This is a fairly well-covered piece of audio gear, so I’m challenged with how to proceed without simply repeating what others have already, and far more capably, written.
Srajan Ebaen, over at 6moons, did his usual fine job of delving under the covers to peek at the clockwork of the amp before running it through his gauntlet of gear. It’s what he does and he does a fine job here.
Jeff Dorgay, over at TONEAudio, also did an overview of the Signature 15, pushing it into a couple of different mainstream systems and capturing the sound, the features, the utility, and the general character of the amp. A refreshing counterpoint to the typical literary excess I tend to find in most online reviews, Jeff’s piece is a tight little exercise in good literary form.
I recommend both as counterpoint and supplemental reading. Go forth!
The short of it is that the Signature 15 from Red Wine Audio is an excellent example of what’s best in the audio high-end. It’s a terrific amplifier. It has its strengths and its shortcomings, as all good products do, but within those parameters, I find it hard to believe that there’s better to be had. Really. This amp is very, very good.
High/Low vs Near/Far
As the name suggests, we have a total of 15wpc coming out of this integrated amplifier, 30wpc if you get squirrelly and hook it up to a 4ohm speaker. To the reasonable man, this says that this amp is not going to mate well with “average” speakers — unless you prefer to run those speakers quietly or you do the bulk of your listening in the near field. Which isn’t a bad idea, actually.
For example, I have a loaner pair of Grove speakers from Fritz Frequencies sitting here on my desk awaiting their turn on the stands and hooked into the main system. The Grove is, kinda-sorta, an homage to all things Dynaudio; it sports a HiVi driver (clone of a Dynaudio driver) with a big 3″ voice coil and is topped by a Morel tweeter (clone of a Dynaudio tweeter). Coincidentally, the HiVi is the same as the one found in some of the Totem speakers I happened to own at one point or another (both Model 1 and Forest). I say all that because not to offer any characterization of the speaker in that context, but rather to submit that these are not easy drivers for a low-output amp to work with.
As they sit here on my desk, just begging for their turn, I ran the Groves through the Signature 15 for several weeks. The speakers were all of 3′ from my bizarrely beautiful ears and about that far apart from each other. This meant that the SPLs were, as a matter of course, sane. And it was in this setup that the baby in the Red Wine Audio amp lineup screamed “This is Sparta!” and just kicked the music all over my desk.
Was it perfect as a near-field amp? Well … maybe not, but whatever shortcomings it had weren’t related to the sonics. I suspect that the majority of “complaints” with respect to this amp will be aesthetic, though I feel like I’m being unfair when I write that. This amp is all about performance built to a real-world price-point. That means there will be sacrifices. The ultra-rare componentry will be absent. We should expect that the uber-fine textures, or the master-class fit and finish, will be absent as well. Certain functionality that a desktop amp might really benefit from, like a head-amp say, will probably be reserved for a higher-priced model. I’m sure that everyone would love to stuff the kitchen sink into this tidy enclosure, but it’s all about choices at this end, and the lower the price point, the more of those choice you have to make.
Used as a near-field amp, you do more looking and touching than you would with a far-field amp. The knobs are under your fingers more often than the remote, and here, Red Wine Audio generally chooses function over form. In their favor, the knobs are chunky and have great action, but they’re simple and rather plain. The faceplate, something I was spending a lot of time staring at this close-up, simply isn’t as robust as the higher-end models, even though the casework, taken as a whole, is very fine and well put together. It doesn’t look anything like a DIY amp, but then, it doesn’t look like audio jewelry either, if you know what I mean. Like the knobs, the box is plain, sturdy, and well-built. Functional. Rugged. Handsome, but not beautiful. More Harrison Ford than Brad Pitt.
Actually, that’s pretty apt. Much as I like the Bradster, his acting is somewhat erratic. Ford, by contrast, has had a much more robust career — and if you like what he brings, you’ll tend to like everything he’s in. Red Wine Audio is like that too. They have a way of doing things, and if you like that, chances are very high that you’ll love this one, too.
What’s to love? Blackness. With the “on-battery” switch toggled, the amp became silent. Like deep-space silent. At close range, everything an amp does or doesn’t do is right in your face — quite literally. But on battery power, a hiss I didn’t even know was there suddenly vanished. There was nothing. No anything. And the music just popped out of that nowhere as if teleported in. Will you think less of me if I admit that this actually caused me to jump, eyes suddenly panicky and wide, during some song transitions? Spooky.
At sane volumes, dynamics were solid, sure footed, and effortlessly handled. Of course, this is near-field, so we’re talking SPLs that are far below the threshold for clipping on an 86dB speaker playing music with a 15dB swing. I think I was cranking at less than a 90dB peak-to-peak, and averaging a bit less than 80dB — again, this was at one meter, so that was plenty loud. And in this sort of environment, the Signature 15 was a crazy-good amp.
Prior to the Grove, I had them hooked into the new Pinot Monitors from Vaughn Audio. With a 94.5dB sensitivity, the Pinots are a good bit more friendly to amps that are output challenged. And while I thought the Signature 15 did great with the 86dB sensitive Fritz speakers in the near field, a jump up in sensitivity meant that the amp could really stretch itself — and I could stick those speakers way out in the room. Ta da!
If I was looking for compact speakers to match up with a Red Wine Audio Signature 15 integrated, I’d start here. With the Vaughns, I could crank it up and fill the whole room. So, I did. I mean, why wouldn’t I? With the output of the amp and the sensitivity of the speakers, I was able to fill my entire basement with the Santana’s “Black Magic Woman” to levels that caused my wife to leave the house entirely on some suddenly necessary chores. The Vaughns, already dynamic champs, drank up the Red Wine by the gallon and an impromptu parade began. Heady stuff.
So, what happens when you hook an amp with 15wpc up to something that’s not sensitive at all? Like Maggies, for example? Well. Honestly? Not much. The Magnepan 3.7s that I use in my reference system turned on and played music, much as they ever did. I couldn’t turn them up very loud, but when I did anyway, the music felt a bit squashed — but they played! Nothing exploded. No animals were harmed. No celestial bodies careened out of place. It just wasn’t terribly awesome. For that, you’d need more ooompf. Maybe something extra, you know, especially for the down low.
Take a look under the speaker outputs. See that? Those are variable-output, line-level outs. Say it with me: subwoofers! So, yeah, if you’re the kind of audio sadist that likes to torture your neighbors with subsonic abuse, you’re all set. The battery life on the Signature 15 is between 6-8 hours, so that should be plenty of time to encourage those neighbors to work up the nerve to call the police. I was able to do some really interesting things to the Vaughns, running them with a pair of Rythmik Audio F12G subs. Insert shit-eating grin here.
The Sound and The Fury
So, what does it sound like, when I wasn’t being stupid with my speaker choices?
Generally speaking, it sounds warm. Not exactly rich, per se, but not neutral. The presentation is not mid range weighted, like some tube amps I can think of, but it is reminiscent of some of them. Yes, the Sig 15 has a real, tube-infused, mid range. But it didn’t feel disproportionate to the rest of the spectrum. It also has real bass. Deep bass, even. That bass was also rather fast and not bloomy or boomy — again, assuming that the speaker/volume match up was reasonable.
Stockfisch, the label, does stunning studio work and the sound quality they’re able to capture and present, even at standard Redbook resolution, is state of the art. On that label, Chris Jones’ Roadhouses and Automobiles has a couple of tracks that I find myself playing when doing comparisons. The main one I got hooked on is “No Sanctuary Here”. On this track, the bass line is thunderous — and I mean that in the way that a summer thunderstorm is ominous and bone-rattlingly threatening as it comes up unexpectedly over the horizon. Play that tune on a full range speaker at volume and every head on the showroom floor will whip around. “What,” they will say, “was that?” This is followed up by a mournful guitar riff who’s decay depends entirely on the playback chain and is punctuated by some startlingly clear cymbal strikes. Audiophiles are getting a lot of mileage on the first 30 seconds of this track. Played through the Sig 15 into the Vaughn or, even better, through the 93dB sensitive $1,400 floor-standing Tekton Lore S, this track was authoritative. But with either, if the speaker could do it, that bass was “all there” — solid, tactile and frightening. Cymbals sounded like lightning-struck brass, with all the gorgeous sheen and shimmer. Decays from struck brass or steel strings faded gently and effortlessly away. I love this track and the Sig 15 not only captured it, I fell for it.
I have a couple of amps on hand that I got to compare the Sig 15 too. Starting with the $500 Miniwatt N3, an EL84-based SET amp with point-to-point wiring, the Miniwatt has a quintessentially tube sound, but is faster than a 300b and has better extension. It’s a tidy little desktop amp. Compared with the Signature 15, the Miniwatt showed less detail, presented a looser bass and showed off a fatter mid range. But! Those 3.5wpc can really crank over both the Vaughn and the Lore S.
My $3,700 Luxman L-505u is on pretty much the opposite side of every spectrum from the Miniwatt N3. At 100wpc in Class A/B, the Luxman is a Stereophile Class A-rated integrated. Like the Miniwatt, it’s a damn fine amp. It’s far more linear through the mid range than the Miniwatt or even the Sig 15. It also has a more propulsive bass and an airier treble range than either. On warmer speakers, like the Grove, and to a lesser extent, the Tekton Pendragon, I prefer the Luxman’s linear watts and it’s deft handling of complex, dynamic music. But on the Vaughn’s, it just wasn’t my cuppa as the combo just sounded thin and somewhat brittle. Here, the Sig 15 crushed it, lending both body and life to the music.
Both the Luxman and the Sig 15 have about the same level of detail retrieval, I think, at least it seemed so on the Tekton Lore S that I thought was the natural mate for the little Red Wine amp. And on that speaker, as with the Vaughn Pinot Monitors, the thermionically blessed Sig 15 simply had the edge over the Lux in sheer sonic pleasurability, even if the latter can play either speaker a lot louder.
Tubes, tubes and more tubes
One of the things you do get is the ability to roll tubes. The JJ E88C, farthest to the right in the pic above, is the stock tube that Red Wine Audio includes with the amp. The very kind and gentlemanly head of Red Wine, Vinnie Rossi, sent along a couple of other tubes for me to try out with the amp.
The Russian-made Genelex Gold Lion E88CC is new-production tube, and a lot of Red Wine owners have indicated that this tube is “faster” and “leaner”, but with better detail, than the stock tube. The one Vinnie sent me, however, was from Cryoset, so this E88C was a $90 cryo’d tube. Fancy. The French-made Miniwatt, farthest to the left, is a NOS tube from the 1960’s. This tube, like several others of vintage manufacture, is said to be more lush and mid range focused. I couldn’t find a price for this particular one, but at a guess, we’re looking north of $100 for a single tube.
Over the course of three weeks, I tried all three and found them all to be remarkably close in sound. So much so that I’m not sure this would be the first thing I’d be doing were I to bring in this amp for my system. Why? The stock tube is great. With the right speakers, like the Tekton Lore S (pictured below), you’ll get detail, speed and deep bass. That’s stock. Tweak if you must, but stock is some good eatin’.
Moving to the Gold Lion, I found the amp cleaned up … a bit. And when I say “a bit”, I mean exactly that — tiny increments! Yes, the bass felt like it went deeper and could have sounded fuller. Treble became more extended — the shimmer on cymbals was possibly more metallic, and decays lasted maybe a mite longer. The whole system had no issues passing The Cricket Test. Of course, the JJ-enabled Sig 15 also passed The Cricket Test! But if I had to swear on it, I’d say that the Gold Lion was just a bit more resolving than the stock setup.
Look at me, hemming and hawing. Splitting hairs is hard, especially when I’m trying to contain my hyperbole to something approximating real-world perceptions. So, with that said, let me offer that when trying to discriminate between the character of these two tubes, it seemed to me to be more a matter of degree than kind. The two tubes seemed very similar to me, it’s just that the Genelex was the more refined of the two, and clearly so. But that said, how much actually separates them? Well, not much. If you like the JJ, the Gold Lion will be a small, but discernible, upgrade. That said, I’d be shocked if I could tell them apart if I wasn’t A/B swapping them and then listening to my demo tracks with a level of clinical focus that strongly indicated a not-so-borderline case of Asberger Syndrome. I preferred the Gold Lion, but it was a close call. Really tough to separate those two.
The Miniwatt was easier, and actually was my favorite tube of the three. It was also very likely twice as expensive as the Gold Lion, as NOS tube prices can quickly head up to several hundred dollars a tube. That said, I really liked the hint of mid range richness it brought, over the Genelex or JJ. Again, in comparison to those other two tubes, the Miniwatt tube also had a bumping backyard full o’ bass and while not as resolving as the JJ tube, it passed The Cricket Test nonetheless.
Vinnie suggested that some NOS Mullard tubes might bring even more focus to the mid range, but he neglected to send any along. [Sigh].
Were it me, I’d skip the NOS tubes for the Signature 15. They’re spendy, and yes, while it’s fun to be able to tune and tweak your gear this way and that, the fact that you get so much bang for your buck with the stock tube just strikes me as the best of all the bargains. Should your curiosity prove too much to bear, you’ll be happy to learn that the amp is resolving enough to sort out your swaps, but be reassured too that it’s not that resolving that all that is good will hinge on the very careful and precise selection of that one bit of glass. You do not, repeat, do not need to spend $300 to make this amp sound great. And while that $300 will impact the sound quality in real and discernible ways, how much so will depend on everything else. To me, in the systems I tried the tube-rolled amp in, each tube change simply nudged the character of the amp a tiny bit in one direction or another. But overall, it was always and very clearly a Signature 15 amp.
Gluing it all together
Half way through the testing/listening time, I got a batch of line-level cabling from Black Cat Cable‘s new Morpheus lineup. I think these cables provided a discrete and discernible step up from my Blue Jeans Cables loom, which is my reference budget cable, and dare I say it, the move from Blue Jeans to the Morpheus cables was more clearly obvious to me than some of the nuances between the various tubes. Morpheus brought more extension and speed, taking some of the focus off the mid range and spreading that love around far more evenhandedly. I think “lean” is probably too strong a word when describing the changes, so I’m going with neutral over the warm-ish and slightly rolled off Blue Jeans cables. This was a welcome adjustment, to me at least, given that the amp falls on the warm and rich side of the spectrum, even with the Gold Lion “lean tube” running the show.
So, here’s the bottom line.
The Red Wine Audio Signature 15 has no business being as good an amp as it is. It is, by far, the quietest amp I’ve ever had the pleasure to use or listen to. It’s creepy-quiet. If matched to the right speakers, you’re going to be blown away. Wait, that’s a crappy cliche. Say, rather, that you’re going to be so amazed that your next waking thought may well find you naked, grinning, and dashing through the streets of your neighborhood while hooting like an owl. $1,500, for this level of sound, is unbelievable. The fact that this is all Made In The USA? Inconceivable. There’s no way this can last.
The Tekton Lore S is a $1,400 wunderkind, cut from the same over-achieving-on-a-shoestring-budget cloth as the Red Wine amp. I can only begin to capture how good this match up is by saying that these two pieces of gear really ought to be sold as a kit. I mean, really. It’s like they were voiced together, and then sent off like a tragically shattered family only to be brought back together in front of a live TV audience, with you as Oprah (you wish!). The joy with which they seem to play together … priceless.
Don’t forget the cables. At $127 per 1m pair for interconnects and $217 per 1.5m pair for speaker cables, I can’t think of a better way to hook the Red Wine to the Tekton. These cables are a natural fit as they play off the strengths of both while introducing no weaknesses. And yes, the system sounded best with these cables, and different without them. Get ’em.
Win, win, and win.
Sadly, I don’t have a source component at this price point that I’m nearly as nuts about, or I’d have a Grand Slam here. Have to stay tuned on that score, I guess.
So, that’s it. Is the Red Wine Audio Signature 15 amplifier for everyone, everywhere, all the time? Probably not. But if you’re careful with your synergy and speaker-matching, I dare you to do better — and if you can, buy that whatever-it-is, too!