# Sq.Ver.02-B Headphone Amplifier (discontinued production)

**Features**

Very compact and small enough to fit in your hand (W:2.4" x H:1" x L:2.3" without volume knob)

Special printed circuit board with copper weight 70um (Standard PCB copper weight is 35um)

Product driving-time is around 17hours/charge (for reference only)

(It was measured actually by HiFiman HE-6. Of course, it is varied depending on your headphones and/or earphones)

Equipped with charge-circuit for Ni-MH or Ni-Cd AAA size rechargeable batteries

Able to drive 16-300ohm headphones or earphones

Able to easily drive 30-150ohm headphones or earphones with excellent performance

General performance is enough to drive headphones or earphones

**Package included**

Sq.Ver.02-B headphone amplifier x1

Ni-MH 1.2V 900mAh rechargeable batteries x2

USB charge cable x1

**Pictures**

**Audio analyzer test results**

Fig.1 Measurement environment

Measurement environment (fig.1)

Agilent(HP) 8903B audio analyzer x2 (for true 2ch. test)

THD+N, Frequency response and Crosstalk test

THD+N test is carried out with 80kHz LPF

TEXIO VA-2230A audio analyzer x1

S/N and Dynamic range test

S/N and Dynamic range test are carried out with A-Weighting filter and 80kHz LPF

Results

Summary

THD+N (1kHz Sine with 80kHz LPF)

Rch=0.006% and Lch=0.007% when output power is 12mW into 30ohm load

Rch=0.005% and Lch=0.006% when output power is 7mW into 63ohm load

Rch=0.004% and Lch=0.006% when output power is 4mW into 100ohm load

Rch=0.005% and Lch=0.005% when output power is 3mW into 150ohm load

Frequency response (20Hz-20kHz Sine)

Rch=+0.18, -0.86dB and Lch=+0.16, -0.86dB into 30ohm load

Rch=+0.24, -0.28dB and Lch=+0.23, -0.27dB into 63ohm load

Rch=+0.25, -0.16dB and Lch=+0.25, -0.14dB into 100ohm load

Rch=+0.13, -0.13dB and Lch=+0.14, -0.13dB into 150ohm load

Crosstalk (20Hz-20kHz Sine)

Rch=-64 and Lch=-67dB into 30ohm load at 1kHz

Rch=-71 and Lch=-73dB into 63ohm load at 1kHz

Rch=-71 and Lch=-74dB into 100ohm load at 1kHz

Rch=-76 and Lch=-74dB into 150ohm load at 1kHz

S/N and Dynamic range(1kHz Sine with A-Weighting filter and 80kHz LPF)

Rch=99.4dB and Lch=99.2dB into 30ohm load

Rch=100.2dB and Lch=100.1dB into 63ohm load

Rch=100.5dB and Lch=100.3dB into 100ohm load

Rch=100.9dB and Lch=100.8dB into 150ohm load

Extensive results

THD+N vs Output power results are shown in fig.2-5

(1kHz Sine with 80kHz LPF)

Relative response vs Frequency results are shown in fig.6-9

(20Hz-20kHz Sine)

Crosstalk vs Frequency results are shown in fig.10-13

(20Hz-20kHz Sine)

Fig.2 THD+N vs Output power into 30ohm load Fig.3 THD+N vs Output power into 63ohm load

Fig.4 THD+N vs Output power into 100ohm load Fig.5 THD+N vs Output power into 150ohm load

Fig.6 Response vs Frequency into 30ohm load Fig.7 Response vs Frequency into 63ohm load

Fig.8 Response vs Frequency into 100ohm load Fig.9 Response vs Frequency into 150ohm load

Fig.10 Crosstalk vs Frequency into 30ohm load Fig.11 Crosstalk vs Frequency into 63ohm load

Fig.12 Crosstalk vs Frequency into 100ohm load Fig.13 Crosstalk vs Frequency into 150ohm load

**RMAA test results**

Measurement environment

Creative E-MU 0204 by ASIO with RMAA 6.2.3 PRO x1

All tests were carried out "without 20Hz-20kHz filter" at RMAA configuration

Results

Summary

See fig.14

Extensive results

Frequency response is shown in fig.15

Noise level is shown in fig.16

Dynamic range is shown in fig.17

THD+N is shown in fig.18

IMD+N is shown in fig.19

Stereo crosstalk is shown in fig.20

Fig.14 RMAA test summary

Fig.15 Frequency response results with RMAA Fig.16 Noise level results with RMAA

Fig.17 Dynamic range results with RMAA Fig.18 THD+N results with RMAA

Fig.19 IMD+N results with RMAA Fig.20 Crosstalk results with RMAA

**Waveform results**

Measurement environment

TEXIO FG-274 DDS Function Generator x1

TEXIO DCS-9515YHK Digital Oscilloscope x1

Results

Sine waves into 30ohm load at 100Hz, 1kHz, 10kHz, 20kHz, 50kHz and 100kHz

See fig.21-26

The top trace is original source

Triangle waves into 30ohm load at 100Hz, 1kHz, 10kHz, 20kHz, 50kHz and 100kHz

See fig.27-32

The top trace is original source

Square waves into 30ohm load at 100Hz, 1kHz, 10kHz, 20kHz, 50kHz and 100kHz

See fig.33-38

Clipped square waveform is shown in fig.39, 40

The top trace is original source

Fig.21 Sine wave into 30ohm load at 100Hz Fig.22 Sine wave into 30ohm load at 1kHz

Fig.23 Sine wave into 30ohm load at 10kHz Fig.24 Sine wave into 30ohm load at 20kHz

Fig.25 Sine wave into 30ohm load at 50kHz Fig.26 Sine wave into 30ohm load at 100kHz

Fig.27 Triangle wave into 30ohm load at 100Hz Fig.28 Triangle wave into 30ohm load at 1kHz

Fig.29 Triangle wave into 30ohm load at 10kHz Fig.30 Triangle wave into 30ohm load at 20kHz

Fig.31 Triangle wave into 30ohm load at 50kHz Fig.32 Triangle wave into 30ohm load at 100kHz

Fig.33 Square wave into 30ohm load at 100Hz Fig.34 Square wave into 30ohm load at 1kHz

Fig.35 Square wave into 30ohm load at 10kHz Fig.36 Square wave into 30ohm load at 20kHz

Fig.37 Square wave into 30ohm load at 50kHz Fig.38 Square wave into 30ohm load at 100kHz

Fig.39 Clipped sq. wave into 30ohm load at 50kHz Fig.40 Clipped sq. wave into 30ohm load at 100kHz

Â©2012-2021 Shintaro Shinozaki