Challenge Amp 1 Headphone Amplifier
Challenge Amp 1 (Discontinued) £349
• Free International Shipping
• 14 Day Returns
• Three Year Warranty

Status: In stock. Dispatched within 3 working days.Out of stock.

Your order will be dispatched by the shipping methods below.

UK Orders: Next Day Courier - delivered by the next working day after dispatch.

International: Tracked Courier Service - usually delivered within 3 - 5 working days of dispatch, but may vary according to country.

Please note that customers located outside the EU may be required to pay to import duties. Please refer to your country's customs office for more information.

The Challenge Amp 1 is a high performance headphone amplifier, carefully engineered for precision and transparency. This powerful and versatile amp will drive virtually all headphones with 'reference grade' fidelity.

It features excellent specifications all round, including vanishingly low noise and distortion, ruler flat frequency response and near 0-ohm output impedance, all vital for a ensuring reference sound quality. The low gain mode and silent background is great for sensitive IEMs, while the high output power will easily drive more demanding headphones such as orthodynamics.

The amp is designed and made in England of predominantly British sourced parts. The wooden enclosures are hand made in Tisbury, Wiltshire from American black walnut and lined with copper shielding, while the 3mm aluminium chassis is brushed, anodised and CNC machined for a solid, high quality finish. The circuit board and most other components come from British suppliers and are assembled and tested in house by us, ensuring every amplifier meets our meticulous standards.




"The Challenge Amp 1 definitely challenged my beliefs about what an amp of its type and cost could do. Highly deserving of being included in InnerFidelity's "Stuff We Like"."

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Pro Audio Web Blog

ProAudioWebBlog Logo"4.5/5 - Tisbury Audio are onto a winner with their CA-1."

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Hifi Pig

HiFi Pig Logo "The looks and sound combine to an almost perfect headphone amp for the price."

Read the full review on

Pro Audio Web Blog YouTube

YouTube Logo Watch the unboxing and review on YouTube


"If you are after a smooth effortless vocal centric performance with good low end extension... the CA-1 could be that right kind of classy addition to your system."

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Old & New Sound

"Clarity and definition is the hallmark of this amp without a doubt... The tone is fantastic and allows the headphones to really be themselves without any influence."

Read the review (English translation):
Original review in Spanish:

"With the CA-1, headphones reach a level that I did not think they could get. I finished with the hair on my arms standing up."

Read the review (English translation):
Original review in Spanish:
Technical Specifications
Distortion Percent Level


THD 100 Hz 0.0004% +6 dBu, 32Ω See (1)
THD 1 kHz 0.0003% +6 dBu, 32Ω See (1)
THD 20 kHz 0.003% +6 dBu, 32Ω See (1)
IMD CCIF 0.0004% +6 dBu, 32Ω See (2)
Maximum Output Volts (RMS) Power Notes
16 ohms 3.4 V 725 mW See (3)
32 ohms 5.5 V 945 mW See (3)
50 ohms 7.1 V 1010 mW See (3)
100 ohms 8.1 V 655 mW See (3)
300 ohms 8.2 V 225 mW See (3)
600 ohms 8.3 V 115 mW See (3)
Gain: Low / High 6 dB (2x) 16 dB (6.3x)  
Noise Floor: Low Gain -110 dBV 3.2 μV RMS See (4)
Noise Floor: High Gain -107 dBV 4.5 μV RMS See (4)
Dynamic Range > 128 dB   See (4)
Output Impedance < 0.2 ohms    
Input Impedance 10 kohms
Freq. Response: 20 Hz - 20 kHz -0.04 dB    
Ch. Balance: full vol. / -45 dB < 0.1 dB < 1 dB typ.  
Crosstalk: 600 Ω / 32 Ω -97 dB -80 dB 1 kHz, 0 dBV
Dimensions 204 x 170 x 74mm 8.0 x 6.7 x 2.9"
Weight 0.9 kg 2.0 lb Not inc. PSU
Power Supply 12 V AC ≥ 1000 mA  
Max Power Consumption 12 W    

All tests BW = 20 Hz - 22 kHz, except THD 20 kHz BW = 20 Hz to 96 kHz.
(1) THD: 10 pass average, high gain setting, 1 V RMS input.
(2) IMD: 19 kHz / 20 kHz 1:1, no averaging, high gain setting, 1 V RMS input.
(3) Max continuous output, both channels driven, 1 kHz sine, ≤ 1% THD.
(4) Noise: A-weighted, no averaging. Dynamic range: ref. 8.3 V RMS.

Specifications subject to change without notice.

PDF Logo For full specifications see:
Challenge Amp 1 Technical Specifications [PDF 40 KB]
Design Details

High Performance Amplifier

The CA-1's circuit is the result of 18 months of development, exhaustive testing and listening trials. It uses a combination of ultra high performance LME49600 output buffers, precision spec. surface mount parts and a compact 'high speed' board layout. Great care has been given to minimise every possible source of audible degredation; noise, distortion, output impedance, frequency response, phase shift and crosstalk are all excellent. It's also efficient, runs cool to the touch and is stable into any load, so you can connect any length cable.

Gain Switching

Low and high gain modes are set to 6 dB (2x) and 16 dB (6.3x) gain. The gain switch controls a high quality relay located directly inside the amplifier's gain stage. This ensures the sensitive areas of the circuit are uncompromised and no performance is lost in either setting.

Power Supply

The mains transformer provides clean AC to the 7,200 µF capacitor bank, which feeds a low noise, low impedance regulated power supply.

We use an off board mains transformer, which is advantageous in a number of ways:

• Isolates audio circuitry from electrical noise, no mechanical hum
• Allows fully regulated dual power supply in compact enclosure
• Immune to ground loops
• Easily upgraded and swapped to different mains voltages

Other features:
• Low noise regulators with local low impedance bypassing
• Remote load sensing for precise regulation
• 'Mutual shutdown' circuitry protects the amplifier and your headphones from power supply failure or use of incorrect power adaptor

Note: The CA-1 requires AC power and will not work with a DC power adaptor.

Muting Relay

A muting circuit with turn on delay and fast acting AC detection protects your headphones from any harmful transients during power on/off. If the AC supply is switched off or interrupted, your headphones are disconnected instantly.
The front LED displays the status of the protection circuitry:
Blue = normal operation.
Green = muting circuit active.
14 Day Trial & Warranty
You can cancel your order and return any products within 14 days of delivery, giving you the opportunity to try them out in your own home with your own equipment.

Click here for our returns policy.

Three Year Warranty

The Challenge Amp 1 is covered by a three year limited warranty on parts and labour. If you get any problems with your item in this time, we'll repair or replace it at no charge, subject to terms.

Click here for warranty terms.
Challenge Amp 1 User Manual [PDF 280 KB]

Challenge Amp 1 Technical Specifications [PDF 40 KB]
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