Yamamoto Sound Craft
CA-04 Line level Tube Preamp

The CA-04 is a high-performance line-level tube preamplifier based on the company's award-winning CA-03 and CA-03L, with an independent line amplifier section and further refined details. It is designed not to inherit the circuitry and sound of older models, but to draw out the hidden charm of vacuum tubes and to bring out a sound with a high volume of information that is applicable to the modern age.

Resistors are made by DALE with good sound, and polypyrene film capacitors with low distortion are used in major parts of the capacitors
Most of the resistors used in the CA-04 are made by the DALE Corporation of the U.S.A. Many DALE resistors are made in accordance with U.S. MIL standards, and their sound quality is unmatched by similar products made in Japan. Their reliability is also several orders of magnitude higher than those for general use.

Polypropylene capacitors made in the U.S. are mainly used for the capacitors. Compared to ordinary chemical capacitors, these polypropylene capacitors have superior response to pulsed signals, and the distortion rate of the capacitors themselves is also very high. Since the difference in sound quality with these capacitors is significant not only in the signal circuit but also in the power circuit, we have improved the sound quality by using polypropylene type capacitors in many parts including the power circuit. In addition, the capacitors in the parts that greatly affect the sound quality are filled with high-strength epoxy resin in a case made of ebony by the company to improve the sound quality.

A brass sub-chassis is used to prevent the effects of vibration, and other measures contribute to vibration isolation.

Vacuum tubes are affected by vibration due to their structure. 6AK5W is a vacuum tube with anti-vibration structure, but vibration still affects the sound. This structure also helps to improve the sound quality. The chassis structure is made of solid cherry wood side panels and a frame structure with stainless steel fittings to provide a strong and vibration-resistant chassis structure.

Beautiful cherry wood front panel and side wood provide a beautiful form.

The front and side panels of the CA-04, are made of Japanese solid cherry wood. The other components are made of a beautiful 2mm-thick aluminum chassis to achieve a beautiful form. This design is shared with the company's A-08 and A-09 power amplifiers, and both are designed to match each other in terms of both design and sound quality as a pair.

The input and output pin jacks are made of chrome copper, original pin jacks, and Teflon sockets are of a highly reliable type.

The input terminals of this unit employ the company's original top-quality pin jacks with machined chrome copper terminals for the external conductors, machined bronze round pin terminals for the internal pins, and Teflon as the insulating material. This pin jack is designed to be connected from the ground side when connecting and disconnected from the hot side when disconnecting, which is also advantageous in terms of safety.


For the vacuum tube socket, a non-resonant Teflon socket, which is highly regarded not only in Japan but also overseas, is used. If the socket is loose, it does not matter how much the amplifier body is strengthened. The company's amplifiers are designed to prevent vibration from the socket portion, and the effect of this will be seen in the sound.

High-quality wire material is used for the power cable, and hospital grade gold-plated terminals are used for the plug.

The power cable of this amplifier uses a high-quality cable with a 3-pin inlet terminal, and the plug uses a National hospital grade plug with unique gold-plated pins. A 3p inlet jack is used on the main unit side, which can be replaced with a cord of the customer's choice.

Tubes used	2 x TTelefunken 6AK5W
Maximum output	8V
Frequency Response	10-150kHz/-0.5dB
Input impedance	50kΩ
Output impedance	1.6kΩ
Line amplifier gain	16dB (approx. 6 times)
Residual noise	0.07mV
Outer dimensions	420(W)290(D)94(H)mm
Weight	6.3kg