Topping A30 is a compact, high-performance desktop headphone amplifier/preamplifier that’s ready to satisfy all daily listening needs. It is dedicated for budget conscious customers, but both its components and build quality are more typical to the more expensive equipment. A30 has two headphone outputs (3.5mm and 6.35mm) with different impedances, 3 gain settings and 2 power profiles.
In order to fit all kinds of headphones, we designed A30 to have 2 working mode (Hi or Lo working voltage), 3 gain set (0db, 9db and 18db) and 2 headphone output with different impedance
A30’s voltage amplification stage uses OPA1611, which is famous for its low noise, high slew rate and an extremely low distortion (0.000015% at 1 kHz). Next step in the signal chain is handled by OPA2134, a high-speed chip that offers superior sound quality and low noise, but it can be replaced thanks to a removable support that allows the user to test different op-amps.
Headphone amplification circuit is based on a TPA6120A2, a high-fidelity headphone amp chip that features a class AB architecture (current-feedback) able to address a wide bandwidth with minimal noise and high dynamic range (126 dB). Three key features make current-feedback amplifiers outstanding for audio. The first feature is the high slew rate that prevents odd order distortion anomalies. The second feature is current-on-demand at the output that enables the amplifier to respond quickly and linearly when necessary without risk of output distortion. When large amounts of output power are suddenly needed, the amplifier can respond extremely quickly without raising the noise floor of the system and degrading the signal-to-noise ratio. The third feature is the gain-independent frequency response that allows the full bandwidth of the amplifier to be used over a wide range of gain settings. All components used for amplification are mounted on separate heatsinks to prevent overheating and interferences in the sound amplification.
Thanks to two operating modes (high/low voltage on the input signal) and three gain settings, user can easily adjust the device to their headphones and find comfortable listening volume and the right amount of gain.
With both RCA input and output on the back panel, the A30 can also work as a preamplifier with hardware volume control that benefits from powerful yet precise op-amps (OPA1611, OPA2134). The hardware volume control is handled by ALPS potentiometer. This means that Topping A30 can be a great partner for a power amplifier or a set of active speakers.
A30 is equipped with a separate linear power supply that effectively isolates the audio signal from the intrinsic noise of an electrical appliance working. 2x15V is delivered by the mains transformer solely to the audio portion, while a secondary output delivers 1x8V to all other components that do not directly affect the sound output – this includes LEDs, logic circuits, relays, etc. Thanks to this approach only one cable is needed for power supply while separating the noise sources from the sound in the circuit. Outsourced linear transformer is kept physically distant from the amplifiers which helps to avoid magnetic leakage and thus causing interference. On top of that, it helps to manage the device’s temperature. WIMA capacitors are used for coupling, and they help to refine the overall performance of the device.
- TPA6120 Hifi Headphone Amplifier
- OP-AMP: OPA1611+OPA2134
- Material: Aluminum
- Analog audio input interface: 1*RCA (L+R)
- Line out: 1*RCA (L+R)
- Headphone output: 1 x 6.35mm/1 x 3.5mm headphone interface
- Input: 1 x stereo RCA
- Line out: 1 x stereo RCA
- Headphone output:
- Suitable headphone impedance: 16 – 600 Ohm
- Gain settings: 0 dB / 9 dB / 18 dB
- 126dB (G = 0dB, RL = 32)
- 121dB (G = 9dB, RL = 32)
- 111dB (G = 18dB, RL = 32)
- Max output power:
- 1551mW x 2 (6.35mm Hi 32Ω, 1% THD + N)
- 291mW x 2 (6.35mm Hi 300Ω, 1% THD + N)
- 152mW x 2 (6.35mm Hi 600Ω, 1% THD + N)
- 757mW x 2 (3.5mm Hi 32Ω, 1% THD + N)
- 258mW x 2 (3.5mm Hi 300Ω, 1% THD + N)
- 143mW x 2 (3.5mm Hi 300Ω, 1% THD + N)
- Max output voltage swing: 26.6 Vpp
- THD+N(@1 kHz):
- 0019% (RL = 32Ω, G = 0dB, IN = 0.5Vrms)
- 0003% (RL = 300Ω, G = 9dB, IN = 0.5Vrms)
- 0006% (RL = 600Ω, G = 18dB, IN = 0.5Vrms)
- Frequency response: 10 – 200 kHz
- Input sensitivity:
- 0Vrms (Hi G = 0dB)
- 3Vrms (Hi G = 9dB)
- 2vrms (Hi G = 18dB)
- 2uV (G = 0dB, RL = 32)
- 2uV (G = 9dB, RL = 32)
- 2uV (G = 18dB, RL = 32)
- Weight: 525 g
- Dimensions: 17 x 12.2 x 3.8 cm
- Power adapter
- User’s manual
- Warranty card