Monday, November 1, 2010
Pass BoZ (Bride of Zen)
After completion of the Pass B1 I decided to try BoZ (Bride of Zen). Once more this is a single jFET (2SK170) preamp but where the B1 is a line driver this preamp has gain. And it has plenty of gain. I used the same Russian 1uf PIO caps and the same 10uf polypropylene (snubbed this time) output caps. In many ways the the preamps share a lot of components. But they sound very different.
Hook-up wire this time is wire wrap wire (WWW). After reading a book on cable construction, less (with regard wire thickness), is more. The Hammond anodised Al case is slightly smaller then the B1.
BoZ is very sensitive to PS noise. Where the B1 is more tolerant of PS noise any PS hum, whistle or buzz can be heard and is amplified. I am currently running BoZ on 4 X 9V lithium batteries for 36V. Both preamps have a less than 20mA current draw.
Sonically the B1 is superior. But BoZ has greater bass weight. B1 can etch greater mid-range and treble detail and produces the music in a very raw and uncoloured manner. Other serious listeners made this comment too.