分类: <span>uncategorised – cn</span>

uncategorised - cn

Bang &#03…

Bang & Olufsen - High Fidelity Stereo Amplifier 608

The High Fidelity Stereo Amplifier 608 was produced from 1961 to 1964 and it's the first Hi-Fi stereophonic amplifier by Bang & Olufsen; that explains its great value, both historical and economic.
The second series had a dark gray front panel but no significant technical changes and together with the Grand Prix receiver it marks a groundbraking step  for the Danish firm's design.

The inner set up is a masterful piece of work: cables are put in order and wrapped in a waxed twine binding to create a solid unique body. The power tubes’ polarisation is fixed and each of them has an accurate Bias' control by specific trimmers, as shown in the restoration's photos.
The circuit is very stable due to a 22pF capacitor parrallel connected to a 100 kOhm resistance avoid auto-swinging. The feedback rate is very low.
The power tubes’ set up is ultralinear.
The direct coupling (no capacitors) between the voltage amplifier anode ECC83 and one of the two tubes for the phase splitter is another device's distinctive trait.
A differential circuit realise the phase reversal, in this way a perfect half - waves' symmetry and a remarkable voltage's gain are achieved.
The tones control circuit is a Baxandall, making symmetrical regulation curves (keep scrolling for answer's curves pictures).
Each final stage (two in all) is made up of an ECL85 (so, in total, there are four ECL85). The ECL85 is velvety like ECL86 but more powerful, indeed the rated output is highed than the same series' receiver Grand Prix Moderne Stereo 608.
It's very appreciable the chance to switch right and left speakers phase: if they were connected without paying attention the exact phase can be restored thanks to a switch on the frontal panel. The result, with the speakers in phase, is substantial; voices and solo instruments are clearly distinguishable and the scene take shape.
Not by chance, B&O became the official supplier of the Danish royal house.

This device, designed in an extremely sophisticated way, does not disappoint the listener's expectations: at first a well-finished and sweet sound can be gathered but by turning the volume knob and loudness switch (below in this page) its strengh and intensity are revealed.
A refined design, the charm of an old fashioned and expansive object, a precise and powerful sound and, last but not least, a small number of models, are all features of this fantastic device.

Designer: Architect Ib Fabiansen (1928 – 2009)

Fabiansen started developing modular units for radios and televisions complementing each other with the house forniture and establishing a pleasant surrounding.
In 1958 he made some cardboard models and presented them to Bang & Olufsen management, that immediately approved its production. So he started sketching the Beolit series and other B&O devices, including Hi-Fi Amplifier 608.
In 1962 he designed Beocord Belcanto recorder, Horizont television and so on, until his last creation for B&O, the gramophone TV/radio Beovision 2000RG.
In the last years working for B&O, he cooperated with architecs Henning Moldenhawer an Jacob Jensen.
".. there was a time when it was far from a certainty that a radio from Bang and Olufsen was a study in good design..It was horrible, simply horrible” sayed back then Fabiansen.
Ten years later Jacob Jensen would become the company's chief designer.


To make the most of this device I chose four songs. The first one is “Una ragione di più” by Ornella Vanoni, a beautiful song with lyrics by Franco Califano, Ornella Vanoni and Luciano Beretta, music by Mino and Franco Reitano. Presented in 1969 on the tv show “Senza rete”, the song is about a woman questioning her relationship, and her hard choice between leaving her partner and trying to revive their love from ashes. Ornella's voice is warm, deep and with a great vocal range, which the B&O 608 conveys in all its richness.

The struggle of a love song counterpoints the struggle for exile and oppression is in the second song I propose. It's of an Angolan songwriter, José Adelino Barceló de Carvalho aka Bonga. The title of the song is “Mona Ki Ngi Xica” ad it was written in 1972, while Angola was under Portuguese rule and the author had to flee to the Netherlands because of his politics involvement to free his nation. The lyrics are in Kimbundu, an Angolan dialect. Here, too, a rough and peculiar voice is reproduced in its wholeness by the 608.

Going on with love sufferings (that's the mood of the day), the third track is about a young man and his love, not returned by the girl he loves. It's the well-known song “Say Say Say” by Paul McCartney and Michael Jackson, recorded in 1983 before their quarrel. It seems that McCartney was quite afraid of dancing together with Jackson in the song's videoclip (we can't blame him), but still a true friendship was born, until Jackson bought the Beatles' recording royalties for 47,5 million dollars, snatching them from McCartney and Yoko Ono.

The fourth and last track is Mahler's Symphony N. 5, written between 1901 and 1902. Its theme, sentimental and painful, turns away from the preceding four symphonies, which are about medieval german poetry. The mighty first movement is driven by trumpets and the vigorous orchestral cue does not scare the 608. It's important that the speakers are properly in order.

 

Ornella Vanoni - José Adelino Barceló de Carvalho (Bonga)

BLUETOOTH

Bluetooth receiver embed

READ MORE >

MULTI PLATFORM CONNECTION

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

READ MORE >

TUBESOUND IMPROVEMENT

- 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.

B&O Grand Prix Moderne 608

B&O Grand Prix Moderne 608
BEOLIT 39

HISTORY

1925 - Two Danish engineers, Svend Olufsen and Peter Bang, start the production of radio equipment in the attic of the Olufsen family, in Struer.
1927 - The first device, called the “Eliminator” (as it allowed to eliminate the battery power and to connect the device directly to the power grid), is commercialized.
A production plant is built in Struer.
1929 - The "Five Lamper" model (five valves) is marketed and is a great success.
1938 - The beautiful Master 40 model arrives, which allows to memorize stations from the keyboard.
1939 - Beolit ​​39 is launched, the first radio with a  bakelite cabinet. From this moment on, the prefix “Beo” will be used for the most prestigious products of the brand.
1941 - During the German occupation, B&O puts on the market the Grand Prix 42CH which has the characteristic of having a tambour door that covers the scala parlante when it is not used.
1945 - The B&O factory is completely destroyed.
1948 - After a rapid reconstruction of the factory, the production of the Grand Prix 48 CH mobile radio is started, the first high-fidelity radio of the Danish company.
60's - A revolution at B&O. The designer Ib Fabiensen designs the new line of devices, Hi-Fi Stereo Amplifier 608, Grand Prix 608 Moderne, Dirigent 609. Also the Beogram 42 turntable is commercialized. It is with these models that the legendary design of B&O devices begins.
70's - In the 60s and 70s, the devices that make B&O famous in the world are produced. The Beomaster 1200 and 3000, the Beogram 1200 and the Beogram 4002, the beautiful giradischi tangenziale. The devices are designed by Jacob Jensen.
80's - The evolution of design continues with the different Beocenter units and the Beogram cd players.
90's - The company decides to market its products through a network of its own exclusive stores. It expands its interests with the production of mobile phones and Mp3 players.
2008 – It suffers considerable losses and a staff reduction and in the following years it returns to devote itself exclusively to the production of High Fidelity devices.
2015 - B&O becomes a partner of HP.

B&O Grand Prix Moderne 608

 

B&O Grand Prix Moderne 608

MAIN FEATURES

Year of production: 1961-64

Power supply: 110-220 V - 75W

Loudspeakers: Screw Plugs for External 4-16 ohm loudspeakers

Output power: 15W each channel
Distortion: <0.5 % a 10W, <2 % a 15 W
Channel separation: - 50 dB
Noise level: - 60 dB
Frequency response: 20-20,000 Hz <1 dB
Min. input level:
Magnetic Pickup 2 mV, DIN 45547  RIIAA equalized
Piezo Pickup:  50 mV
Aux: 100 mV,
Microphone: 160 mV
Tuner: 50 mV

Measurements (LAP): 465 x 180 x 208 mm / 18.3 x 7 x 8.2 inch
Net weight: 10.5 kg / 23 lb 2 oz

5 Tubes: ECC83 ECL85 ECL85 ECL85 ECL85
8 Transistors: 2xAC107, 6xAC126(OC75)

Controllo toni

In these pictures we can see how much the tune's control system is efficient: in the ones above there's the controls' position in the amplifier, in the ones below the real response curve measured with Wandel&Goltermann WM-20 wobbulator. Measurament done on 4 ohm resistive load.
In the first two pictures on the left we can see the tunes in Flat position: the answer, from 20 to 20000 Hz, stays between ± 1 dB. Others pictures explain themselves.

LOUDNESS CONTROL

The device has a remarkable loudness control system. We know that our ears, listening at low volume, perceive better medium frequencies, losing the low and high ones. If low frequency sounds are emitted, medium frequencies are easily perceptible by human ear than low, very low and high ones. That's why, for these listening levels, manufacturers implemented automatic mechanism to amplificate low and high frequencies.

Today this control practice is seen as a forced sound's alteration and is not implemented in amplifiers. Sometimes is not inserted at all, but if it's stil present there's the possibility to exclude it with a knob on the front panel.

On B&O Hi-Fi Amplifier 608 there is a switch for low, medium, high, referring to the listening volume.
With the switch on LOW, loudness control (exalting low and high frequencies) applies at 10 Phon on the Fletcher – Munson curve; with this setting, sound level acheivable operating on volume knob is gentle and is suitable for listening at a low volume.
Putting the switch on MEDIUM, loudness control applies at 50 Phon; low and high frequencies are slightly exalted, you can get a higher sound level and it's good for listening at a medium volume.
With the switch on HIGH there's no more loudness control and response is linear on all frequencies but sound level you get operating on the knob is not maximum. Thanks to this setting you reach amplifier's full power and it's right for listening at its highest volume.

Bang & Olufsen – Grand Prix Moderne 608K

LOUDSPEAKERS

This stadio amplificatore  is gifted with noticeable transparency and detail.
The coupling with high-efficiency loudspeakers with neutral tone is therefore very suitable to enjoy these peculiarities to the fullest.
The loudspeakers must be connected with banana plugs on the outputs, respectively:

Højre - Right channel
Venstre - Left channel

The Bang & Olufsen loudspeakers, designed to be coupled to the Grand Prix Moderne Stereo 608, were the Type S (left) and Type L (right) models.
The recordings I posted on this page were made with TRIO-KENWOOD KL333 loudspeakers. I chose these speakers for their efficiency and the very high cut-off frequency that makes them sound almost like full-range speaker.

Bang & Olufsen – Grand Prix Moderne 608K

Beginning from the left in the upper part, the first knob you meet is that of inserting the filters. The switch has 4 positions.

OFF - No filter is active - Linear response
RUMBLE - Very low frequencies are attenuated to avoid reproducing the mechanical noises of the turntable
SCRATCH - The high frequencies are attenuated to attenuate the defects of damaged discs when listening.
RUMBLE + SCRATCH - Both filters inserted
Attentions! The RUMBLE filter introduces a 45 degree phase shift at the cut-off frequency and both filters proportionally attenuate all the frequency band of the respective working range. Avoid using them if possible, better couple the amplifier to a good turntable and treat the records with care.

Below we find the INPUT SELECTOR
PHONO - Turntable with magnetic head
TAPE - Recorder / AUX
RADIO - Tuner / AUX
MICR - Microphone

Then we find the MONO / STEREO / PHASE REVERSE switch
This last position of the switch allows to invert the phase of one of the low impedance outputs (loudspeakers) to have all the movements of the cones in phase.
Still to the right the two tone controls LOW and HIGH. Above the tone controls is the display that indicates their position by highlighting the response curve of the amplifier.

Still on the right we find the BALANCE between the two channels, right and left.
The largest knob is the VOLUME knob with built-in ON / OFF switch. Turning the knob clockwise turns on the amplifier.
Above we see the 3-position LOUDNESS switch.

REAR SIDE

110V-220V voltage change
Switch Speaker Impedance 4 Ohm - 16 Ohm

OUTPUT

2 x additional US type mains voltage sockets (220-110V)
Screw connectors for left and right speakers
2 x line signal RCA sockets (e.g. for recording)

INPUT

2 x RCA plug - Pick-up
2 x RCA plug - TUNER/AUX
2 x RCA plug - TAPE RECORDER/AUX
2 x RCA plug - Microphone

RESTORATION STEPS

THE USUAL AMAZING LAST IMAGE
Grand Prix 609 K Moderne uncategorised - cn

Bang &#03…

Bang & Olufsen – Grand Prix Moderne Stereo 608

Bang & Olufsen - Grand Prix Moderne Stereo 608

The Grand Prix Moderne Stereo 608 is the first stereo receiver produced by Bang & Olufsen.
From this derives its great historical and economic value.
Produced in 1961, it represents not only an evolution, but a real epochal changeover in the design of the Danish brand.

In the inside, the execution is exemplary. The cables are well arranged and wrapped in a ligature with waxed string that collects them in a single, very solid body.
The power supply consists of an independent block, separate and far from the amplifiers.
The AM / FM radio section is equipped with a medium-frequency double stage to improve the selectivity of the device.
A section of a ECC83 double triode is used to compensate for the attenuation introduced by the Baxandall tone control section.
Very few radios, even among high-class models, were equipped with a Baxandall circuit for tone control. The builders almost always preferred simpler and cheaper circuits, even if the circuit response were not completely symmetrical.
The two amplifiers, one for each channel, are made of a couple of ECL86s. For a total of four ECL86s.
All are mounted on their own vertical board so that the final valves, the four final valves, are arranged horizontally in order to better dissipate the heat. In this way, in fact, the tubes cool uniformly throughout their length.
The triode sections of the ECL86 ensure phase inversion while the pentode sections are connected in Push-Pull and constitute the outuput amplifier.
The power supplied is approximately 10W per channel.
Everything about this device was based on the search for quality. On the other hand, the B&O was proud to be the official supplier of the Danish royal house.

The restoration of this device was thorough.
The amplifier stages have been completely renewed. Each component has been replaced with a high quality correspondent or audiophile.
All the old carbon composite resistors have been replaced, with 10% tolerance but almost all altered and very noisy.
The excellent but unfortunately aged Mustard condensers have all been replaced with Auricap audiophile.
All electrolytics have been replaced with components capable of withstanding high temperatures.
The original bakelite socket of the tubes have been replaced with new high-quality ceramic sockets and high-quality gold contacts.
The valves have been selected all with equivalent characteristics, so as to avoid imbalances between one channel and another.

The results of this excellent project and of the very high quality of the components used in the process are the extreme definition and the sweetness of reproduction.
I believe the Grand Prix Moderne Stereo 608 is especially suitable for recordings with voices or solo instruments.
New Age and electronic music is reproduced with great satisfaction.
The fact that this warm and precise sound is played by a fascinating and rare machine from the 60s just complements the invaluable magic.

The sweetness this machine impresses me with makes me think that it might be possible to use it in music therapy or sound baths. Although for this purpose the use of live instruments is unsurpassed.
But this is a complex and controversial topic and it will be the subject of in-depth studies and discussions in the future.


The first track of the playlist I chose in order to test this device is Sit tecum timor suus, from Giacomo Carissimi's Historia di Job (Marino 1605 - Rome 1674).
It belongs to  the musical genre called Oratorio, and in particular of the Oratorio in Latin and with a biblical subject, of which Carissimi is one of the greatest exponents.
This musical genre has very ancient origins, as it comes from Passions and Mottetti. This is very interesting, because being detached from the liturgical function it exalted the practice of music for the purpose of spiritual elevation. Music as an instrument of diffusion of elevated principles was strongly pursued by Filippo Neri who, similarly to the Lutheran rite, intended to bring the evangelical message closer to the people.
Going back to Carissimi, chapel master in the Basilica of Assisi and then choirmaster in the Germanic College of St. Ignatius of Loyola in Rome, in the Historia he uses both monody and polyphony, emphasizing, according to some critics, the expressive power of the work. From the manuscripts it appears clear that the instrumental element is the pipe organ, rarely accompanied by bowed or wind instruments.
After Carissimi, the Latin Oratorio will lose importance while the vulgar Oratorio will continue to be practiced.
In Naples, Alessandro Scarlatti writes La Vergine Addolorata, a mature work with alternating refrains, arias and instruments that accompany the recitative. This use of the orchestra brings the work closer to the genre of drama. The second track of the playlist is drawn from this wonderful Oratorio.
In Venice the Oratory, clashing with the profane melodrama prevailing at the time, is expressed in the works of Giovanni Legrenzi, Baldassare Galuppi and Benedetto Marcello, up to Juditha triumphans by Antonio Vivaldi, which will be discussed in a future review.

B&O Grand Prix Moderne 608

B&O Grand Prix Moderne 608

La pazienza di Giobbe - Sebastiano Ricci - Museo Civico di Belluno

BLUETOOTH

Bluetooth receiver embed

READ MORE >

MULTI PLATFORM CONNECTION

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

READ MORE >

TUBESOUND IMPROVEMENT

- 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.

B&O Grand Prix Moderne 608

B&O Grand Prix Moderne 608
BEOLIT 39

HISTORY

1925 - Two Danish engineers, Svend Olufsen and Peter Bang, start the production of radio equipment in the attic of the Olufsen family, in Struer.
1927 - The first device, called the “Eliminator” (as it allowed to eliminate the battery power and to connect the device directly to the power grid), is commercialized.
A production plant is built in Struer.
1929 - The "Five Lamper" model (five valves) is marketed and is a great success.
1938 - The beautiful Master 40 model arrives, which allows to memorize stations from the keyboard.
1939 - Beolit ​​39 is launched, the first radio with a  bakelite cabinet. From this moment on, the prefix “Beo” will be used for the most prestigious products of the brand.
1941 - During the German occupation, B&O puts on the market the Grand Prix 42CH which has the characteristic of having a tambour door that covers the scala parlante when it is not used.
1945 - The B&O factory is completely destroyed.
1948 - After a rapid reconstruction of the factory, the production of the Grand Prix 48 CH mobile radio is started, the first high-fidelity radio of the Danish company.
60's - A revolution at B&O. The designer Ib Fabiensen designs the new line of devices, Hi-Fi Stereo Amplifier 608, Grand Prix 608 Moderne, Dirigent 609. Also the Beogram 42 turntable is commercialized. It is with these models that the legendary design of B&O devices begins.
70's - In the 60s and 70s, the devices that make B&O famous in the world are produced. The Beomaster 1200 and 3000, the Beogram 1200 and the Beogram 4002, the beautiful giradischi tangenziale. The devices are designed by Jacob Jensen.
80's - The evolution of design continues with the different Beocenter units and the Beogram cd players.
90's - The company decides to market its products through a network of its own exclusive stores. It expands its interests with the production of mobile phones and Mp3 players.
2008 – It suffers considerable losses and a staff reduction and in the following years it returns to devote itself exclusively to the production of High Fidelity devices.
2015 - B&O becomes a partner of HP.

B&O Grand Prix Moderne 608

 

B&O Grand Prix Moderne 608

MAIN FEATURES

Year of production: 1961

Superheterodyne IF: 468/10700
9 AM Circuits
13 FM Circuits

Wavebands:
Medium Waves, Long Waves, 2 x Short waves, FM

Loudspeakers
Banana Plugs for External loudspeakers

Dimensions (LHD): 635 x 240 x 275 mm / 25 x 9.4 x 10.8 inch
Net weight: 12 kg / 26 lb 6.9 oz

Tubes 11:
ECC85 ECH81 EF89 EBF89 EM84a 2 x ECC83 4 x  ECL86

 

Bang & Olufsen - Grand Prix Moderne 608K

AERIALS

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 see the rotation mechanism and the position indicator of the aerial.
The reception sensitivity with internal aerials is very good. This unit was in fact produced in a period when there were not many radio stations and those available fairly apart from each others.
Using an external aerial sensitivity is further increased.

Bang & Olufsen - Grand Prix Moderne 608K
Bang & Olufsen – Grand Prix Moderne 608K

SEPARATE CONTROL TUNING BETWEEN AM AND FM

The unit is equipped with mechanisms that control separately the AM band tuning and the FM band.
The tuning knobs are coaxial.
The largest crown controls the FM band.
The frontal knob, smaller, controls the AM bands (short, medium and long waves).

Bang & Olufsen – Grand Prix Moderne 608K

TUNING INDICATOR

The magic eye has of course been replaced.

Bang & Olufsen – Grand Prix Moderne 608K
Bang & Olufsen – Grand Prix Moderne 608K

LOUDSPEAKERS

This stadio amplificatore  is gifted with noticeable transparency and detail.
The coupling with high-efficiency loudspeakers with neutral tone is therefore very suitable to enjoy these peculiarities to the fullest.
The loudspeakers must be connected with banana plugs on the outputs, respectively:

Højre - Right channel
Venstre - Left channel

The Bang & Olufsen loudspeakers, designed to be coupled to the Grand Prix Moderne Stereo 608, were the Type S (left) and Type L (right) models.
The recordings I posted on this page were made with Grundig 306A loudspeakers. I chose these loudspeakers for their detail and for the very deep bass they can express.

Bang & Olufsen – Grand Prix Moderne 608K

CONTROL PANEL

Bang & Olufsen – Grand Prix Moderne 608K

The front side can be imagined as divided into two horizontal sections.
In the upper part, the first knob is that of the volume with built-in loudness.
Coaxially, the ferrite antenna control knob can be seen.
Then, we see the AM scale for short, medium and long waves. The FM scale.
In the center we find the Magic Eye, which indicates the best tuneing of the different stations.
On the right of the dialglass, then, we see the two separate tuning controls.
The rear knob, bigger, controls the FM band.
The frontal knob, smaller, controls the AM bands.

In the lower section we find in the order:

BAS - Bass Control
Loudspeakers Selection knob with the following functions:
- Reverse of DX / SX channels
- Normal
- 4 progressive volume levels of additional loudspeakers

AFBR - ON / OFF
+ EKTRA - Insertion of additional loudspeakers
EKSTRA - Insertion of main loudspeakers
STEREO - Stereo / Mono
GR - Turntable (Pressing together GR and LB the TAPE input is selected)
FERRIT OG / INDTR AFBR - Ferrite Antenna (AM) / Automatic Frequency Control (FM)
LB - Long Waves
MB - Medium Waves
KB2 – Short Waves 2
KB1 – Short waves 1
KB1 + KB2 - Recorder
FM - FM
BALANCE - Right and left channel balance
DISKANT - Treble

Bang & Olufsen – Grand Prix Moderne 608K

REAR SIDE

Antenna Input:
- (Sx brown socket) Antenna for AM and Ground pin
- (Red socket) FM Antenna
- (Dx brown socket)  Antenna for AM and FM both and Ground pin

Tape Recorder Input (Beocord).

External loudspeakers:
Højre - Right channel
Venstre - Left channel
Ekstra - Additional loudspeaker
Ekko H - Additional Right channel
Ekko V - Additional Left channel

Turntable Input (pick-up)

RESTORATION STEPS

THE USUAL AMAZING LAST IMAGE
Bang & Olufsen – Grand Prix Moderne 608K
Graetz Sinfonia 422 uncategorised - cn

Graetz Si…

GRAETZ Sinfonia 522 (88 – 108 MHz)

GRAETZ SINFONIA 522

Dalla seconda guerra mondiale fino agli anni Sessanta, Graetz è stato considerato uno dei più prestigiosi produttori di radio, anche se non ha mai raggiunto performance di vendita elevati a causa del costo elevato e delle condizioni economiche dell'Europa in quell'epoca.
Gli apparecchi Graetz sono sempre stati apprezzati sia per la loro finitura curata ed elegante ma soprattutto, per la ricerca costante di soluzioni acustiche innovative ed i relativi brevetti.
La serie Sinfonia è la più prestigiosa tra produzione Graetz con stadio finale in classe A.
Tra queste la SINFONIA 522 è l'ultima dotata di Raumklang mit Schallkompressor  (Surround sonoro con Compressore). I modelli successivi, certamente per questioni economiche, verranno privati di questo geniale, ma costoso, sistema di diffusione del suono.

Lo Schallkompressor verrà descritto approfonditamente più avanti, nella pagina, basti dire per ora che alcuni altoparlanti diffondevano il suono attraverso un percorso appositamente progettato che rendeva impossibile localizzare esattamente da dove arrivasse il suono, rendendo l'ascolto esattamente identico in tutti i punti di una stanza.

I toni medio-alti si diffondono in tutte le direzioni attraverso la griglia, che sembra una semplice decorazione, posta nel lato superiore del mobile.

L'effetto che ne deriva è entusiasmante, una dolcezza dei toni acuti derivante dal tweeter a cono anteriore, unita ad una profondità del basso provocata dai muscoli dei due grossi woofer, con una ampiezza dell'immagine sonora, derivante dal supertweeter compresso a flauto, che non ha eguali in apparecchi monofonici.
Non parlo di alta fedeltà naturalmente, ma di gradevolissimo rapimento sonoro.

La Graetz aveva 4 linee di apparecchi con ShallKompressor:
- la Musica (la più piccola, 1 woofer, 1 mid, 1 tweeter)
- la Melodia (la media, 2 woofer, 1 mid, 1 tweeter)
- la Sinfonia (la grossa, 2 woofer + grandi, 1 mid ellittico, 1 tweeter + grande)
- la Fantasia (come la Sinfonia ma con finali 2 EL95 al posto di una EL84)

Grandi radio, dal suono piacevolissimo, da ascoltare per ore.

 

Questo è l'apparecchio con Compressore Sonoro esteticamente più bello prodotto dalla Graetz nel 1958

Graetz Sinfonia 522

 

ESTENSIONE BANDA FM
La frequenza della banda FM è stata estesa a 88 - 108 MHz

CONTINUA >

BLUETOOTH
Ricevitore Bluetooth integrato

CONTINUA >

CONNESSIONE A DISPOSITIVI DIGITALI
Ogni apparecchio viene dotato di un cavo adattatore per connettere qualsiasi dispositivo digitale.

CONTINUA >

ELABORAZIONI TUBESOUND

- Banda di Frequenza FM allargata a 88 - 108 MHz. Le radio a valvole prodotte in Germania negli anni 50/60 sono famose in tutto il mondo per la loro eccellente sonorità, la bellezza delle loro finiture, la robustezza ed il loro standard di costruzione senza compromessi.
Purtroppo la banda FM di estende dai  87.5 ai 100 MHz  per cui ricevono solo alcune stazioni.
Dopo attenti studi ed un gran numero di provesiamo stati in grado di allargare la banda ricevibile da 88 a 108 MHz.
Naturalmente abbiamo dovuto ricostruire anche la scala parlante, identica all'originale, fatta con gli stessi materiali e le stesse tecniche, ma con il nuovo intervallo di frequenza.
Il risultato è perfetto. Un apparecchio originale ma con la possibilità di ascoltare qualsiasi stazione in qualsiasi parte del mondo.
Ricevitore Bluetooth integrato – Questa unità può essere equipaggiata con un ricevitore BLUETOOTH alimentato direttamente dall'apparecchio Questo rende possibile usare l'amplificatore da qualsiasi dispositivo digitale esterno, come IPAD, Smartphone, o sofisticate stazioni multimediali. Potrete ascoltare le vostre Stazioni Web o le vostre musiche preferite senza cavi in giro per la stanza. Su richiesta è possibile anche montare un Ricevitore Wireless.
Connessione Multi-Piattaforma – L'apparecchio viene fornito di un cavo di adattamento che permette di collegarlo a qualsiasi dispositivo digitale come A Iphone, Smartphone, Laptop, CD Player etc. Questo cavo speciale permette di adattare l'impedenza tra l'apparecchio ed i moderni dispositivi. Inoltre i due canali stereofonici vengono fatti confluire in un unico canale monofonico senza incrementare il carico dell'unità sorgente.

Graetz Sinfonia 522

 

graetz factory

 

LA STORIA

La Ehrich & Graetz AG fu fondata nel 1866 a Berlino da Albert Graetz (1831-1901) e dal commerciante Emil Ehrich (morto nel 1887) con il nome di "Lampen-Fabrik Ehrich & Graetz OHG" (E & G).
PetromaxNel 1897 l'azienda passa sotto il controllo dei figli di Albert, Max Graetz, e Adolf Graetz. L'azienda cresce rapidamente, e nel 1899 vengono costruiti nuovi complessi industriali a Berlino, negli Stati Uniti, Francia, Regno Unito, e Bombay.
Intorno 1910-1916 Max Graetz sviluppa la famosa lanterna Petromax. Intorno al 1925 la fabbrica produce anche radio e altri apparecchi elettrici chiamati Graetzor.

Altena Graetz FactoryDurante la seconda guerra mondiale, proprio come nella prima guerra mondiale, la società fa parte dell'industria bellica. Con l'uso di lavoratori forzati da Francia, Russia, e nei Paesi Bassi la società fa enormi guadagni.
Alla fine del mese di aprile 1945 la fabbrica viene rivendicato dall'esercito russo.

Nel 1949 l'azienda entra a far parte del programma del "Popolo", "VEB-VolksEigenerBetrieb" e dal 1950 "VEB Fernmeldewerk, Berlin Treptow (RFT)." VolksEigenerBetrieb, significa che la fabbrica era di proprietà del popolo per il popolo.

Nel 1948 Erich, e Fritz Graetz fonda una nuova società a Altena, in Germania nota con il nome Graetz, come successione della azienda di famiglia persa a Berlino. La nuova società produce principalmente radio e TV.
Nel 1961 l'azienda viene poi venduta a standard Elektrik Lorenz (SEL) AG, e dal 1987 è di proprietà della società finlandese Nokia.

CARATTERISTICHE PRINCIPALI

Anno di produzione: 1957/59
Supereterodina IF: 468/10700
8 Circuiti AM - 13 Circuiti FM
Gamme d'onda: Onde Medie (OM), Onde Lunghe (OL), Onde Corte (OC), FM (UKW)
Altoparlanti:
2 largabanda ellittici
1 mid/tweeter
1 tweeter a tromba con flauti
Dimensioni (LHP) : 680 x 400 x 305 mm / 26.8 x 15.7 x 12 inch
Peso netto: 16 kg / 35.242 lb
Valvole 7: ECC85, ECH81, 2xEF89, EABC80, EL84, EM34
Antenna rotante in ferrite per AM

Graetz Sinfonia 522
Graetz Sinfonia 522

Nella naturale evoluzione del modello Sinfonia alla Graetz hanno iniziato ad usare altoparlanti a tromba.
Gli altoparlanti a tromba hanno il vantaggio di avere una membrana molto piccola e leggera. Questo si traduce in una capacità di raggiungere frequenze molto elevate con una ridottissima distorsione.
Come tutti gli strumenti musicali questo tipo di altoparlanti è composto da generatore del suono e da un risonatore. In un violino le corde vibrando emettono il suono, ma è la cassa armonica che lo amplifica e lo colora.
Negli altoparlanti a tromba la piccola e leggerissima membrana vibra e poi la tromba amplifica, e talvolta modifica, il suono.
La tromba ha lo svantaggio di essere fortemente direttiva. A pochi cm dal suo asse l'intensità del suono cambia notevolmente. Il sistema a tromba, pur essendo molto efficiente e con bassa distorsione non è adatto 
Gli ingegneri Graetz hanno preferire una tubazione accordata invece della tromba per le caratteristiche di maggiore direzionalità.
La pressione dell'onda sonora via con il quadrato del rapporto tra diametro e lunghezza del tubo. Per questo motivo alla Graetz parlano di compressore sonoro.
Quindi dalla piccola emissione della membrana del cono si ottiene una grande radiazione sonora all'uscita dei tubi.
Inoltre poichè il rapporto tra lunghezza e diametro del tubo è molto grande si ottiene una propagazione simile alla propagazione su un condotto di lunghezza infinita. Le fessure di uscite sono poste a distanze diverse per ottenere questo effetto di assenza di risonanza. Lo schema equivalente è quello di un ciruito LC dove i fori si comportano come induttanze. 
Il risultato di questa caratteristica, unita alla particolare forma e posizione delle fessure di uscita del suono è che la frequenza di risonanza è attorno ai 12 kHz e questo sistema viene fatto lavorare nella fascia che va dai 700 Hz  ai 10 kHz, proprio dove si ha la massima sensibilità dell'orecchio umano, e dove si colloca la voce e la quasi totalità degli strumenti musicali.
Oltre ai vantaggi di assenza di distorsione e di efficienza la assenza di risonanze ha come risultato una notevole morbidezza di ascolto.
Da ultimo questo condotto produce un lieve ritardo, di pochi ms che inducendo un minimo riverbero naturale ottiene come effetto finale quella profondità scenica che rende questo apparecchio incredibilmente appagante all'ascolto, pur essendo monofonico.

 

ALTOPARLANTI

Come già detto in precedenza Schallkompressor  significa Surround sonoro con Compressore.

Faccio notare che questa azienda applicava questi concetti e queste soluzioni (surround, compressione del suono) alle apparecchiature commerciali, e siamo nel 1958.

Come ormai oggi sanno tutti le note basse per loro natura si diffondono in maniera omnidirezionale nell'ambiente, per cui è piuttosto difficile localizzare un subwoofer ad occhi chiusi.
Gli altoparlanti che diffondono le note acute invece sono estremamente direttivi per cui il loro posizionamento rispetto alla posizione d'ascolto è molto critica, per cui basta spostarsi un poco dalla posizione d'ascolto prevista per perdere parte del messaggio e del dettaglio della parte più alta dell'informazione sonora.

Questo problema è stato affrontato nell'evoluzione degli impianti Hi-Fi con i sistemi più diversi.
La Graetz lo risolse all'epoca in maniera estremamente efficace con il sistema 4R nei modelli Sinfonia precedenti e Schallkompressor  nei modelli dalla 422 in poi.

Graetz Sinfonia 522
Graetz Sinfonia 522

CONTROLLO TONI CON INDICAZIONE DEL LIVELLO

Il sistema di controllo dei toni è molto efficiente. Sopra le grandi manopole dei controlli di tono troviamo una banda che si illumina progressivamente indicando l'enfasi data alla banda su cui agisce.

Graetz Sinfonia 522
Graetz Sinfonia 522

ILLUMINAZIONE INDICATORE TONI

Premendo uno qualsiasi dei tasti del gruppo Klangregister i controlli di tono vengono esclusi perchè vengono esaltate le frequenze previste dal tasto scelto.

Per questo motivo anche le luci che illuminavano la scala indicante la posizione dei controlli di tono vengono spente.

Si riaccenderanno premendo il tasto Raumklang e tornando quindi alla determinazione manuale della curva di risposta preferita.

ABSCHALTUNG

Tre tasti sono raccolti nel gruppo Abschaltung (Disattivazione) e sono rispettivamente:

Aussen-L(autsprecher) - Altoparlante esterno

Mag(isches)-Auge - Occhio magico

Raumklang - Registri musicali predefiniti

KLANGREGISTER

Tre tasti sono raccolti anche nel gruppo Klangregister (Registro musicale), questi sono molto intuitivi e sono rispettivamente:

Sprache - Voce

Solo - Solo

Orchester - Orchestra

graetz sinfonia 4r-221 aerials

ORIENTAMENTO ANTENNA

Antenna in ferrite rotante con finestra che ne indica la posizione.

L'antenna in ferrite si ruota con la manopola grande dietro alla manopola del volume,

All'interno del mobile è presente un dipolo per la ricezione FM ed una antenna in ferrite orientabile per la ricezione AM.

La sensibilità in ricezione con le antenne interne è molto buona.

CONTROLLO SINTONIA SEPARATI TRA AM E FM

Il sistema di sintonia è un'altro gioiello.
L'apparecchio è dotato di meccanismi di sintonia separati per le bande AM e per quella di ciascuna delle due bande FM.
La manopola della sintonia è una sola ma un selettore commuta su sistemi di cavi (tutti di acciaio) e pulegge separati a seconda della banda.

graetz sinfonia 4r-221 control am fm
graetz sinfonia 4r-221 tuning indicator

INDICATORE DI SINTONIA

L'occhio magico ovviamente è stato sostituito.

COMANDI

Graetz Sinfonia 522

A sinistra si trova il comando del volume (con loudness incorporato) ed assialmente a questo il comando di rotazione dell'antenna in ferrite.
Si vede l'indicatore della posizione dell'antenna.
L'occhio magico che indica la perfetta sintonizzazione di ciascuna stazione.
La scala AM per le Onde Lunghe, Medie, Corte e la scala FM.
Sotto da sinistra troviamo nell'ordine la manopola del controllo dei bassi, i tasti di accensione, giradischi, registratore, i tasti per sintonizzarsi sulle Onde Lunghe, Medie, Corte, FM, la manopola del controllo degli acuti.
Sotto ogni tasto è indicata la banda di frequenza interessata.
Vi è infine la manopola della sintonia, il cui movimento è molto piacevole essendo supportata da un grosso volano.
Sotto ancora troviamo le due grosse manopole del controllo dei bassi e degli alti.
Assialmente alla manopola di sintonia si trova un selettore per il controllo della selettività in AM.
I registri ed i tasti di esclusione sono stati visti precedentemente nei particolari.

graetz sinfonia 4r-221 rear side

LATO POSTERIORE

Uscita per altoparlanti esterni.
Presa per registratore (tonbandgerat).
Ingresso giradischi (tonabnehmer)
Ingressi antenna AM ed FM e presa di terra.

RESTORATION WORKS

LA CONSUETA BELLISSIMA NOTTURNA FINALE
graetz sinfonia 4r-221
Philips Uranus Tonmeister B7D52AS philips - cn

Philips U…

PHILIPS URANUS TONMEISTER B7D52AS

PHILIPS URANUS TONMEISTER B7D52AS

Philips products in Italy have always been a little ignored in the HI-FI world: they were linked to the other thousands of low technological content products, appliances, consumer products and so on that this producer has made through the years.

Giorgio Vasari – La mutilazione di Urano da parte di Crono, XVI secolo – Palazzo Vecchio, Firenze

Nothing more wrong and superficial.
Philips is a manufacturer with a huge know-how. One of the best tuners in the world comes from them, the AH673.
One of the most broadband speakers in the world the AD9710 comes from them.
Even the invention of the compact cassette and then of the Cds comes from them.
They made maybe the best CD mechanism in the world, the CDM1, the first DVD recorder, the technology of the devices produced from a certain date with the Grundig, Marantz, B&O and other marks.
So, who snubs Philips does it for lack of knowledge.

Presented the manufacturer, let's talk now about the machine.

In greek mithology, Uranus god of the sky, Gaia's husband, threw his children in the bowels of the earth as long as they born to avoid their supremacy. Gaia, horrified, made for her 12th son, the titan Cronus, the adamantine sickle. Cronus evirated Uranus and from his genitals thrown in the sea was born Aphrodite.
Probably in the choice of the name at the Philips headquarters refered to the magnitude of the divinity, but it's a fact that the Uranus Tonmeister B7D52AS is one of the best tube receivers ever made by this manufacturer.
Built to compete with Telefunken Opus, Nordmende 3004, Grundig Stereomeister, owes the second part of its name “Tonmeister – Master of Sound” surely to the care it has been studied with, in any detail.

The output stages are made of couples of pentodes in Push-Pull with Voltage Negative Feedback without frequency correction. In this way it is ensured the maximum linearity with the less compression effect possible, undesireable effect typical of the Negative Feedback circuits. Other manufacturers made other choices and this determines the different personality of these devices.
The Philips by this point of view distinguishes for its timbre neutrality.
The pre-amplifier stage is provided with many equalization possibilities but I prefere to listen excluding them: I don't feel the necessity with these loudspeakers there's no acoustic deformation to correct.

The radio-frequency stage is of a very high level and classical setting provided with excludable AFC. Interesting the typical little IF transformers, difficult to de-tare and insensitive to fashes.

Even in this case I matched for this try-out the Uranus with its cousin Marantz CD94 MKII, wonderful machine with CDM1 component and a pair of TDA1541A in antiphase, one of the best existing machines, and to a pair of Cabasse Dinghy 222, high efficiency speakers described later.

The stations stay perfectly stable thanks to the AFC, so the listening of the tuner is very relaxing. The listening from the CD or other sources is timbrically very balanced.
Listening from an Ipod is possible and comfortable.

Even in this case its an authentic vintage Hi-Fi System with no compromises, for those who know exactly what they are buying.

 

STEREO DECODER

The device is equipped with the rare Stereo Decoder, allowing you to listen to a multitude of FM Stereo broadcasts in stereo

DETAILS >

SEPARATE LOUDSPEAKERS

It is possible to connect any speaker, preferably with high efficiency.

DETAILS >

BLUETOOTH

Built-in Bluetooth receiver

DETAILS >

MULTI PLATFORM CONNNECTION

Each radio is equipped with a special cable that connects with any digital source.

READ MORE >

TUBESOUND ENHANCEMENT

- Separate loudspeakers - Using separate loudspeakers is an important option for stereo receivers. This allows you to couple the receiver to speakers best suited to particular space, design or acoustic performance requirements. The most suitable loudspeakers are analysed later, under loudspeakers.

- Stereo Decoder - The device has an integrated Stereo Decoder. This allows you to listen to stations that use this transmissions system in stereo. Many stereo receivers are not equipped with a Multiplexer so they work in stereo only when you select the record player’s /Recorder/Aux input . Such receivers, in listening to the radio, send the same signal to both channels, so listening is monaural. This is not the case with the Concertino 2380, which is totally beyond stereo.

- Built-in Bluetooth receiver - This unit can be equipped with a BLUETOOTH receiver powered directly from the device. That makes it possible to use the amplifier from any digital device, IPAD, Smartphone, or sophisticated multimedia station. You can listen to your wireless Web Stations or favorite music around the room. On request, we can also mount a Wireless Receiver.

- Multi Platform connections - Along with the device, we can also provides you an impedance adapter cable to connect any digital source, such as iphone, smartphone, computer, CD player, etc. This purpose-built cable adapts different impedances of modern digital equipment. Also the two stereo channels are collected into a single flow without increasing the load input unit.

HISTORY

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.

MAIN FEATURES

Year of production: 1966/67

8 Circuiti AM
12 Circuiti FM

Wavebands:: LW, MW, SW, FM

Operating voltage (CA): 110; 125; 220; 240 Volts

Mobile in legno con frontale chiudibile

Dimensions (LHP): 562 x 195 x 280 mm / 22.1 x 7.7 x 11 inch

Net weight: 13 kg / 28 lb 10.1 oz (28.634 lb)

Potenza d'uscita: 8 + 8 W

11 Valvole: ECC85 ECH81 EF89 EBF89 EM84 ECC83 ECC83 EC92 EC92 ELL80 ELL80

Rotating ferrite aerial for AM bands

Philips Uranus Tonmeister B7D52AS
Philips Uranus Tonmeister B7D52AS

OUTPUT POWER STAGE

The output stage has been already briefly described in the introduction of the machine, its a clasic Push-Pull in AB class that produces an 8W power per channel.

The interesting fact is the load resistence that excludes automatically when the speakers' jacks are plugged in, avoiding the overload of the final stadium in case of powering it up without speakers connected.

AERIALS

The device is equipped with two aerials. A ferrite for AM ranges and a wire loaded for the FM range.

Listening to AM was already considered unimportant at the time, outlined by FM features.

Philips Uranus Tonmeister B7D52AS
Philips Uranus Tonmeister B7D52AS

BANDBREITE SCHALTBAR

The correction system of the frequency response, quite antiquate command in such a machine but at the top those years, is made of three buttons that instert three pre-defined equalization curves.
I prefere to listen with the “Jazz” button switched.

TONE CONTROLS

The tone 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.

Philips Uranus Tonmeister B7D52AS

SEPARATE CONTROL TUNING BETWEEN AM AND FM

The unit is equipped with mechanisms for keeping separate the AM and FM bands.
The movement is transferred to both mechanisms with a system of pulleys and separated gears.

TUNING INDICATOR

Another exclusive detail, this device is provided with 2 magic eyes. The first, on the left indicates when and with what power we are receiving a stereo channel. The second, on the right, indicates the tuning of each station.
Both the magic eyes are new.

Philips Uranus Tonmeister B7D52AS

AUTOMATIK BUTTON

The Automatik button is the one of the AFC that permits to maintain always perfectly tuned a station once tuned in.
That is not to be used during the research of the station, otherwise the receiver would concentrate only on the most powerful stations.
Once tuned-in the prefered station pressing this button the receiver will correct automatically possible frequency skiddings, keeping always perfectly tuned.

CONTROL PANEL

Philips Uranus Tonmeister 752

Coaxially, we find the balance knob.
The magic eye that indicates the presence of a stereo station.
Going on, we find the AM scale for the Long, medium, and short waves and the FM scale.
Furher on the right we find the tuning knob.

The magic eye that indicates the perfect tuning of each station.
Below we find in the order: bass controls, on and off buttons, the three EQ buttons, the mono/stereo button, and the selection of the inputs buttons (Turntable, Recorder/CD, AFC, long medium short waves, FM)
We find in the end the treble control.

Philips Uranus Tonmeister B7D52AS

LOUDSPEAKERS

I used the Dinghy 221 and 222, prefering the last ones even if more expensive, because they keep almost every feature of the single-driver (the woofer is cut at 5000 Hz) with an extension, on the tops and on the lows that the 221 can only dream.

Because of the crossover the efficiency is lower than 2db but still remains very high, settling at 96db.

This feature allows the Telefunken to be used normally at a fraction of its real power, for the benefit of linearity.
The Dinghy sound very fast despite the appearence, the string instruments come out of the speakers with an effortlessness that makes them get close to the Open Baffle.

The loudspeakers are of very high quality, made on Cabasse detailed bill.
The cabinet is well finished and its dimensions are incredibly limited for the performance they offer.
The material published is taken from the very interesting trans-apline forum dedicated to this prestigious brand: vedi

REAR SIDE

AM and FM antenna inputs and ground socket.
Output for external speakers.
Socket for recorder (tonbandgerat).
Turntable input (Tonabnehmer)

Philips Uranus Tonmeister B7D52AS

RESTORATION STEPS

THE USUAL AMAZING LAST IMAGE
Philips Uranus Tonmeister B7D52AS