Jeff Rowland Design Group Continuum S2 Integrated Amplifier | REVIEW

Four hundred watts per channel. The Jeff Rowland Design Group Continuum S2 (website) has four hundred watts per channel. In over forty years of being an audiophile, including the twenty-plus years I’ve been reviewing hi-fi components, I’ve never had that much power at my disposal before.

By modern standards, the Continuum S2 isn’t the most powerful power amplifier out there—I can think of a few four-figure monsters turning heads right now. But I’m the guy whose all-time favorite SET had two juicy watts per channel. I’m the guy who followed the vaguely Brit-fi attitude of never needing more than 50 watts per channel, preferably in an integrated amp because English cottages are so tiny, just like one-bedroom apartments in the San Fernando Valley where I spent my journeyman years, and you need all the space you can get. Even now, in 2021, my reference amplifier is just 25 watts per channel, but it’s all gorgeous Class A and can be switched to 100wpc AB if needed, something that rarely happens, to be honest.

What am I going to do with four hundred watts per channel?

To make things more complicated, the Volti Audio Razz loudspeakers arrived at my house at roughly the same time as the Rowland Continuum S2. A horn loudspeaker with a 97dB sensitivity with four hundred watts of amplification? So I paired up the Razz with the Pureaudio Duo2—the class A amp I’ve already mentioned—and I was fortunate enough to still have the Vimberg Ameas in the house. Another stroke of luck—the Marten Oscar Duos also came in for review, and they matched beautifully with the Jeff Rowland Design Group Continuum integrated amplifier.

Would I resist trying the Volti Audio RAZZ with the Continuum S2? Pipe down, I’m trying to tell a story here.

Continuum S2

The Jeff Rowland Design Group Continuum S2 integrated amplifier is not a new product, but it does sport a new feature—the HP Phono card. When JRDG’s Lucien Pichette approached me to possibly review the latest Continuum, that was the selling point. Or, as Lucien explained: “It’s the closest you can get to the Conductor without being the Conductor.”

That’s a significant point to bring up since I actually reviewed the multiple input JRDG Conductor phono preamplifier last year, and it was one of the finest phono preamplifiers I’ve used. The Conductor sounded so clean and detailed and involving—the idea of getting a big chunk of that sound in an inboard unit of an integrated appealed to my appreciation for simplicity.

There was just one problem—what the heck is an HP phono card? Hewlett-Packard’s making phono preamplifiers now? And they’re supposed to be awesome or something?

I sheepishly asked Lucien to elucidate for me. Turns out that HP simply stands for High Performance. You know, I try my hardest to look smart in front of guys who know better—guys like Jeff Rowland and Lucien Pichette. But I’m also a guy who just spent way too much time searching on the internet for “Hewlett-Packard phono preamplifiers.”

Jeff Rowland, the man himself, stepped in with more detail on the HP phono card:

“It was our first recent experience with an amorphous transformer, which could arguably have been foundational in our acceptance of the amorphous technology. But long before that, amorphous core technology goes back to the late 70’s with their use in tape recorder heads in the tape machines of the era. To be clear, the amorphous transformer in the HP card was not a custom transformer, and Lundahl had already produced and availed it generally before we decided to use it.”

Lucien added, “A few have described it as a killer card, and a bargain when paired with the Continuum S2.”

Moving on, the Jeff Rowland Design Group Continuum S2 integrated amplifier is beautifully made and unusual. The first part is a given—we’ve all seen those gorgeous faceplates with the undulating and hypnotic patterns buffed into the solid blocks of aircraft-grade aluminum. (Did you know JDRG refers to the faceplate as the “console”? I like that.) But the Continuum is unusual because it is so beefy and heavy and yet it’s slightly more compact than you expect it to be.

This has been Jeff Rowland’s signature for a long time, putting a lot of solid-state amplifier into relatively small boxes. (By the way, the Continuum weighs in at 35 pounds, but it seems heavier because of the smallish dimensions.) When you look at all the features, however, you realize that every cubic millimeter of this amp has been carefully planned.

That solid aluminum chassis, for example, is sealed—this ensures trouble-free operation and isolation from RF and EMI. Switch mode power supplies are used because they are “vanishingly quiet.” The preamp section is taken directly from the highly-regarded JDRG Capri 2 preamplifier. The inputs and outputs are balanced, and you get those nifty Cardas speaker connectors.

Nothing about the Continuum S2 integrated says “we had to cut some corners to get it into one chassis.” At the same time it’s not a huge box or, even worse, a two-chassis “integrated” amplifier which are becoming more and more common. I know, I get the separate power supply reason, but I still think it’s silly—especially when Jeff Rowland can do all this in a box of this size.

Sound

When it comes to the overall sound of the Continuum S2, I can come at it from several different directions. One suggests, in that old audiophile way, that the Continuum is so neutral that it simply gets out of the way of the music, it sounds like nothing, just as it should, blah blah blah. Both Scot Hull and I have come to an agreement that this description is woefully inadequate and we will frown upon it. It’s sort of a cop-out for not being able to determine what the amplification is actually doing for the system. I spent many months with the Continuum S2, however, and in the beginning that’s how I felt. The Continuum was doing everything I expected from it. Operation through the remote control was fluent, and every feature worked perfectly the first time.

After a few weeks with the Continuum S2, I came up with a description that feels closer to the truth. It isn’t that the JRDG is getting out of the way of the other components in the system and letting them shine, it’s that the Continuum provides the foundation that allows everything else to perform at its best. It elevated the performance of the system every time it was used, so isn’t that a sonic signature in its own way?

I’ll mention a very obvious example. We just awarded the Vimberg Amea loudspeakers the Product of the Year for 2020. That was primarily based on its performance while powered by the Jeff Rowland Design Group Continuum S2 integrated amplifier. When the Ameas got up on stage to accept the award, they thanked Jeff Rowland first.

As I mentioned earlier, the Continuum spent time with other fabulous speakers—the Marten Oscar Duos, the Acora Acoustics SRB and my reference Brigadier Audio BA2 monitors. Same deal. Throw them on the Rowland so we can hear them at their best.

I think this feeling of certainty the Continuum brought to the system, a sense that every component was part of a beautiful and well-oiled machine, is partially due to those 400 watts per channel. I’m not taking away anything from Jeff Rowland’s prodigious skills as a designer and engineer, but I can’t help but think of that saying in the industry: “Power is your friend.” I’ve never really succumbed to that theory. I bet if you take all of the amplifiers I’ve owned over the years and averaged the wattage, it’d be something like 35.

After my time with the Continuum S2, I started to get it. Big power won’t let you down. Everything should work because you have plenty of power. That sounds silly, but here’s why it might be true. As I mentioned, I really wanted to listen to the Rowland with those Volti Audio Razz loudspeakers. I thought the Continuum S2 would really show off the Razz’ surprisingly refined attributes, but the Razz’ 97 dB efficiency seemed like such a bad match for 400 wpc. I asked Greg Roberts of Volti Audio what he thought. He told me my ears would pop before the speakers would.

Yes, it was a strong match, preserving the vivacious spirit of the Razz and revealing tons of inner detail. Imagine if it was the other way around, an SET with a pair of Maggies perhaps? With the Continuum, power’s the kind of guy you can trust, the kind of guy you can drink a beer with, the kind of guy who doesn’t mind if you puke in his car. Power.

The Not Hewlett-Packard Phono Card

So the HP phono card on the Continuum S2 is as close as you can get to the Jeff Rowland Design Group Conductor? Really? The Conductor starts at $8500 for the basic model that just offers a single MM input—my review sample with parts upgrades and multiple inputs checked in at over $14K. That’s more than the entire Continuum with the HP phono card, which is $11,599. (The base model Continuum S2 is $10,499 and the version with the standard phono card is just $10,849, with a DAC a $500 option.)

In other words, the HP phono card is $1100. A Conductor with the same input capabilities is going to be around $10K. Is this possible? Let’s see what I said in my review last year:

“Versatility is certainly important when it comes to phono stages, but it would mean nothing if the sound quality doesn’t rise to the same standard. The Jeff Rowland Design Group Conductor is obviously one of the finest phono stages I’ve encountered, a quiet and capable (and yes, gorgeous) piece of kit that brought my enjoyment of vinyl to an entirely new level.”

I also had plenty of analog rigs on hand to evaluate the HP phono card: turntables from Thorens, Gem Dandy, Technics and LSA, with plenty of cartridges such as the Soundsmith The Voice and both my ZYX Bloom and a new ZYX Ultimate Airy X. I lamented during the Conductor review that I only had cartridges—albeit excellent ones—that retailed in the $1000 to $1200 range. (We’re talking Hana and ZYX though, so again, pipe down.) Both The Voice and the Airy achieved new highs in my current system through the HP phono card, by the way.

I also threw in a couple of ringers, two stand-alone phono preamplifiers that retail in the $4000 to $5000 range—the Pureaudio Vinyl and the Pass Labs XP-17—and plugged them into the aux inputs on the Continuum S2. You know I’m not into comparisons, but I’m mentioning the other two because of what I said about the S2’s ability to make each component perform its best. No, the $1100 inboard phono card did not embarrass the more expensive phono stages, and each phono stage retained its initial character: the Pureaudio’s Class A warmth, the Pass Labs’ adamant neutrality and the HP phono stage’s…

…wait, there it is again. That sound. That feeling of power and control and everything humming together—ironically, with no hum—as a precision machine. No electronic artifacts, no glitches, just pure quiet and the giddy anticipation of more music. The HP phono card did have supports from the Nordost QKORE grounding units, the AudioQuest Niagara 3000 power conditioning and Furutech NCF products all over the place.

But wow. Silence. And power. Silent power. That captures so much of the essence of this fabulous integrated amplifier.

Conclusion

You know I like integrated amplifiers. I’ve got the room and the equipment rack to do big set-ups—monoblocks, if you want, or two-chassis preamplifiers or even three of those QKORE units—but I still get a thrill from the idea of having it all in a single box—power amp, preamp, phono pre, maybe even a DAC. You clear some space on your rack, and now you have room for a second turntable! At least that’s why I’m digging premium integrated amps right now.

As I said, I hate comparisons. But with the Jeff Rowland Design Group Continuum S2, I have those same warm feelings as I did with the Vinnie Rossi L2i integrated amplifier I reviewed last year. Those feelings are partially culled from the idea that “enough with all the black boxes, enough with the system mismatches, enough with so many things that can go wrong.” Like the L2i, there’s just a feeling that this is how you want it, and you don’t need to worry about a thang from now on. There are differences in price, options, power, features and sound between these two remarkable integrated amplifiers, but you have that same sense that you’re being taken care of.

Those 400 watts per channel have certainly captured my attention as well, given me something new to chew on. I seem to be obsessing about this one feeling that the Continuum S2 inspires, a supreme confidence that takes competence to the nth degree, way beyond the level of damning with faint praise that a word like confidence can otherwise bring to the table. Is that the power? Or we will still hear all that goodness in, say, a 125wpc Jeff Rowland Design Group power amplifier because he’s such a thorough, thoughtful engineer who spends so much time thinking of ways to make it sound even better? Would that smaller amp come with a price–$3250–that would make it a no-brainer for audiophiles who need that same sense of a well-oiled machine?

Okay, maybe that’s a hint.