|Reason Amps SM40 HeadSummary: Deep, lush cleans, with bright, ballsy and aggressive overdrive. The SM40 is a classic rocker’s wet dream come true.Pros: Touch-sensitive and expressive. The voltage sag in the 5U4 is just enough to create almost a reverb quality as the signal fades. Truly lovely sound!
• Output: 40 watts RMS @ 10% THD
Tone Bone Rating: 5 – This is a blues and classic rock machine!!!
This review is a long time in coming as I evaluated the SM40 over a month ago, but as they say, better late than never. As many may know, I’ve had a love affair with the SM25 that the Reason guys sent me to review, and that amp will be in my rig (see my review here). In my view, very few amps can match it in versatility. It is an extremely expressive amp that is capable of producing lush, ringing cleans, to searing overdrive. And according to both Anthony Bonadio and Obeid Kahn, the founders of Reason Amps, the SM25 Combo was built specifically with versatility in mind. It is very pedal-friendly, and StackModeTM is the greatest thing since sliced bread!
But sometimes, you just don’t want or need that kind of versatility because with versatility comes compromises. For instance, the SM25’s Normal or clean channel breaks up a little earlier than you’d expect though I actually rarely if ever play at the volume so it’s a none-issue for me. Since I play a variety of styles, versatility is a key factor in my decision on an amp. But that versatility is lost on those who just don’t need it. And mind you, that’s not a bad thing. It’s merely a matter of choice, which is why you have a number of amp options to choose from with Reason Amps. Premier Guitar already covered the SM50, which gives a fair picture of the SM50’s capabilities – though I do have to take issue with Premier Guitar giving it the “Loud As Hell” award. It’s not just a noise-maker. It’s just that you’d swear the SM50 is 100 Watts as opposed to 50 Watts. It’s an extremely powerful and expressive amp with classic EL-34 goodness.
The SM40, on the other hand is a very interesting take based upon EL-84 output tubes. Where the SM25 and SM50 are based on EL-34’s in Class AB fixed-bias configuration, the SM-40 is built around two EL-84’s operating in Class A Cathode Bias configuration. Like the other Reason Amps, the SM40 has two independent channels with the trademark StackModeTM “channel,” that combines the fully amplified signals from both Normal and Bright Channels in a series with an extra gain stage, while retaining both the volume and EQ control that each channel contributes to the combination.
The Story Behind the SM40
I called the Reason guys up to shoot the breeze a bit yesterday, but to also pick their brains about the SM40, Obeid Kahn (Reason’s amp designer) and I had a great conversation about the story behind the SM40. For all intents, and purposes, the SM40 was Reason’s first production amp. Obeid had gone through several prototypes before he finally produced the SM40 which included StackMode. Previous versions had completely independent channels with separate inputs, then evolved into switching between the two, then finally evolved into connecting the two channels in a series. So the SM40 could be considered the eldest sibling in the Reason amp line and the first successful incarnation of StackMode.
How It Sounds
The SM40 is targeted at blues and classic rock players, and it definitely shows that in the way it’s voiced. Moreover, there’s something really special about the clean tone of an EL-84-based amp. It’s naturally chimey and glassy, and guitars that have that natural quality bring that tone out even more. On the Normal channel, the kind of voicing is beautiful; chimey with lots of mid-range, but not overdone. And there’s TONS of clean headroom in this channel, which makes it ideal for use with pedals. Put a booster in front of this channel, and you get that AC-30-like breakup, which is subtle and smooth. Very nice.
The Bright channel, on the other hand, is actually not that much brighter than the Normal channel. In fact, the tonal differences between Normal and Bright are so subtle that you’d think there’s no difference at all. But that’s by design. Unlike the SM25 which was built around versatility, the SM40 is a much more focused machine, which is why you only get volume and tone on any channel or mode, as opposed to the SM25 which includes a 3-band EQ on the Normal channel. The idea behind that makes sense: Players who buy this amp will mostly play a certain style of music and don’t want to be bothered tweaking knobs to dial in their sound. Not that the amp can’t be used in a variety of genres, but players who play this won’t want to stray from the general tone the SM40 produces.
Similarities between the channels aside, the real kicker for me is the StackMode “channel,” which combines Normal and Bright channels in a series, while retaining both volume and tone shaping in both channels. This really opens up a whole new pallette of tones you can produce. It’s super-expressive, and because you’re essentially working with three gain stages in a series, this mode makes the amp incredibly responsive to volume knob and attack. Dime the volume on your guitar, and you can get tons of overdrive. Back it down and pick lighter, and the tone cleans right up. In my tests of both Reason amps, StackMode was pretty much all I used, unless I was playing something where I needed a pure, glassy clean tone for which the Normal channel excels.
An interesting switch labeled Odd/Even resides on the control panel. This is a harmonics switch that works with the phase splitter in the final gain stage. The idea behind it is that at super-high gain, you start getting a “notch” type of distortion. Flipping the switch smooths that out. I actually didn’t notice that much of a difference with the switch in either Odd or Even positions, but maybe that was because I was only 3 feet from the amp, and it was cranked! 🙂 For the most part though, the switch won’t have too much of an effect until you get into really thick overdrive.
The SM40 was tested with a Strat copy and a Saint Guitars Benchmark with humbuckers. With the Strat copy, you’re immediately taken to the roots of blues. The chimey vibe really comes out with single coils, and I found myself closing my eyes to take in the sweetness. With the Benchmark, the SM40 grew big balls of steel. Not that you’d do metal with this amp, but humbuckers make the SM40 want to growl. It’s really nice.
The SM40 is a sweet amp, and like its sibling, the SM50, it’s really made for the stage. It’s expressive and ballsy, and is meant to be played hard. As both Anthony and Obeid have both told me, this amp is made for active musicians. And while I wouldn’t want to keep people from buying it because it sounds so good, by the same token, I wouldn’t recommend it for bedroom use. You wouldn’t be able to take advantage of its full range of tones.