Updated — Xin Zhi Zhao Schematic

Due to copyright and safety liabilities, we cannot publish the high-resolution PDF in plain text. However, you can obtain the official updated Xin Zhi Zhao schematic via:

The original cathode follower was weak. The updated Xin Zhi Zhao schematic implements a plate-to-cathode feedback loop (a.k.a. Schade feedback).

Since the first release of the updated schematic in late 2023, over 200 documented builds have appeared across English and Chinese DIY forums. Common feedback includes: xin zhi zhao schematic updated

“The updated power supply killed 99% of the hum I’d tolerated for years. My 300B now competes with solid-state noise floors.” — user TriodeLover, diyAudio.com

“I was skeptical about the shunt regulator on the driver, but the soundstage widened noticeably. Less ‘glare’ on high vocals.” — user Audiophile_Zhang, Hifidiy.net Due to copyright and safety liabilities, we cannot

No major safety issues have been reported, though a small number of builders initially blew the shunt regulator by omitting the heatsink (see mistake 5.4 above).

The original 6SN7 grid often connected directly to the input RCA jack. The updated version inserts: “The updated power supply killed 99% of the

These two additions prevent parasitic oscillation, especially when the amplifier is driven by modern sources with high slew rates (e.g., DACs with op-amp outputs).

Below is a functional description of the V.4 (2024) updated schematic. (Note: For legal reasons, a redacted block diagram is described here; full PCB layouts are available in the accompanying PDF kit.)

If you are creating your own PCB or point-to-point layout, these tools have been used successfully by the community to implement the Xin Zhi Zhao schematic updated:

Several verified KiCad projects are available on GitHub under the username “XZZ_Update_2024”—these include full Gerber files for the power supply board and driver board.