Yamamoto Sound Craft CA-04 Tubular Line Level Preamp

CA-04 is a vacuum tube preamplifier dedicated to high performance line level, which refines the details by independent line amplifier part based on the company's CA-03,CA-03L, which received several awards. It is designed not to inherit old types of circuits or sounds, but to bring out the hidden attractiveness of vacuum tubes and to bring out the high amount of information that is used in modern times.

DALE has good sound resistance, and polypyrene film condenser with less distortion is used for condenser.
Most of the CA-04 resistors are made by DALE. Many DALE resistors are made according to MIL standards in the United States, and their sound quality is so good that they cannot be compared with the same class of domestic products. The reliability is also several steps higher than the general use.

The condenser is mainly made of US polypropylene capacitors. This polypropylene capacitor is more responsive to pulsing signals than ordinary chemical capacitors, and the capacitor's own distortion rate is very good. The difference in sound quality in this condenser greatly affects not only the signal circuit but also the power circuit, so we measure the sound quality by adopting polypropylene type of many parts of the capacitor including the power circuit. In addition, the company fills the ebony case with high-strength epoxy resin in the condenser of the part which greatly affects the sound quality to improve its sound quality.

Contributing to vibration prevention by adopting brass sub-chassis to prevent vibration effects

Vacuum tube is affected by vibration over its structure. 6AK5W is a vacuum tube incorporating an anti-vibration structure, but the effect of vibration on sound remains. The CA-04 has a strong sub-chassis made of brass under the substrate to prevent vibration and improve sound quality by joining the substrate and sub-chassis at a critical point. In addition, the chassis structure is made of solid solid cherry wood with side panels and a frame structure with stainless steel fittings.

Beautiful cherry blossom front panel and sidewood for beautiful form

CA-04, the front panel and side panel of the wood panel are made of Japanese cherry wood. Other parts have a beautiful aluminum chassis with 2mm thickness. This design is in common with the company's A-08,A-09 power amplifier, and both are designed to match both sound quality as a pair.

I/O pin jack, chrome copper, original pin jack, high reliability type made of Teflon used in socket

The input terminal of this machine adopts chrome copper sharpening terminal for external conductor, and the inner pin adopts the round pin terminal of neighboring bronze shaving, and the company's original finest pin jack adopting Teflon as insulation material. This pin jack is connected from the earth side when connecting, and it is a structure that leaves the hot side when pulling, so it is advantageous in the safety side.


The vacuum tube socket uses a non-resonant type-flon socket made by the company, which is highly valued not only in Japan but also overseas. If the socket is loose, no matter how much amplifier body is enhanced, there is no point. Since the amplifier of the company is a structure that prevents vibration from the socket part, the effect appears greatly in the sound.

High-quality wire material is used for power cable, and a hospital grade gold plated terminal is used for plug.

The power cable of this machine adopts a high quality cable with a 3p inlet terminal, and the plug part uses a unique gold plated pin for the National hospital grade plug. Since 3p inlet jack is used on the main body side, it is also possible to exchange it to the customer's desired code.

Use vacuum tube	TTelefunken製6AK5W 2本
Maximum output	8V
Frequency Characteristics	10-150kHz/-0.5dB
Input Impedance	50kΩ
Output Impedance	1.6kΩ
Line amplifier unit gain	16dB (about 6x)
Residual noise	0.07mV
Outer dimension	420(W)290(D)94(H)mm
Weight	6.3kg