TEST: Framus Cobra Head

 There really aren't that many anymore. We are talking about German amplifier manufacturers who do not have their products manufactured under license in the Far East, but instead outsource the jobs locally and consciously accept the higher wage and ancillary wage costs.

One of these representatives is the Framus company, whose Cobra Head, which I have for testing, is manufactured in Markneukirchen.


Construction:

The Cobra Head is a head that has the typical “briquette” shape. With dimensions of 72.5 cm x 28.5 cm x 26.5 cm (W x H x D), it fits on any standard 4x12" cabinet without protruding unattractively at the back or on the side. At 18.3 kg, it is in the middle class in terms of weight and can be lifted onto a full stack by a strong pair of men's arms with a little momentum.

Visually in classic black, the Cobra Head has a decorative metal front grille, which both protects the technical interior and significantly enhances the look of the device. Corner protectors and a strong carrying handle made of transparent plastic do the rest.

The amp is based on all-tube technology, in which a total of 5 ECC83 (3x selected for the different distortion stages, 2x standard for phase inversion stage and effects path buffer) in the preamp and a selected EL34 quartet in the power amp ensure an output power of 100 watts.

The Cobra has a three-channel structure, whereby the basic sound characteristics can vary greatly within the individual channels using mini switches. With a little imagination, you could talk about almost 6 different sounds, although “only” three sounds can be accessed via foot switch or MIDI control.

The three channels Clean, Crunch and Lead each have 6 individual controls, which control the gain, presence and volume range in addition to the classic three-band tone control treble, middle and bass. There is the mini switch mentioned at the beginning for each channel, which increases the highs in the clean range (bright) and slightly thins out the midrange, and activates a low-mid boost in the crunch and lead channel (notch).

In the master area there is a “Deep” control, which thickens the overall sound in the lower midrange, the mixing control for the parallel FX loop and two independent master volume controls so that the volume can only be briefly increased during a solo passage without changing the sound. Kudos to everything that makes us more independent from the FOH ;-) No offense, guys.

On the back, on the left side, we are greeted by the cold appliance power plug and an easily accessible main fuse. A little tip on the side: I've never had a main fuse blown without one of the output tubes ultimately being blown. Therefore, you can replace the fuse, but always have a calibrated replacement duo / quartet of power tubes ready in an emergency, you will need them.

The three channels of the Cobra, as well as the two master volume controls, can be switched via a foot switch or via a MIDI interface, which is why the head has a MIDi In or MIDI Thru for looping through the switching signal. In order to be able to operate the three channels and the master volumes using the foot switch, you have to use a button with a Y-connector and 2 stereo jacks, or you can use the in-house switch (button) of the type FR S4 M, which is not included in the scope of delivery .

The integration of MIDI control of the channels plus the two master volume controls via a corresponding floorboard is a welcome expansion in terms of flexibility within a more or less complex routing of floor pedals or 19" rack components, as you can set up several switching processes with one switching process Run it once and generate your personal setup with 128 storage spaces.

In addition to the FX loop, the head also has a line out and two speaker outs, which can each be switched to 4, 8 or 16 ohms. (By the way, the correct calculation of the total resistance seems to be one of the eternal mysteries for stage managers at festivals. No matter where I have played so far, whether in front of 300 people in the Odenwald or in front of 30,000 in Korea, not once where the full stack wasn't would have incorrectly said 16 ohms....)


Practice:

After switching on the amplifier, an LED chain inside the head floods the mirrored interior with a red light. Pretty... Just like the chrome-plated pot knobs, which look great. However, with their raised appearance, the buttons sacrifice much of their visual functionality. Unfortunately, after about 3 meters you can no longer tell what value the pots are at. Function follows form.

What is immediately noticeable from the first tones on the clean channel is the extremely neutral basic sound of the amplifier. Despite the EL34 equipment, the nasal midrange, which tends to play forward with these power tubes, remains very balanced and subtle. The channel proves to be very clipping resistant; even with the gain control fully opened, only very subtle crunches come out.

Activating the Bright Switch not only increases the treble but also lowers the midrange, which also makes humbucker-equipped guitars sound more “single-coiled” (forgive me for this incontrovertible comparison). The channel does its job quite pleasantly, almost inconspicuously, but without adding any excessive softening to the sound.

When it comes to input sensitivity, channel 2 continues where channel 1 left off. Even at low gain settings, clear distortions can be heard, which can be continuously increased to a strong lead. Here too, the neutral sound of the head is noticeable. Although you can undoubtedly recognize the characteristic “EL34 mid-knödel”, it is nowhere near as prominent as, for example, the British protagonist heads from Marshall and VOX.

But anyone who now believes that they will find a German counter-offensive to the American soft-focus faction is mistaken. In a kind of middle ground, the Cobra Head stays exactly between the bone-hard Brit corner on the one hand and the sometimes cottony American soft-clipping department.

This impression is reinforced in the third channel, where, despite additional distortion, the amp never runs the risk of suffocating in the half-wave cut sludge and indefinable basic mud in the middle of high gain.

The notch switches prove to be very effective and also give the amp a very high degree of flexibility. When boost is activated, channels 2 and 3 get a powerful mid-range boost, which makes the amp sound significantly more powerful and voluminous. This effect can be further enhanced with the Deep control, so that even downtunings in the major second plus category have a very powerful effect on the speakers.



Conclusion:

The Framus Cobra Head is a top that falls between all the stools in terms of sound and that is precisely why it fills a gap that is little or not occupied in this form. With an unusually neutral basic alignment plus the highly effective notch and deep switcher, the amp manages to reproduce all the sounds that are needed in a rock and metal-oriented band.

A successful fusion between flexibility and practicality plus a strong touch of exotic bonus, well done!

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Additional Informations:

German vacuum tube amplifiers, also known as Vollröhrenverstärker, represent a rich tapestry of engineering innovation, craftsmanship, and sonic excellence. Their journey traces back to the early 20th century, intertwining with the developments in radio technology, electronic amplification, and the rise of the hi-fi culture. This article aims to delve deep into the origins, key milestones, and technological advancements that shaped the landscape of German vacuum tube amplifiers.

**Early Beginnings:**
The story of German vacuum tube amplifiers begins in the late 19th century with the pioneering work of figures like Ferdinand Braun, who laid the groundwork for vacuum tube technology. However, it was the post-World War I era that witnessed the rapid evolution of electronic amplification, driven by the demands of burgeoning radio broadcasting and telecommunications industries. German companies like Telefunken, Siemens, and AEG played pivotal roles in advancing vacuum tube technology, setting the stage for the development of audio amplifiers.

**The Birth of Vollröhrenverstärker:**
The term "Vollröhrenverstärker" translates to "full tube amplifier," emphasizing the exclusive use of vacuum tubes in the amplification circuitry. In the 1930s and 1940s, German engineers began experimenting with vacuum tube designs optimized for audio amplification, leading to the emergence of the first Vollröhrenverstärker models. These amplifiers were characterized by their robust construction, meticulous craftsmanship, and a commitment to sonic purity.

**Post-World War II Renaissance:**
The aftermath of World War II saw a resurgence of interest in high-fidelity audio equipment, fueled by the desire for cultural rejuvenation and technological progress. German manufacturers such as Telefunken, Grundig, and Siemens capitalized on this trend by producing a new generation of vacuum tube amplifiers designed for the burgeoning home audio market. These amplifiers featured innovative circuit topologies, premium components, and meticulous attention to detail, reflecting Germany's reputation for engineering excellence.

**The Golden Age of German Hi-Fi:**
The 1950s and 1960s marked the golden age of German hi-fi, characterized by a proliferation of vacuum tube amplifiers renowned for their exceptional sound quality and craftsmanship. Brands like Dynaco, Dual, and Braun gained international acclaim for their innovative designs, pushing the boundaries of performance and aesthetics. German engineers pioneered novel circuit topologies such as push-pull, class-A, and ultralinear configurations, enhancing amplifier efficiency and fidelity.

**Technological Advancements:**
The relentless pursuit of audio perfection drove continuous innovation in German vacuum tube amplifier technology. Engineers explored new materials for transformer construction, refined circuit layouts to minimize signal distortion, and experimented with novel tube configurations to optimize amplifier performance. Advancements in tube manufacturing processes, such as improved vacuum sealing techniques and cathode coating materials, further elevated the reliability and longevity of vacuum tube amplifiers.

**Cultural Impact and Iconic Designs:**
German vacuum tube amplifiers not only excelled in technical prowess but also made significant cultural contributions. Iconic designs such as the Telefunken V72 and Siemens Telewatt V300 became emblematic of an era characterized by meticulous craftsmanship and timeless elegance. These amplifiers transcended their utilitarian function, becoming objects of desire for audiophiles and collectors alike.

**Enduring Legacy and Contemporary Revival:**
While the advent of solid-state technology in the 1970s heralded the decline of vacuum tube amplifiers in mainstream audio, the legacy of German Vollröhrenverstärker endured among enthusiasts and connoisseurs. In recent years, there has been a resurgence of interest in vacuum tube amplifiers, driven by a renewed appreciation for their warm, euphonic sound signature and nostalgic appeal. Modern manufacturers such as Leben, Octave, and AudioValve continue to uphold the tradition of German vacuum tube craftsmanship, combining heritage-inspired designs with state-of-the-art engineering.

**Conclusion:**
The evolution of German vacuum tube amplifiers is a testament to the ingenuity, craftsmanship, and passion of generations of engineers and artisans. From humble beginnings to global recognition, Vollröhrenverstärker have left an indelible mark on the world of audio reproduction, embodying the pursuit of sonic perfection and the enduring allure of analog craftsmanship in a digital age. As technology marches forward, the legacy of German vacuum tube amplifiers remains a timeless symbol of excellence in audio engineering.