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L-100 maintence help

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  • L-100 maintence help

    I'm doing work on a newly aquired L-112. Canadian built I assume,
    because the serial number is CAN-##,### . I haven't checked the tubes
    or speakers but i think its a '66. This organ is on the chopping block.


    It was free, stinks like its spent many years in a smokey house.
    A few keys were broken and some broke in response to moderate
    intentional stress. Sounded fine, though the generator howels. </p>

    now its in about 97 pieces spread around the basement and I need some
    advice. Oil and removing broken keys was easy. Though one key seemed to
    be sticking, on closer inspection the actual contact switch was
    sticking inside the manual. I kept digging deeper and eventually
    decided that since i'm this far in I may as well disassemble the
    drawbar assembly. Cut ahead 5 hours and now the entire wiring loom is

    I'm fairly sure the stuck note went away just by
    playing with the contact switches. Since its exposed i'm wondering
    about a few things:</p>


    1) key contact leaning. How do I
    do this? I see the full length busbar assembly. Do i just slide the
    assembly over by pulling at the end where the 9 bars are connected?</p>

    2) Can waterfall keys fit on the L100?</p>

    3) Adding bass to the lower octave. How would this be done?</p>

    4) Adding foldback. Any feedback appreciated. </p>



  • #2
    Re: L-100 maintence help

    Hi Johnny,</p>

    1. On the left side of each manual there is a thing called "busbar shifter", which can be pulled by i.e. a thick wire.</p>

    2. No, do the diving boards keys really disturb you? </p>

    3. The low octave tonewheels are just absent in L100 generator.

    4. Find an junk manual from hammond, and fill the remaining key contacts.</p>


    Don't try to make an B3 out of L100! I have tried to do it - realigined the magnets, and installed an AO-29 preamp. It sounded nice, but the main limitation is that an L100 don't have keyboard tapering - the tones are not so smooth and balanced as in B3. You can't overcome it. However, L100 is an great instrument for rock - it has an shrill and excitement in it's sound (a lot of treble tones), cuts like a knife through the band. It is definetly not for jazz players.

    Anyway, good luck!</p>



    • #3
      Re: L-100 maintence help

      Thanks for the quick reply. I really appreciate it since this thing
      can't be in pieces for more then a week or it risks staying that way.
      Yea i'm not looking for THE B3 sound from a L...but i figured that
      since its so far in adding foldback may not be a bad idea. </p>


      1) You just shift the whole bar over so the contacts land on a fresh part of the busbar?</p>

      2) Re: waterfall keys: Nah, just curious</p>

      That low octave thing is crazy...there are no instructions and by the
      looks of it its just a home made electronic circuit. I was more
      interested in wiring the bass pedals to the lowest octave. Meaning I
      find the wires that go from the generator to the pedals, clip them at
      the pedals, and re-attach them where? Would it be unrealistic to remove the lower right hand plastic end block and add a few keys with a simple homemade trigger?</p>

      Thanks! When I find my donor and expose the wiring loom, I remove the
      baklite metal thingies that i want, but where do I snip off their
      attached wire? Do i need to undo the loom? Once i'm that far, do I just
      solder that end to its appropriate location on the wire terminals under
      the manual? [post script: Those wires are CRAZY THIN...and must be
      shielded I do they use such fine wires? less


      I got a few more for ya here...I'm chopping this organ...its canadian made, rough exterior condition...etc.</p>

      Regarding the volume pedal: It needs the option of being disconnected,
      though this particular model has the light/shutter volume system. I'm
      sure I can rig up some 6 pin connetor that can handle the 2 RCA signal
      cables and 2 wires...but is it worth it? Would a modern volume pedal
      stuck in the signal chain do just as good? If I do the latter, is
      it just a matter of connecting a jumper RCA between the 2 volume pedal
      sockets on the amp? </p>


      6) Regarding the donor
      organ: I can get my hands on a solid state R-100 ( ). Its not
      functioning...the TG seized up long ago, no more internal
      speakers/leslie, broken keys, tabs...etc. Is there anything else of
      value other then the key contacs? I.e. would the TG, if revivable be
      worth transplanting into the L-100, frankenstein styles?</p>


      I've said it before...looking at that wiring loom especially...someone built this thing!. Its amazing that this was done by hand in the 60's and even in way earlier models.



      • #4
        Re: L-100 maintence help

        Hi Johnny,</p>

        1. Yes, in 95% cases it is ok</p>

        3. You can try with wiring the pedals. There is a place for extra contact set on lower and upper manual as far as I remember. The homemade circuit on the website which I gave you is just an simple frequency divider. You can do this with TTL/CMOS logic and a few opamps. You do not need to wire extra contacts to do this</p>

        4. You HAVE to use those wires, because they have an 16 ohm resistance. They are here for not to short the pickups when multiple keys pressed. Unsolder them near the terminals with those black cables.</p>

        5. There is no logic explanation for swapping the TG! I think that the contacts would be the only thing you can use from this organ.</p>

        Would you do something with the vibrato? It is really poor...

        You can leave the pedal and use a modern substitute. In earlier L100 Hammond used potentiometers instead of light bulb/LDR. Simply copy from this schematic , but change the potentiometer in your volume pedal to 25k/audio. </p>

        You see, they were hand-soldered, and the Hammonds are still alive. They are build like tanks!


        • #5
          Re: L-100 maintence help

          Thanks for all the good advice, Jon.</p>


          What if I
          want to use an external volume pedal? When the old pedal is removed, I
          would believe there to be an open circuit, hence no sound. Would a RCA
          jumper be all that I need? (pedal in &gt; pedal out would theoretically
          yield full volume all the time?)</p>

          Re: vibrato, the real fix is to get a leslie! I never use vibrato.</p>



          • #6
            Re: L-100 maintence help

            Well, I don't like Leslies. They are so common! I like to hook to an guitar amp the most.</p>

            In my chops I always connect an external volume pedal as in this schematic. An 470 pF capacitor gives extra treble response at low volumes. One picture express more then 1000 words so do it like on the picture.</p>



            • #7
              Re: L-100 maintence help

              Jon, Stellar work!! I'm impressed. Just to clarify, those circles
              above "TO PREAMP/AMP" are the RCA connectors where the volume pedal
              normally plugs in? So I need a stereo plug with 2 male RCA's running
              off it?</p>

              Any particular volume pedal recomended? (Expression pedal
              or volume pedal? two different things. Expression = 1 male tereo plug,
              vs Volume = 2 female 1/4" in/ through pedal used in effects
              chain). Can you clarify?</p>



              On the topic
              of chopping, do you have any recommendations or should I just throw the
              power amp &amp; reverb springs up top and away she goes...?</p>


              • #8
                Re: L-100 maintence help

                Hi Johnny,

                Yes, those are the RCA plugs. Definetly expression with one plug. I draw the plug on my schematic.</p>

                If you don't use vibrato you can throw away the vibrato amp. It's the larger one. If you do this connect together the terminals called BROWN (BN) and BLACK (BK). You will get more distortion then. If you have an experience in electronics you can also remove the power amp. When you play through Leslie it is useless, but you should make an HT power supply. If you don't have experience please don't do it because you can easily electrocute yourself. Tube eqipment is quite dangerous.</p>

                Anyway, I'm looking forward for any questions</p>


                • #9
                  Re: L-100 maintence help

                  Ok, you asked for it! just teasing...</p>

                  I don't use the
                  vibrato but its worth keeping. As for the power amp, I've decided to
                  keep that too even though i'm not using it for its main purpose
                  (driving the speakers). I'm fairly knowledgeable about saftey in these
                  things...not touching capacitors or anything like that. Also its been
                  unplugged and dismantled for a few days. </p>


                  on...I've got my donor busbar/key contact assembly. I dont really
                  understand the word document instructions i found...attaching the new
                  contact to the appropriate frequency lug is where it loses me. </p>

                  Also what have you used for legs and cover for the underside of the organ once its chopped?</p>



                  • #10
                    Re: L-100 maintence help


                    I think that leaving the main amp is just adding of extra weight. </p>


                    In my chops I make legs of steel pipes. It looks like Hammond X-66 then. I also build a special enclosure for pedals and they are connected by computer-type D-SUB 15 connector. Unfortunetly, I dont't have photos of any of my chops which would be helpful.


                    • #11
                      Re: L-100 maintence help

                      Those instructions are a bit bare...but here goes:</P>

                      1) count thesolderterminals from the lowest note to the highest note, there should be 91 lugs, andthe 92nd is the ground?mark off lugs 80 through 91. the lug number corresponds to the frequency number...correct?</P>

                      2) break the solder joints on the ground terminal. (again which one is ground)</P>

                      3) use a multimeter continuity tester to figure out which of those ground wires connect to which key contact. Judging by the position of the key contact and whichever busbar it connects to, I re-rout its wire to the appropriate frequency lug. </P>

                      4) Then I start at the bottom busbar, and i look at the colour of the wire that connects to it to figure out which harmonic it is. Iinsert my new key conact and look at the chart in that word document to see whichfrequency it should connect to...</P>
                      <P mce_keep="true"></P>

                      am i on the righttrack?Can I use a continuity tester throughout the process to make sure signal is flowing from the key contact to the frequency lugs?</P>
                      <P mce_keep="true"></P>

                      thanks again</P>


                      • #12
                        Re: L-100 maintence help

                        There are 74 on lower and 74+ground on upper - frequencies starting from 18 to 91. </p>

                        Your instructions are correct.</p>

                        good luck</p>


                        • #13
                          Re: L-100 maintence help

                          so i'm pulling apart the old key contact assembly...</p>

                          there are
                          different coloured wires that all appear to be the same thickness
                          except for one row of contacts which had a darker red wire which was a
                          bit thicker then the rest of the lot. Can the thicker wire contacts be
                          used for the foldback job?</p>


                          Also whats the deal with these wires (they're bare) come they don't short out by touching one another?</p>


                          Thanks so so so much for the help with this. it really is scary when you first look at all those wires</p>


                          • #14
                            Re: L-100 maintence help

                            They are isolated. You should found the ones with 16 ohm resistance. Unfortunetly I don't remember the color so check it with multimeter.</p>

                            good luck</p>


                            • #15
                              Re: L-100 maintence help

                              What happens if you use a wire that is not 16 ohm?</P>

                              Bad news, I can't find any!here's what i've found:</P>
                              <P mce_keep="true"></P>

                              Thicker wire, dark red = 10.6 ohm</P>

                              blue = 35 ohm</P>

                              red = 37.5 ohm</P>

                              green 104 ohm</P>

                              gold = 23.6 (this one makes up most of the wiring harness) ohm</P>

                              letme know</P>