german radios - fr Archives

Graetz Präludium 23F – fr

6th septembre 202430th septembre 2024
par giovanni

From the Second World War until the 1960s, Graetz was considered one of the most prestigious radio manufacturers, although it never achieved high sales performances due to the high cost and economic conditions of Europe at that time.
Graetz devices have always been appreciated both for their elegant and refined finish but above all, for the constant search for innovative acoustic solutions and the related patents.
The Graetz Präludium 23F was the most prestigious stereo receiver produced by Graetz from 1966 to 1968.
It is the last tube receiver produced by Graetz. It therefore benefited from all the know-how on tube amplifiers developed by the Berlin company since 1932.
In that period every important manufacturer, German or Japanese, offered a model of receiver, "Receiver" in German. Telefunken produced the two models Opus 2430 and 2550, Nordmende produced the Steuergerät 3004 Stereo, Grundig the Stereomeister series, 300, 3000, 15.
With this device, Graetz entered the delicate sector of "High Fidelity" devices as conceived in that period.
The tuner section is equipped with a multiplexer so that stations that broadcast in stereo are received in stereo, a real gem for the time.
The FM converter is equipped with AFC (Automatic Frequency Control) so that when you tune in close to an FM station the Praludium automatically centers itself at the point of maximum emission making listening pleasant and free from disturbances, as far as the reception conditions allow.
The low frequency stage is classic but with some interesting details. The Volume potentiometer for example is equipped with three sockets for a more progressive variation of the Loudness correction level, thus avoiding the annoying variation of the response curve as the Volume of the device increases, typical of simpler devices equipped with only one or in the best of cases two sockets on the potentiometer.
The feedback circuit and tone control are much simplified compared to the previous configurations used by Graetz designers. The feedback level remains low, ensuring a natural and stable sound.
The controls are very soft, simple and intuitive to operate.

The acoustic tests and recordings that we normally publish for each device on the Compilation page were not carried out because the result would depend mostly on the speakers chosen and not so much on the device itself.

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 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 (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.

3055 - fr

Grundig 3055/56 – fr

1st août 20245th août 2024
par giovanni

Also this reviews will be accompanied by a section with graphs of technical measures of the most important parameters.
There is no such thing anywhere else, as far as I know. Not even the manufacturers themselves detailed the technical features of their own devices at this level.
This new section has been developed for an objective comparison of different devices.
In order to avoid interpreting the measurements incorrectly, it is very important to read the warnings carefully the first time.

The Grundig 3055/56 was the most powerful radio model with a class A amplifier produced by the German company in 1956.

The FM converter stage is particularly interesting. In fact, it is equipped with double amplifier and oscillator circuits that can be selected via two buttons on the front. Furthermore, in the dialglass there are two identical FM bands, FM1 and FM2. Pressing the UKWI button and rotating the tuning knob will move the UKWI scale indicator, pressing the UKWII button and rotating the tuning knob will move the UKWII scale indicator. In this way it is possible to store an FM station in the UKWI band and another FM station in the UKWII band. The Grundig 3055 and 4055 are the only radios in the entire German production of that period to have two FM bands.

Unlike the previous model, Grundig 3055W/3D, the 3055/56 model is equipped with a rear socket for the remote control. The remote control allows you to turn the device on and off, vary the volume and choose one of the predefined equalizations present on the remote control.

The low frequency stage is an excellent example of a Class A amplifier with the famous EL84 pentode with well-known sonic characteristics.
The preamplifier is made up of the triode section of an EABC80. The circuit is classic and very well tested. The high quality of the sound is given by the excellent quality of the output transformer and its considerable size, which together with the good quality of the air gap laminations and the alternating winding of the copper layers reaches saturation very late.

The feedback, as usual, is moderate, and intervenes on the response curve. The resulting sound is very open, with great presence on the medium and high tones and sufficiently damped bass.

The cabinet is very sturdy and free of vibrations and resonances.

The speakers:
There are five speakers, three on the front and two on the sides.
It is a huge elliptical full-range driver and two electrostatic tweeters. On the sides we find two large elliptical full-range drivers.
The entire frequency range is sent to these full-range drivers with a slight cut in the upper part, in reality the actual cut of the upper part is mechanical.

All this translates into an exciting dynamic, brilliance of sound, lack of oscillations of the canvas in the presence of low frequencies, making listening to this beautiful device very realistic and pleasant.

The first song is by Etta James, it is I'd rather go blind recorded live in Montreaux in 1975. Etta James whose real name is Jamesetta Hawkins is one of the most beautiful and famous voices of blues and rock. Also memorable is her "At last" published in 1960. Etta passed away in 2012 due to diabetes and a serious leukemia after having fought for years with health problems and drug abuse. The song was written together with a singer-songwriter from Detroit, Ellington Jordan (Fugi), while the latter was in prison. In her autobiographical book James wrote that the song was about having been blind in her love life and in her daily habits. The version that is proposed here was recorded live in Switzerland, at the famous Montreux festival in 1975. In this interpretation Etta James, already a mature artist, was able to involve the audience by showing off her powerful voice, singing at times even without a microphone, and also exchanging a few jokes with the audience during the song. A true artist.

The second song performed by Chico Barque is entitled O que serà (a flor da pele). This very famous song is by Milton Nascimento (Milton Silva Campos do Nascimento), a recognized Brazilian composer who has collaborated with artists of the caliber of Wayne Shorter, Pat Metheny, Paul Simon, Cat Stevens, Quincy Jones. O que serà is a sweet song, in the classic Brazilian melodic style that tells of falling in love and its inevitable consequences, "What will it be, What happens inside us and what shouldn’t ... Who have no rest, nor will ever have, Who is not tired, nor will ever be, What has no limit". Francisco Buarque de Hollanda, real name Chico Barque is a Brazilian singer-songwriter, politically engaged against the Gorillas regime, exiled in Italy in 1969, he is also a poet, screenwriter and novelist. He also played with Stefano Bollani.

The third song is performed by Louis Armstrong, and is the famous song What a wonderful world. It is a song written by Bob Thiele and George David Weiss expressly for Armstrong. The two, Thiele and Weiss, were not yet very well known and the collaboration with Armstrong was an incredible opportunity for them. It was such a huge success that it overtook the Beatles from the first place in the English charts. In the USA it did not have the success it deserved because it was hindered by the number one of ABC records, Larry Newton, who wanted a swing song in the wake of "Hello, Dolly!" Armstrong was 62 years old at the time, his lips destroyed by the mouthpieces of the trumpet and his heart suffering, Thiele and Weiss created something that Louis could sing with his heart rather than with his voice. The song celebrates the wonders of the world, the beauty of nature and kind people. The song was included in the soundtrack of "Good Morning, Vietnam" directed by Barry Levinson.

The fourth song performed by Luciano Pavarotti and Barry White is the equally famous You'r the first, the last, my everything. Peter Sterling Radcliffe, a friend of White, wrote it in 1956 in a country style, calling it "You're My First, You're My Last, My In-Between". When White heard it, in 1973, he immediately liked it. While keeping almost all the chords, he changed almost all the lyrics and the melody. White had worked as the manager of the female trio "Love Unlimited" in the 60s and 70s. From 1972 he began recording under his own name. "You'r the first, the last, my everything" was released in 1974, on the album "Can't Get Enough" and was an immediate success. Pavarotti's splendid voice made it even more enjoyable.

BLUETOOTH

Bluetooth receiver embedn

MULTI PLATFORM CONNECTION

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

– 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.

1930 - At 22 years old Max Grundig begin a radio repair business.

1939 - The II world War start. Grundig works primarily for the Wehrmacht and repair of telecommunication equipment.

1945 - Immediately after the war, the demand for repair work was very great. Max Grundig built the first two Grundig appliances: the Tubatest tube tester and the Novatest testing device.

1947 - Start the sale of a kit radio, the Heinzelmann. The unit is the basis of success, sold more than 15,000 pieces.

1950 - Very high frequency (VHF) is introduced to Germany and places new demands on the industry. Grundig launches the 380 W on the market.

1952 - The first television channel starts up in Germany. After intensive research, Grundig launches the FS 080 onto the market. In the same year the first portable tape recorder Reporter 500 L is created.

1956 - After a lot of radio produced with progrssively high performances was produced the Concert Radio 5080 equipped with an equaliser, which has five controls and a visual display.

1965 - A new factory is established in Braga, Portugal. The Satellit 205 is one of many appliances in the Satellit series. This product marks the beginning of Grundig production of high-quality global receivers.

1970 - The Audiorama 7000 Hi-fi was produced, it has twelve dynamic speaker systems in one speaker.

1976 - The Reel Tape Recorder TS 1000 is equipped for semi-professional use.

1980 - The slim-line Hi-fi Tuner ST 6000 and the Monolith Hi-fi Dynamic Flat Top Antenna, which has 22 speaker systems, are two particularly popular appliances in the new hi-fi range.

1984 - After severe drop in sales Philips increased its stake in Grundig 31.6 percent and takes over the corporate management.

1997 - Philips pulls out of its involvement with Grundig.

2003 - The company files for bankruptcy.

2008 - Turkey's Koç Holding took full ownership of Grundig Multimedia B.V., the parent company of Grundig Intermedia GmbH in Nuremberg.

Courtesy of: Grundig

MEASURED TECHNICAL FEATURES

IMPORTANT REMARK
(to be read carefully at least the first time)

The following measures have been carried out in order to compare, from an electrical point of view, the devices that will be reviewed on this site. It is not possible to make comparisons with measurements made by other laboratories on different devices. The instrumentation and measurement conditions are probably very different.
The instrumentation used for the measurements is obsolete and unprofessional. We believe that more precise instrumentation is not necessary due to the tolerances of the human auditory system. Distinguishing a distortion of 1% from one of 1.1% or 1.001% only makes sense from the electrical point of view. Probably no one can hear the difference by ear. Only a child and very few lucky people can perceive the difference between a flat response curve up to 16 KHz and one up to 20 kHz.
The perception of sound depends on many factors, namely the age of the listener, the listening environment, the musical genre that is being reproduced, the listener's expectations, his or her listening habits and knowledge and many other factors, besides of course the quality of the other devices. Therefore, there is no direct and unique relationship between the results of the measurements made and the pleasantness of listening to a specific device.

BANDWIDTH

Normally the measurement of the bandwidth is done on a resistive load. Therefore, the deformation caused by the loudspeakers' inductive load and the effect of the mechanical resonance of the speakers themselves on the feedback circuit are not considered. The effects are by no means negligible, the measurements carried out on a purely resistive load are always very linear but they don't coincide with the real frequency response.

On the other hand, this response curve was measured on an inductive laod, that is, with its own loudspeakers.
The frequency response measurements were made with a sinusoidal generator and a Wandel & Goltermann WM – 20 level meter.
You can see the actual frequency response on the vobulator' screen.

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.

german radios - fr

Graetz Sinfonia 522 (88 – 108 MHz) – fr

22nd mars 202422nd mars 2024
par giovanni

From World War II until the 1960s, Graetz was considered one of the most prestigious radio manufacturers, although it never achieved high sales performance due to the high cost and economic conditions of Europe at that time.
Graetz devices have always been appreciated both for their refined and elegant finish but above all, for the constant search for innovative acoustic solutions and the related patents.
The Sinfonia series is the most prestigious Graetz production with a class A final stage.
Among these, the SINFONIA 522 is the last one equipped with Raumklang mit Schallkompressor (Surround sound with Compressor). 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 the page, suffice it to say for now that some speakers spread the sound through a specially designed path which made it impossible to locate exactly where the sound was coming from, making listening exactly identical in all points of a room .

The medium-high tones spread in all directions through the grille, which looks 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, which has no equal in monophonic devices.
I'm not talking about high fidelity of course, but about very pleasant sonic rapture.

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

Great radios, with a very pleasant sound, to listen to for hours.

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.

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.

capella 753 - fr

Philips Capella 753/4E/3D – fr

21st février 202421st février 2024
par giovanni

The Philips Capella 753/4E/3D was the company’s flagship model back in 1955, but in reality, the brand was working towards making it the best piece of technology to come out of Germany, blowing away the competition.

As a matter of fact, they met their goal and produced a unique piece of technology, for both the German and World Wide market.
It’s peculiarities are:

A motorized Tuning
6 memorizable stations
4 power tubes (2xEL84 and 2xUL84)
Dedicated amps for Hi and Low frequencies
An Iron-Free coupling output (OTL)
High Damping Factor with Negative Feedback circuit
4 High impedance speakers

Even though the Philips Capella 753/4E/3D boasts a noticeable size, it’s woodwork, frames, and speaker covers contribute in giving it a much sleeker, eye-pleasing look to complete any furniture display.
The Low frequencies are particularly deep thanks to the separated OTL amplifiers and to the impressive size of the subwoofer, approximately 26cm in diameter (more or less 30 inches).
I suggest making good use of the mid-tweeter, as this successfully crafted speaker (17 cm in diameter) makes the mid and Hi frequencies pleasant and true to life, especially if seated in front of the Machine.

High and Mid Frequencies sections
The FM group is of the variable permeability type.
It has a high amplification and stability. Being equipped with an automatic noise suppressor in the presence of signals below 1.7 V, the output is muted to avoid hearing rustling and noise when searching for stations.
The de-emphasis circuit is set to 50 uS, valid all over the world except for the USA and South Korea. In these countries, the filter should be increased to 75 uS.

The AM section is equipped with a rotating antenna for the OM and OL bands. The antenna can be controlled by a knob on the front.
The mid-frequency sections are composed of three separate filters for AM and FM. The first of these filters is adjustable. The second is the amplifier filter and the third filter further increases the selectivity of the device.

The Motorized Tuning and the amplifier section are examined in detail in the following sections.

All the listed solutions translate into a very low distortion, an increase in power, and a pleasantness of use hardly ever obtained in other appliances.
This is the Philips Capella 753/4E/3D

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.

In 1891, the brothers Gerard and Anton Philips, started to produce the first incandescent bulbs in Eindhoven.
Later, Philips specialized in the production of electro- medical equipment, and in 1918 introduced the first X-ray tube.
In the following years, Philips began specializing in the broadcasting industry. In 1932 the company succeeded in selling over one million radio equipment and became the world’s first producer.
During the Second World War, Philips transferred to the Netherlands Antilles, and returned to the Netherlands at the end of the conflict.
In the second post- war period, began the production of the first televisions, then the launch of the music cassettes in 1963 and the production of the first integrated circuit in 1965.
In 1982 Philips launched with Sony the first compact disc player.
In 1984 Philips acquired the control of the German Grundig.
In the 90's Philips faced a financial crisis.
In 1991 it inserted on the market the Video CD and it is one of the first companies in the world to develop high definition television.
In 1999 Philips established a joint venture with LG Electronics, named LG Display, which ends in 2009.
In 2006 together with Sony launched the first Blu-ray.
In 2009 Phillips launched the first full-HD LCD TV in 21:9 format.
Phillips holds 48,000 registered patents.
Currently, the production is focused on low- energy lighting products and LED systems and services for diagnostics and production of medical devices.

The preamplifier consists of two stages. At the entrance, the volume potentiometer is equipped with three sockets for physiological correction (loudness). The intervention curves are visible in the first graph.
Philips considers the frequency of 800 Hz to be the center of the audible band, so the treble and bass controls are calculated to enhance the frequencies above and below that value. The choice of this frequency is very important for the musicality and the pleasantness perceived by listening to the device.
In the second graph the frequency response of the preamplifier, with the tones enhanced to the maximum. You notice the different equalization you get by listening to the AM bands (Long Waves, Medium, Short) or listening to the FM band and PHONO.

The final stages are two distinct, one for the low frequencies and one for the high frequencies. These amplifiers control separate speakers, a 26 cm woofer for the bass and three speakers for mid/high frequency, with the 17 cm front speaker disconnectable for 3D effect.
The most interesting feature of these final stages is that they are without an output transformer.

The feature that makes this device very interesting is that each final stage uses a pair of EL84 / UL84 in an ironless configuration, ie without an output transformer (the known critical point of the final stage).
The output stage uses the operating principle called Shunt Regulated Push-Pull (SRPP) used today in HIGH-END amplifiers.
The output transformer limits the bandwidth of the entire amplifier. The bass is limited by the inductance of the primary winding, the treble is limited by the parasitic capacitance resulting from the alternation of the primary and secondary windings. The alternating winding of the primary and the secondary windings is also necessary to improve the coupling and thus reduce the dispersed flow.
The reduction of the dispersed flow increases the damping. This is essential in the loudspeakers mounted inside the cabinet of the radios, which do not work in hermetically closed boxes, and which are therefore free to move almost without resistance from the surrounding air.

The two output tubes (EL84, UL84) of each channel, four final valves in total, are connected in series with DC-DC coupling. Each UL84 is configured as a triode.
The output is taken from the cathode of the UL84. The speaker has an impedance of 800 ohms, identical to the average impedance that occurs on the catode, whereby direct coupling (without transformer) is possible between the final stage and the loudspeaker.
The Philips Capella 753 is therefore totally free of all the problems deriving from the output transformers.

The damping of the loudspeakers is kept high by the low dynamic resistance of the feedback loop.

Another feature of the Philips Capella 753/4E/3D is motorized tuning and preset memory.
Using 6 keys on the keyboard it is possible to memorize 3 FM stations, 2 in Medium Waves and 1 in Long Waves.
Pressing one of the storage keys via a cable pulls the lever H. The opposite side of that lever is pushed towards the disk R. This disk is divided into two parts with different diameters. Depending on how the disc is positioned, the lever H moves by activating a switch that turns the motor to the right or left until the lever H is fitted on the groove on the disc R. At this point, the motor stops. The R disks are rigidly connected to the axis A1 and through frictions to the R disk.

Tuning procedure

When a memory key is pressed, the motor will start to turn to the right or left according to the above.
Through the gears, Z1, Z2, Z4, Z5 the axis A1 is turned. Through the gears, Z6, Z7 the variable capacitor is rotated, which stops when the lever H engages in the groove of R.
To memorize a station, simply press the button on which it is to be stored, pull the tuning knob and turn it to the desired station.

The 28 cm loudspeaker, with a 25 mm diameter magnetic core, is placed at the front.
A front 17 cm mid-tweeter can also be switched off if you want to increase the 3D effect.
On the two sides, there are two elliptical tweeters pointing upwards. Radiating to the ceiling of the room to take advantage of the reflections of the environment that add to the direct radiation produce an expansion of the soundstage.
There are no dangers of stationary wave due to the working frequency of these speakers.

There are several options for connecting external speakers.
It is, in fact, possible to connect an external woofer, excluding or not the internal woofer while leaving all the other speakers active.
It is possible to connect external medium-high units, excluding or not the internal mid-tweeters, while leaving the internal woofer active.
It is possible to connect woofers and external medium-high units, excluding or not all, or some, internal speakers.

In the center of the speaker panel is the Magic Eye which indicates the perfect tuning of each station.
KLANGREGLER - Low Tone Indicator (FA Key) and High Tone Indicator (SOL Key).
Just below we find the large Volume knob, with built-in automatic loudness correction.
Coaxially you can see the 3 position Speaker Selector Lever (External Only - Indoor + Outdoor - Indoor Only)
Below we find the two coaxial knobs arranged horizontally, which respectively command the Bass Tones and the Treble Tones.
In the middle, we see the dial scale of the AM bands on a dark background (Long Waves - Medium - Short) and the dial scale of the FM band on a golden background.
FERROCEPTOR - Indicator of the position of the internal ferrite antenna. This internal antenna (excludable with the HA key) is used in the OM and OL bands. The internal antenna must be rotated until the best tuning is achieved.
Just below we find the large knob of the Manual Tuning, whose movement is very pleasant being supported by a large flywheel.
ZEIGER - Coaxially you can see the drive lever of the Motorized Tuning. It can be moved in the two directions, to the left or to the right.
Finally, underneath again we find the Rotation knob of the Ferrite Antenna.

To store a station you must:
1 - press the desired memory key.
2 - Pull the tuning knob and tune to your favorite station.
3 - Release the tuning knob.

german radios - fr

Grundig 5005W Enhanced- fr

21st février 202421st février 2024
par giovanni

The Grundig 5005W was the progenitor of a new line of Grundig radios model. The 5005W line will be followed, with some modifications, by the 5010, the 4010 and other less and less prestigious series.
From the previous top of the range model, the Spitzen-Super UKW 495W inherits the beautiful full-range speakers, one of which is equipped with a coaxial electrostatic tweeter.
There are also many mechanical elements in common with the 495W, the chassis has a very similar setup as does the high frequency group and the variable capacitor, the keyboard and much more. The tuner section is instead more elaborate, sensitive and selective and the low frequency section has completely changed.

The FM converter stage is interesting. Unlike the usual stages composed of the classic ECC85 double triode (specially designed for this), an ECF12 pentode/triode was used on the 5005W. The pentode section is used as an antenna amplifier and is very quiet for a pentode. The triode acts as an AF oscillator. There is then a further medium frequency amplifier pentode, an EF15, before entering the grid of the ECH11 amplifier/mixer.

The low frequency stage is an excellent example of a Push-Pull amplifier, with two EL41s, the most powerful compact tubes at the time.
The phase inverter stage consists of a double triode Ecc40 in "Anode follower" configuration. Also in this case the characteristics of the tube are important. To have correct driving of the two final EL41s, which work in Push-Pull, one on the positive half-waves and one on the negative half-waves, it is advisable to check the signal present on the two grids of the final pentodes. The configuration of the inverter might make you think that the two triodes of the ECC40 work symmetrically, but this is not the case. The first triode works as a preamplifier while the second has only the purpose of inverting the signal, indeed, it has a slightly negative amplification. The advantages of this type of inverter are the high voltage available at the output to effectively drive the finals and the high rate of internal feedback which guarantees a high linearity of response compared to other types of cheaper inverters.

The counter-reaction is moderate, and affects the response curve. The resulting sound is very open, with great presence in the mid and high tones and sufficiently damped bass.
The cabinet is very robust and free of vibrations and resonances.

The speakers:
There are three speakers, all on the front.
These are two full-range cones of 25 cm each and a coaxial electrostatic tweeter which is inserted when the TA button or the UKW/FST button is pressed.
The advantage of having two separate full-range speakers is that for the same amount of air moved, the cones and the voice coil support are much lighter to move, so each speaker is much faster and more responsive. All this translates into more responsive and muffled bass and without serious resonances.
The die-cast baskets ensure the mechanical rigidity of the speaker itself, therefore again reduction of resonances and greater efficiency of the transducer (no force is dissipated in the vibration of the basket).
The entire frequency range is sent to the full-range speakers and the high part is cut mechanically.

The front canvas covering the speakers is never completely transparent from an acoustic point of view.
For this reason the only way to obtain maximum performance from the appliance is to eliminate it.
We can build a false frame in which the original canvas has been installed. This frame attaches to the speaker panel with magnets.
In this way it is possible to detach it when you want to listen to music with maximum transparency and put it back in its place when the radio is at rest to protect the speakers from dust and to restore the original aesthetic appearance of the device.

All this translates into exciting dynamics, brilliance of sound, lack of canvas oscillations in the presence of low frequencies, making listening to this beautiful device very realistic and pleasant.

The first song is the famous Moanin' written and arranged by Charles Mingus. There are actually two different jazz classics called "Moanin'." Both are blues-based songs with gospel music influences. Both evoke, in different ways, a sense of pain but also a sense of exuberant life.
The song was recorded in 1959, the group members included four sax players, John Handy, Jackie McLean, Booker Ervin and Pepper Adams, two trombones, Jimmy Knepper and Willie Dennis, Horace Parlan on piano, Dannie Richmond on drums and Mingus on bass .
The original lyrics of Moanin', by Jon Hendricks and known on the popular album by Art Blakey and the Jazz Messengers, begin like this:

Every Mornin' finds me moanin'I'm alone and crying the bluesI'm so tired of paying the duesEverybody knows I'm moanin'

Every evening I am moanin''Cause of all I the trouble I seeLife's a loosing gamble to meEverybody knows I moanin'

Lord, I spend many a days and nights alone with my griefAnd I pray, really and truly praySomebody will come and bring me relief

The second song is "Smooth Operator" published by Sade in 1984. It was the song that made Sade famous in the USA. The song appears on her debut album, Diamond Life. "Smooth Operator" is about a charming con man who seduces high society women into getting money from them and breaking their hearts.
Despite the cold-hearted lyrics, this song is also often used in cinema in scenes of a romantic encounter.
An interesting curiosity: the music producer Robert Millar recorded the song for a demo to present to the record company to obtain a contract. Epic Records liked it so much that he released it exactly like that, without having it recorded again in the studio.

The third song is Walk On The Wild Side by Lou Reed. The song is very well known. From a musical point of view it is rather simple, supported by a bass line with repetitive "Du du du" choruses and an interesting baritone saxophone solo. The text, however, is the most provocative one could have imagined at the time. It talks about the gender world and male prostitution. Each verse introduces a new character, Holly (Holly Woodlawn), Candy (Candy Darling), Little Joe (Joe Dallesandero), Sugar Plum Fairy (Joe Campbell), and Jackie (Jackie Curtis). All cronies of the Andy Warhol Factory, as well as Lou. A cross-section of the Big Apple's underground.

The fourth song is Yakety Sax written by saxophonist Boots Randolph and guitarist James Q. "Spider" Rich. The song became famous as the closing song on The Benny Hill Show. It is a piece of "instrumental novelty song", a light piece of music which is usually, but not in this case (instrumental), accompanied by a fun and topical text. The song is inspired by Yakety Yak recorded in 1958 by the Coasters from which it took its title. Yakety Yak is a slang expression that means to talk for a long time for nothing, to chat in vain.

And finally, to really put the device to the test, the final part of the drum solo from Led Zeppelin's Moby Dick. In this piece the skill of John Henry "Bonzo" Bonham is expressed at the highest levels. Artistic heir to Ginger Baker, Bonham had developed spectacular right hand/left hand/foot sequences, which were particularly exciting for him in live concerts. The piece is really difficult and requires great strength, and probably also great anger. Bonham's life was filled with fights, trashed hotel rooms, drinking, orgies, except when he was at home in his cottage in Worcestershire. Bonham died at the age of 32 after choking on his own vomit one drunken evening.

BLUETOOTH

Bluetooth receiver embedn

CONNESSIONE A DISPOSITIVI DIGITALI

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

– 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.

1930 - At 22 years old Max Grundig begin a radio repair business.
1939 - The II world War start. Grundig works primarily for the Wehrmacht and repair of telecommunication equipment.
1945 - Immediately after the war, the demand for repair work was very great. Max Grundig built the first two Grundig appliances: the Tubatest tube tester and the Novatest testing device.
1947 - Start the sale of a kit radio, the Heinzelmann. The unit is the basis of success, sold more than 15,000 pieces.
1950 - Very high frequency (VHF) is introduced to Germany and places new demands on the industry. Grundig launches the 380 W on the market.
1952 - The first television channel starts up in Germany. After intensive research, Grundig launches the FS 080 onto the market. In the same year the first portable tape recorder Reporter 500 L is created.
1956 - After a lot of radio produced with progrssively high performances was produced the Concert Radio 5080 equipped with an equaliser, which has five controls and a visual display.
1965 - A new factory is established in Braga, Portugal. The Satellit 205 is one of many appliances in the Satellit series. This product marks the beginning of Grundig production of high-quality global receivers.
1970 - The Audiorama 7000 Hi-fi was produced, it has twelve dynamic speaker systems in one speaker.
1976 - The Reel Tape Recorder TS 1000 is equipped for semi-professional use.
1980 - The slim-line Hi-fi Tuner ST 6000 and the Monolith Hi-fi Dynamic Flat Top Antenna, which has 22 speaker systems, are two particularly popular appliances in the new hi-fi range.
1984 - After severe drop in sales Philips increased its stake in Grundig 31.6 percent and takes over the corporate management.
1997 - Philips pulls out of its involvement with Grundig.
2003 - The company files for bankruptcy.
2008 - Turkey's Koç Holding took full ownership of Grundig Multimedia B.V., the parent company of Grundig Intermedia GmbH in Nuremberg.

Courtesy of: Grundig

Year of production: 1951
Superheterodyne IF 468/10700
9 AM circuits
9 FM circuits

Wavebands:
Long wave: 150 - 310 KHz
Medium wave 1: 515 - 950 KHz
Medium wave 2: 950 - 1620 KHz
Short wave 1: 5,9 - 8,6 MHz
Short wave 2: 8,6 - 12,5 MHz
Short wave 3: 12,5 - 18 MHz
FM: 86,5 - 100 MHz

Loudspeakers:
2 x 24 cm Fullrange
1 x coaxial electrostatic tweeter

Dimensions (LHD): 706 x 396 x 288 mm / 27.8 x 15.6 x 11.3 inch
Net weight: 19.5 kg / 42 lb 15.2 oz

10 tubes: ECF12 EF15 ECH11 EBF15 EM71 EAA11 EF11 ECC40 2x EL41

MEASURED TECHNICAL FEATURES

IMPORTANT REMARK
(to be read carefully at least the first time)

The following measures have been carried out in order to compare, from an electrical point of view, the devices that will be reviewed on this site. It is not possible to make comparisons with measurements made by other laboratories on different devices. The instrumentation and measurement conditions are probably very different.
The instrumentation used for the measurements is obsolete and unprofessional. We believe that more precise instrumentation is not necessary due to the tolerances of the human auditory system. Distinguishing a distortion of 1% from one of 1.1% or 1.001% only makes sense from the electrical point of view. Probably no one can hear the difference by ear. Only a child and very few lucky people can perceive the difference between a flat response curve up to 16 KHz and one up to 20 kHz.
The perception of sound depends on many factors, namely the age of the listener, the listening environment, the musical genre that is being reproduced, the listener's expectations, his or her listening habits and knowledge and many other factors, besides of course the quality of the other devices. Therefore, there is no direct and unique relationship between the results of the measurements made and the pleasantness of listening to a specific device.

BANDWIDTH

5050W - fr

Grundig 5050W Enhanced- fr

15th octobre 20237th février 2024
par giovanni

The Grundig 5050W was the most prestigious model produced by the German company in 1953. The version we present in this review has been modified in order to maximize the performance of this device.

The FM converter stage is particularly interesting. Unlike the usual stages composed of the classic ECC85 double triode (specially designed for this) two separate tubes were used on the 5050W in order to avoid any capacitive interference between the antenna amplifier stage, consisting of a single EC92 triode and the oscillator stage /mixer, consisting of a double ECC81 triode. The stability and silence characteristics of this stage are excellent. It is only recommended to be very careful when replacing the ECC81 due to the differences in interelectrode capacitance between tubes from different manufacturers, which could cause differences in the operation of the stage.

The power output stage is an excellent example of a Push-Pull amplifier, with two EL84s with well-known sonic characteristics.
The phase inverter stage consists of a double triode Ecc81 in "Anode follower" configuration. Also in this case the characteristics of the tube are important. To have correct driving of the two final EL84s, which work in counter-phase, one on the positive half-waves and one on the negative half-waves, it is advisable to check the signal present on the two grids of the final pentodes. A possible correction can be obtained by intervening on the R8-R53 divider but the modification requires a certain amount of expertise and equipment.

The feedback is moderate, and affects the response curve. The resulting sound is very open, with great presence in the mid and high tones and sufficiently damped bass.
The cabinet is very robust and free of vibrations and resonances.

There are four speakers, all on the front.
These are two full-range cones of 25 cm each and two coaxial electrostatic tweeters which are inserted when the TA button or the UKW/FST button is pressed.
The advantage of having two separate full-range speakers is that for the same amount of air moved, the cones and the voice coil support are much lighter to move, so each speaker is much faster and more responsive. All this translates into more responsive and muffled bass and without serious resonances.
The die-cast baskets ensure the mechanical rigidity of the speaker itself, therefore again reduction of resonances and greater efficiency of the transducer (no force is dissipated in the vibration of the basket).
The entire frequency range is sent to these speakers and the high part is cut mechanically.

The front canvas covering the speakers is never completely acoustically transparent.
For this reason, the only way to obtain maximum performance from the appliance is to eliminate it.
We built a dummy frame into which the original canvas was installed. This frame attaches to the speaker panel with magnets.
In this way it is possible to detach it when you want to listen to music with maximum transparency and put it back in its place when the radio is at rest to protect the loudspeakers from dust and to restore the original aesthetic appearance of the unit.
As an example, we publish on the page a photo of a device previously made with detachable canvas.

All this translates into exciting dynamics, brilliance of sound, lack of oscillation of the canvas in the presence of low frequencies, making listening to this beautiful device very realistic and pleasant. With a pinch of eccentricity.

The first song Elli is taken from Avishai Cohen's album Continuo. The album consists of 10 songs where Cohen's bass is always present. The entire album is inspired by traditional Middle Eastern music with great attention to classical music and with energetic solo cues that make it one of the artist's most interesting productions. Amos Hoffman contributed the characteristic sound of his instrument, an oud, to some songs on "Continuo".

The second piece is the famous "Ave Maria" by Franz Schubert performed by the tenor Luciano Pavarotti. Schubert composed ''Liederzyklus vom Fräulein vom See'' (Song Cycle from the Lady of the Lake) in 1825, inspired by the poem The Lady of the Lake'' by Walter Scott. The third lieder of Schubert's work, it was composed for the female voice but is often performed by baritones or tenors.

The third song is taken from Ana Caram's album "Postcard from Rio". This is Samba Torto, a song by Antonio Carlos Brasileiro de Almeida Jobim. Tom, as Jobim called himself, knew how to blend samba and jazz, giving life to Bossa Nova. Tom then made Bossa Nova known in the USA and around the world. His most famous album, “The Man From Ipanema”, is worth listening to.

The fourth song is the very famous Back to Black by Amy Winehouse. Literally Back to Black actually means returning to a state of depression after the end of a love relationship. She herself specifies that it is a state of despondency in which the pain of loneliness drowns in alcohol and drugs. The reference is to her tormented history with Blake Fielder-Civil, which led to her death after a physically and psychologically toxic marriage, where Amy, already debilitated by eating disorders, did not last long.

The fifth song is Corpus Christi Carol by Benjamin Britten performed by Jeff Beck. Corpus Christi Carol was first performed by Leslie Woodgate. The text appears to be an allegory in which the crucifix is described as a wounded knight, and the knight could be Christ who bleeds incessantly for the sins of humanity. The lyrics of Britten's re-edition were taken from the Christmas carol "In the cold/grey, midwinter" by the English poet Christina Rossetti.