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Trilogy Audio 931i Headphone Amplifier

Trilogy Audio 931i Headphone Amplifier
 Trilogy Audio 931i Headphone AmplifierTrilogy Audio 931i Headphone Amplifier 
(£1,125.00 Exc. VAT)

Delivery In 5-7 Days

Free U.K. Delivery


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01892 532 995

  • High current design
  • Two inputs
Trilogy Audio
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Why buy from us?

Trilogy Audio 931i Pure Class A Single Ended Headphone Amplifier

The way we listen constantly moves and evolves. With more of us interested in quality headphone listening than ever before, we decided to make a headphone amplifier with a wider reach. The brief for the 931 project was to keep all of the essential elements that make the highly acclaimed 933 so successful but at a significantly lower cost. The 931i (improved) may be affordable, but its performance and quality is still pure Trilogy.

The 931i is a fully discrete design, no generic integrated circuits are used, so designer Nic Poulson can control all the active circuit's crucial parameters, optimising performance for its intended application only. The small, light drivers found in headphones are very closely coupled to the ear and as a result are ruthlessly revealing.

Like its bigger brother the 933, the audio circuit operates in pure single ended Class A with active constant current sources. Each channel has a single continuously biased output device. The main benefits of this topology are that the output is free from crossover distortion, and the device is held at a constant temperature. An oversized linear power supply gives good operating headroom for the active circuitry. All these elements combine to give excellent small signal resolution while maintaining good drive capability.

There are two stereo line inputs, audio grade ALPS volume control and quality components from branded sources used throughout. Assembly is totally by hand in our UK workshops. The output devices dissipate enough heat to need heatsinking. An extruded off the shelf heatsink would serve here but we chose to employ a custom CNC machined part. Semiconductors are sensitive to mechanical vibration and their operating characteristics vary with temperature. The sound quality benefits of attaching the output devices to a high mass with low resonant signature and large thermal inertia more than offset the increased costs.

The standard finish is a soft natural silver, enhancing the quality of the beautifully finished casework. Our lustrous paint finishes are a luxurious option for those wishing to add their own individual touch.

Intelligent design can overcome the constraints of finite resources. The 931i carries all the traits that make its bigger brethren such involving musical performers. Detailed, spacious, communicative, the 931i is indisputably Trilogy through and through.

Shipping typically 5-7 days
Size: 140*237*50 (W*D*H), including connectors  140*244*50(W*D*H) 
Packaged Size: 240*350*85 (W*D*H) 
Weight: 1.7 Kg 
Packaged Weight: 2.3 Kg 
Power consumption: 16 Watts 
Inputs: 2 Stereo line 4 RCA phono sockets 
Input Impedance: ≥50K Ohms 
Gain (max): 18dB 
Frequency response: 20-20KHz +/- 0.5dB 
Output impedance: ≤ 10 Ohms 
Output Power: 
  • 800mW into 60 Ohms
  • 200mW into 300 Ohms
Distortion (THD): ≤ 0.05% 10mW into 300 Ohms 
Signal to Noise Ratio: ≥ 85dB A Weighted

UK Delivery

  • FREE delivery via DPD Local By 12pm on orders to value over £300, including one hour delivery window service 'Predict & Follow My Parcel'.
  • Royal Mail Special Delivery By 1pm costs between £5.00 - £10.00 on orders to value under £300, dependent on weight.
  • Saturday or Sunday delivery available upon request for supplemental charge.

EU Delivery

  • £25 delivery charge 'Flat Fee' via DHL Europe by Road service (5-7 days) which provides comprehensive tracking of shipments online.
  • £50 delivery charge 'Flat Fee' via DHL Europe by Air service  (2-3 days) which provides comprehensive tracking of shipments online.
    Receiver is responsible for the payment of local Duties and Taxes.

USA & Canada Delivery

  • Services based on your order being shipped to the U.S. and Canada are calculated as follows:
    £100 delivery charge 'Flat Fee' via DHL international 'Day Definite' service per parcel.
    Receiver is responsible for the payment of local Duties and Taxes.


  • Not all products are available for order into Europe, USA & Canada


  • Full manufacturer's warranty on all new purchases. Standard warranty is typically 12 months to 2 years with some goods coming with 6 years manufacturer's warranty.
  • Goods purchased in UK and EU are covered by the Consumer Contracts Regulations.

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