Thank you all, I have one more question.
This is the Opera's specification. would this power be sufficient to operate the k1000s?
2 headphone outputs( 0/120 Ohm output impedance ); Maximum output 13V / 500 mA; Gain switch: maximum gain factors -5 / +8 dB; Crossfeed filter switch; 2 pairs of analog inputs, input impedance 12 kOhm; 1 digital S/PDIF input; 1 digital USB-input; 1 pair of volume-controlled preamplifier outputs. Gold-plated input jacks; Silver plated headphone jacks (Neutrik); Silver plated heavy duty switches; Alps Blue potentiometer for volume control; 25 Watts toroidal transformer for the analog section; 7 Watts toroidal transformer for the digital section; 110V and 220V mains power switchable; Power uptake 12 Watts; Built-in groundloop breaker; Schottky rectifying diodes in the power supply; Double regulated voltage lines; Low impedance electrolytic buffer capacitors (Nichicon); Total Buffer capacity 80.000 uF.; Bypass capacitors in the power supply.; Polystyrol and polypropylen capacitors in the signal path; Metalfilm resistors in the signal path; LM6171 opamps biased into class-A using LM334 current sources; 2 BUF634 buffer amplifiers at left and right headphone output channel; (Active) balanced headphone ground; 3 BUF634 buffer amplifiers at the balanced ground headphone output channel; PCM2704 as USB-to-S/PDIF receiver; CS8420 as S/PDIF receiver (in high-jitter-reduction mode); PCM1794 D/A converter-chip; LM6171 opamps biased into class-A for I-V conversion; Sampling frequencies / resolution: 8..96 kHz / 16, 20, 24 bit (S/PDIF);32, 44.1, 48 kHz / 16 bit (USB). Star-grounding; Ultra short signal paths; Signal paths and signal path components at the bottom side of the PCB for maximal shielding. Weight: 3.9 kg. Size: 27.6 x 27.8 x 8,7 cm.
