NEW 9W*2 6*8 Push 300B Class A single-ended high-fidelity tube power amplifier, 717A 6J8P 6*8 pre-stage push, 30HZ-20KHZ

【Features】

1. The 300B uses a DC filament for lighting, and a multi-turn precision adjustable potentiometer is used to adjust the balance. It is close to the speaker with a sensitivity of 90DB, and there is only a slight AC noise.

2. The well-known Nanjing 6*8 pentode is used to drive 300B, and the output power can reach 9W×2 or more. It is suitable for pushing speakers with an impedance of (4- 8) ohm and sensitivity above 88db.

3. Output rated power: 9W*2 (Because the tube has the advantage of strong overload capability, the actual undistorted output power is equivalent to 50w+50w transistor power amplifier! Since all tubes are working in Class A amplification, the distortion is small, The timbre is sweet, soft, and high in endurance!)

4. Use metal film resistors with a precision of up to 1% and imported electrolytic capacitors. The power filter capacitors use PHILIPS main capacitors and Japanese brand sub capacitors.

5. C (capacitor) L (10H 0.25A choke coil) R (resistance) C multi-stage filtering, high signal-to-noise ratio.

6.Use 300W full power low temperature rise power transformer, 30W output transformer made of Japan Z11 iron core, 250MA 10H choke coil.

7. The coupling capacitor adopts the TE MKP film copper pin capacitor customized by our company, the sound is very mellow, and the high frequency is slender and transparent! Better than WIMA.

8. The electron tube of this machine adopts Sugon 5Z3PA pendant filament rectifier tube×1, Nanjing 6*8 front stage push tube×2, Lin Lai 300B power amplifier tube×2. (If the preamplifier tube is replaced with Nanjing or European and American tubes, the effect will be better. 3 types of tubes have imported replacement tubes, which can be purchased according to personal preference. 5Z3P can be directly replaced with 5U4G, 5AR4, 5Z4P, 274B, 6 meters 8 It can be replaced with 6J8P, 6SJ7, and XD 717A is highly recommended)

9. The circuit board is designed in strict accordance with the principle of graded grounding, and the layout is reasonable and neat. The power board and the amplifier board are arranged separately, and the signal-to-noise ratio is high.

10. Machine size: width 430MM, depth 330MM, height 220MM (including the height of the tube)

11. Machine net weight: 16 kg

12. Chassis material: The top plate is a 2MM thick painted iron plate, and the bottom plate is a 1MM thick perforated mesh plate, which has a good heat dissipation effect. The wooden frame is made of red walnut logs instead of veneer. The thickness of the wood is 20mm, which is strong and reliable and not easy to deform. The four-corner foot post is made of pineapple grid wood with a diameter of 35mm. The feet are 1cm high.

Circuit structure reference drawing:

【PCB版成品机内部图】

电感已经升级为10H 0.25A