Vermes
Advanced Member level 4
It is a design of modernization of popular Diora amplifier WS442 (WS432 without LED indicators of input selector and shape and filter indication).
What was changed:
- all electrolytes were changed
- all transistors in preamplifier were changed to low noise
- resistors and capacitors in important parts of the preamplifier (sound tone regulator) were changed
- all components in power transistors were changed
Those changes reduced noises produced by the amplifier. Quiescent currents are effectively compensated. There is also a delayed turning on speakers soldered in the place provided by the manufacturer. Two yellow LEDs were used in a place of burned-out frames as backlight.
List of elements used:
- BC560
- BC550
- BD911
- BD912
- BD137
- BD139
- BD140
- 1% resistors
- electrolytic capacitors
- ceramic capacitors
Pictures:
Link to original thread - Modernizacja WS432, czyli zbliżamy się do Hi-endu