capella Archives – Luxuryradios

Philips C…

14th 10 月 202414th 10 月 2024
by giovanni

In this review we analyze two very similar devices, the Philips Capella Reverbeo B7X14A and the Philips Capella Reverbeo B7X43A.
The two models are completely identical except for the fact that the B7X43A has a stereo decoder, while the B7X14A does not.
With the B7X14A, therefore, FM stereo transmissions are received in mono.
The front differs due to the presence of the stereo indicator in the B7X43A.
Both models are equipped with two Class A final stages, with an EL84 for each channel. Therefore, with both, stereo listening is provided when the source is a turntable, a tape recorder, a CD player or Bluetooth.

The most important feature on both models is the presence of the electro-mechanical reverb circuit, which can of course be excluded by a button on the front. The Philips reverb will be analyzed in detail below.
These two top-class Philips devices are the only German-made radios equipped with reverb. Saba, Grundig and Philips included reverb as an option on some rare top models of their large radio cabinets, but no classic radio was equipped with reverb.
The effect of reverb is very pleasant especially in sacred music, choirs and chamber music. In rock and jazz music, however, it generates excessive confusion in my opinion and it is preferable to exclude it with the appropriate button.

When you insert the reverb, the two channels are automatically connected and the playback becomes monophonic.
One last warning, pressing the HI-FI or SPRACHE buttons inserts equalizations set by the manufacturer, which are not configurable, and the Bass and Treble knobs no longer have any effect.

The presence of reverb, the double cone speakers arranged at an angle and the futuristic line for the time make it one of the most appreciated and sought-after devices of the Philips production of the time.

The first track is a Reveberation Example. This is a recording of any FM broadcast where you want to hear the reverb effect. The recording starts with the reverb on, then you hear a "Stack!" and the reverb is turned off, then turned on again and so on. This way you can appreciate the level of reverb that Philips has planned for this device. In fact, although it is clearly a distortion of the sound, it is very interesting, the songs seem to come from inside a large room, or a church, and the effect is incredibly pleasant.

The second track performed by Abdullah Ibrahim is called Cape Town to Congo Square 1. Adolph Johannes Brand (Abdullah Ibrahim) is a South African pianist and composer. His music often draws inspiration from the music he listened to in his childhood in the multicultural port areas of Cape Town, ranging from traditional African songs to church gospel, Indian ragas, and more modern jazz. She manages to blend American jazz, Duke Ellington's big band compositions with the revolutionary innovations of Ornette Coleman and the avant-garde of the 60s.

The third song is performed by Ella Ronen & Sam Cohen, it is called I just want to see you. It is part of the album “The Girl With No Skin”. A very interesting project where the singer, poet and activist addresses the burning issue of being a woman today, with all the conflicts and contradictions, the rediscovered strength and weakness. "I just want to see you" talks about the couple and the difficulties of being yourself and being a couple when instead we are continuously encouraged to play roles. A very sweet song that gives energy and hope. "I don’t want to be your mother / I don’t want to be your muse / I don’t want to take your freedom / I don’t want to make you choose / I just want to see you"

The fourth song performed by Buena Vista Social Club is the famous Amor de loca juventud. (Love of the Crazy Youth) written and composed by Rafael Ortiz in the 30s is a song with influences from black music from the neighboring United States, very popular in Havana in those years. Buena Vista Social Club was the name of a club in Havana (Cuba), whose entrance was reserved for people of color. Almost forty years after the club closed, a group of Cuban musicians merged into the Afro-Cuban All Stars. The Californian guitarist Ry Cooder also participated in the initiative. The album Buena Vista Social Club was released in 1996. In 1999, Wim Wenders directed a documentary about the entire story of the production and the members of the orchestra, also entitled Buena Vista Social Club.

The fifth song performed by Francis Poulenc is his Stabat Mater Dolorosa. In late 1950 Francis Poulenc began writing the Stabat Mater, FP148 for soprano solo, mixed choir and orchestra dedicated to the memory of the stage designer Christian Bérard, a dear friend of Poulenc, who had died the previous year. s Poulenc had shared with Bérard the experience of rediscovering his faith after going on a pilgrimage to the Sanctuary of Rocamadour. This is one of Ozawa's historic Boston recordings. The pure and crystalline voice of the American soprano Kathleen Battle marries perfectly with Poulenc's sacred pieces. The Stabat Mater "Stava la madre" is a Catholic sequence from 1200 attributed to Jacopone da Todi. The first part of the sequence begins with the words Stabat Mater dolorósa and is a meditation on the sufferings of Mary, mother of Jesus, during the Passion and crucifixion of Christ.

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.

This type of reverb was developed by Bell Labs in the 30s for the organs of Laurens Hammond to obtain a spatial effect that aimed to replicate the natural reverb of a church even in the small rooms of a house. In the 60s and later they were used in the amplifiers for musical instruments of all the most famous manufacturers, Fender, Vox, Marshall and others.

The mechanical part of the spring reverb is composed of three fundamental elements, the Input and Output Transducers, the Transmission Springs and the Suspension Springs. Essentially the audio signal is sent to the piezoelectric transducer located at one end of the transmission spring, the vibrations reach the transducer located at the other end of the springs after being subjected to oscillations, reflections and delays. The output of the transducer is sent mixed with the direct sound source to create the final output signal.

PHILIPS decided to implement this incredible mechanism in its most prestigious devices, the CAPELLA REVERBEO B7X43A and B7X14A.
The reverb units used by Philips are of the double spring type, which unlike the triple spring type return a more evanescent and characteristic sound, not obtainable with digital convolution reverb algorithms.
A button on the front allows you to insert/disinsert the reverb circuit. Inserting the reverb automatically switches the channels to monophonic. Listening to both music and speech with the reverb inserted is a fascinating and fun experience.

The speakers used on both channels are the very special AD3800AM.
These are 20 cm bicone speakers with an impedance of 800 ohms.
The frequency response extends from 70 to 18000 Hz, and they are equipped with a 9500 Gauss magnet.
The speakers are mounted facing the front corners in order to accentuate the stereophonic effect when the listener is positioned at least one meter away from the radio.

There are several options for connecting external speakers. Naturally, any external speakers must also have an impedance of 800 ohms.
It is possible to connect external speakers, excluding or not the internal speakers.

capella 753 - cn

Philips C…

15th 12 月 201730th 8 月 2023
by 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.

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.