When Only the Best Will Do

The Ray Tubes RESERVE 300B isn’t for everyone. It’s the distillation of decades of experience. With a bespoke design, small-batch production, and meticulous selection, the Ray Tubes RESERVE Collection reveals audio details you never knew were there.

Hand selected and tested, the Ray Tubes RESERVE 300B is designed specifically for hi-fi audio applications. Featuring gold-plated pins and our monocrystalline carbon Magic Coating, the RESERVE Collection easily outperforms New Old Stock and new production alike. Fewer than 5% of production meets our standards.

The 300B is a legendary tube. Introduced in 1938, it powered the cinemas of Hollywood’s Golden Age. Audiophiles have treasured it for decades for its low noise and good reliability. Ray Tubes is proud to introduce our take on a classic.

Sound Characteristics

The RESERVE 300B delivers warm and elastic low frequencies, delicate and layered midrange, clear and smooth high frequencies, and rich details. Its moderate dynamic range and wide, well-defined soundstage offer a good sense of space and clarity.

1. Bass Performance
   Warm and elastic, offering a delicate and textured low-end ideal for genres like jazz and folk.
2. Midrange Performance
   Full-bodied and emotional, particularly in vocals and strings, with transparent and rounded sound showcasing rich layering and warmth.
3. Treble Performance
   Clear with an airy feel, smooth and detailed, presenting rich nuances with a natural and gentle sound that avoids excessive brightness.
4. Dynamics and Soundstage
   Moderate dynamic range effectively highlights contrasts in loud and soft passages. Soundstage is wide and well-defined, with excellent depth and space, making it suitable for smaller ensemble music.

Technical Specifications

• Tube Type: 300B
• Tube Socket: 4-pin
• Power Output (Pout): 6.6 W

Filament Specification

• Filament Voltage (Uf): 5 V
• Filament Current (If): 1.2 A

Maximum Rating

• Anode Voltage (Ua): 480 V
• Anode Dissipation Power (Pa): 40 W

Cathode Current (Ik)

• Self Bias: 100 mA
• Fixed Bias: 70 mA

Interelectrode Capacitance

• Input Capacitance (Cin): 9 pF
• Output Capacitance: 4.3 pF
• Transfer Capacitance: 15 pF

Static Parameters

• Anode Voltage (Ua): 300 V
• Grid Voltage (Ug): -60 V
• Anode Current (Ia): 60 mA
• Transconductance (Gm): 5.5 mA/V
• Internal Resistance (Ri): 0.7 kΩ
• Amplification Factor (μ): 3.85

Package Contents

• Set of four, two, or single vacuum tube
• User handbook featuring burn-in guidelines
• Certificate of authenticity and warranty

Compatible Amps

Explore Ray Tubes' Tube Amp Compatibility List.

The Ray Tubes One Year Warranty

Most vacuum tubes are notoriously fickle. That’s why warranties are rare. But we trust our products and we’re proud to offer our One Year Warranty against manufacturing defects. For more details, check out our warranty page.