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Adding line out to Silvertone 1484

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  • Adding line out to Silvertone 1484







    I'd like to add a line out for pre-amp purposes on my silvertone 1484 amp head.</p>


    TheAdmiral has been talking to me about this in another thread but I wanted
    to give it it's own spot. I believe he has</p>


    then info I need and will provide it here. Thanks!</p>


    </p>



    </p>



    </p>

  • #2
    Re: Adding line out to Silvertone 1484

    Found it! Waiting for your parts arrival.
    Hammonds: A; AB; B3; D; E; 6-M3's; 2-A100; T582C.
    Leslies: 3-31H; 21H, 22H, 4-44W; 46W; 25; 47; 45; 125; 50C; 51; 55C; 2-120; 122; 122A; 145; 147; 245; 770; 825; 2-102; 2-103; 300.
    Wicks 2/5 pipe organ; Yamaha upright; Kurzweil Micro Piano & Micro B with M-Audio Oxygen 61; Yamaha DGX520; Wurlitzer 4100 (it came with a Leslie!). Peavey KB100 keyboard amp. Peavey Bass Guitar. Yes, I have A. D. (acquisition disorder) and don't want it cured.

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    • #3
      Re: Adding line out to Silvertone 1484



      eddie</p>

      Nice little crate. Didn't realize Silvertone made an amp with a beefy 6L6 output stage. Thats a good size output transformer but the power transformer looks a bit thin however. They pulled a clever trick with that one; the secondary has a pair of 80V independent windings plus a 25V winding and the ubiquitous 6VCT winding. They used full wave doublers on the two 80V windings and connected them in series to get up to 480V. It uses more parts this way but the main capacitors can be smaller and cheaper 150V rated units, and they could use the same power transformer for future transistor amp models using a 120VDC B+.
      </p>

      Looking the schematic over, you have two choices; </p>

      1) disconnect speaker and power brake load with 40W 4-ohm + .22-ohm 5W series resistors and tap your line out from across the .22-ohm. You can make up the 40W 4-ohm with a pair of 8.2-ohm 20W in parallel, or a quad of 15-ohm 10W in parallel
      </p>

      2) pull the two 6L6's and tap signal thru 0.047uF 400V capacitor from the final 12AX7 channel mixing preamp stage before the phase splitter. The summed signal from the two preamps appears at the junction of the two 68K resistors R24 and R25. It should go to a high impedance input (like about 1Meg)</p>

      I'm sure the Admiral's info will get you there. Just be careful, this amp uses DC over 400V so be very careful if you implement option 2 (or something like it) that requires tapping into internal nodes. I see the cord has been changed to a 3-pronger; I presume the "cap 'o death" has been removed and the AC hum switch is no longer necessary. Remove the switch and that gives you a chassis hole for a phone jack as the preamp output. </p>

      exp
      </p>

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      • #4
        Re: Adding line out to Silvertone 1484



        I'll let you know Admiral thank you!</p>

        </p>

        expiano - is that the far right switch that says ground I presume? That is great if I can unhook that and use it for the 1/4inch jack!
        </p>

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        • #5
          Re: Adding line out to Silvertone 1484

          Update - I have everything needed except the test leads. Should have bought them local didn't expect ebay to take so long.. hopefully a couple days and I'll be set.

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