The signal to noise ratio of CA-03 and CA-03L and EQB-01 amplifier improved sharply.

The signal to noise ratio of CA-03 and CA-03L and EQB-01 amplifier improved sharply.

At our company, the circuit of CA-03 and CA-03L and EQB-01 amplifier was improved completely lately, and the signal to noise ratio of the amplifier was raised sharply.

CA-03 and CA-03L and EQB-01 is an original circuit system which uses a pentode for an amplification part, and there was established reputation in the sound quality from the former.

However, on the character of a pentode, it was difficult to remove the ripple noise of a power supply, etc., and it was not able to make a noise level low enough.

At our company, various improvement was tried, the circuit board was redesigned newly, and these problems were conquered.

The noise level succeeded in lowering to a value low enough, and began shipment by the advanced type from a shipped part of the degree in April, 2008.

The main improvement parts divided the ripple filter of the power supply into each of each stage from the rectification circuit separately, and they improved it so that each stage might be supplied from the independent power supply.

Conventionally, the rectification circuit changed into both waves rectification what was all the wave rectification systems, and raised the regulation.

The ignition to the heater of vacuum tube Telefunken 6AK5W prepared the rectification circuit which became independent to each six vacuum tubes, and lost interference of the mutual vacuum tube.

Moreover, the amplifier circuit reconciled acquisition of a big profit, and the fall of the noise by resetting an operating point as the optimal point, while a basic circuit maintained the same system.

The profit of equalizer amplifier is setting to 58dB the place which was a high gain type and was 54dB in 1kHz conventionally.

Although the gain of the usual equalizer amplifier is 34dB, the equalizer amplifier of our company is a setup larger 24dB than it.

The noise in the state decreased 2.3mV sharply from conventional 4mV.

Thereby, the signal to noise ratio attained 110dB.

Since this gain has obtained the equalizer amplifier of our company only with two vacuum tubes, and it is very simple, there is no lack of the amount of information.

Although it is the CR type circuit composition generally made disadvantageous at the signal to noise ratio, it is proving that this can obtain the quite good signal to noise ratio with directions for use.

Since about 28v of maximum outputs occur, it can respond also to MM cartridge and high-output MC cartridge of a big output as well as MC cartridge.

MC cartridge YC-03S of our company and YC-03M are actually connected directly, and it has a level which can be used.

Since the output of the YC-03 S/M cartridge of our company is 0.25mV, most MC cartridges can be used connecting directly.

Freshness is high and the amount of information of the sound of MC cartridge which does not use a Step up transformer improves sharply.

In addition, as for the input impedance of the equalizer part of the amplifier of the CA-03 grade of our company, 100 ohms is the optimal.

CA-03 and CA-03L and EQB-01 is the composition with completely same equalizer amplifier circuit.

EQB-01 is the composition of having omitted the line amplifier part from CA-03 and CA-03L, and having excluded input volume and a selector switch.

Moreover, the circuit board manufactured newly changes the thickness of copper foil into 70micro from conventional 35micro, and is raising sound quality by plating with gold.

These improvement considers it as a minor change for the time being, and I continue and sell appearance and a price, without changing.

The person of search needs to examine a new preamplifier.

Moreover, the person of use already receives improvement for CA-03 of our company, CA-03L, and EQB-01 to a new style circuit board in yen150,000.

Since I exchange the whole circuit board, you send amplifier in use and it becomes the clearing work in our company.

The person of hope needs to inform directly to our company.

I indicate the characteristic of advanced CA-03, CA-03L, and EQB-01 below.

CA-03L standard

- Form : Vacuum tube type preamplifier - use vacuum tube : product made from Telefunken 6AK5W 6 piece

<<Line amplifier part>>

- maximum output: -- 8V - frequency characteristic: -- 10-150kHz (-0.5db) - output impedance: -- 1.6komega - line amplifier part profit: -- 14dB (about 5 times) - residual noise: -- 0.13mV - signal to noise ratio: -- 92dB

<<Equalizer amplifier part>>

- maximum output: -- 28V - frequency characteristic: -- 30-15kHz(+-0.5db) - input impedance: -- 47komega, 1komega, and 100 ohms - output impedance: -- 4.8komega- amplification rate: -- 58dB/1 kHz

(The gain of the usual amplifier is a setup larger 24dB than a standard because of about 34dB.)

- residual noise: -- 2.3mV - signal to noise ratio: -- 110dB - outside dimension: -- 420(W)290(D)94(H) - weight: -- 6.3kg- price yen398,000 * Dual type type volume control volume is adopted.

Many characteristics of EQB-01 are the same as the phono equalizer part of CA-03L.



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