Yamamoto Sound CraftCA-04 Tube-type line-level preamplifier

The CA-04 is a high-performance line-level tube preamplifier based on the award-winning CA-03 and CA-03L, with an independent line amplifier and further refinement of the details. It is not designed to inherit old circuits and sounds, but to bring out the hidden charm of vacuum tubes and bring out the informative sounds that can be used today.

The resistors are made by DALE, which has a good sound, and the condenser is a polypyrene film capacitor with low distortion in the main part
Most of the resistors of CA-04 are made by DALE in the United States. Many of the resistors made by DALE are made according to the MIL standard in the United States, and their sound quality is so superior that it cannot be compared with those of the same class made in Japan. Its reliability is also several levels higher than that of general use.

In addition, polypropylene capacitors made mainly in the United States are used for condensers. Compared to ordinary chemical capacitors, this polypropylene capacitor has a superior response to pulsed signals, and the distortion rate of the capacitor itself is also very good. Since the difference in sound quality between capacitors has a significant impact not only on the signal circuit but also on the power supply circuit, we are trying to improve the sound quality by adopting a polypropylene type capacitor for many parts of the capacitor, including the power supply circuit. In addition, the condenser, which greatly affects the sound quality, is filled with high-strength epoxy resin in an ebony case by the company to improve the sound quality.

Contributes to vibration isolation by adopting a brass subchassis that prevents the effects of vibration

Due to their structure, vacuum tubes are not insignificant susceptible to vibration. Although the 6AK5W is a vacuum tube with an anti-vibration structure, the vibration still has an effect on the sound. The CA-04 has a strong brass sub-chassis underneath the board, and the board and sub-chassis are joined at key points to prevent vibration and improve sound quality. In addition, the chassis structure is strong and vibration-resistant with side panels made of solid cherry wood and a frame structure made of stainless steel fittings.

Beautiful form is achieved by adopting a beautiful cherry wood front panel and side wood.

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

The I/O pin jack is made of chrome copper and the original pin jack is used, and the socket is made of Teflon, which is a highly reliable type.

The input terminals of this unit use machined chrome copper terminals for the outer conductor, round pin terminals machined from neighboring bronze for the internal pins, and the company's original top-of-the-line pin jacks that use Teflon as the insulation material. This pin jack is connected from the ground side when connected, and is separated from the hot side when unplugging, which is advantageous in terms of safety.


The vacuum tube socket uses the company's non-resonant Teflon socket, which is highly regarded not only in Japan but also overseas. If the socket is loose, there is no point in strengthening the amplifier body no matter how much you strengthen it. The company's amplifier has a structure that prevents vibration from the socket part, so the effect is greatly visible in the sound.

High-quality wire rod for power cable and hospital-grade gold-plated terminals for plugs

The power cable of this unit uses a high-quality cable with a 3P inlet terminal, and the plug part uses National's hospital-grade plug with a unique gold-plated pin. A 3P inlet jack is used on the main unit side, so it is possible to replace it with the cord of your choice.

Vacuum tubes used	2 pieces of 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
Exterior Dimensions	420(W)290(D)94(H)mm
weight	6.3kg