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Thread: FS: DIY Type 76 Valve Line Level Preamplifier

  1. #1
    Join Date: Dec 2014

    Location: Midlands

    Posts: 59
    I'm Matt.

    Default FS: DIY Type 76 Valve Line Level Preamplifier

    Due to an impending change around I have this cracking pre amp for sale.

    Some comments from the builder:

    The balanced output transformers are from Sowter.
    Yes, a single gain stage using a 76 direct coupled to a cathode follower using a 7193/2C22 single triode. The cathode followers could also be 6J5’s as the valve sockets are wired to accommodate either the 7193 with the anode and grids on the top caps, or 6J5’s with all connections at the valve sockets.

    There is provision inside the case to store and insulate the anode and grid top caps if 6J5’s are used"
    The input selector switch is made by Elma in Switzerland. Gold plated contacts. I believe Goldpoint use a similar switch body, but they use a small PCB to mount the contacts.

    The 10uf Solen capacitors are decoupling capacitors for the B+ power supply. The gain stage is direct coupled to the cathode follower.
    Gain controlled by 50k ohm stereo stepped attenuator with 24 steps. The output impedence is approximately 365 ohms and will drive long cable runs and difficult loads. Input impedence is 50K ohms.

    There are 5 valves used: 2 x Type 76 and 2 x Type 7193 for the preamp stage and 1 x 6AX4GT for the soft start on the HT supply. The signal valves are vintage (1930/40s). The builder has a plentiful supply of spare valves should you need them.

    Comes with a comprehensive manual/design guide which details some of the alternative valves that could be used such as Type 37 which will give slightly lower gain (13dB) compared to the Type 76 (15dB).

    As you can see, the workmanship and quality of components/build are very impressive, I shudder to think what this would cost built by one of the well known manufacturers inside a fancy case.

    725 Collection only from Nottingham as I don't have a sturdy enough box to ship, or could meet up somewhere around east mids.

















    Last edited by Matt_J; 04-08-2019 at 11:53.

  2. #2
    Join Date: Sep 2016

    Location: West London

    Posts: 26
    I'm Andy.

    Default

    This, IMHO, must be counted among the best three audio components that have come up for sale this year. Very tempted! PM incoming

    Sent from my SM-N950F using Tapatalk

  3. #3
    Join Date: Jun 2015

    Location: London/Durham

    Posts: 3,075
    I'm Lawrence.

    Default

    Nearly bit the first time but need to reduce box count. Must.... Say.... No....

    Sent from my POT-LX1 using Tapatalk

  4. #4
    Join Date: Dec 2014

    Location: Midlands

    Posts: 59
    I'm Matt.

    Default

    Yes it's certainly a one off, or close to it.

    Still available by the way.

  5. #5
    Join Date: Jan 2009

    Location: Essex

    Posts: 20,882
    I'm openingabottleofwine.

    Default

    Beautifully built piece of kit! Good luck with the sale.
    Barry

  6. #6
    Join Date: Dec 2014

    Location: Midlands

    Posts: 59
    I'm Matt.

    Default

    Weekend bump and price drop to 675.

  7. #7
    Join Date: Dec 2014

    Location: Midlands

    Posts: 59
    I'm Matt.

    Default

    still available

  8. #8
    Join Date: Mar 2017

    Location: London N2

    Posts: 1,593
    I'm Edward.

    Default

    Matt, just to help your sale would you you be able to say who the builder is and if s/he is available for servicing this wonderful looking item should the need ever arise?
    Main: Tidal/Roon > MiniITX > Metrum Hex > LDR > either Radford STA25 V or Trilogy 968 > Tannoy (Eaton or Berkeley).
    2nd: Tidal/Roon > Roopio on Pi > Chevron Paradox > Firebottle Buffer > Sugden Masterclass IA-4 > Kudos Cardea


  9. #9
    Join Date: Dec 2014

    Location: Midlands

    Posts: 59
    I'm Matt.

    Default

    The comprehensive service/owners manual has contact details for the builder, who also has a stock of all the tubes should they be needed.
    Last edited by Matt_J; 17-08-2019 at 11:50.

  10. #10
    Join Date: Jun 2015

    Location: London/Durham

    Posts: 3,075
    I'm Lawrence.

    Default

    I think you should probably take his personal email off the thread and share it with the eventual buyer. Apologies if you've already OK'd it with him. Just to add I contacted him via PM when I was interested in it the first time and he's very helpful.

    Sent from my POT-LX1 using Tapatalk

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