6J1X2+6N3X2+6Z4 bile preamplifier circuit diagram

DFN1006 TP-RCLAMP3321P ESD Diode Low Capacitance

Photocoupler

6J1X2+6N3X2+6Z4 bile preamplifier circuit diagram

The tube amplifying circuit is generally larger than the transistor amplifying circuit, but because it has many components of the even harmonics, the human ear sounds quite good in sound, and the performance is soft and resistant. The characteristics of strong music. Nowadays, it is a practical practice to combine the advantages of the tube and the transistor with the low-distortion and transistor for power amplification, that is, the power amplifier with low distortion and transistor for power amplification. It is also one of the favorite games played by audio FAN at home and abroad.

As a pre-existing electronic tube, there are many internationally popular classic lines to refer to, such as Marantz, and Maotian, Matisse circuit, the tone is also classic, but it uses the tube 12AX7, 12AT7 and other tubes, the price is also copied It is very expensive, the price is not high, how to DIY according to the actual situation, the price is not high, but the quality of the performance is very satisfactory. The pre-biliary level is the topic that most of our fans are most concerned about. Here, this site introduces a SSE-T01 bile preamplifier, which is a circuit diagram of the famous Japanese singer's famous Mr. Sudo (one of the Japanese daring masters), and made some improved preamplifier boards. The circuit consists of two 6J1, two 6N3 and bile rectifier 6Z4. The circuit diagram is as follows:

Japanese Sudo's masterpiece, the circuit is directly coupled, using a cathode output. In the circuit, the front stage uses 6J1 for each channel, and the output stage 6N3 for each channel makes the double-transistor parallel low-impedance cathode output, which is better than the output impedance characteristic of the original circuit type.

It is commendable that the preamplifier of the gallstone-coupled power amplifier made by this circuit has excellent sound quality. The sound quality of the "cholerodesis" power amplifier used by Sudo to use the circuit as the front stage has been obtained by almost all Japanese audio experts. Group: Dashijin, Tsuchiya, Sato Dinghong, and Nasu, Bae Yusuke, and Ohara Yufu, etc., are highly appraised and affirmed.

So far, the general experience is that when the front-end load is abnormal, the direct-coupled circuit will quickly deteriorate the distortion characteristics and be susceptible to the change of the bias voltage. However, it has been proved that the direct coupled tube amplifier is very good in performance, its distortion is very low, and the example distortion is about half lower than that of RC coupling. Of course, this cost is to sacrifice some high-frequency characteristics, reducing the high-end -3dB point from 105KHz to about 85KHz. If measured by the international standard IEC document of high-fidelity audio amplifier, this indicator has far exceeded the specified standard, which can fully meet the sound-requirement requirements of high-fidelity Line amplifier. Only on the characteristic curve of 6J1 bile duct, it has been very exciting; the measured index of this board: effective frequency range 20～55000Hz±1.5dB; total harmonic distortion ≤0.3; A weighted signal-to-noise ratio ≥85dB.

The PCB design of SSE-T01 is as follows:

PCB board diagram

The SSE-T01 bile preamplifier is very rigorous in design and materials. It adopts a strict grounding measure, and the high voltage part and signal channel, the power part and the amplified part are far away and separated by a separate ground line. Design, the only coupling capacitor in the audio channel uses WIMA MKP4 dedicated audio fever capacitor, the resistor uses high quality metal film resistor or DALE resistor. It is well known that the amplifier has a big difference between the wiring and the ordinary transistor circuit. That is, the power frequency AC noise will be introduced, and the signal-to-noise ratio difference is a headache in the manufacture of the amplifier. In the design of this board, it is found that the voltage fluctuation of the mains in different regions and different time periods is large. If the voltage of the power supply is not accurate, the voltage of the filament has a great influence, or even fails to work normally, such as the above two factors. The impact, sometimes the voltage of 6.3V will reach about 7V. In fact, the fluctuation of the voltage of the filament has a much greater impact on the sound quality than the fluctuation of the screen voltage. The filament voltage that is too high or too low will cause the tube to age quickly. This point has been discussed specifically on other networks.

The traditional AC filament power supply, on the other hand, is easy to cause the power frequency to dry. The general practice is that the transformer center tap is grounded, the shunt resistor is grounded, the filament is added with a high voltage, etc., but I think it can solve the voltage instability very well. The problem with the power frequency is the DC regulated power supply. The SSE-T01 board is cleverly used to double-voltage rectifier to make the 6.3V voltage rise to 12.6V, and then rectify into DC and then through two three-terminal regulators in parallel to increase the maximum. The filament load current is obtained by connecting a diode in series with the second pin of the three-stream voltage regulator to obtain a stable DC voltage of about 12.6V, and then connecting the two 6J1, 6N3 filaments in series to the DC voltage of 12.6V after the voltage regulation treatment, so that In addition, the high-voltage power supply part adopts 6Z4 bile rectifier tube, which plays the role of tuning sound on the one hand and high voltage delay on the other hand. This board performance is better than ordinary diode rectification power supply.

In addition, the appropriate screen pressure for the tube makes the tube have a good working point. The board appropriately increases the working voltage of 6J1 according to the actual audition, which makes the board particularly soft in listening sense, and the performance of each frequency band is excellent. In addition, there is no negative feedback added to the circuit, and the intermodulation distortion is small.

Supply voltage:

Filament: 6.3V/1A; 6.3V/1.5A; 230V/0.1A

Bile pre-plate component list

Component code parameter REMARK

7812A three-terminal regulator integrated IC

7812B three-terminal regulator integrated IC

B1 two-legged blue terminal block connected to high-voltage AC power supply (6Z4)

B2 two-legged blue terminal block to 6.3V AC power supply (6Z4)

C1 Ce1 100p Ceramic Capacitor

C2 Ce2 MKP4 1u German-made audio capacitor for fever

C3 400V/220U

C4 400V/220U

C5 400V/22u

C6 MKP4 400V/1u German special audio capacitor for fever

C7 C8 16V/6800U X2

C9 220u/25v

D1 D2 IN4001

D3 D4 IN5404

D5 IN4001

JP1 three-legged blue terminal block and pin socket Audio in

JP2 three-legged blue terminal block and pin socket Audio Out

JP3 2-pin blue terminal block 6.3V AC IN

Rm Rn 100-1K adjusts the amplitude of the input signal, here with 100

R1 Re1 1K

R2 Re2 1K has been changed (on board labeled 10K)

R3 Re3 470k

R4 Re4 1k

R5 Re5 10K-15K/2W Adjust this value to make the screen voltage of 6J1 150-165V

R6 Re6 33k/1W

R7 Re7 100K

R8 2k/2w has been changed

R9 150k/2w

R10 2k/2w has been changed

R11 Re11 1K/2w

RJ 0.5-1 rectifier bile filament power supply adjustment resistor

V3 6Z4 J rectifier bile (new light inventories)

V1a 6J1 J preamplifier bile (new in Beijing stock)

V1b 6J1 J preamplifier bile (new in Beijing stock)

V2a 6N3 T buffer output gallbladder (new in Beijing stock)

V2b 6N3 T buffer output gallbladder (new in Beijing stock)

Three-terminal regulator radiator 2

Fixed plate copper column 4PCS with normal volume potentiometer 1 attached signal line