Spec RSP-901EX

Spec RSP-901EX


More than an accessory

You could recognize at one hearing, PSP-901EX is not only an audio-accessory but also a real audio-gear for improving the sound quality of your system dramatically. The sound will be more clear and natural throughout entire range with 901EX. You could feel and experience more real sound with a full of musicality. In a word, you could be convinced that 901EX brings out fully potential of your audio system!!

The operating principle of “Real-Sound Processor” had been made in public on the Japanese specialized magazine named MJ, “AUDIO TECCHNOLOGY” by Mr.Yasui throughout 1971. He just drought out this concept as ” Impedance Correction” for speaker. Yasui-san was a senior amateur researcher and a person of authority of semiconductor linear amplifier. At that time he got into the conclusion that only the pursuit of improving the static characteristic of power amplifier could never bring the superior sound. And also he set up the importance of amplifier’s dynamic characteristic including the actual movement of speaker to get musical sound. But still right now, after more than 40 years passed, we regard his view point as an excellent insight and much further a relevant challenge for the present “audio-technology”. Sorry to say, we should recognize we only know the improving the dynamic characteristic of the system consisted of amplifier and speaker might be an extremely important factor for getting superior sound quality. For that matter, we are not able to reach at an effective measuring method to be fixed the dynamic behaviors and also expose the real relations between the characteristic and our hearing. We suppose, so many reasons might exist. But one of the major difficulties of analysis of the dynamic characteristic would be speaker itself. Needless to say, speaker is the transducer which converts some electric energy to kinetic motion. But if we were to say frankly, this transducer would be a collectivity of imperfect characteristic for being driven by amplifier. How fluctuant the impedance frequency characteristic is, you know. Yes it might be quite simply the hard load of amplifier. But also you should remind one more thing, “Counter-electromotive Force” of speaker. The motion of speaker is started in the magnetic circuit or voice-coil of the unit by the current be flowed from amplifier on Fleming’s left-hand rule and at the same time this motion raises up counter-electromotive force in the voice-coil by Fleming’s right-hand rule. It is true that amplifier drives speaker, but would be the fact that speaker affects amplifier by this counter-electromotive force. And this counter-electromotive current returns to the amp via the speaker cord, making it difficult to drive speaker in accordance with the input signal. And this current causes negative effect especially on the traditional semiconductor linear amplifier. Since the transfer function of semiconductor is poor in linearity compared to tube, this type of amplifier inevitably needs correct the static characteristic by performing negative feedback circuitry. But this negative feedback makes the amplifier stage vulnerable to the counteraction, counter-electromotive current from speaker, causing complicated phase delays inside of amplifying stage. Needless to say, this physical phenomenon hurts the sound quality of the audio system including amplifier and speaker.

How does "Real Sound Processor" work?

Richer sound

Because again, our “Real-Sound Processor” has two major functions, one is making an improvement to reduce the fluctuations of speaker’s impedance frequency characteristic. The other is absorbing that counter-electromotive current from speaker including network composed of some inductors. Accordingly, the processor makes amplifier possible to drive the speaker more faithfully for sound source, improving the sound resolution and the start-up, also reproduces natural resonances. Above all you could find out the deep, rich and fascinating tonal characters you have never experienced before and also agree how amplifier could drive speaker easily!!

We had tried so long time to seek out improving the sound quality of “Real-Sound Processor” and learned that only the tonal or the sound quality of the parts, resistor and capacitor decide the sound itself. You should recognize that the perfect characteristic resistor and capacitor has never existed at all ages and countries. For example, capacitor is consisted of mainly capacitance, small quantity of resistance and inductance. Also we should remind the matter of material’s physicality. Sometimes when we make hearing tests for capacitor, we feel the unique tonal character of dielectric material or electrode itself.
But fortunately early 2014, we met up with the outstanding quality parts. It was the highest quality and state-of-art hermetic seal oil-filled capacitor, named “Green Cactus” series made in USA, by Arizona Capacitors, Inc. This type of capacitor could make it possible to get the live and natural sound of new “Real-Sound Processor”. And in this summer we released RSP-701 for our domestic market. And now thankfully, 701 is the successful product in the field of audio-accessories.
By the way, language above all Japanese is far away from European language.
They say that Japanese is vowel sound but compared to this Japanese, major European language is made of consonant. And this consonant is surely consisted of high frequency spectrum. So we supposed that European might have more sensitive hearing for high range than ordinary Japanese and determined to change to another “Green Cactus”, it reproduces much finer mid-to-high range. And also we converted the resistor adopted in 701 to another one which has the smoother and more open air character.
As well, please pay attention to the appearance of RSP-901EX. It’s like a jewelry box made of real spruce from north America with string instrument’s color. And 901EX’s box is produced by famous “Shirakawa Co., Ltd” at Hida-Takayama, beautiful historic town. You will see also woodworking is the Japanese traditional handicrafts.

We believe firmly that RSP-901EX could bring out the full potential of your system and you could fully enjoy the “Real-Musicality” through “Real-Sound” of 901EX!!

From producer

Additional materials

We care for our clients by providing them with the necessary information.

On the belief that “ the joy of music is only found in ‘Real-Sound’”, we have been developing and marketing high-end audio products with the wish of communicating and sharing the sensations, also excitement of our “Real-Sound” music with our customers.
Through High End 2014 in Munich, we will demonstrate four integrated amplifier models including the RSA-F3EX, M3EX, V1EX and 717EX.
With extensive use of latest Class D solutions boosting revolutionary speaker drive power and advanced energy-saving performance these amplifiers deliver beautiful tones and fully dynamic sound, in a word true richness of music someone has never hear before.
And also REQ-S1EX, a phono equalizer amplifier fusing the latest semiconductor technology and matured analog technology, will allow the listeners of analog LP records to rediscover the fascination with “the ultimate high-resolution sound”.