6h30 SRPP preamplifier MK II
Description:
The time had come to revisit our 6H30 SRPP preamplifier as my brother needed a preamplifier between his PH3 RIAA and 6C33 single ended 15Watt. He had a few wishes for the new preamplifier:
1) operate in class A mode, be based on triode vacuum tubes and have good sound
2) the preamplifier should only have one input and one output
3) the volume should be controlled through a motorized Alps volume potentiometer
4) it should be possible to remote control the amplifier volume by an Apple infrared remote
5) the volume potentiometer should operate in a continuously jerk free mode
6) preferably use a modified power supply from our PH3 RIAA
the obviously choice for us was a MK II of our 6H30 SRPP preamplifier as we have been very pleased with it and it fulfill all my brothers requirements beautifully.
Picture gallery:
Click on the picture to enlarge it and read our comments and advice.
The populated power supply PCB. We use a LR8N3 high voltage regulator from microchip which feeds a TIP162 darlington transistor. The remote control receiver is also placed on this PCB and is based on a 18F1320 PIC also from microchip.