耳擴 Headphone AMP

A modern portable amplifier with a classic circuit design. The National+ is an Opamp-less design; using 10 matched pairs of triodes in a discrete component layout. This approach to amplification delivers a robust sonic presentation that compliments a wide variety of musical styles and tastes.

The National+ housing is CNC’d from a single block of aluminum, providing exceptional protection for ‘on the go’ applications. Sized at just 3.38”x1.8”x.75”, its diminutive footprint conceals a versatile performer. Capable of pairing with sensitive earphones when in ‘low gain’ it is also capable of driving planar magnetic headphones while in its ‘high gain’ setting.

The easy to use National+ features a 3.5mm single-ended input and output. This offers a simple solution to amplify your portable high resolution digital audio player or the sensitive low level signal from your favorite DAC. Its output provides 3 gain stages to provide the perfect match for an audiophile’s earphones and/or headphones.

Carrying case, USB cable for charging and ALO audio amp straps included with The National+.

Specification of the Power Amplifier Unit

T-Amp IC Tripath TA2024
Output Power 2x15W @4ohm
2x6W @8ohm(RMS)
Signal-to-Noise Ratio (SNR) 98dB
Dynamic Range 98dB
IHF IM Distortion 0.10% @ 1W, 4ohm
THD+Noise Audiophile Quality 0.03% @ 9W 4ohm
0.1% @ 11W 4ohm
0.1% @ 6W 8ohm
High Power 10% @ 15W 4ohm
10% @ 10W 4ohm
Power Efficiency 81% @ 15W 4ohm
90% @ 10W 8ohm
Input Audio IN RCA (Left/Right) x 1
Power Socket (5.5mm/2.1mm) x 1
Speaker OUT RJ45 x1
Other Volume & Knob Power ON/OFF switch x
Power Indicator (Blue LED) x1
Power Supply DC 12V-13.2V (max.)
4.2 Specification of the Headphone Amplifier Unit
Signal-to-Noise Ratio (SNR) 92dB
Power Output 3.0 Watts per channel on 33 Ohm
Headphone
Frequency response 15 Hz – 100 kHz -1db
Input Impedance 10k Ohms
Input Audio CD IN RCA (Left/Right) x 1 [3Vpp max.]

Specification of the Pre Amplifier Unit

Input Impedence 10K Ohms unbalanced
Max Input Level +18dBV
Frequency Response 25Hz – 150KHz (+/- 3dB)
Output Power 450 mW/side,THD+N:0.1% (@16 Ohms)
108 mW/side,THD+N:0.1% (@300 Ohms)
Maximum Gain 20 dB/channel
Input Audio CD IN RCA (Left/Right) x 1 [3Vpp max.]
Audio IN 3.5mm jack (Left/Right) x 1
Power Socket (5.5mm/2.1mm) x 1
Output Audio Headphone OUT 3.5mm jack x 1
Switch Knob Audio and power switch x 1
Power Supply DC 12V-13V (max.)
4.4 Specification of the AC Adaptor
AC Input Universal AC 100V-240V/50-60Hz
DC Output DC 12V 5A (60W)
DC Plug DC 2.1mm
Ripple & Noise <= 25mV
Over-load Protection 105%-150%
Over-voltage Protection 115%-150%