Yamamoto Sound Craft CA-03 Vacuum Tube Phonoiko Built-in preamplifier

Divide the ripple filter of the power supply from the rectifier circuit separately for each stage and supply each stage from the independent power supply. The rectification circuit is double wave rectification and the regulation is improved. The ignition of the heater of the vacuum tube Telefunken 6AK5W has provided an independent rectification circuit for each of the six vacuum tubes, eliminating interference with each other's vacuum tubes. The amplifier circuit achieves both great gain and noise reduction by setting the operating point to the optimal point.


The gain of the equalizer amplifier is high-gain type and 58dB at 1 k Hz. The gain of the normal equalizer amplifier is about 34 dB, which is 24dB large setting. The SN ratio achieved 2.3mV by reducing noise 110dB. The company's equalizer amplifiers get gain with only two vacuum tubes and are very simple, so there is no lack of information. Although it is a circuit configuration of CR type, it achieves quite good SN ratio. The maximum output is about 28V, so it can support not only MC cartridges, but also large MM cartridges and high power MC cartridges. The company's MC cartridge YC -03S,YC-03M (output is 0.25mV) is directly connected and can be used without using a boost transformer. The MC cartridge's sound is high in freshness and greatly improves the amount of information. The input impedance of the equalizer part of the amplifier such as CA-03 is optimal for 100Ω.

Line Amplifier

Use vacuum tube	Telefunken製6AK5W x6
Maximum output	8V
Frequency Characteristics	10-150kHz/-0.5dB
Output Impedance	1.6kΩ
Line amplifier unit gain	14dB (about 5x)
Residual noise	0.13mV
S/N ratio	92dB

Equalizer Amplifier

Maximum output	28V
Frequency Characteristics	30-15kHz/+-0.5dB
Input Impedance	47kΩ,1kΩ,100Ω
Output Impedance	4.8k
Amplification rate	58dB/1kHz
Residual noise	2.3mV
S/N ratio	110dB
Size	420(W)290(D)94(H)mm
Weight	6.3kg