Pass Zen - Owner Completion

SCompRacer
SCompRacer Posts: 8,505
edited April 2013 in DIY, Mods & Tweaks
I bought this owner completion Pass balanced Zen pre amp from someone here who owned it briefly and moved on to something else before finishing it themselves. It only had one pair of SE inputs connected. Thanks to Fred for some Zen tips and suggesting I turn the pre amp board 90 degrees. Relocating the pre amp board allowed for shorter and better routing of wiring.

I also moved the attenuator/selector forward slightly as clearance was tight by second pair of outputs. I just left it with one pair of balanced/SE outputs. I did connect the two balanced and four SE inputs to the selector. Input/output grounds are star grounded at their respective side of board. I just used twisted pairs from an old chunk of Cat5 cable I had laying around.

I also wanted a chassis to chassis ground. Rather than look for different umbilical connectors, I eliminated one pos and neg power wire from the original two each to the pre amp board. That freed up two pins and one was used for chassis to chassis ground. I still need to get some parts to secure the toroidals.

It sounds really good for a simple design with no exotic parts (but the boards do have quality parts). It is quiet, no hiss or hum at full volume no music playing, no spikes/pops from speakers when changing sources. It doesn’t knock my recapped/tuned up Krell KSL pre off the rack, but it is worthy of a really nice enclosure and upgrades.
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
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Comments

  • zingo
    zingo Posts: 11,258
    edited April 2013
    Congrats! It is a very nice circuit and I'm glad you're getting good use out of it!
    Jake
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  • FTGV
    FTGV Posts: 3,649
    edited April 2013
    That Pass is a sharp fella.
    Nice work Rich,no hum or other extraneous noises is a huge victory for Diy.
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  • FTGV
    FTGV Posts: 3,649
    edited April 2013
    FTGV wrote: »
    That Pass is a sharp fella.
    Nice rework Rich,no hum or other extraneous noises is a huge victory with Diy.
    Fixed
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  • schwarcw
    schwarcw Posts: 7,339
    edited April 2013
    Hey Rich! There is a lot of empty space in there for some mods!:loneranger:
    Carl

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  • blairfrischx
    blairfrischx Posts: 259
    edited April 2013
    I dig it! Glad someone picked it up from zingo who was willing to work with it further. That's a pretty preamp.
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  • headrott
    headrott Posts: 5,496
    edited April 2013
    Nice Rich! Glad you are enjoying it.
    Relayer-Big-O-Poster.jpg
    Taken from a recent Audioholics reply regarding "Club Polk" and Polk speakers:
    "I'm yet to hear a Polk speaker that merits more than a sentence and 60 seconds discussion." :\
    My response is: If you need 60 seconds to respond in one sentence, you probably should't be evaluating Polk speakers.....

    "Green leaves reveal the heart spoken Khatru"- Jon Anderson

    "Have A Little Faith! And Everything You'll Face, Will Jump From Out Right On Into Place! Yeah! Take A Little Time! And Everything You'll Find, Will Move From Gloom Right On Into Shine!"- Arthur Lee
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  • zingo
    zingo Posts: 11,258
    edited April 2013
    schwarcw wrote: »
    Hey Rich! There is a lot of empty space in there for some mods!:loneranger:

    Like a second PS board and two more transformers... :mrgreen:
    Jake
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  • SCompRacer
    SCompRacer Posts: 8,505
    edited April 2013
    Hell yes, get that parts count up!:biggrin:
    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 *
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