6h30 SRPP preamplifier MK III
Description:
Update now with electronic files! The time had come to build a new preamplifier as replacement for our Aleph P clone as we wanted to go valve/tube based preferably triodes from pickup to loudspeaker.
We chose to design the new preamplifier around our 6H30 SRPP preamplifier as we are very pleased with the sound, the simple power supply requirements and the amplification of 20 dB.
Our other requirements was:
1) enough connections: 8 inputs, 2 selectable outputs, 2 pass through monitor output/input,
2) a low pass or subsonic filter for when we are playing vinyl records,
3) the potentiometer should be motor driven,
4) remote controllable through an aluminum Apple infrared remote
5) use old school alpha numeric LED displays
6) calculate and show amplification in dB
For futher details take the time to browse through the pictures as they contain valuable information and experience from the building process of the preamplifier.
Picture gallery:
Click on the picture to enlarge it and read our comments and advice.
The board feature 8 inputs, 2 outputs, 2 optional monitor pass through connections, mono/stereo/reverse, configurable attenuation (7-20dB), filter defeat/subsonic/low cut. All controlled through an I2C bus and PCF8574's and ULN2803A's darlington buffers.