Stax
STAX SRM-500T Hybrid Electrostatic Headphone Driver
Best hybrid driver for audiophiles seeking rich, detailed electrostatic sound.
The STAX SRM-500T is a hybrid DC amplification driver unit featuring a custom low-noise dual FET input and vacuum tube output using 6FQ7/6CG7 tubes. It replaces the SRM-006tS, offering improved sound quality through a newly designed power transformer for enhanced efficiency. This driver unit is designed to deliver exceptional performance for electrostatic headphones, providing a rich and detailed listening experience. Its robust construction and advanced circuitry ensure a high-fidelity audio output, making it a valuable component for audiophiles seeking superior sound reproduction.
$1349.10
More SRM Options
Owner Satisfaction
4.5
/ 5
Category Rank
397
/ 759
#397 in Headphone Amplifiers
Price vs Category Average
-3%
Below average
Type
FET input + vacuum tube output hybrid DC amplification driver unit
/ FET input + vacuum tube output hybrid DC amplification driver unit
Who it's for
- Listeners wanting tube warmth paired with solid-state precision
- Serious collectors prioritizing long-term build quality and reliability
- Audiophiles seeking absolute transparency and microscopic musical detail
Who should skip it
- Users preferring a low-maintenance, set-and-forget audio experience
- Owners of dynamic or planar magnetic headphone collections
- Budget-conscious buyers exploring high-end audio for the first time
Performance breakdown
Sonic Transparency
Hybrid circuitry delivers a remarkably clean and nuanced electrostatic listening experience.
Tube Warmth
The 6FQ7 tubes provide a lush, organic texture to the midrange.
Power Efficiency
Redesigned transformer architecture ensures stable, consistent power delivery for demanding tracks.
Build Integrity
Robust chassis construction reflects the premium craftsmanship expected from Stax engineering.
Connectivity Versatility
Dual RCA and XLR inputs offer flexible integration for high-end systems.
Frequency Extension
Exceptional high-frequency response captures every micro-detail in complex recordings.
Key Specs
Type
FET input + vacuum tube output hybrid DC amplification driver unit
Vacuum tube
6FQ7/6CG7
Frequency response
DC - 90kHz
Gain
60dB
Harmonic distortion
0.01% or less
Input impedance
50kΩ
Maximum output voltage
300Vrms
Bias voltage
DC 580V
Features
- Hybrid amplification design with FET input and vacuum tube output
- Utilizes 6FQ7/6CG7 vacuum tubes for output stage
- Custom-made low noise dual FETs for input stage
- Newly designed power transformer for improved efficiency
- High-fidelity audio reproduction with detailed sound
- Robust construction for durability
- Designed for electrostatic headphones
- Supports a wide frequency response up to 90kHz
- Provides a bias voltage of DC 580V
- Offers both RCA and XLR input options
What customers say
Customers consistently praise the STAX SRM 500T for its exceptional sound quality, noting its ability to drive Stax electrostatic headphones with remarkable clarity and detail. Many highlight the significant upgrade it offers over entry level drivers, revealing new layers in their music. While the price point is premium, users generally perceive strong value given the sonic performance and robust build, considering it a worthwhile investment for serious audiophiles seeking the unique Stax experience. The unit's reliable operation and elegant design also receive positive mentions.
Know before you buy
The hybrid design combines the precision and low-noise characteristics of a solid-state FET input stage with the warmth and harmonic richness of 6FQ7/6CG7 vacuum tubes. This balance ensures you get a detailed, high-fidelity sound without sacrificing the musicality often associated with tube amplification.
Yes, the SRM-500T features the standard 580V DC bias voltage required for all current Stax electrostatic headphones. It is designed to drive the entire Stax lineup effectively.
The SRM-500T is a direct successor that features a newly designed power transformer. This update improves overall power efficiency and contributes to a cleaner, more refined audio output compared to the previous model.
Yes, the unit provides both RCA (unbalanced) and XLR (balanced) inputs. This allows you to easily switch between different audio sources without needing to unplug cables.
Like any tube-based equipment, the 6FQ7/6CG7 tubes will eventually need replacement after extended use. However, the unit is built with robust components to ensure long-term reliability and straightforward operation for the user.
You can expect a highly detailed and transparent sound profile that extends up to 90kHz. The hybrid circuitry preserves the nuance of your recordings while adding a subtle, natural texture to the midrange and high frequencies.
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