and much more modest) successor

I reminisced about each of those previous private case research when I noticed on Reddit final November that audio tools producer Schiit (who I’ve talked about earlier than) was doing a $99 (vs $149 MSRP) last-call sellout of its Rekkr 2W/channel amplifier. The Rekkr product web page is not stay on the producer’s web site, however right here’s a January 2, 2025, snapshot courtesy of the Web Archive. Inventory photographs (nonetheless energetic on Schiit’s internet server as I sort this) to start out:

Sure, it actually is that small:

and got here in each black and—briefly—silver patina choices:

Now for a peek on the internals:

For these of you continue to scratching your head at that earlier 2W/channel energy output spec, enable me to reassure you that it’s not a typo. Extra exactly:

• Stereo, 8 Ohms: 2W RMS per channel
• Stereo, 4 Ohms: 3W RMS per channel
• Mono, 8 Ohms: 4W RMS

That final one’s notably fascinating to me; maintain that thought. For now, right here’s a visible trace:

Extra:

• Frequency Response: 20Hz-20KHz, ±0.01dB, 3Hz-500KHz, ±3dB
• THD: <0.001%, 20Hz-20KHz, at 1V RMS into 8 ohms 
• IMD: <0.001%, CCIR, at 1V RMS into 8 ohms
• SNR: >120dB, A-weighted, referenced to full output 
• Damping Issue: >100 into 8 ohms, 20-20kHz
• Acquire: 4 (12dB)
• Enter Sensitivity: AKA Rated Output (Vrms)/Rated Acquire. Or, 4/4. You do the maths.
• Enter Impedance: 20k ohms SE
• Crosstalk: >80dB, 20-20kHz
• Inputs: L/R RCA jacks for stereo enter, change for mono enter on R jack
• Topology: absolutely discrete, absolutely complementary present suggestions, no capacitors within the sign path
• Oversight: over-current and over-temperature sensors with relay shutdown for faults
• Energy Provide: 6VAC, 2A wall-wart, 12,000µF filter capacitance, plus boosted, regulated provide to enter, voltage achieve, and driver phases
• Energy Consumption: 12W most 
• Measurement: 5” x 3.5” x 1.25”
• Weight: 1 lbs.

And right here’s a hyperlink to the Audio Precision APx report PDF (additionally nonetheless energetic as I write these phrases; if not by the point you learn them, you’ll be able to get to it from the Web Archive product web page cache).

Goal utilization particulars

How on earth did Schiit rationalize the event and (much more notably) subsequent productization of such a seemingly underpowered product? Right here’s the intro to firm co-founder (and chief analog design engineer) Jason Stoddard’s “Much less Energy, Extra Higher” put up on the Head-fi discussion board, which accompanied the general public unveil of Rekkr (and its Gjallarhorn “huge brother”, which is nonetheless within the product line) on February 23, 2023:

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

Let’s begin with the TL;DR:

• As a result of they don’t hiss like a demon cat, drilling slowly into your synapses and draining your soul.
• As a result of let’s face it, how a lot energy do you want for desktop audio system?
• As a result of, reaaaaaally let’s face it, how do your neighbors really feel about 100,000 watts in case you share partitions with them?
• As a result of these little suckers in all probability get rather a lot louder than you suppose.
• As a result of they sound actually, actually good.

Briefly: much less powah. Moar higher.

A brand new concept, sure. However perhaps one you may get behind.

These subsequent few paragraphs from his put up have been particularly resonant for me, as you’ll perceive now that I’ve shared my very own private low-power audio amplifier heritage with you:

A Billion Years In the past…I had a compact Lifelike receiver that did 10 watts per channel into 8 ohms. Along with some tiny Minimus-7 audio system, it sounded fairly darn good. And it acquired pretty stupidly loud, sufficient that my mother and father actually regretted me stepping into music.

In some way this vintage receiver and audio system burrowed its approach into the again of my thoughts and sat there for, like, 40 years. As a result of I all the time loved the way in which it sounded. And I attempted to copy the expertise again and again.

I commend the full put up to your consideration, however for now, I’ll dive into element on a couple of of Jason’s overview factors. First off, what did he imply by “As a result of they don’t hiss like a demon cat, drilling slowly into your synapses and draining your soul”? He was contrasting Rekkr’s Class AB strategy to what various noisier (he believed, at the least, and at the least on the time) Class D amplifiers exhibit. My private take: he may need been proper about Class D a couple of years in the past, particularly within the near-field configurations he’s particularly advocating for Rekkr, however not. Extra on that in a follow-up put up to come back.

Utilization necessities

Talking of near-field, let’s try to quantify his remark, “As a result of let’s face it, how a lot energy do you want for desktop audio system?” Close to-field interprets to (amongst different issues) “shut proximity”, i.e., audio system situated 5 toes (1.5 meters) or much less away from the listener. Why’s this essential? It’s as a result of sound depth follows the inverse sq. legislation: doubling the space from a sound supply reduces the depth to one-quarter of its authentic worth (stated one other approach: the sound degree might be down by 6 dB). There’s a useful on-line calculator (together with others) for ascertaining sound degree variance versus distance on Crown Audio’s System Design Instruments webpage. And to my earlier feedback: near-field speaker configurations are conveniently-for-Jason additionally most certainly to lead to listener-discernible amplifier-generated “hiss”.

Straight above that calculator is one other one we’re going to concentrate on most at this time, titled “Amplifier Energy Required”. Observe that sound degree is a operate of a number of elements:

• Distance (already mentioned)
• Speaker sensitivity, which signifies how effectively a speaker converts electrical energy into sound. It’s measured in decibels at a selected distance (normally 1 meter) from the speaker when 1 watt of energy is utilized. The upper the sensitivity (which for any single- or multi-transducer setup additionally varies with frequency; the spec’d worth is a median), the louder it’ll sound for a specific connected-amplifier energy output. Or stated, one other approach, the upper the sensitivity the much less energy is required to hit a given sound degree.
• And, after all, the amplifier’s per-channel energy output functionality (optionally additionally permitting for headroom to stop clipping brought on by sound degree “peaking”). That is partially depending on the speaker impedance load that the amplifier is linked to (decrease impedance = larger output energy). Reference, for instance, the sooner Rekker specs.

Crown Audio’s “How A lot Amplifier Energy Do I Want?” essay gives a superb assessment of those elements, together with their relevance to completely different sorts of music and listening environments. I’ll solely supply one warning: the corporate’s enterprise mannequin notably focuses on stay sound venue setups, so though the essay ideas stay related for the house, you’ll have to tweak the specifics a bit. For now, let’s plug the next values into the web calculator:

• Distance: 1.5 meters
• Desired sound degree: 85 dBSPL
• Speaker sensitivity: 85 dB (at 8 ohms)
• Headroom: 3 dB

The calculated outcome? The required per-channel amplifier energy is simply 4W (per channel for a stereo setup). Lower the speaker-to-listener distance, and/or the height sound degree (and/or related headroom), and/or improve the speaker sensitivity, and the per-channel amplifier energy necessities additional plummet.

To wit, belief me after I inform you that I didn’t proactively twiddle with the enter values to give you any explicit calculator output finish outcome. In actual fact, they really overshoot these of the setup I’m planning on hooking up shortly after finishing this preparatory write-up. It’s based mostly on a set of Audioengine P4 passive audio system:

rated at 88-dB sensitivity and 4-ohm nominal impedance. Their possible regular distance to me might be extra like 3 toes, not 5 toes, i.e., 1.5 meters (however we’ll persist with 5 toes for now). And when Jason postulates about how “neighbors really feel about 100,000 watts in case you share partitions with them”, in my case, that’s my spouse, who I doubt will lengthy tolerate 85 dB (and even shut) sound ranges spreading from my workplace all through the remainder of the home. That stated, do that information set:

• Distance: 1.5 meters
• Desired sound degree: 85 dBSPL
• Speaker sensitivity: 88 dB (at 4 ohms)
• Headroom: 3 dB

And also you’ll uncover that the outcome, 2W/channel, is much less than the 3W/channel (4 ohm) output energy capabilities of a single Rekkr. To substantiate or deny the calculator declare, I’m going to check out this single-amp configuration first. After which, since I occur to have a pair (two pairs, really, each black and silver units) and it’s really easy to configure them in monoblock mode (the consumer handbook is right here on Schiit’s web site, for all of the implementation particulars), I’ll strive ‘em that approach, too. Stand by for outcomes to come back in a follow-up put up (or a couple of) quickly.

Is greater all the time higher?

As is commonly the case with my writeups, my motivation right here wasn’t simply to inform you a couple of diminutive audio amplifier that seemingly punches above its weight. And it additionally wasn’t simply to quantify for you that, in actual fact, at the least for its goal utilization eventualities, Rekkr’s weight was precisely proper. It was to make use of this case research for instance of a bigger-picture scenario: that within the absence of in-depth understanding on the contrary, customers are all the time going to imagine that “greater numbers are all the time higher”…even when these greater (energy output, on this case) numbers include greater worth tags, and/or require housing product in greater (and heavier) kind elements, and/or have greater related distortion specs, and/or…you get my drift.

I strongly suspect that lots of you, whether or not you’re within the audio trade or one other, usually battle with “loopy numbers-for-sake-of-numbers, power-nervosa specsmanship” (see under for the verbiage reference) calls for out of your goal prospects and/or your individual firm’s advertising and marketing, gross sales, company execs and others, typically motivated by your rivals’ statements and new-product actions. I’d love to listen to extra in regards to the specifics of your varied conditions and the way you take care of them. Please pontificate along with your ideas within the feedback; your fellow readers and I sit up for studying and responding to them. Thanks upfront!

Jason delves into this understandably irritating dichotomy on the tail-end of his February 2023 put up, which I’ll reproduce in full in closing, preceded by the reality-check calibrating contents of a subsequent put up he made final November when phrase of the Rekkr discontinuation turned recognized to the group: “Rule 1 of all enterprise: don’t make what folks don’t purchase.”

The “much less energy, extra higher” manifesto

Now, some persons are nonetheless not satisfied. They need extra energy. And that’s nice. Possibly I’ll stack two Vidar transformers in a Tyr chassis and do a 300WPC stereo amp. Most likely not, as a result of it will additionally require a panic fan, and I hate followers, however after final yr’s ordering debacle, we acquired a lot of Vidar transformers to play with.

However I’d say, hold an open thoughts. You may be stunned.

We’re sooooooo conditioned to need extra, extra, mooore, moaaarrr! that I feel generally we lose perspective, like I did after I began this amp journey. And that may rapidly devolve into venerating one thing that may produce big energy above every thing else—even when we don’t want that energy.

I imply, right here’s the factor. I’ve had desktop methods for ages. Loads of them used a 60W built-in amp—first the Sumo Antares prototype, then the Ragnarok, then the Rag 2. And every of them had a standard denominator: I by no means used even a fraction of these amp’s output energy.

And yeah, I’ve additionally had desktop methods based mostly on powered displays. Together with ones that prefer to brag they’ve like 1000W for the woofer and 50,000W for the tweeter and that seems like 10,000,000W and and many others. (Nicely, perhaps a little bit of hyperbole there, however you already know what I imply: powered displays with a bunch of watts and claims of hitting 1XXdB at 1 meter and different foolish numbers.

And every time, these mega-powered methods have been used as soon as for that circus trick of giant output—then turned down to be used at common listening ranges.

As a result of, you already know, yeah, they go loud, however Rina’s yelling at me from the opposite room.

And every time, these mega-powered methods didn’t final lengthy on the desktop—their infernal hisssssssssssssssssssssss drove me bonkers, and I went again to passive.

So, yeah, one thing used for a celebration trick as soon as (however then annoys the neighbors) with the added bonus of the unrelenting hiss of a demonic cat drilling its approach into your ears…yeah, no thanks, not for me.

Apart: and sure, I do know, there are professionals which have legit makes use of for such displays, and individuals who don’t have to fret about neighbors. Not dissing these. Simply asking: do you really want it? Can you employ it? Or is it simply loopy numbers-for-sake-of-numbers, power-nervosa specsmanship?​

Sooooo…perhaps it’s time to recalibrate.

To sit down again, and suppose, “Do I actually need energy for the sake of energy?”

Sure. I do know. It’s a difficult concept.

However perhaps, simply perhaps, it’s time for one thing much less energy, extra higher.

 —Brian Dipert is the Editor-in-Chief of the Edge AI and Imaginative and prescient Alliance, and a Senior Analyst at BDTI and Editor-in-Chief of InsideDSP, the corporate’s on-line publication.

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