New Power Amplifier !
300B single stereo amplifier A-09S
Non-feedback system single amplifier which adopted as the output tube 300B which occupies the status as a reference pipe of a present-day tube amp
A-09S is the power amplifier of the single stereo system which adopted famous 300B as the output tube.
The basic circuit has adopted the self-bias system of CR combination which uses pentode for a voltage amplification 300B single stereo amplifier A-09S.
In the amplification part, the natural acoustic field has been obtained taking advantage of the merit of the basic characteristic without the negative return with the non-feedback system.
The outstanding sound which carried out the one rise in ranking with the amplifier of conventional our company by reexamination from refinement of the ignition system of 300B or a drive circuit and the foundations of the parts to be used was realized.
The troydal type transformer of an establishment meter is distorted by adoption and the combined use with a Teflon insulating paper to all the transformers, and outstanding sound with little admiration is realized.
The troydal core transformer of the high-B type which excelled all in the regulation extremely is adopted as the power transformer of this machine, an output transformer, and each choke coil.
A troydal core transformer is acknowledged because the performance and sound quality are excellent.
Usually, since the troydal and the transformer are using the core of the shape of a ring without a joint, they can obtain the sound which the regulation excelled in instantaneous power well.
However, since there was no joint in a core, it was not able to be used for portions which send DC current, such as an output transformer and a choke coil.
A part of core was cut for it at our company, the slit was prepared, and it was made not to be influenced by DC current.
The output transformer which was excellent in the characteristic and sound quality with the regulation saved which was excellent with this was completed.
Moreover, the overly low impedance coil was designed and adopted also as the choke coil using the troydal core which prepared the slit.
That usual in the impedance of the choke coil has realized the value of 30 ohms for the place of 100 to about 200ohms.
The sound where the influence of the voltage drop by a choke coil decreased by this and which was excellent in a feeling of a lively motion was obtained.
Those transformers are working for maintenance of quality, such as carrying out fill it up of the quality epoxy resin in the company, in order to maintain sound quality.
A standard considers it as an output tube option, and enabled it to select the product made by JJ and Emission Lab by liking so that an output tube can be chosen freely.
I prepared for the sales specification of A-09S what combined what combined 300B of JJ of Russia with the type of the output tube option, 5U4G made from Emission Lab (Emission Lab) of Germany, and a 300BXLS vacuum tube.
To the output tube 300B, the difference in sound is great respectively, and I also regard that you exchange by liking and look for a favorite sound as one of the pleasure of an audio.
A-09S is designed so that almost all 300B of each company can substitute as it is, and adjustment is unnecessary at all.
Adjustment of ham balance etc. is also unnecessary and the sound highest by no adjusting is obtained.
Both the waves rectification DC ignition circuit by a Schottky diode is adopted as the ignition circuit of the heater of a 300B vacuum tube.
The capability of 300B was pulled out to the maximum extent.
DC ignition circuit by the Schottky diode of low impedance is adopted as the output tube portion of A-09S.
Since the current capacity of a transformer is fully taken and it enables it to correspond also to the big heater current up to about 2A, it is possible to substitute and use almost all 300B types of vacuum tube.
Both the waves rectification system was adopted as the portion which supplies the heater voltage of a 300B vacuum tube.
Since the regulation is excellent, both waves rectification becomes advantageous also to the sound quality of 300B.
We adopted the highly efficient Schottky diode of the U.S. IR company as the rectifier by audition.
Furthermore, what has daringly small capacity was selected to the smoothing condenser, the product was chosen, and the sound excellent in speediness has been obtained.
Usually, the ham balancer etc. to be used were omitted and improvement in the freshness by the simplification of a circuit was aimed at.
Balance adjustment resistance of a heating circuit adopts the usual small value of the 1/10th place, and makes current feedback of cathode the minimum.
The first rank highly efficient German highly efficient pipe C3m was adopted as the pipe, and the high-quality sound driver stage consisted of low noises.
Five highly efficient pole pipes C3m are adopted as the first rank of A-09S amplifier.
Although this vacuum tube is seldom generally known, it is the high performance and the vacuum tube of high reliance which were designed for telephone lines in Germany and which were developed comparatively in the second half.
A development age will be most as a vacuum tube in the second half in 1962, therefore various kinds of electrical properties are excellent, and it is the feature that sound quality is very beautiful.
Although this vacuum tube is enclosed with the case of the metal as a locktal tube, it removes that case and is using it at our company with a glass tube.
Thereby, the sound in which sound quality is still more natural was obtained.
A mesh plate is beautiful and this vacuum tube has charm also in appearance.
In A-09S, the stability which was excellent in stabilizing screen grid voltage in this vacuum tube, and the low rate of distortion have been obtained.
A novel and beautiful design is realized for a woody system material in combination with adoption and a champagne gold aluminum alloy transformer cover on a chassis.
A woody system material called the complite of 18mm thickness is adopted as the chassis of this machine.
This material is a material excellent also in intensity and electrically which laminated the thin single plate of cherry tree material, and poured in and hardened phenol resin.
The intensity, and heat resistance and electrical insulation properties have the performance equivalent to phenol resin.
Moreover, the aluminum alloy of 2? thickness which gave alumite plating excellent in the side board and durability made from cherry tree material is adopted as a transformer cover, and it is made beautifully.
The socket made from inhouse Teflon currently evaluated highly by high performance and high reliability from all over the world is adopted extensively.
The tube socket of our original currently evaluated highly by the merit of the reliability and sound not only the inside of Japan but overseas is extensively adopted as these machine sockets.
The body of the socket of our company plates the Teflon excellent in temperature characteristics and an electrical property with gold at the round pin of the next door bronze manufactured by cutting, and is using it as the reliable socket at adoption and a pin.
All the pins have structure which begins to be deleted from the round bar of next door bronze, puts in a slit, and holds the leg of a vacuum tube exactly.
Therefore, where a vacuum tube is put to a socket, the leg of a vacuum tube is held firmly, there is no shakiness of a vacuum tube, and there is an effect which prevents the influence which external vibration has to a vacuum tube.
The poly pyrene film capacitor with little distortion [ product / with a sufficient sound / made by DALE / capacitor / adoption and ] by a main part is adopted as resistance.
The resistance currently used for A-09S has adopted the product made by U.S. DALE as almost all portions.
To the large-sized resistor, metal tunic resistance and large-sized surface mount type resistance are properly used [ the metalclad type of the unguided type ] for the winding type highly precise in an inside capacity type at the type of small capacity.
It excels, so that the sound quality can compare neither with the thing of the domestic class by the same product made by DALE.
moreover, the reliability is also markedly boiled for the parts made according to U.S. MIL specifications and standards, and is high.
Moreover, the polypropylene capacitor is mainly adopted as a capacitor.
This polypropylene capacitor is excellent in the response to the signal of that palace nature compared with the usual chemical capacitor, and a capacitor's own rate of distortion is also very excellent.
Since the difference in the sound quality in this capacitor influences greatly not only in a signal circuit but in a power supply circuit, it has measured the improvement in sound quality by adopting a polypropylene type for the capacitor of most including a power supply circuit.
Although the characteristic of these capacitors is very excellent, it has a weak point where foil resonates easily, only for the state which rolled round the film.
Therefore, in A-09S, filling adhesion of these polypropylene capacitors is carried out with the epoxide resin adhesives of high intensity at its company at the case of an ebony or bakelite, and the increase of the intensity of a capacitor and sound quality are raised further.
- Adopt the original pin jack of our company of chromium copper adoption as an input terminal, and adopt the speaker terminal made from pure copper as a speaker terminal.
The input terminal of this machine has adopted the highest-class pin jack of our original which chromium copper began to delete to an external conductor, adopted the round pin terminal of next door bronze shaving 出し as the internal pin for the terminal, and adopted Teflon as an insulation material.
pure copper shaving appearance was carried out to the output terminal, and I have adopted the large-sized terminal of Teflon insulation by gilding.
It is using at this that the thick thing speaker cable to 8mm diameter is also connectable.
The beautiful very hard African ebony round bar of sound is adopted as the leg.
By the beautiful thing of sound, it was begun to delete acknowledged African ebony material to the leg of this machine, and it is adopted as it.
This African ebony material is a material which has obtained evaluation beautiful sound for the material actually used for oboe or a clarinet and high also as arrangement base material of our company.
It is fixed to the chassis made from a direct complite, and the leg supports the whole weight exactly in order to obtain the merit of intensity and sound.
A quality wire rod is adopted as a power cable, and a hospital grade gilding terminal is adopted as a plug.
The power cable of this machine has adopted the hospital grade plug of Matsushita Electric Works as adoption and a plug part for the quality cable with the inlet terminal of 3p.
The gilding plug pin of special make is adopted as the pin of the plug.
Moreover, since I have adopted 3p inlet jack as the main part side, exchanging for the code of Mr. User's hope is also possible.
If the quality of a tube amp improves, change of the sound quality by a power cable will come to appear sensitively.
Please also enjoy change of the sound by a power cable.
Standard
Form: 300B single stereo power amplifier
Use vacuum tube: 300B 2pcs. C3m 2pcs. 5U4G 1pc. (a standard is without Output tubes)
Maximum output: 8W+8W,
Frequency characteristic: 15 to 22 kHz (-3dB)
Residual noise: 0.6mV
Input impedance: 200kohm
Weight: -- 18.8kg
Outside dimension: -- 500 (W) -- 294 (D) -- 208 (H)