Ebay Classic organs

Collapse

Announcement

Collapse
No announcement yet.

Still getting occasional "pop" when switching speeds on 147RV

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Still getting occasional "pop" when switching speeds on 147RV

    I installed the EIS-147 relay in my Leslie 147RV but was getting a "pop" sound through the speakers when switching speeds. I've gone so far as to replace the switch, diode and wiring from the switch to the Hammond C3 junction box, and removed all twist connectors in the Leslie amp so that wires are connected directly from the relay to the terminals. I also have the relay wires as far away from the audio wires as possible in the Leslie amp. This all helped reduce the pop and I guess I could live with it, but I was wondering if there's anything else I could do to try to eliminate that annoying pop? It happens with both an old Leslie cable and a newer one.

    Could replacing the preamp tubes help?

    Would a 2-position switch be a better option? I don't even need the brake feature.

    I might just bite the bullet and get a pro technician out here to check it out.

    #2
    Mine did that and I was told to install a cap on the switch itself. I'm not a tech and maybe this is a hack fix but that was over 20 years ago and it hasn't popped since.

    Comment


      #3
      Putting a cap across the switch is typically a good idea on a standard switching setup but with SS repays, that cap can cause problems. It can allow enough current to fool the SS relay into thinking the switch is closed when it's not. I haven't tested this on the EIS-xxx.

      One "issue" with the 147 class is the unbalanced, single ended input wire running inside the Leslie cable along side the AC power and the AC switching lines. I have seen in some older cables the signal wires encased in shielding within the large cable. However most cables have no shielding. Just a twisted pair for the signal wires. This is good for balanced lines but not that helpful for unbalanced.
      You could make a custom cable where the AC wires are separated from the signal wires. (Two cables)
      Geo

      Comment


        #4
        Originally posted by clem View Post
        Mine did that and I was told to install a cap on the switch itself. I'm not a tech and maybe this is a hack fix but that was over 20 years ago and it hasn't popped since.
        Yeah I wondered if that would help - I may give it a try.

        Originally posted by geoelectro View Post
        Putting a cap across the switch is typically a good idea on a standard switching setup but with SS repays, that cap can cause problems. It can allow enough current to fool the SS relay into thinking the switch is closed when it's not. I haven't tested this on the EIS-xxx.
        I know the EIS-147 is supposed to handle arc suppression but also wondered if putting one on the switch would interfere with the operation of the relay.

        I actually wired one of the old caps from the 147 amp across pins 2 & 5 on the amp socket and I think it helped a little. Also, I've been monitoring all this with the back covers off the Leslie with the back facing me on the left side of the organ. According to this article, "placing your Leslie on the left side of your organ is guaranteed to cause hum." So I put the covers back on and moved the Leslie to the right side and I think I'm good - if I don't play anything and move the switch, I sometimes hear a very small pop, but I never hear it when playing. Plus, some additional noise is caused by the motor switching which I intend to rebuild.

        Thanks for the advice!

        Chris

        Comment


          #5
          Hello,

          The EIS relay has a microcomputer. Probably a microchip Pic but I'm not sure because it is top secret.

          But i'm sure, one of its inputs is fitted with a filter which detects the 3 states of the control signal.
          = 110V> Slow.
          = No voltage> Fast.
          = DC present by a rectifier insered in the circuit > Stop.
          As the PICs only accommodate a voltage between 0 and 5 Volts I think there is already a shaping of the control voltage by resistors and capacitors which makes the energy in the control circuit ivery small.

          To find out if this circuit is an issue. It's very simple. Just unplug the motors. If the pop persists, the problem is in the control circuit. Then, it may be necessary to add a serial resistor.to decrease the energy in this circuit.

          I see this is a 147RV. Have you tried unplugging the reverb ?

          JP

          Comment


            #6
            Originally posted by Jyvoipabo View Post
            Hello,

            The EIS relay has a microcomputer. Probably a microchip Pic but I'm not sure because it is top secret.

            But i'm sure, one of its inputs is fitted with a filter which detects the 3 states of the control signal.
            = 110V> Slow.
            = No voltage> Fast.
            = DC present by a rectifier insered in the circuit > Stop.
            As the PICs only accommodate a voltage between 0 and 5 Volts I think there is already a shaping of the control voltage by resistors and capacitors which makes the energy in the control circuit ivery small.

            To find out if this circuit is an issue. It's very simple. Just unplug the motors. If the pop persists, the problem is in the control circuit. Then, it may be necessary to add a serial resistor.to decrease the energy in this circuit.

            I see this is a 147RV. Have you tried unplugging the reverb ?

            JP
            Thanks for the reply. The reverb amp isn't powered up, though the amp will power on if I plug it in. The Leslie was missing all the back panels when I bought it, so there's no reverb tank.

            As far as the relay goes, I have unplugged the motors and the pop persists through the speakers. I wired a cap across pins 2&5 on the amp socket, but haven't tried one at the switch - I'll probably try it just to see if it helps with the problem and/or interferes with the relay operation.

            But I'm most interested in the idea of adding a resistor to the circuit. What kind should I use and where would it go?

            Thanks!

            Chris

            Comment


              #7
              This case is really weird.

              When it's weird, it often comes from a mass problem or poor contact somewhere.

              Have you cleaned all the plugs, sockets and scraped all the pins of the tubes in the organ and in the leslie?

              Also try running a direct ground wire between the Leslie and the organ.

              If you want to add resistance. It must be inserted in series in one of the wires of the half moon.
              I have no idea the value. Can be between 1000 and 10000 Ohm.
              But by measuring the voltage across its terminals, you should not exceed 20VoltAC when the speed is slow. Which should be enough to allow the relay to operate.

              JP

              Comment


                #8
                Originally posted by Jyvoipabo View Post
                Have you cleaned all the plugs, sockets and scraped all the pins of the tubes in the organ and in the leslie?
                No I haven't - just saw a video the other day about doing that with DeoxIT so I definitely will. Also, I've never replaced any of the tubes in the organ or speaker and I have no idea the history of the speaker before I bought it some 15 years ago or the organ which I bought last year. I supposed it would be wise to purchase new sets?

                Originally posted by Jyvoipabo View Post
                Also try running a direct ground wire between the Leslie and the organ.
                I'll try this too - I'm assuming from the organ ground to the speaker's amp chassis?

                Originally posted by Jyvoipabo View Post
                If you want to add resistance. It must be inserted in series in one of the wires of the half moon. I have no idea the value. Can be between 1000 and 10000 Ohm. But by measuring the voltage across its terminals, you should not exceed 20VoltAC when the speed is slow. Which should be enough to allow the relay to operate.
                Great - Thanks again!

                Comment


                  #9
                  I just installed the EIS 147 relay with the stop feature in a 147. I ran the red/purple twisted pair (switching voltage) directly soldered to pins 2 & 5 making sure I crossed the audio in at a right angle. No pops. Appears to be working well.
                  Now I have stop on the 21H (2 speed motors with an EIS 122 relay) and the 147.

                  Jim

                  Comment


                    #10
                    Originally posted by Jaim View Post
                    I just installed the EIS 147 relay with the stop feature in a 147. I ran the red/purple twisted pair (switching voltage) directly soldered to pins 2 & 5 making sure I crossed the audio in at a right angle. No pops. Appears to be working well.
                    Now I have stop on the 21H (2 speed motors with an EIS 122 relay) and the 147.
                    That's cool - do you happen to have any pictures of how the wiring looks? I'm not clear on how you "crossed the audio in at a right angle". I think I had to untwist the red/purple wires so they would reach - I wonder if that could be part of the problem?

                    Comment


                      #11
                      In the stock amp, the AC in on pins 3&4 as well as the switching voltage from pins 2&5, the wires take a immediate 90 degree turn at the plug and are routed along the front of the chassis. In the EIS relay, the red/purple pair come from the back side of the relay box and aren't long enough to run to the front of the chassis and then across to the plug. you want to minimize the amount of area where the red/purple pair are in the vicinity of the green wire (audio in) from pin 6. From an installation point of view, it would probably been better to wire nut the red/purple pair to the existing wires.

                      Jim

                      Comment


                        #12
                        Good idea.

                        This is an opportunity to check the wiring of the Leslie because there are several possibilities and may be wiring tips or even errors that can cause possible trouble.

                        The big problem was that the 147 and the 122 had the same connectors. But they are not compatible. To avoid damage, sometimes Wire 5 is not used and Relay 2 is connected to Live Pin4 in the Leslie.

                        At the time I made a small diagram to find out.

                        JP
                        Click image for larger version  Name:	147Connector.jpg Views:	0 Size:	48.0 KB ID:	724893
                        Attached Files

                        Comment


                          #13
                          Connecting the relay to pin 4 in the Leslie makes it a 6C type. The pin 4 to 5 bridge in the 147 kit never made any sense. But I'm sure there was some reason way back when to do so.

                          Jim

                          Comment

                          Working...
                          X