Premier 751 Vibraphone (Job No: 1327)

There are a lot of vibraphones coming through my workshop at the moment, including the Premier 751. In fact, when I pause to think about it, I seem to have been working continuously on various aspects of the Premier vibraphones for nearly a year now. Whether I have been developing moulds for reproducing the rubber parts, making jigs for the metal components, or working on whole new assemblies, there always seems to be something going on with these vibes.

What I find is that work comes in waves; for months all I seem to have worked on are vibes, before that I just seemed to be doing timpani, then I had three sets of tubular bells in a row… So this is what has happened, and the result is that my stock of parts is being used up. I keep stating that these parts are obsolete because the instrument isn’t produced any more, so now I have been forced to come up with alternative solutions which all take a lot of time over prolonged periods.

Instead of focusing on particular details, with this post I decided to give more of an overview of the work I do. What you will see in the video is that jobs are never as straight forward as you would think, and soon I find myself surrounded by bits…


10 comments on “Premier 751 Vibraphone (Job No: 1327)

  1. David Hurford

    Hi Paul – great video, very interesting.

    I get a lot of fun with the Premier you worked on for me. So far, I don’t use it with the motor much, but having seen your video I thought I’d check the earth connectivity. It turns out the earth core doesn’t connect to the metalwork! From what you’ve said, you would expect it to, and you’d see this as a safety hazard. I think there must be a failure of the earth connection inside the motor. Is it a difficult job to take the motor off (or apart) and have a look for this?
    All the best,
    David

    Reply
    • pauljefferies

      Hi David,

      I’m glad you are enjoying the vibe. Before I answer your question, I need to clarify a couple of points. When you say, “I’d check the earth connectivity”, did you use a multimeter? I cannot remember which motor you had, but I think it has a 3 stage pulley to control the speed as opposed to the later motors which have a thumb wheel, is this correct?
      Regards,
      Paul

      Reply
  2. David Hurford

    Hi Paul, nice to hear from you.

    Yes, I used a multimeter. The motor doesn’t have a thumb wheel, but it doesn’t have a three stage stepped pulley either. The pulley has perhaps has two stages, but the smaller step is so small that the rubber O ring is too slack, and the vanes don’t turn.
    Experimenting with using the motor (I’ve hardly used it till now), I’m realising I quite like the vibe sound with the rotating vanes, so I’d like to get it working properly (although the motor is quite noisy, as perhaps you remember). No chance of getting a quieter motor, I suppose?
    Regards,
    David

    Reply
    • pauljefferies

      Hi David,

      Returning to your initial question regarding earth continuity on the motor, without seeing which motor you have it, is impossible for me to give a definitive answer. The reason why I asked about the speed control is because if the power goes directly to the motor, it is probable that the motor unit is double insulated which would negate the need for an earth connection.

      Regarding motor noise, the first thing to do is to run the motor with no belt attached, then apply lateral pressure to the pulley with your finger. This will isolate the motor from the resonators whilst replicating the tension of a belt and confirm that the noise originates from the motor.

      There is little point in changing a 40 year old motor with something 20 years old, so I produce a replacement motor kit, but they are not cheap because quality motors are expensive, I then make the motor carriage, modify the electronics and assemble the whole lot. I will check my records and email you with a current price and see which belt you had, so if I have a smaller size I can send you one.

      Regards,
      Paul

      Reply
      • David Hurford

        Hi Paul, sorry about the delay but thanks for yr email.

        Yes it’s definitely the motor making the noise – there even if the belt is disconnected completely. It’s a Citenco, type FP/I. I imagine the noise is from the gearbox.

        Good to know it’s perhaps double insulated – perhaps that’s why there’s no continuity between earth lead and frame.

        I don’t think I’ll run to a new motor. I’m only learning to play at the moment, couldn’t really justify it.
        A new belt might be nice though, if you’re able to identify the right one.

        I’d really like to lower the height of the pedal, because I have some difficulty operating it. I’m hesitant to unscrew the connecting rods a little bit from the ball joint at the top, for fear of stripping the threads. I suppose one possibility might be to ask you to make up some rather longer connecting rods. Would that be a possibility, and if so what might the price be?

        All the best,
        David

      • pauljefferies

        Hi David,

        I will, at some point, write a blog post with all the different types of motor unit that have been fitted to Premier vibraphones. My brain just doesn’t really work well with things like model numbers, but the determining factor on Premier vibes is the method of speed control. Anyway, I will explain in detail when I write the post. Whichever motor you have, it predates 1979, which is probably the reason why it is noisy.

        I will do some paperwork this week, so will find out what belt you need and send it when I am doing that. At that time I will calculate a price for the longer rods.

        Regards,
        Paul

      • David Hurford

        Thanks Paul. No hurry at all.

        I haven’t said what length rods, of course. Let me know if you need this information in order to quote – I think it will be about 1″ to 1 1/2″ longer than at present.
        Best wishes
        David

  3. Keith Scott

    Paul:

    Some time ago I acquired a 701, shoddy frame was first thing to go – after I examined the damper mechanism etc. The bars have a nice timbre , different from musser, deagan, yamaha … kind of a singing quality – no doubt due to alloy. I have recently purchased a set of bars for the 751 , however the set is missing 2 bars, F#3 (2″ wide) and A#5 (1.5″ wide). What alloy would you recommend to match the timbre and the surface finish of the premier bars? I have access to 2024 , 6061 and 7075 tempered alloys. I maybe be able to use the A#5 bar from the 701 set, since they both are 1.5 ” wide ( will need to check nodal hole placement and length for compatibility). The other question relates to the 751 frame, in particular what are the bar pin spacings on rails 2 & 3 for 2″, 1.75″ and 1.5″ wide bars. I have noticed on deagan instruments , that this spacing seems to be 7/16″ + given bar width – do you concur? My plan is to construct an appropriate frame for the 751 , and keep the 701 bars as backup parts where applicable – any guidance in regards to this will gladly be appreciated!

    Keith

    Reply
    • pauljefferies

      Hi Keith

      Two difficult questions!

      First, the bar alloy question:
      Premier Percussion are a customer of mine, so I am restricted to what I can say with regards to the specific alloy, but you are correct in also mentioning the tempering. It is not sufficient to just buy the correct alloy, the treatment processes of the alloy also affect the sound. Massive amounts of protectionism surrounds this information for commercial reasons. The other problem is that I do not know the answers off the top of my head, instead I would have to go through all my notes, research any gaps, and compare my technical data to the three alloys you mentioned. As you will appreciate, that will take time to do, and I have a business to run. What I will say is that if I were in your position, I would just try; if you are making the note, then experiment.

      With the hole spacing: 7/16″ in a measurement that makes sense to a european is 11.1125mm which sounds about right.

      regards,
      Paul

      Reply
  4. David Hurford

    Thanks Paul. No hurry at all.

    I haven’t given you the length of rod needed, of course – let me know if you need this in order to quote. I think it will be approx.1″ to 1 1/2″ longer than at present.
    Best wishes,
    David

    Reply

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