Sunday, March 10, 2024

“Aspire” - Psvane 6SN7 globe preamp

 


















After checking the expensive tubes of one of my preamps I'd sold to another one came up bad. I purchased the one good tube and helped the owner acquire replacements. I had a few parts on hand including the enclosure, most passive parts, ceramic socket, remote control Alps pot and the power tranni. Inverting the enclosure made assembly much easier and after some masking I sprayed back and top for good visual effect. The front is a natural silver frost, untouched.  

A mix of carbon and metal film make the resistive compliment and 5W wire wounds on the 4XPi HT filter. Two 1A diodes rectify the HT then 350uf of high voltage caps do the smoothing and storage. Cathode bi-pass caps are NP types and are bi-passed by 0.1uf polies.  Output caps are high grade audio polies and always sound excellent. Three inputs can be switched from the front and the preamp is silent in operation. Hookup wire is fine silver plated copper wire and WBT silver solder is used in the signal path. As always with these retro looking sphere/globe 6SN7s the sound is full bodies and transparent. Yet another well performing simple tube preamp and a good used of parts I've had for way too long.