Who is this Adrian Socnik? Well, the man already has a few years under his belt, especially when it comes to his technical experience. He originally comes from measurement technology, but discovered his passion for the world of tubes many years ago. Years of research into vintage treasures paved the way for his own designs.
We last tested his JTM 18 and cabs in February 2012. An encounter that left a very convincing, not to say overwhelming, impression. So the bar for the MC 30 is pretty high.
construction
Okay, as far as the basic concept of the amp is concerned, I have the cat...
already let out of the bag. However, the interesting mixture based on the AC30 circuit is not the only good thing about this amplifier. But let's first focus on the basic substance.
If you reduce the good old AC30 to the essentials, the core features that remain are the top boost circuit in the preamplifier and the 4¥ EL84 power amplifier that works in cathode bias. The MC 30 stands on this foundation. Vox fans know that the term top boost stands for the two-band tone control, which in the early days of Vox was a retrofitted module that was mounted on the back of the combo; because the first generation of the AC30 had no tone control at all, if you look at the not exactly earth-shattering tone cut/treble control behind the phase control.
driver level. Vox later turned it into its own “Top Boost” channel. A decision of legendary significance, as we know today. The original technical design remains unchanged to this day. Adrian Socnik has added a second circuit that is equally historically valuable. At the same time, he was able to draw from his own program. There are replicas, you could also say modern interpretations, of the amplifiers from the first Marshall generations. The product names say it all: JTM 18, JTM 65, JTM 66, JTM 67, JTM 68. In short, he has dealt intensively with the so-called Plexi era and researched it extensively. As a partner for the top boost channel, Adrian chose his JTM 68, which has the highest gain level and is the most aggressive in sound character. We'll be curious to see how this preamplifier gets along with the EL84 power amplifier.
A specialty of the Gladius amplifiers is the elaborately designed power switching. The corresponding power switch is on the back and, depending on the model, offers five or (as here) six levels. The reduction is sufficient to well below one watt. Here, as with so many other products, we don't simply use power resistors that burn up the power of the output stage, but rather the voltage ratios are varied. Attention, this has nothing to do with London power scaling, which has recently received increasing attention and manipulates the voltages via a semiconductor control circuit. With Gladius, power switching is based on a specially designed mains transformer supplying the required voltages. A much more complex principle, which is also correspondingly cost-intensive.
A second additional equipment element can be recognized by the standby switch, which has three levels. Shows two operating modes
The thick-walled aluminum chassis is brushed on the outside and therefore looks particularly elegant. Two contoured, milled aluminum blocks reinforce the construction on the sides. Another nice detail: mostly stainless steel/VA screws and nuts are used. Inside, you can see a picture-perfect workmanship: star-shaped ground guide, finely soldered, no dirt from flux or similar, you can hardly beat that in terms of quality.
Otherwise we see the usual suspects from the boutique scene, such as Mallory 150 capacitors and Silver Micas, potentiometers from Alpha, etc.
The only minimal drawback in the design: the two control knobs on the back protrude slightly beyond the housing.
practice
Vox and Plexi, that can be fun. Wait, before we get excited about it, we should remember that the fascination is the labeling, which hides the fact that the power amplifier can work with (presence) or without (boost) negative feedback. Correct, that's nothing special in itself and you can definitely find a feature like this in other amp manufacturers. However, with the MC 30 you can change the negative feedback using a foot switch! If you know that the dynamics and the gain potential change drastically, you can already imagine how useful and helpful this setup could be in practice. Well, we'll see soon.
Adrian Socnik has taken it upon himself to not just copy the early Marshalls in a banal way, but to push the technical concepts to the extreme.
On the one hand, he relies on the very best components, and on the other hand, he takes up the mechanical design from back then and refines it.
old amplifier treasure is the result of a complete, interacting electrical system. Finally, in tube circuits, the mutually dependent voltage conditions (along with the type of components and tubes) ensure a variety of interactions; There's a living cycle pulsating there. If you change an assembly as important as the power amplifier, the consequences are serious. Therefore, you shouldn't really expect the MC 30's JTM-68 channel to be particularly similar to its ancestors. Finally, it drives an EL84 power amplifier, which sounds significantly different than an EL34 counterpart. Compared to the EL34, the EL84 can generally be described as being generally denser in the mids, more singing in tone, sweeter, and less harsh in its overdrive character. That's exactly why it is so popular: it delivers the British character without being as radical as the EL34. So, in a sense, the Top Boost channel plays first fiddle. To what extent does he resemble his great role model? It's a good thing that the author of these lines - as loyal readers have long known - is a self-declared fan of the old models (and has both heard and owned a considerable number over the years). The perfect reference is available on site for assessment: a perfectly fit red panel AC30 from around 1964 with Blue Bull Dog Celestions. So you quickly connect the speakers to the Gladius and you're ready to go. It's quite clear that the timbre has hit the twelve. The MC 30 has the same tonal features as its historical great-grandfather. But there are certainly audible differences.
A striking peculiarity of the old AC30 is how airy, hollow transparency mixes with soft, flattering mids and glassy brilliance in the highs. The MC 30 behaves differently, it reduces the airiness a bit in favor of more stability and a little tighter pressure. Some people might see that as a loss,
Complex power switching
others are pleased that the MC 30 produces the original sound of the AC30 with more power. It is also characterized by extreme precision in the representation of details and maximum sensitivity. Think about what he delivers in this regard. I like to put it this way: The amp can almost hear the small breeze of your fingers when they just brush past the strings, that's how sensitive it is. Signal processing also sets standards in the fine detailing of overdrive components. How subtly saturation and distortions develop in the sound image is something you can't find on every corner, even in the boutique scene. The icing on the cake is the treble reproduction. Powerful, more specific, fuller than the old AC30, it produces a lot of brilliance, but appears particularly smooth and almost never intrusive - unless the instrument is massively provoking something like that. For the reasons mentioned above, it goes without saying that the JTM-68 channel largely develops the same (outstanding) qualities as the top boost channel. The timbres are of course slightly different. At least we do
Clean area, don't talk about really drastic differences. What you notice superficially is that the AC30 channel favors the high mids, while the JTM-68 section is much more balanced. Things get much more exciting when you look at the overdrive range.
tet. How gratifying: the Marshall channel actually produces the characteristically hoarse, scratchy distortions in a very typical manner. Who would have thought that this would be so authentically possible in the current technical context. Aggressive and striking, the JTM-68 channel is a flawless retro rocker.
Switching off the negative feedback brings out new, interesting and absolutely useful dimensions for both channels. Sure, as expected, the volume increases slightly, but at the same time the sound becomes rougher, in a positive sense, coarser in the highs. The player also experiences a little more give in the attack in this operating mode. So the response becomes softer. But not nearly so much that the MC 30 would possibly lose its beautiful stability. In addition, the mid-range spectrum thickens across the broadband. Simply put, the amplifier offers significantly more intense, more complex distortion. It is therefore almost obvious to see/use the negative feedback switching as a means of rhythm/lead change. Works great.
And it is precisely in this context that power switching plays a complementary role. Because the gain level or distortion intensity of such straightforward amps is always directly dependent on the volume, you basically need a way to keep the final volume under control. The MC 30 achieves this extremely elegantly. Its tonal qualities are largely retained in the reduction stages. Logically, the listener subjectively experiences a certain loss of fullness and pressure when the volume drops significantly. But this is solely because the sound event is perceived less through the body (or the top of the skull). In order to objectify the circumstances, it is advisable to assess the microphoned signal. Go ahead, most people will be surprised at how consistent the MC 30's performance is in terms of power reduction. In any case, we definitely see it as a practical plus here.
alternatives
Somewhere in the wide world of boutique amps - and only there - there may be models that are as elegant as the MC 30 concept. With its plastic depth, the MC 30 sounds as if it were freeing the reproduction of its ancestors from a veil. The functionally convincing power reduction and the negative feedback switching significantly increase the usage value and make the concept of the MC 30 practical and variable in use.
It is well known that amplifiers of this quality class are not available at dumping prices. Given the fact that Gladius products are manufactured in small series and carefully handcrafted, making them luxury items to a certain extent, the high price is understandable and quite justifiable, true to the motto: It has always been a little more expensive, a special taste to have
