fantasia Archives – Luxuryradios

Graetz Fa…

6th 10 月 20246th 10 月 2024
by giovanni

From the WW2 until the end of the 70s, the Graetz brand was one of the most prestigious German radio manufacturers.
Graetz devices have always been appreciated both for their elegant and refined finish and for the constant search for innovative acoustic solutions and related patents.
The Fantasia series is the most prestigious in all Graetz production.
Among these, the FANTASIA 622 is the last one equipped with Raumklang mit Schallkompressor (Surround sound with Compressor). The subsequent models, certainly for economic reasons, will be deprived of this ingenious, but expensive, sound diffusion system.

The Schallkompressor will be described in depth later on in the page, suffice it to say for now that some speakers diffused the sound through a specially designed path that made it impossible to locate exactly where the sound was coming from, making listening exactly the same in all points of a room.

The medium-high tones spread in all directions through the grille, which seems like a simple decoration, placed on the upper side of the cabinet.

The resulting effect is exciting, a sweetness of the high tones deriving from the front cone tweeter, combined with a depth of the bass caused by the muscles of the two large woofers, with a breadth of the sound image, deriving from the compressed flute supertweeter, that has no equal in monophonic devices.
I am not talking about high fidelity of course, but of very pleasant listening.

In all German radios produced for the European market before 1964 the FM band went from 87.5 to 100 MHz because at the time the FM transmitters were limited to those frequencies. In the following years in the most prestigious devices the FM band reached 104 MHz. Only a few years later the FM band was extended to the current 108 MHz.
In this Graetz Fantasia 622 the FM band goes from 88 to 108 MHz. This allows you to listen to all the stations that currently transmit in Frequency Modulation and not only the stations that transmit between 88 and 100 MHz like all the other German radios of that period.

Graetz had 4 lines of devices with ShallKompressor:
- the Music (the smallest, 1 woofer, 1 mid, 1 tweeter)
- the Melody (the medium, 2 woofers, 1 mid, 1 tweeter)
- the Sinfonia (the large, 2 + large woofers, 1 elliptical mid, 1 + large tweeter)
- the Fantasia (similar to the Sinfonia but with 2 EL95 power amps instead of one EL84)

The tuner section of the Fantasia 622 is similar to the excellent one of the Sinfonia 522 but the power amp is a Push-Pull of two EL95 pentodes. The output power is superior to any other Graetz equipped with Schallkompressor. With the Push-Pull output there is also a decrease in distortion and an increase in response linearity.

FM FREQUENCY RANGE

FM frequency range widened from 88 up to 108 MHz

BLUETOOTH

Bluetooth receiver embed

MULTI PLATFORM CONNECTION

Each radio is equipped with a cable for connection to any digital device.

- FM frequency range winded from 88 up to 108 MHz - The tube radios produced in Germany in the years 50/60 are famous worldwide for their excellent sound quality, the beauty of their furniture, their strength and for their construction standards without compromise. Unfortunately the FM band extending from 87.5 to 100 MHz for which are scarcely usable in most cases. After careful study and a lot of tests we were able to obtain a frequency range by this unit from 88 to 108 MHz . We have also reconstructed a display exactly identical to the original, made with the same materials and the same techniques, but with the new frequency span. The result is perfect. An original device, but with the ability to listen all stations in any country.
– Bluetooth receiver embed – The unit is equipped with a BLUETOOTH receiver powered directly by the receiver power supply. This makes it possible to control the amplifier from any external digital device as an IPAD, a Smartphone, or a sophisticated multimedia station. So you can hear your preferred web station or your lossesless file without cables on the room. Wireless Receiver can be equipped upon requests.
– Multi Platform Connection – A customized adaptation cable to connect any digital device as Iphone, Smartphone, Laptop, CD Player etc. will be provided with this radio. This special cable suits the different impedances between the modern equipment and the receiver. Furthermore the two stereo channels flow into one without increasing the load to the input unit.

The Ehrich & Graetz metalworks was a factory established in 1866 in Berlin by Albert Graetz (1831–1901) and the tradesman Emil Ehrich (died 1887) under the name “Lampen-Fabrik Ehrich & Graetz OHG” (E&G).
By 1897 the firm was controlled by Albert’s sons, Max Graetz, and Adolf Graetz. The company grew rapidly, and in 1899 a factory complex were built in Berlin, in the United States, France, the UK, and Bombay.
Around 1910-1916 Max Graetz developed the famous Petromax Lantern. Around 1925 the factory also produced radios, and other electrical appliances under the name Graetzor.

In the Second World War, just as in the First World War, the company was part of the war industry. With the use of forced laborers from France, Russia, and the Netherlands the company made huge gains in production.
At the end of April 1945 the factory was claimed by the Russian army.

In 1949 the firm became part of the “peoples” program, “VEB-VolksEigenerBetrieb” and since 1950 “VEB Fernmeldewerk, Berlin Treptow (RFT).” VolksEigenerBetrieb, means that the factory was owned by the people for the people (Communism).

In 1948 Erich, and Fritz Graetz founded a new company in Altena, Germany known by the name The Graetz Firm, which was successor to the lost family company in Berlin. The new company produced mainly radios, and televisions.
In 1961 the company was then sold to Standard Elektrik Lorenz (SEL) AG, but since 1987 has been to the present owned by the Finnish company Nokia.

In the natural evolution of the Sinfonia at Graetz model they began to use horn loudspeakers.
Horn speakers have the advantage of having a very small and light membrane. This translates into an ability to reach very high frequencies with very low distortion.
Like all musical instruments, this type of speaker is composed of a sound generator and a resonator. In a violin the strings vibrate and emit the sound, but it is the sound box that amplifies and colors it.
In horn speakers the small and very light membrane vibrates and then the horn amplifies, and sometimes modifies, the sound.
The trumpet has the disadvantage of being highly directive. A few cm from its axis the intensity of the sound changes considerably. The horn system, although very efficient and with low distortion, is not suitable
Graetz engineers preferred a tuned pipe instead of the horn due to its greater directionality characteristics.
The pressure of the sound wave goes with the square of the ratio between diameter and length of the tube. For this reason at Graetz they talk about a sound compressor.
So from the small emission of the cone membrane a large sound radiation is obtained at the exit of the tubes.
Furthermore, since the ratio between length and diameter of the pipe is very large, propagation similar to propagation on a duct of infinite length is obtained. The output slots are placed at different distances to achieve this non-resonant effect. The equivalent scheme is that of an LC circuit where the holes behave like inductors.
The result of this characteristic, combined with the particular shape and position of the sound output slots, is that the resonance frequency is around 12 kHz and this system is made to work in the range from 700 Hz to 10 kHz, precisely where the maximum sensitivity of the human ear, and where the voice and almost all musical instruments are located.
In addition to the advantages of absence of distortion and efficiency, the absence of resonances results in a notable softness of listening.
Lastly, this duct produces a slight delay, of a few ms, which by inducing a minimum natural reverberation obtains as a final effect that scenic depth which makes this device incredibly satisfying to listen to, despite being monophonic.

As previously mentioned, Schallkompressor means Surround Sound with Compressor.

I would like to point out that this company applied these concepts and these solutions (surround, sound compression) to commercial equipment, and it was 1958.

As everyone now knows, bass notes by their nature spread omnidirectionally in the environment, so it is rather difficult to locate a subwoofer with your eyes closed.
The speakers that spread the high notes, on the other hand, are extremely directive, so their positioning in relation to the listening position is very critical, so it is enough to move a little from the intended listening position to lose part of the message and detail of the highest part of sound information.

This problem has been addressed in the evolution of Hi-Fi systems with the most diverse systems.
Graetz solved this extremely effectively at the time with the 4R system in the previous Sinfonia models and the Schallkompressor in the models from 422 onwards.

On the left there is the volume control (with built-in loudness) and axially to this the rotation control of the ferrite antenna.
Above you can see the antenna position indicator.
The magic eye that indicates the perfect tuning of each station.
The AM scale for Long, Medium and Short Waves and the FM scale up to 108 MHz.
Below from the left we find in order the bass control knob, the power buttons, turntable, recorder, the buttons for receive Long Waves, Medium Waves, Short Waves, FM, the treble control knob.
The frequency band involved is indicated when you push each button.
Finally, there is the tuning knob, whose movement is very pleasant as it is supported by a large flywheel.
Below again we find the two large knobs for bass and treble control.
Axial to the tuning knob there is a selector for controlling selectivity in AM.
The registers and the exclusion buttons have been seen previously in detail.

922 - cn

Graetz Fa…

23rd 10 月 20187th 6 月 2022
by giovanni

Graetz is one of the most prestigious German radio manufacturers. The Graetz Fantasia 922 Luxus - Stereosuper was the flagship model in 1960.
Graetz devices have always been appreciated for their refined and elegant finish, as much as for the innovative acoustic solutions and their respective patents.
In designing the line of their flagship model, Graetz designers chose a classical and statuary kind of elegance.
The cabinet is in dark wood and the paint is very shiny. The sides with their variable width make the profile look slimmer. The base looks wide and solid, without making cabinet look heavy.
The strongly embossed texture of the canvas covering the speakers, the golden lines highlighted on the dark display and the light knobs make the visual impression even more pleasant and lively.
The stylistic attention, as in Graetz's tradition, is very accurate.

The Amplifier Section is the best that could be imagined at the time.
The Volume potentiometer has two sockets for loudness (red). As known, in fact, when listening at a very low volume the bass frequencies and the treble are not perceived with the same sound intensity as the mid, which appear to be predominant.
The loudness modifies the response of the preamplifier stage specularly to the Fletcher-Munson curves. This allows to maintain the correct perception of the sound, even at low volume levels.

The Tone Control was designed using the complex Baxandall circuit (green). The advantage of such circuit is its high precision, while the disadvantages are its cost and construction complexity. Much simpler and cheaper circuits were normally used. But not in this device.

The Balance (pink) is inserted into the feedback circuit. It works by changing the percentage of signal that is downgraded/relegated to each of the two channels. This signal is in inverted phase compared to the main signal. In this way, by acting on the balance, the level of one channel is lowered in comparison with the other and, at the same time, the distortion is reduced.
By turning the knob at the ends, this type of balance does not cause a reset of the volume of the channels as in the modern balance control, but it is to be considered a “fine” adjustment of the level between the two channels.

The Phase Inverter (blue) is of the Catodina type. As an advantage, it is very well-balanced. This circuit is still used in hi-fi amplifiers.

The Push-Pull section (blue) uses two separate tubes (EL95) for each channel. The EL95 are pentodi expressly designed for audio use.
In the receivers, even high-class, provided with Push-Pull output power, bulbs were normally used, which enclosed multiple valves (ELL80, ECLL800). In this way, space and components were saved. But if one of the pentods inside thei complex tube decays differently, the reproduction is altered, with an exponential increase in the crossover distortion. These multiple tubes, once common, are rare and expensive today, so the replacement can be economically significant. The use of separate pentods, as in the Graetz Fantasia 922, eliminates this problem, and it is possible to select pairs of EL95 with the same characteristics.
Only the Graetz Fantasia 922 and 1022 and the Telefunken Opus 2430/2550 use 4 x EL95 in the stadio finale.

The Tuner Section is also very well taken care of.
The most interesting feature is the high selectivity of this device, due to the twin IF stage. The two EF89 pentods and the numerous IF transformers, in fact, are visible in the photos.
In FM an additional transformer has been implemented, accordato all'interno del convertitore in order to make more stable and insensibile ai disturbi the reception of such frequencies.

Finally, the L0udspeakers set.
The Graetz 922 Luxus features 6 loudspeakers. Four are placed frontally and two on the sides.
The four front loudspeakers are two tweeters and two oval wideband. The tweeters are placed in front of the wideband, on the same axis. This particular arrangement has the great advantage of making the origin of the sound close to that produced by a point source.
This characteristic corresponds to a very linear scatter diagram, and therefore to a much more regular realistic sound image than if the tweeters and the woofers were placed side by side.
The two loudspeakers placed on sides are, at such power level, the mid / tweeters, and allow a balanced listening from any position with respect to the radio, frontally or sideways.

This last feature makes the device very enjoyable as for daily listening. You will no longer want to turn on the HI-FI system ...

BLUETOOTH

Bluetooth receiver embed

MULTI PLATFORM CONNECTION

Each radio is equipped with a cable for connection to any digital device.

- Bluetooth receiver embed - The unit is equipped with a BLUETOOTH receiver powered directly by the receiver power supply. This makes it possible to control the amplifier from any external digital device as an IPAD, a Smartphone, or a sophisticated multimedia station. So you can hear your preferred web station or your lossesless file without cables on the room. Wireless Receiver can be equipped upon requests.
- Multi Platform Connection - A customized adaptation cable to connect any digital device as Iphone, Smartphone, Laptop, CD Player etc. will be provided with this radio. This special cable suits the different impedances between the modern equipment and the receiver. Furthermore the two stereo channels flow into one without increasing the load to the input unit.

The Ehrich & Graetz metalworks was a factory established in 1866 in Berlin by Albert Graetz (1831–1901) and the tradesman Emil Ehrich (died 1887) under the name "Lampen-Fabrik Ehrich & Graetz OHG" (E&G).
By 1897 the firm was controlled by Albert's sons, Max Graetz, and Adolf Graetz. The company grew rapidly, and in 1899 factory complexes were built in Berlin, in the United States, France, the UK, and Bombay.
Around 1910-1916 Max Graetz developed the famous Petromax Lantern. Around 1925 the factory also produced radios, and other electrical appliances under the name Graetzor.

In the Second World War, just as in the First World War, the company was part of the war industry. With the use of forced laborers from France, Russia and the Netherlands the company made huge gains in production.
At the end of April 1945 the factory was claimed by the Russian army.

In 1949 the firm became part of the "peoples" program, "VEB-VolksEigenerBetrieb" and since 1950 "VEB Fernmeldewerk, Berlin Treptow (RFFT)." VolksEigenerBetrieb, means that the factory was owned by the people for the people (Communism)

In 1948 Erich, and Fritz Graetz founded a new company in Altena, Germany known by the name The Graetz Firm, which was successor to the lost family company in Berlin. The new company produced mainly radios and televisions.
In 1961 the company was then sold to Standard Elektrik Lorenz (SEL) AG, but since 1987 has been to the present owned by the Finnish company Nokia.

As previously mentioned, the most luxurious model produced by Graetz in 1960, the Fantasia 922, features 6 permanent magnet speakers.
The low and middle notes are reproduced by two large conical speakers, elliptical 26x17 cm.

High-pitched notes are reproduced by four cone loudspeakers. Two measuring 10 cm and two 6cm.

From the acoustic point of view, the interesting thing is not only the number of loudspeakers, but also their placement. The two 6 cm tweeters, in fact, are attached to the frontal Mid/Woofer, in a concentric position.
This is always my favourite placement and it is used in many of the best modern diffusers, such as KEF, TAD and Tannoy and many more.
The main advantage of a coaxial is the linearity of the off-axis response, both on the horizontal and vertical plane.
With the traditional positioning of the loudspeakers, the mid/woofer next to the tweeter, the off-axis listening is consistently disturbed by the phase cancellations caused by the length differences of the route between the two drivers.
The 3D graphics on the side display the measurements off the vertical axis of a box with coaxial loudspeaker KEF LS50 and one with traditional positioning of the YG Anat III. The difference is noticeable. (source: www.acousticfrontiers.com )

While frontally such an excellent configuration was used, what was done laterally is no less. In fact, on each side was installed a cone tweeter, protected by a metallic dome, Isophon HS10.
This loudspeaker has a very wide frequency response, from 1.000 to 20.000 Hz. So that all frequencies with pretty strong directivity features are reproduced also laterally.
The response to low frequencies is entrusted to the big frontal elliptics. In fact, low-frequency waves – as they are not directive by nature – do not need lateral loudspeakers in order to be perceived.

With this set of loudspeakers placed as described, the response is clearly quite linear from all angles, frontally, laterally and three-quarter.

As they are loudspeakers with an Alnico magnet, they are very efficient. The 7 Watts of each of the two channels are transformed into a noticeable acoustic pressure.
To provide a reference, during the listening at “normal” volume, not bothersome, a 0,2 Watt power delivery on the loudspeakers is measured.
The sound power is thus amply sufficient to sonorize even large environments.
The use of two separate Mid/Woofers has another advantage. The cones have less inertia compared to a larger single cone. In this way, the dynamic response is quick, and the lows are curbed and without resonance.
This feature allows to make the most of the AUX-in with lossesless digital files or CD, providing a brilliant reproduction rich in dynamism.

The tones control system is very efficient. Above the large tone control knobs there is a band that lights up gradually indicating the emphasis on the band on which it acts.

By pushing any of the Klangregister buttons, the tone-controls are excluded, since the frequencies connected with the chosen button are enhanced.
For this reason, the lights that enlighten the scale which indicates the tone-control position are turned off, too. They can be turned on again by pushing the Raumklang button and switching back to the manual setting of the favourite response curve.

Inside the cabinet there is a dipole for FM reception and a ferrite rotating aerial for AM reception.
Ferrite aerial can be rotated from the outside to achieve a perfect tuning of the device in the AM.
In this picture you can see the rotation mechanism, and the aerial position indicator.
The reception sensitivity with internal aerials is very good. This unit was in fact produced when there were not many radio stations, and those available were far from each other.
Using an external aerial sensitivity is further increased.

Left from the top:
- The Magic Eye that indicates the perfect tuning of each station.
- The antenna position indicator.

- The volume control (with built-in loudness)
- Axially this balancing.
- The rotation command of the ferrite antenna is still in axis.

- The bass control knob

In the center:
The AM display for long, medium, short waves and the FM display.

Right from the top:
The BANDBREITE indicator (High / Low selectivity in AM)
The tuning knob, whose movement is very pleasant being supported by a large flywheel
On the same axis there is a selector to control the selectivity in AM.
-The treble control knob.