Vacuum Tube Phono Equalizer AmplifierEQB-01
Vacuum Tube PreamplifireCA-03L
Vacuum Tube PreamplifireCA-03

●The conversion of the thought is necessary to obtain good sound!
CA-03, CA-03L, EQB-01 are the amplifier that used the vacuum tube that had the characteristic that absent for formerly whichever. The thought to the vacuum tube amplifier of our company is nonexistent to succeed the circuit and sound of an old type, draw the vacuum tube of charm that hid and had and be in that draws the many sounds of the quantity of information that passes in the present. The vacuum tube has the wonderful thing that is not inferior to a contemporary transistor and FET etc. in terms of the tone quality, although the time when it was developed is very old. We think those that be the important point to a contemporary vacuum tube amplifier to draw the charm that hid.

●How the vacuum tube amplifier from this manages the pentode is an important point.
To recently including it the triode tube has been spent on most of the pre amplifiers. There is a difficult face to obtain the sound of it over the triode tube although be obtained a comfortable sound to the ear handily certainly. The sound that is difficult fresh and overflow to the speed impression was materialized that use the pentode that there were few cases it is used conventionally in our company actively and obtain in the triode tube. It is as the finish that adopts a comparatively new miniature tube in CA-03, CA-03L, EQB-01 and satisfaction go to both of the tone quality face and noise.

●Adoption of 6AK5W made of Telefunken in all the circuits
The vacuum tube that our company adopted in CA-03, CA-03L, EQB-01 is the vacuum tube that the ordinariness is treated as for the high frequency with the types called 6AK5W (5654). As for the 6AK5 vacuum tube that becomes this antecedent, there is the record that development that time took the prize as an excellent invention, with the thing that we developed although America is Western electric originally. Because this vacuum tube is evaluated the excellent performance and was mainly used to the devices and measuring device etc. for the high frequency a lot the the number of the vacuum tube that at present is subsisting is abundant and highly efficient Kan is cheap obtaining comparatively. It understood that it is possible to draw a very excellent tone quality by try to use this vacuum tube in our company and devising the use method. Understanding that the vacuum tube made of Telefunken is having an extremely excellent tone quality in this 6AK5W vacuum tube especially we adopted the 6AK5W vacuum tube made of Telefunken to the equalizer amplifier and all the line amplifier department.

● 2 steps the development of the direct association CR style equalizer amplifier
Adopting this 6AK5W to the equalizer amplifier with 2 steps of direct association probably we developed the first 2 steps of direct association CR style equalizer amplifiers in the world. Because the CR style equalizer does not use NFB the tone quality is liked that natural and hardness is nonexistent. However, there is case it is more disadvantageous with the signal-to-noise ratio in comparison with the NF style equalizer and seem to have there been few cases it is adopted to the pre amplifier made of the maker. By managing the pentode in our company doing this problem the clear the consistency of the signal-to-noise ratio and natural tone quality were materialized. Another characteristic of this equalizer amplifier is in that omitted the high resistance that enters into the series inside the equalizer amplifier that was necessary inevitably in the CR style equalizer amplifier. It inserts high resistance into the series into the series to obtain the equalizer curve in the CR style equalizer and make the impedance the source and have obtained the equalizer curve by using the CR element. The resistance that we usually insert in the circuit is not able to disregard the influence to the tone quality of the resistance because the high resistance called 200-300k Ω is used. We substitute this high resistance with the load resistance of the plate of the first grade in our company and make the resistance the circuit impedance and have obtained the equalizer characteristic. This method is impossible realization in the triode tube and there is the high impedance characteristic of a pentode and be a realization possible circuit. Also, being directly associated meantime without obtain high input impedance by using same 6AK5W to the 2nd step of the equalizer amplifier and using the condenser it is driving it. This is applying the circuit, with the method that our company confirms with the power amplifier and be adopting the size of the effect. By this the high quality that absent to formerly the sound of the equalizer amplifier department is self-confident that it was obtained. Also as for the circuit of the equalizer amplifier the amplification rate is set up to raise by the use of the pentode. Therefore the product of the high output type of the MC cartridge is becoming possible even to input directly. Also, even the connection that went through the step up transformer is possible because the biggest output of the equalizer department has obtained the high value called about 28V. As for the input impedance the change is coming to be produced with 3 points of 100Ω, 1k Ω, 47k Ω. There is not a difference in the sound quality because the equalizer department of EQB-01 and CA-03 are employing the same circuit.

●Adoption of the single no feedback amplifier of 6AK5W in the line amplifier department
6AK5W made of Telefunken is being used to the line amplifier department (the flat amplifier department) of CA-03, CA-03L with the single no feedback. It pours a somewhat much current into 6AK5W of small and make the load resistance as much as possible and be lowering the output impedance. It is as the moderate gain of about 14dB in our company because we become difficult to use it even if the amplification rate of the flat amplifier department is so too high. Also only the current feedback is applied without using the bypass condenser for the cathode department of the vacuum tube of this flat amplifier department and be using. Therefore, without having the fixed number at the time of except for the output condenser 10 Hz-150kHz to-the low area characteristic of the flat amplifier department has materialized the extremely wide frequency characteristic that calls it with 0.5dB within

●We adopt the L pad attenuator to the volume adjustment
CA-03 be adopting L pad style attenuator to the volume adjustment department of adoption and stereo volume to CA-03L. This attenuator is set up to the highest-class 27 point of contact 4 league rotary switch made of the Seiden Co., Ltd. precisely by using the MIL spec. metal foil resistance made of a highly efficient U.S. DALE company. As for the volume that is used to the volume adjustment of this part generally, there is fairly much right and left deviation, especially the user-friendliness may bad because the level difference of the right and left is easy to result at the time of the small volume. There is extremely little right and left deviation in this L pad style attenuator to it and-it is able to adjust it precisely to at the time of the small volume called -60dB. Also, as for this attenuator be able to call the quality of the tone quality with the highest level because only 2 pieces of resistance are becoming the structure that constantly passes. However, this attenuator prepared even the type that changed this part to 2 usual league ceremony volume, because the cost becomes expensiveness fairly. The product is CA-03L. Please select the circuit inside the amplifier of both according to the budget because there is not a change at all.

●A functional large print foundation adoption CA-03, CA-03L, EQB-01 adopt a large print sircuit to each CA-03, CA-03L, EQB-01 and accomplished the stabilization of the stability and quality of the product the electric circuit of the inside. In many cases, it able to depend on the technology of the worker in the case of the hand wiring, although even the pre amplifier has been carried out that do 1 unit of hand wiring 1 unit in the vacuum tube amplifier and the difference easy to result and the stabilization of the quality there was a difficult face of. Establishing most of the parts to 1 sheet of print bord to improve the part in our company we measured the stabilization of the quality. However, the main part that is easy to influence the tone quality establishes the jacket line in the outside particularly, because it is not desirable from the DC resistance minute of a print pattern that the wiring of all the parts are caused in the print bord and be preventing the deterioration of the tone quality.

●The resistor and the like that adopt the good DALE company production of the sound to the resistor and the like and be using the few polypropylene film condenser of the distortion for adoption CA-03, CA-03L, EQB-01 for a main part to the condenser are adopting the U.S. DALE company production to most of the parts. The volume line style, we are using appropriately the metal foil resistor to the type of the small capacity to the middle capacity type. With the whichever same DALE company production the tone quality is excellent as it is not able to compare it with the thing of the same class of the domestic production. Also it is high greatly due to the part that even the reliability was made in conformity with the MIL spec. of U.S.
Also we are mainly adopting the polypropylene condenser to the condenser. The responsiveness to the signal of the palace nature of the ratio sob this polypropylene condenser excels in a usual chemical condenser and also even the distortion rate of condenser oneself excellent very much. To influence largely also in the power supply circuit not only the signal circuit most of the condensers including the power supply circuits the difference of the tone quality in this condenser adopts the polypropylene type we are measuring the tone quality improvement through the means.

●For instance, we adopt sub Shashih made of the brass where prevents the influence of the vibration it is to the vibration control diligently.
The vacuum tube receives the influence of the vibration not a little constructionally. We are able to catch the influence to the sound by the vibration fairly none the less, although 6AK5W that our company is adopting is the vacuum tube that adopted the vibration control structure. Because we are adopting a large print foundation in CA-03, CA-03L, EQB-01 there is the influence of a vibration not a little to the vacuum tube on the foundation through the foundation. Therefore preventing the vibration by establish firm sub Shashih made of the brass under the foundation in our company and joining the foundation and sub Shashih at important points department it is causing to useful it for the tone quality improvement. Also the Shashih structure is firm by the frame structure by the side panel and stainless steel metal fittings by the undirt material of a firm cherry tree material and be as strong Shashih structure to the vibration.

●Beautiful form was materialized beautiful form in Shashih of realization CA-03, CA-03L, EQB-01 with the adoption of the side wood of beautiful champagne gold aluminum Shashih and cherry tree material of the thick 2 mm with the adoption of the side wood of beautiful champagne gold aluminum Shashih and cherry tree material. Both are considered to match the design target even the tone quality face as the pair and this design with A-02, A-07 power amplifier and common thing of our company. Also, we are able to promote even this combination because we are able to be against the target matching that we design with the A-08 power amplifier of our company.

●To input-output pin Jacques the chromium copper production, our company original pin Jacques the input terminal of this adoption machine is adopting our company original highest-class pin Jacques who is to the outside conductor the shaving of chromium copper and send the terminal, to the inside pin the neighbour bronze shaving and adopt the that circle pin terminal and adopted the Teflon as the insulation material. This pin Jacques is connected from the ground side when he connects and be an advantage also in the cheap entire surface because he is becoming the structure that cuts from a hot side when he draws out it.

●To the power cable the high quality line material, the hospital grade gold plating chromium copper terminal the power cable of this adoption machine is adopting the high quality cable to the hospital grade plug of National to the adoption, plug department to the plug by using an original gold plating chromium copper pin of with the inlet terminal of 3p.
Even that we exchange to the cord of the hope of the customer is possible because we are adopting 3p inlet Jacques to this side of the body. When the quality will improve even the vacuum tube amplifier the change of the tone quality by the power cable comes come to turn up sensitively. Even the change of the sound by the power cable please have fun.

EQB-01 spec.
● Form: tube phono equalizer amplifier ● use vacuum tube: 6AK5W made of Telefunken 4 ● biggest output : the 25V ● frequency characteristic: 30-15kHz (+-0.5db) the ● input impedance: 47k Ω, 1k Ω, 100Ω ● output impedance: 4.8k Ω ● amplification rate: 54dB/1kHz ● external form measure: 420 (W) 290 (D) 94 (H) the ● weight: 6.3 kg the

CA-03 spec.
● Form: the tube pre amplifier● Use vacuum tube: 6AK5W made of Telefunken 6 tubes ●Biggest output: 8V <the line amplifier department>● Frequency characteristic: 10-150kHz (-0.5db)● Phono input impedance: 47kΩ, 1kΩ, 100Ω● Output impedance: 1.6kΩ<the line amplifier department>● Line amplifier gain: 14dB (about 5 times) ● biggest output: 25V ● Frequency characteristic: 30-15kHz (+-0.5db)● Input impedance: 47kΩ, 1kΩ, 100Ω● Output impedance: 4.8k Ω● Amplification rate: 54dB/1kHz ● External form measure: 420 (W) 290 (D) 94 (H)● Weight: 6.3 kg *27 point resistance change ceremony L pad style attenuator adoption

CA-03L spec.
● Form: the tube ball ceremony pre amplifier● Use vacuum tube: 6AK5W made of Telefunken 6 tubes● Biggest output: the 8V <the line amplifier department>● frequency characteristic: 10-150kHz (-0.5db)● Phono input impedance: 47k Ω, 1k Ω, 100Ω● Output impedance: 1.6kΩ● Line amplifier department gain: 14dB (about 5 times) <the equalizer amplifier department> ● biggest output: 25V ● Frequency characteristic: 30-15kHz (+-0.5db)● Input impedance: 47kΩ, 1kΩ, 100Ω● Output impedance: 4.8kΩ● Amplification rate: 54dB/1kHz● External form measure: 420 (W) 290 (D) 94 (H)● Weight: 6.3 kg the
Adopting*volume adjustment volume other parts are the same as CA-03.

Yamamoto sound craft Co., Ltd. 〒675-1323 Hyogo Pref. Ono-shi Sakaki town 726 TEL0794-62-5655 FAX0794-63-6405



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山本音響工芸株式会社 675-1323兵庫県小野市榊町726 TEL0794-62-5655 FAX0794-63-6405
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