Finally the Pass J-FET Bride of Zen (BOZ)

[Audiodoc]

Finally my Pass BOZ preamplifier is completed thanks to sachin for the matched SK170s.

Board is from Jims Audio. R-core supplying the preamplifier board while the Toroid is supplying the input selector and LDR volume control board.

Although the Board states that it should provide 16V after regulation it is only providing around 14V. The circuit functions normally though. The input selector LED are color coded, left to right RCAs, Red-Green-Blue-Yellow.

 

[mpw]

Looks excellent audiodoc !! Please let us know how it sounds..

Congrats and well done.

Mpw

 

[corElement]

That looks absolutely superb!

 

[Audiodoc]

Compared to the extremely neutral pass B1 buffer this one adds a characteristic richness to the sound with accentuation of the bass. Currently my B1 is connected to my MyRef Rev E. Will do a detailed listening session this weekend.

Made this to form a pre power combo with a simple gainclone utilizing premium components and the same cabinet with a plain front fascia. The gain on the Pass BOZ preamplifier should pair well with the same.

Skipping the input trim pots makes it necessary to adjust the output voltage of the source to prevent distortion however it keeps the signal path shorter.

 

[sachu888]

Congratulations Doc,
your builds are always good,nice placement of parts.

Regards,
Sachin

 

[captrajesh]

Nice build as usual from Audiodoc. Wondering why a preamp has such elaborate heat sinks.

 

[kanwar]

Nice build, Audiodoc........

 

[Audiodoc]

The heatsinks are just decorative in this case. Basically I am pairing it with a LM3886 gainclone in a matching chassis in which the heat sinks are functional. The two will form a great pair. The circuits for the same are ready, will do the testing and assembling in the coming weeks, have been held back due to a pair of nuts and bolts!

 

[captrajesh]

At one point, I was considering building BOSOZ but chickened out due to the complexities involved in procuring the components. Isn't the BOZ older design than the BOSOZ?

 

[Audiodoc]

Yes the BOSOZ is a more recent design however more complex. Had procured the jims audio board thereby was tempted to build the same to compare with the B1. I believe FM anilva also has built one.