Monday, March 9, 2009
I had built two head phone drivers (HPs) for my low impedance Grado and Audio-technica head phones. I also discovered they were very good line buffer\drivers due to their low output impedance and high input impedance. They are named Woody and Woody Pro. due to the fact the the single transistor per channel is bolted hard to a block of Asian timber.
In Woody Pro. dual encapsulated mini-toroid transformers drive ultra-fast diodes and 40,000uf of filtering plus resistive ripple reduction to produce two very clean supplies. Twenty 10uf polypropylene capacitors are paralleled to produce 2 X 100uf output caps. There are two selectable inputs. The first input and output have both RCA and 6.5mm phone jacks connected.
Each channel has one 2N3055 in an emitter follower configuration. The sound is immediate, clean, with good bass extension bass and fast. Because Woody Pro. is an emitter follower 10% of the input signal is lost. This has never been a problem with most sources deliver around 2V.