LM-513PA Vacuum Tube Monoblock Power Amplifier

At the heart of the amplifier sit two strictly matched PSVANE WE300B power tubes, operating in a genuine Class-A single-ended configuration. Revered in audiophile circles for its lush midrange richness and organic harmonic texture, the 300B tube breathes lifelike texture into vocal performances and acoustic instruments. Precision tube pairing ensures consistent stereo channel balance and uniform tonal accuracy across the entire soundstage.

Custom‑built using premium‑grade materials, this purpose‑designed transformer assembly constitutes the cornerstone of the amplifier’s sonic performance.

Wide‑Bandwidth Single‑Ended Output Transformers
Constructed with high‑grade EI cores and an optimized wide‑bandwidth winding topology, these output transformers faithfully preserve the full musical character of the 300B tubes while extending frequency response across the complete audio spectrum. They yield tight, well‑controlled low‑end reproduction and refined high‑frequency detail, without compromising the signature smooth tonal quality inherent to tube amplifiers.

High‑Headroom EI Power Transformers
Oversized EI‑type power transformers deliver generous power headroom for the entire system. This robust power supply maintains rock‑solid, consistent performance even through highly dynamic musical passages, preventing signal compression and preserving crisp transient detail.

The preamplifier stage utilises two 12AT7 and two 6SL7 vacuum tubes, precisely calibrated to produce clean, linear voltage gain with minimal artificial tonal coloration. It feeds the 300B power tubes with a pristine, adequately‑driven audio signal. For high‑voltage power supply, dual 274B rectifier tubes replace solid‑state rectification, delivering smoother, more organic power feed which enhances the inherent warmth and musicality of the amplifier’s output.

Every unit is meticulously hand-built using precision point-to-point internal wiring, eschewing mass-produced printed circuit boards. This artisanal approach minimizes signal path length, reduces parasitic capacitance and electromagnetic interference, and preserves the finest micro-details in your music. The construction method also enhances long-term reliability and serviceability, ensuring enduring performance for years of listening.

Only audiophile‑grade core components are deployed to preserve signal integrity while maintaining excellent everyday practicality.

Japanese ALPS Audio‑Grade Volume Potentiometer
A genuine ALPS audio‑grade volume potentiometer is implemented within the signal path. It delivers ultra‑smooth, precise volume adjustment with outstanding channel tracking and linearity, ensuring accurate level matching across all listening volume settings.

Premium Remote Control
The supplied remote handset grants fingertip access to core operational functions. Enjoy seamless volume adjustment and one‑touch mute directly from your listening position.

The amplifier features a practical plug-in tube cover system that balances safety and user flexibility. The covers shield the vacuum tubes during operation, insulating against high operating temperatures and preventing accidental contact. Their tool-free, plug-and-play design also allows for quick, effortless removal, making tube rolling and routine maintenance simple and accessible.

The LM-300IA PLUS delivers a gentle, pure and smoothly detailed sonic presentation, staying true to the classic 300B tube aesthetic. With a full-bodied midrange, refined treble and articulate, well-paced bass, it excels across a wide range of musical genres — from vocal jazz, classical chamber music and folk to soft pop and acoustic recordings — making it a versatile and engaging centerpiece for any home audio system.