Really beautiful sound promotion module 01

Internal circuit diagram of the SAM module. Modern high-speed
FET input devices all use similar circuits, such as OPA627. Figure 3-2 is the internal circuit of the HD AM module
of the Japanese Marantz Company. 6 HDAM can be said to be famous, and many of Marantz's high-end CD players , PM15 advanced power amplifiers all use it. Comparing these two circuits, it can be found that the internal circuit of SAM has an extra stage of common -base amplifier, that is, the input circuit is common-source common-base amplification, while HDAM is only common-source amplification. Due to the low withstand voltage and small transconductance of the field effect transistor , the open-loop gain of HDAM is not large and can only be used in low-voltage situations. The effect of replacing ordinary operational amplifiers is naturally superior. However, modern power amplifiers require high driving voltage and small distortion, so HD AM is not suitable. SAM can withstand higher power supply voltages . There are two types of SAM : one is type A; the other is type B. Type A is suitable for small signal amplification, and the power supply voltage range is ±15V ~ ±40V; type B is driven by the voltage in the power amplifier , and the power supply voltage Can be as high as ±ssv, output voltage swing only lower than the supply voltage