Grundig 5010 Radio finally arrived 蓬蓬声十足

After much waiting, my Grundig has finally arrived. It was well packed and in addition to double boxes, there is a protectve wooden box to protect during transportation. I have  to buy a hammer in order to remove the wooden exterior box. The Grundig 5010 is the most powerful monophonic device ever built by this brand. 

Grundig produced various classes of appliances. Those in the 1xxx series are the cheapest, those in the 2xxx and 3xxx series are middle class, those in the 4xxx and 5xxx series are high class. Obviously the 5010 belongs to the higher class series, and it shows.

• The electronic circuit of the 5010 is the most elaborate one could imagine in a commercial device built in 1952. The final stage is made up of a pair of powerful EL12 in Push-Pull. No other manufacturer has used these expensive valves in pairs. 
• The output transformers are two, separate, one for the low and one for the medium-high. The one for the bass has double secondary winding, one for the mid-woofer and one for the feedback circuit.
• The medium-high transformer is also equipped with a double secondary winding, one for the cone mid-tweeter and one for the electrostatic tweeter.
• The bass and treble crossovers consist of capacitor and inductance networks. Truly remarkable.
• Tone controls are applied on the feedback network, further reducing distortion, but risking introducing instability when the potentiometers are in their extreme positions.
• The phase reversal for push-pull is obtained by a double ECC40 triode, where each section pilots one of the two EL12s.
• The preamplifier is composed of the triode of an EABC80.
• The filtering of the power supply consists of a Pi-Greek filter of capacitors and inductance.
• The FM antenna circuit consists of an EF80 pentode and the local oscillator from an EC92 triode.
• The variable capacitor is composed of many sections being unique, for the AM and FM bands.

The interior of the Grundig is very clean and it comes with the Siemens EL12 tubes.Perhaps at the later stage, I may want to try some vintage EL12 tubes.

There are three loudspeakers, all produced by Grundig. The main wide band measures 13.8 in of width for 7.9 in of height. It covers a part of the radio's width and that is so big. A very interesting feature is that they are equipped with an adjustable basket. This allows me to center the cone movement with respect to the magnetic system.

The electrostatic tweeter is mounted in front of the main broadband. This gives a remarkable sense of presence to the musical reproduction. The coaxial speakers allow to locate the position, the depth with respect to the listener, of the various instruments or of the voice with remarkable precision. It is a solution that I have always appreciated and that is found in the best radio sets.

The mid-tweeter has an oversized magnet. It has to tolerate considerable power peaks because it is cut very low. The acute are unexpectedly crystalline whilst remaining very sweet. The cones are cellulose treated and they are to this day in perfect condition, without any deformation or structural failure. The radio was built when they had to last "at least" the life time of the owner. From 195/3 till now, perhaps, I am the 3rd or 4th owners of the Radio.

Both the Grundig 5010 and Telefunken Opus 7 have different characteristics with the Telefunken sounded more more elegant and the Grundig 5010 sounded with good base and powerful hifi sound. I was truly overwelmed by the Grundig sound! 蓬蓬声十足