Stax
Stax SRM-700 Series
Best electrostatic amplifier for discerning audiophiles seeking premium, high-fidelity sound.
The Stax SRM-700 Series offers a choice between two distinct electrostatic headphone amplifier models: the 700S, featuring an all-FET configuration for pure solid-state amplification, and the 700T, which combines FET input with a vacuum tube output for a hybrid sound. Both units deliver exceptional audio fidelity with a wide frequency response and very low harmonic distortion. They are designed for high-performance audio systems, providing a premium listening experience for discerning audiophiles. The amplifiers feature robust build quality and are engineered to drive demanding electrostatic headphones with precision and clarity.
$4699.00
Owner Satisfaction
4.7
/ 5
Category Rank
52
/ 733
#52 in Headphone Amplifiers
Price vs Category Average
+236%
Above average
Type
700700
/ All-stage FET configuration DC amplification driver unit (S) / FET input + vacuum tube output hybrid DC amplification driver unit (T)
Who it's for
- Audiophiles seeking absolute clarity and microscopic musical detail
- Stax owners wanting peak performance from their electrostatic headphones
- Serious listeners prioritizing long-term durability and premium craftsmanship
Who should skip it
- Budget-conscious buyers looking for entry-level audio solutions
- Listeners who own multiple types of non-electrostatic headphones
- Users with limited desk space or poor ventilation
Performance breakdown
Electrostatic Drive Capability
Effortlessly powers even the most demanding Stax electrostatic headphones with ease.
Sonic Transparency
Delivers an incredibly clean signal path with vanishingly low harmonic distortion.
Dynamic Range
Wide frequency response captures every nuance from deep bass to air.
Build Integrity
Robust chassis construction ensures long-term reliability for high-end audio setups.
Hybrid Versatility
Dual model options allow users to choose between solid-state or tube.
Connectivity Options
Balanced XLR and RCA inputs provide flexible integration for modern systems.
Key Specs
Type
All-stage FET configuration DC amplification driver unit (700S) / FET input + vacuum tube output hybrid DC amplification driver unit (700T)
Frequency response
DC – 100kHz
Gain
60dB
Harmonic distortion
0.01% or less (1kHz/100Vrms output)
Input impedance
50kΩ (RCA), 50kΩx 2 (XLR)
Maximum output voltage
450Vrms (1kHz) (700S) / 340Vrms (1kHz) (700T)
Bias voltage
PRO 580V
Dimensions
240W x 103H x 393D mm (maximum protruding portion included)
Features
- Choice of all-FET or hybrid tube/FET amplification
- Discrete dual FET circuitry for low noise output
- Wide frequency response for detailed sound reproduction
- High maximum output voltage for driving demanding headphones
- Multiple input options (RCA, XLR)
- Robust build for durability and performance
What customers say
Customers consistently praise the Stax SRM 700 Series for its exceptional build quality and the unparalleled audio fidelity it delivers. Owners frequently highlight the amplifier's ability to unlock the full potential of Stax electrostatic headphones, creating an incredibly transparent and detailed soundstage. While a significant investment, the consensus points to a premium experience that justifies the cost for serious audiophiles seeking a reference level listening setup. The robust construction and refined sound are recurring themes, underscoring its position as a top tier component.
Know before you buy
The SRM-700S uses an all-FET solid-state design for a clean, precise, and highly detailed sound. The SRM-700T is a hybrid model that pairs a FET input with a vacuum tube output, offering a slightly warmer, more organic tonal character.
Yes, both models feature the standard 580V PRO bias output, making them compatible with all current Stax electrostatic earspeakers.
Yes, both the 700S and 700T include both RCA (unbalanced) and XLR (balanced) inputs, allowing you to integrate them easily into a variety of high-end audio setups.
The SRM-700S offers a higher maximum output voltage of 450Vrms, while the SRM-700T provides 340Vrms. Both are more than capable of driving demanding Stax headphones to high volume levels with excellent headroom.
While the solid-state 700S reaches optimal performance quickly, the vacuum tube output stage in the 700T benefits from a brief warm-up period of 10 to 15 minutes to ensure the tubes reach their stable operating temperature.
With dimensions of 240mm wide and 393mm deep, they have a relatively compact footprint for high-performance gear. However, ensure you have adequate ventilation space around the unit, especially for the 700T, as vacuum tubes generate heat during operation.
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$4699