Symphonic Line RG7 MK4 power amp


ReMusic Spark Award

If I should describe the Symphonic Line RG7 MK4 power amp with a simple concept, I could use an oxymoron: bad to doing well.

I say that, because the power amp has the strength of master and tame all the tough speakers, treating them badly up to the marrow. This amp is also able to keep out the essence, the edible part of the music hidden behind every sound cortex, although apparently impenetrable.

The Symphonic Line is simply phenomenal. The lower is the efficiency of the drivers, the more it feels at ease.


Spark in the Dark Symphonic Line RG7 MK4


Addenda - May 6th 2016, Munich High End: at the sides, Giuseppe Castelli and Roberto Rocchi, ReMusic Executive Editors, in the middle, Herr Rolf Gemein, CEO and owner Symphonic Line, with our Spark in the Dark award.


The high efficiency? Kryptonite!

I have matched it with a pair of Klipsch Heresy II series loudspeakers: the sound seemed coming out from a radio of the ‘40s, not even well tuned.

My trying to understand the phenomenon has taken into account the fact that tough power amps, Mark Levinson 334 above all, can give great performances also in synergy with speakers whose sensitiveness is higher than 95 dB.

Clearly, the solution of the enigma had to be find in the technical specifications.

The busy Executive Editor Castelli came to my aid suggesting considering the damping factor. He told me that in an old system he had in the past, he could easily handle a pair of electrostatic panels with a Symphonic Line amp.

Actually, the RG7 power amp presents a Dampfungs faktor equal to 800.

This value means that our machine works with a very low output impedance, around 0,01 ohms: and from here comes the incomparable driving ability. We are in front of a declared listening philosophy that makes the brand from Duisburg peculiar: no cones can offer resistance in absolute manner, but you have to make them vibrate in the correct way. A rise time of 0,8 micro seconds, which is pure sap for the loudspeakers, adds itself to the damping factor.


Rolf Gemein, Symphonic Line’s founder and plenipotentiary, is at the fourth version of this amp, for sure the most mature. All his electronics are handmade in Germany and any aspect of the development is not casual. The size of the RG7 are anomalous. The power amp has no extension in depth, but is a compact body whose lack of tail is compensated by being higher. It shows an extraordinary massive structure, with a 5 mm cabinet and an 8 mm mirrored front fascia on which is discretely printed the company logo. No LEDs, no buttons or switches: the on/off is on the back panel, in the middle, supportive of the IEC mains input, with a red LED that informs if the unity is working. There are two reasons for this physical/dimensional option. The first one coincides with the need of an easier transport of about thirty kilos of weight, the second is making the signal path the shortest possible.


The inside leaves breathless. The symmetry is total, the logistic is witty and functional, as required for a dual mono circuit. In the middle, imposing, reign two 350 VA tower toroidal transformers, well shielded and dampened. On the left, as on the right, are two batteries with five filter capacitors each, selected to emit the same energy in all the frequencies. Altogether, they can develop 130.000 mF of capacity: strong point!

Everything is excellence within the Symphonic Line and many are the innovations. Not fewer than eight diodes per channel, FET for the input stage, looking for a high impedance, while the power transistors are bipolar and all marked Toshiba. The printed circuits are made of epoxy resin of high thickness and the heat sinks have been reinforced. The reference inner wiring, made by Symphonic Line, is of wide section and with platinum ends. In platinum are also the WBT binding posts, which offer a strong and safe closing. The inputs are only RCA.

We are in front of top German craftwork.

By deepening the knowledge of this fantastic electronic, you are pervaded by a deep feeling of harmony. The designer himself declares that the harmonic interaction is applied not only to the frequencies, but also to the mechanical parts. The resonance speed of all the parts through which the signal flows, from the mic to the components, has to be harmonized so to avoid a proportional decay of the listening pleasure. This is thought, meditation, impulse, hearth, not just engineering. Gemein intends to interact with the music and the instruments for its reproduction, not only through the ear, but with mind, soul, with the entire person, in the pursuit of the enchantment and the lasting vibrations. If he feels joy, he can make the others happy. Very often a new material, a transistor or a capacitor, are a pole of attraction for an evolution that can, in turn, develop the hearing and the sensitiveness of the nervous system. These are the reasons why, also after twenty years, the devices can be updated and brought to a superior category.

One of the main aims of the evolution is reaching the tonal balance. A circuit can be very slow, or too fast: both the extremes are negative. Also a band width equal to one megahertz is not an index of quality. One of the fundamental attributes that feed the virtue of an electronic is the imperceptibility of the transients by the listener. The transit from one harmonic state to another should not be detectable.


I have had this feeling. I had promised to make feel at ease the Symphonic Line, so I started my test with a “German” record: I wonder why by Wolfgang Bernreuther, an LP realized by Clearaudio in 2003. It is an atypical work as far the artists are concerned. In bewilderment, you see how a Teutonic guitarist can compose a blues masterpiece that seems to be born from the delta bowels of Mississippi river. The first notes of Crossroads, by Robert Johnson, are upsetting. His voice is intact, full, dense, and authentic, without echoes, without anticipations. Every touch of the strings, every breath into the saxophone, comes to life in the exact moment of its creation, and it never passes the space/time borders of its natural dimension. The passage to the relaxed harmonies of Fire and rain by James Taylor, to the vivacity of The sky is crying by Elmore James, is perfect. A great amplifier, to be considered like that, has to impose itself as a dominator and undisputed master of the art, or of the artistic content of the musical support. The power of the Symphonic Line is concentrated in the dexterity of keeping the inertia of the playback, also in presence of sharp changes of rhythm, tone and colour. Ours does not yield to delays or quickening, but gives energy in constant structure, never in progressive or decaying way, but punctually reactive to the tone.

These features emerge more evident when on the platter plays Songs for Drella, LP, Sire Records, 1990, a work that the friends/rivals Lou Reed and John Cale dedicated to the memory of their mentor Andy Warhol. Here you get aware of the intrinsic meaning of the dynamic concept, whose intensity does not come from primitive and deceptive measurements in decibels, but from an interactive and vital relationship among the constituent elements of the sound message, that is silent background and instruments, voice included. Focus yourselves on this task, try to follow the paths of the insane vocalizes of the two artists, and the feud between the learned afflatus of a viola got crazy by electricity and the lyricism against the submitted candour of the guitars, exteriorly tame but wild under the skin. You will exactly understand what I mean speaking of transients and dynamicity. Every vocal and instrumental emission, the obscure depth of the silent background, have their own intrinsic value, their place, their appreciation. A Fender will play as a Fender, a Steinway as a Steinway, a Stradivari as a Stradivari: this is meant to be.


If what I said before is not enough, there are two other aspects that cast the Symphonic Line RG7 MK4 on the absolute, on transcendence.

The good Rolf has applied to his creature the Feng Shui theory, which attributes to the vivacity of the green, yellow, red and orange, a positive incidence on emotions and on cognitive processes. In front of mixed bright colours, you feel a sense of well-being, because the senses are stimulated under the emotional and intellectual point of view. An emblem are the manufacturer’s labels, which show up on the surface of the back panel and on the top of the transformers.

The philosopher’s aura of the Symphonic Line has been enhanced by the virtues of the C37 lacquer by Dieter Ennemoser, that impregnates the single components of the amplifier: capacitors, resistances and coils. At the basis of this compound, acronym of carbon-37, is founded a theory that is inspired by the essence of the human body and its temperature, in strict relation with the organic matter that presents a similar chemical composition. According to the Tyrolese lutist, unfortunately passed away, when you use the product you create a firm harmonic relation between the treated subject and the individual, which are put on a kind of vibratile communication. Granted that the human sensations are not universal, a recent study on violins has demonstrated the efficacy of the C37 theory. A professional musician in a blind test has classified as winner not a Stradivari, but a recent lacquered Ennemoser violin. I have a bottle of C37 lacquer: one day I will try it.


You cannot state that the RG7 is a trivial common electronic. On the contrary, despite its discrete look, it reveals itself as a magic box. When operational, you feel like making louder, although it does not loose its essence at very low volumes too. I have had the felling of catching also the natural reverberations of the sounds, as the instruments were structured and tangible in the room.

Masterly is the proposition of the low frequencies, with a depth beyond nature. As a reference are to be considered the mid-high, so strong, present, never aggressive. This device, with a power of 140 W into 8 ohms, in class AB, has a strong personality and gives sound performances of gold quality. It puts at disposal elements of study and speculation from philosophy to pure technique, with a marked esoteric nobility. To appreciate it entirely you have to remove every mental superstructure conditioned by specifications and electric parameters, which are unfamiliar to other homologous electronics of the same level.


The Symphonic Line “is” one of the few amplifiers that can affect the listener culturally, contributing to the supply of all the analysis and comprehension keys of the phenomenon known as music listening.

I have no doubts: Spark in the Dark!



Official technical specifications:

Power rating: 2x140W sinus at 8ohms, 2x250W sinus at 4ohms, 2x330W sinus at 2ohms

Currency: 60A per channel

Damping factor: over 800

Input impedance: 1V at 1OkOhm

Dimensions: 450x150x210mm WxHxD

Weight: ca. 28kg

Finish: chrome or aluminium black/silver

Distortion: not audible

Frequency range: 2Hz-400kHz

Slew rate/speed: 80Vµsec

Note: on complex demands, electrostatic loudspeakers and loudspeakers which demand low impedances, stable down to 1ohm


Official Italian dealer: to Il tempio Esoterico website

Official current price in Italy: 7,500.00 EUR

Associated equipment: to Giuseppe "MinGius" Trotto's system





Dear Mr Giuseppe Castelli

we are very happy about your Test Symphonic Line RG 7 MK 4 you Write very Fine and correct about our since 30 Years working for live Music with Dynamik and Heart in Natural Absolute High Fidelity.

Thanks and for your very good Magazine happy Future.

Rolf Gemein, Symphonic Line


by Giuseppe
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