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  • Carver C-4000/4000t Upgrade and Restore

       (1 review)

    Nelion Audio

    The Carver C-4000 and 4000t are similar but also very different. However, restoring them and upgrading them are similar enough to include together. These preamps require a complete overhaul after nearly 40 years of use. We replace all the electrolytic capacitors with either high temp, long life type, bi-polar or low ESR where appropriate. We tear the unit down completely and recondition all the wipers on the attenuation knobs and buttons. Some units require factory updates and power supply fixes. All of these units also require the phono amps, time delay, auto correlator and sonic holography circuits to be tuned and calibrated. The unit is also cleaned and polished, fully tested and we listen to it to ensure it sounds better than ever. The results of our work are stunning!


    Gundry Filter Circuit for C-4000/400t



    Sonic Holography Frequency Response (stock):



    Sonic Holography Frequency Response With Gundry:



    Note the two 'dips'. This enhanced equalization expands the holographic imaging of the SH processing to our natural, non-linear perception of sound location.


    It's function is to attenuate frequencies which our ears are naturally very sensitive too, such as baby crying and sirens. By adjusting the frequency response of some audio processing, such as Sonic Holography, the result is a better sound image, especially at high volume levels where certain mid-range frequencies dominate our ear/brain system and smear our perception of depth and detail in the music.


    Signal Path Upgrade

    The line out amp stage and tone circuits are pretty simple and elegant for these preamps. But if you want even tighter response and lower noise, go for this upgrade to make the unit even more blissful to the ears. We will install high grade op-amps in place of the stock RC4136 chips, 1% metal film resistors and Polypropylene Capacitors in critical areas of the Line Out amp and Tone Control in addition to the already impressive components used for the Base Restore.



    High quality parts and expert workmanship.





    Gundry Filter board installed on the Sonic Holography PCB.



    New LEDs for the faceplate.




    Restore Price: $450

    Gundry Filter for Sonic Holography: $60

    Signal Path Upgrade: $100

    LED color change: $50

    Remote control Volume: $175

    IEC socket: $50

    Comes with Nelion Audio 3 year parts and labor warranty.


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    John Smallwood

       8 of 8 members found this review helpful 8 / 8 members


    Years ago, when they first were sold, I had a C-4000 but had to sell it.  Recently, I wanted to return to the pre-amp but I was hesitant because of its complexity and age.  Luckily, I found Nelion through the Carversite, and reading the recommendation from Bob Carver about Greg's work was all I needed to see.  I bought the nicest one I could find and shipped it to Greg.  I received it last week, and it sounds fantastic.  I can't take my eyes off it, and can't stop listening to it.  Although it is a complex piece, if you truly admire Bob Carver's work it's a privilege to have one of these as the heart of your system, and it's great to have Greg and his team to bring it back to spec and beyond.

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