Forum Top Banner Ad

Collapse

Ebay Classic organs

Collapse

Announcement

Collapse
No announcement yet.

R100 / H100 Percussion driver and gate circuits

Collapse
This topic is closed.
X
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • R100 / H100 Percussion driver and gate circuits

    Greetings,
    I'm new to the forum and a Hammond beginner. I recently bought an R100 series organ which I'm trying to get fully functional. My first questions are about the percussion triggering, which seems to be only half working. Some of the circuits
    from the R100 are also found in the H100 service manual, so it might related to the H100 series also.

    These are the symptoms:

    1) Some notes trigger percussion and others don't. The keys that don't trigger are, starting from the lowest note: D#, F#, G, B, D, G, A#, B, D, D#, G, B, D, D#, F#, G, A#, B, D, D#, F#, G, A#, B - so there is a bit of a pattern to the layout of the non-triggering percussion keys, but it's not exactly repeated in every octave.
    2) The notes that don't trigger will sound if played straight after a note that does trigger, but with repeated key presses the percussion will fade out and not re-trigger.
    3) If a non-triggering key is held down continuously, then no other keys will trigger until that key is released.
    4) If a key that does trigger is held down, then all the other (triggering) keys will trigger and simultaneously re-trigger the held key, but non-triggering keys will not trigger but will re-trigger the held key if released quickly.
    Sorry it's a long list, but I'm trying to be thorough. Any thoughts?

    In the service manual it states (section 2-10) PERCUSSION AND REITERATION DRIVER 128-000001: 'Percussive can be "Touch Control" or LEGATO.' What does this mean? Is it 2 different things or 2 names for the same thing?

    There is a Percussion gate amplifier 117-000001 (section 2-11) and also an Alternate percussion gate amplifier 117-000002, but the manual doesn't state what these are for - I'm thinking one might be for the keys that are not triggering and it's failed somehow, but I can't find any confirmation.

    I did a whole series of modifications on a T500 earlier this year, including a re-trigger modification that changed it from every note triggering percussion, to only re-triggering after all keys have been released - this is my preferred mode if at all possible for the R100.

    I have a few more questions, but I'll leave them for another time. Any light that can be shed on the percussion situation would be most appreciated.

  • #2
    Hammonds are not my forte, but I'm familiar with percussion circuits in the X-77 and H100 series, so hopefully, I can provide some useful information

    Originally posted by Saltech View Post
    1) Some notes trigger percussion and others don't. The keys that don't trigger are, starting from the lowest note: D#, F#, G, B, D, G, A#, B, D, D#, G, B, D, D#, F#, G, A#, B, D, D#, F#, G, A#, B - so there is a bit of a pattern to the layout of the non-triggering percussion keys, but it's not exactly repeated in every octave.
    Most likely this a contact issue, rather than a problem with any percussion assembly.

    2) The notes that don't trigger will sound if played straight after a note that does trigger, but with repeated key presses the percussion will fade out and not re-trigger.
    3) If a non-triggering key is held down continuously, then no other keys will trigger until that key is released.
    4) If a key that does trigger is held down, then all the other (triggering) keys will trigger and simultaneously re-trigger the held key, but non-triggering keys will not trigger but will re-trigger the held key if released quickly
    This is the way "Touch Response" percussion is supposed to work and is normal. Only the initial pressed key triggers the percussion. No other keys will trigger the percussion as long as the initial key is held down, but their notes will decay at the same rate as the initial note. Hence "Touch Response" as what percusses and how it decays is dependent on the degree of legato playing.

    "Touch Response" is actually a technical limitation of the tonewheel Hammonds due to the way they are keyed. Hammond reframed this limitation as "feature" and it found a niche especially among jazz players. It wasn't until the advent of LSI Hammonds, with electronic keying, that Hammonds had true percussion.

    In the service manual it states (section 2-10) PERCUSSION AND REITERATION DRIVER 128-000001: 'Percussive can be "Touch Control" or LEGATO.' What does this mean? Is it 2 different things or 2 names for the same thing?
    See above. H and X-77 models "legato" mode causes the percussion to trigger each time a key is pressed, even if other keys are down. Again, because of the way these organs are keyed, there is a limitation in that each additional key pressed not only triggers its own percussion, but also retriggers the percussions of all the notes currently held.

    There is a Percussion gate amplifier 117-000001 (section 2-11) and also an Alternate percussion gate amplifier 117-000002, but the manual doesn't state what these are for - I'm thinking one might be for the keys that are not triggering and it's failed somehow, but I can't find any confirmation.
    The X-77 introduced "twin mallet" percussion whereby certain (marimba and xylophone) reiterated percussion voices would alternate between two notes an octave apart when a key was pressed. That's the function of the Alternate percussion gate.

    I think your problem lies with the percussion trigger key contacts under the non-functioning keys.
    -Admin

    Allen 965
    Zuma Group Midi Keyboard Encoder
    Zuma Group DM Midi Stop Controller
    Hauptwerk 4.2

    Comment


    • #3
      Thanks for the quick response. I did think it could be contacts, but because of problems with the same keys in different octaves, I thought it might be something else. Also I've found one key that doesn't trigger the percussion 95% of the time, but very occasionally it will, which suggests a dirty contact. Guess I'm going to have to take it apart...

      Comment


      • #4
        Originally posted by Saltech View Post
        Thanks for the quick response. I did think it could be contacts, but because of problems with the same keys in different octaves, I thought it might be something else. Also I've found one key that doesn't trigger the percussion 95% of the time, but very occasionally it will, which suggests a dirty contact. Guess I'm going to have to take it apart...
        Try shifting the bus bars first.
        -Admin

        Allen 965
        Zuma Group Midi Keyboard Encoder
        Zuma Group DM Midi Stop Controller
        Hauptwerk 4.2

        Comment


        • #5
          Originally posted by Admin View Post
          Try shifting the bus bars first.
          OK, I finally got around to this, and shifted the busbars on the upper manual. I then had to play all the keys many times to get them to work again, which I guess confirms that the busbars did move. But the percussion problem persists as before, with the exact same keys not working. They won't initiate a percussion voice, but they will sound at the correct pitch if played after a working key. This seems to indicate that the percussion voice is getting key contact information from the non working keys, but they can't initiate a percussion note.

          Comment


          • #6
            Originally posted by Saltech View Post
            They won't initiate a percussion voice, but they will sound at the correct pitch if played after a working key. This seems to indicate that the percussion voice is getting key contact information from the non working keys, but they can't initiate a percussion note.
            Yes, that's because there are two contacts involved for percussion. One which routes the audio through the percussion gate and one that triggers the gate open. The audio contact is good, the trigger contact isn't.

            There are number of threads on H100 percussions currently running on the Forum. Here's one with a similar problem. In this case it appears that although it's contact related and will require the manuals to be removed to fix, it's not actually the contact, but a resistor connected to the contact.

            https://www.organforum.com/forums/sh...514#post490514
            -Admin

            Allen 965
            Zuma Group Midi Keyboard Encoder
            Zuma Group DM Midi Stop Controller
            Hauptwerk 4.2

            Comment

            Working...
            X