Pass DIY Zen Balanced Pre Amp
SCompRacer
Posts: 8,513
DIY Pass Class A Zen balanced pre amp. IIRC Fred called it the BOZOZ? I got this from zingo in this FS thread.
http://www.polkaudio.com/forums/showthread.php?144542-Feeler-Nelson-Pass-Balanced-Zen-Line-Stage&highlight=pass+pre
I chose the ‘as it was’ option and completed it in this thread.
http://www.polkaudio.com/forums/showthread.php?147377-Pass-Zen-Owner-Completion&highlight=pass+pre
I moved some things around and wired all inputs. It has two balanced and four single ended inputs. It has two sets of outputs but I left it wired with just one pair of balanced and one pair of single ended outputs. I patched around the IEC connector. I fastened the toroidal transformers to chassis with bolts. The umbilical cord can be lengthened if you wish to have PS on a different shelf. (I’ve had no issues stacked). I stuck some labels on controls and inputs, which could be redone better.
It also comes with a second power supply, some instructions I downloaded and the short chassis connector. Sell the second PS or get more toridals to build a dual mono PS. The second power supply remains untested; that is I never connected it to the toroidals and measured for output.
Some folks have done no expense spared builds with these, they are that good. Great design, neutral, quiet pre amp. It is worthy of a better chassis; this one has some scars. No thumps when changing sources or volume. Stepped attenuator does make mechanical clicking noise when turned, but no pops through speakers when turned.
A couple RAS members tried this in their system and reported no issues. Oh, except for lack of remote. I made a short operational video and posted it on youtube (link below). I switch the input (one balanced and one single ended connected to my DAC) and move the volume control.
Asking $350 shipped in CONUS.
http://youtu.be/nGWwcqTwA98
http://www.polkaudio.com/forums/showthread.php?144542-Feeler-Nelson-Pass-Balanced-Zen-Line-Stage&highlight=pass+pre
I chose the ‘as it was’ option and completed it in this thread.
http://www.polkaudio.com/forums/showthread.php?147377-Pass-Zen-Owner-Completion&highlight=pass+pre
I moved some things around and wired all inputs. It has two balanced and four single ended inputs. It has two sets of outputs but I left it wired with just one pair of balanced and one pair of single ended outputs. I patched around the IEC connector. I fastened the toroidal transformers to chassis with bolts. The umbilical cord can be lengthened if you wish to have PS on a different shelf. (I’ve had no issues stacked). I stuck some labels on controls and inputs, which could be redone better.
It also comes with a second power supply, some instructions I downloaded and the short chassis connector. Sell the second PS or get more toridals to build a dual mono PS. The second power supply remains untested; that is I never connected it to the toroidals and measured for output.
Some folks have done no expense spared builds with these, they are that good. Great design, neutral, quiet pre amp. It is worthy of a better chassis; this one has some scars. No thumps when changing sources or volume. Stepped attenuator does make mechanical clicking noise when turned, but no pops through speakers when turned.
A couple RAS members tried this in their system and reported no issues. Oh, except for lack of remote. I made a short operational video and posted it on youtube (link below). I switch the input (one balanced and one single ended connected to my DAC) and move the volume control.
Asking $350 shipped in CONUS.
http://youtu.be/nGWwcqTwA98
Salk SoundScape 8's * Audio Research Reference 3 * Bottlehead Eros Phono * Park's Audio Budgie SUT * Krell KSA-250 * Harmonic Technology Pro 9+ * Signature Series Sonore Music Server w/Deux PS * Roon * Gustard R26 DAC / Singxer SU-6 DDC * Heavy Plinth Lenco L75 Idler Drive * AA MG-1 Linear Air Bearing Arm * AT33PTG/II & Denon 103R * Richard Gray 600S * NHT B-12d subs * GIK Acoustic Treatments * Sennheiser HD650 *
Post edited by SCompRacer on
Comments
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Folks, this is a BEAUTIFUL pre. If it had a remote I dont think it ever would have made it to the Flea Market.
Rich, I am sure I will come to regret not picking this up, but am glad it will be staying in the family."....not everything that can be counted counts, and not everything that counts can be counted." William Bruce Cameron, Informal Sociology: A Casual Introduction to Sociological Thinking (1963) -
ooooh, very nice - no reason to apologize about its cosmetics; it's fit-for-purpose, which is what matters.
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mhardy6647 wrote: »ooooh, very nice - no reason to apologize about its cosmetics; it's fit-for-purpose, which is what matters.
I could very easily fix the cosmetics and bring it up to the appearance standards of my monoblocks...The Gear... Carver "Statement" Mono-blocks, Mcintosh C2300 Arcam AVR20, Oppo UDP-203 4K Blu-ray player, Sony XBR70x850B 4k, Polk Audio Legend L800 with height modules, L400 Center Channel Polk audio AB800 "in-wall" surrounds. Marantz MM7025 stereo amp. Simaudio Moon 680d DSD
“When once a Republic is corrupted, there is no possibility of remedying any of the growing evils but by removing the corruption and restoring its lost principles; every other correction is either useless or a new evil.”— Thomas Jefferson -
nooshinjohn wrote: »I could very easily fix the cosmetics and bring it up to the appearance standards of my monoblocks...
Buy it John
... "....not everything that can be counted counts, and not everything that counts can be counted." William Bruce Cameron, Informal Sociology: A Casual Introduction to Sociological Thinking (1963) -
yeah... we're enablers ;-)
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Rich is a master craftsman. Anything he touches becomes a piece of functional, high quality art. For the money this preamp is a no brainer.Carl
