Distortionless Maiko Pre-amp module for US $100 includes postage.
Burr Brown best op amp was used as input stage. The complementary output stage is class A biased. 2 independent pre-amps on one board.
Maiko Pre-amp
Specification : left / right channel
| Amp channels |
left and right preamp channel on one board |
| Output voltage |
+10 volt to -10 volt. Peak to Peak. |
| Freq. response |
1Hz to 500 kHz at 0 dB to -0.1dB |
| Total harm. dist. |
0.001% at 1 kHz 1 kilo ohm load ( unmeasurable ) |
| Input voltage |
10 volt rms (max) |
| Voltage gain |
5 times (14 dB) |
| Ch. separation |
110 dB. |
| Input impedance |
10 kilo ohm / 100 PF. |
| Bandwidth |
Unity gain bandwith = 800 Kc. |
| Rectifier filtering |
Fused AC input with IC voltage regulators & zener diodes. |
| Volume control |
pot with shield extension cable for panel mounting. |
| Supply voltage |
AC input @ 15 volt center tapped, 80 mA. |
| Features |
jumper selection for direct input or via capacitor . |
| Board size |
100 mm x 150 mm |
A pre-amp is a must for any high end audio system. It is an adaptor between different signal sources such as CD drive, turntable, tuner and the power amplifier. To define this distortionless pre-amp circuitry, we use the best op amp available by Burr Brown as input stage. The complementary output stage is biased at class A operation. Fused rectifier together with Cascade DC regulation using IC voltage regulator and zener diode are used. Basically it's two stand alone mini amplifiers designed for left/right channels, thus all you need is a 15 volt AC source.
Much effort and consideration was spent on the component lay-out and board routing to achieve a low noise factor and high channel separation. It was done with computer software simulation and finallized by instrumentation measurement and musicians listening.
The pre-amp amplified the detail signal and provided enough voltage swing to drive the power amp, thus covering the complete bandwidth of your signal source. This circuit was designed to capture the smallest micro dynamics music without sacrificing the loudest macro dynamics has to offer.
