iBasso
iBasso PB5 Portable Balanced Vacuum Tube Headphone Amplifier
Best portable amplifier for audiophiles seeking rich, tube-driven sound on-the-go.
Experience the captivating warmth of vacuum tubes with the iBasso PB5 portable headphone amplifier. This device brings the sought-after tube sound to a mobile format, powered by dual KORG Nutube 6P1 vacuum tubes for rich, harmonic audio. Its unique six-battery system ensures a pure and robust power source, delivering pristine sound reproduction. The PB5 boasts impressive driving power, capable of up to 1700mW+1700mW into 32 ohms, making it ideal for demanding headphones. Enjoy an uncompromised listening experience on the go with its precise stepped attenuator and microphonics-reducing design.
$1499.00
Owner Satisfaction
4.6
/ 5
Category Rank
268
/ 807
#268 in Headphone Amplifiers
Price vs Category Average
+7%
Above average
Output Power
1700170032
/ mW+mW @ Ω
Who it's for
- Audiophiles seeking classic tube warmth in a portable package
- Listeners using demanding planar magnetic or high-impedance headphones
- Mobile enthusiasts wanting a stackable, high-performance audio setup
Who should skip it
- Commuters needing all-day battery life and cool-running equipment
- Casual listeners shopping for budget-friendly audio gear
- Users preferring low-maintenance, rugged gear for travel
Performance breakdown
Tube Harmonic Richness
Dual Nutube technology delivers authentic, lush warmth in a portable frame.
Driving Power
Effortlessly handles demanding high-impedance headphones with massive output headroom.
Power Supply Purity
Six-battery architecture ensures a clean, noise-free signal for critical listening.
Volume Precision
Stepped attenuator provides tactile, accurate control over delicate gain adjustments.
Microphonics Control
Advanced vibration reduction keeps the tube signal clear during mobile use.
Portability
Substantial build quality prioritizes audio fidelity over lightweight, pocketable convenience.
Key Specs
Output Power
1700mW+1700mW @ 32Ω
Tube Type
Dual KORG/Noritake Nutube 6P1
Recommended Headphone Impedance
8~600Ω
Output Voltage
9 Vrms (4.4mm balanced), 4.5 Vrms (3.5mm SE)
Frequency Response
20Hz-40kHz +0.5dB/-2dB
Dimensions
139*82*28mm
Weight
352g
Average Play Time
10.5 hours
Features
- Rich vacuum tube sound
- Pure power from six-battery system
- High driving capability
- Precise volume control
- Vibration reduction for clarity
- Premium component build
- Portable tube amplification
What customers say
The iBasso PB5 earns high praise for delivering genuine, portable vacuum tube amplification. Users consistently highlight its rich, warm, and highly musical sound signature, noting the Korg Nutube technology creates an expansive, three-dimensional soundstage. This unit expertly drives demanding headphones with authority and low noise. While its size and battery life reflect the necessary compromises for tube power, the premium build quality is appreciated. For serious listeners prioritizing superior sonic performance over ultimate portability, the PB5 is highly recommended as a masterfully executed component.
Know before you buy
No, the PB5 is a dedicated analog headphone amplifier. It does not contain an internal DAC, so you will need to connect it to an external source, such as a digital audio player or a standalone DAC.
Yes, the PB5 is highly capable and supports headphones with impedances ranging from 8Ω up to 600Ω. With an output power of 1700mW per channel at 32Ω, it has enough driving force for most demanding audiophile headphones.
The dual KORG Nutube 6P1 tubes provide the classic, warm harmonic distortion associated with traditional vacuum tubes. This adds a natural richness and depth to your music that solid-state amplifiers often lack.
The six-battery configuration is designed to provide a clean, stable power supply to the tubes and internal circuitry. This isolation helps minimize electrical noise and interference, ensuring a pristine signal path for your audio.
While the PB5 is powerful, it features precise volume control via a stepped attenuator, which helps maintain channel balance at lower volumes. However, due to its high power output, it is best suited for headphones that require significant current.
The PB5 is engineered with a specialized vibration-reduction design to mitigate microphonics, which are common in tube-based devices. This ensures that physical movement or vibrations do not interfere with the clarity of your audio playback.
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$1499