Improvement of British HINARI laser stereo combination sound

Next, the host part was modified from three aspects. The first is the power supply part. The original main power amplifier rectifier diode
R1, 1 5 2 (the fast recovery rectifier current is 1.SA),
is replaced by the fast recovery diode FR301Q (3A). To replace,
connect a 0. lplF/63VCBB
capacitor in parallel on each bridge arm. The filter capacitor C161 has a capacity of only 2200teF,
which is far from meeting the requirements for large dynamic playback.
Three 4 700VF/50v electrolytic capacitors are connected in parallel at both ends in order to
overcome the split Due to the influence of inductance
, a 0.47uF CBB capacitor should be connected to each electrolytic capacitor to
improve its high-frequency characteristics. The second step is to use the audio equalization network for
each frequency band and the input and output capacitors C61, C62;
C67, C68; C77, C78; C81, C82; C87,
C88; C89, C90; C93, C94; C98, c99;
C121. The CBB capacitor is replaced and the other capacitors
remain unchanged. Finally, modify the power amplifier circuit as shown in Figure 5-141. Replace the input clol.C102 (10VF/50V) electrolytic capacitor with
a CBB capacitor. Be careful not to use tantalum capacitors, otherwise the sound will be hard; remove the 4.7k0 from the input to ground. Resistor (located on the lower
base plate), solder the metal film resistor of lSOkfl. Increase the Clll.C122 coupling capacitor from 470VF/50V to 1000t,F/50v
(preferably use high-quality electrolytic such as sapphire), and connect a 1VF CBB capacitor to both ends, and the modification will be successful.
    After the above improvements, the mid-range and midrange are clearly layered, the bass is thick and powerful, and full of elasticity. Even if the equalizer is pushed all the way to
the center , the sound is still beautiful and pleasant. If the original pair of speakers are used, the bass hole is sealed and the treble hole is sealed. Install a 3-
inch speaker to really feel like you're on the scene. Readers who have this type of machine may wish to give it a try.