Rega RP1 Motor Noise

Discussion in 'Audio Hardware' started by Art K, Jan 2, 2012.

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  1. Art K

    Art K Forum Resident Thread Starter

    Location:
    Corvallis, Oregon
    I really enjoy the sound of the Rega RP1 however I have grown somewhat tired of the motor hum. I can hear it from my listening position. This is not hum from the speakers as there is a bit of that as well, especially as the cartridge nears end of the record. But the truly irritating hum is the one coming directly from the motor. Anyone experience this and have a solution?
     
  2. blakep

    blakep Forum Resident

    For $50 or possibly less you could purchase a variac or variable output transformer like the top one here:

    http://www.kelinginc.net/VariableACOutputTransformer.html

    and plug the RP1 into it. Start the RP1 at 120V and then ramp the voltage down on the transformer/variac to around 70-80 V.

    Disadvantages: You have another piece of equipment to locate next to your turntable and an additional step in playing your records that takes about 10 seconds.

    Advantages: This should go a long way to reducing or entirely eliminating your motor hum and the table should sound better as well as a result of lowered motor vibration.
     
  3. Art K

    Art K Forum Resident Thread Starter

    Location:
    Corvallis, Oregon
    Thanks for the response. I hope there is another way because that thing certainly is not going anywhere in my listening space.
     
  4. blakep

    blakep Forum Resident

    :D Yeah, I kind of thought that too. But after I heard what it did with my table there was no losing it. You just have to get creative. A nice little marble topped plant stand for it and, voila, it is kind of an Architectural Digest addition to you system, LOL!

    Would be nice if you could order in designer colors but I don't believe that is the case. :winkgrin:
     

    Attached Files:

  5. Art K

    Art K Forum Resident Thread Starter

    Location:
    Corvallis, Oregon
    Beautiful setup you have:righton:. Does it have a fan in it, or does it make any kind of noise of it's own. What makes you sure that it will solve the issue? If it's silent and would solve the problem (without any deterioration of the sound) I would figure out the aesthetics.
     
  6. blakep

    blakep Forum Resident

    No fan and it's dead silent. Not only should your sound quality not deteriorate, it should improve. It has for me. I tried this out on a lark after Harry Weisfeld from VPI suggested it in a thread at Audio Asylum as the options for me to upgrade the power supply for my table started at around $500-$600 for an older used power supply and ranged into the $800 to $1500 area if I switched over to a new DC motor and upgraded power supply for the DC motor.

    Consider this: while very expensive upgraded power supplies like the VPI SDS, Linn Lingo, Naim Armageddon clearly do other things as well, one of the most significant things they do for tables using AC Synchronous motors is drop the voltage following startup. This, in turn, significantly reduces motor noise and vibration, resulting in a lowered noise floor and improved sound quality.

    The nice thing is you can achieve much of what those upgraded supplies do for about $50 (or $80 or so if you're looking at delivery-you're looking at around 10 pounds for one of these so they're pricey to ship), even if they are a bit ugly and demand an extra manual step in record play.
     
  7. Art K

    Art K Forum Resident Thread Starter

    Location:
    Corvallis, Oregon
    I just ordered it, sure hope it works! :)
     
  8. You're hearing the actual physical hum of the motor? How much motor related noise do you hear over the speakers?

    My new year resolution is to get my turntable quiet enough that I can enjoy it. I have a Pro-Ject Debut III and the motor noise rumbles and makes obvious noise in the music at 60 Hz, 120 Hz and 240 Hz. Irritating.

    I'm going to try to quiet down my Debut III. If that doesn't work well enough I was thinking maybe I'd try an RP1 or?

    Maybe the variac would work with my Debut III as well?
    To use it you start the table spinning at 120V and then dial it down before putting the needle on the record. I guess lowering the voltage lowers the torque of the motor. Would it cause any extra wear or damage to the motor?
     
  9. Art K

    Art K Forum Resident Thread Starter

    Location:
    Corvallis, Oregon
    Don't hear much noise through the speakers...more as the record nears the end.

    Mostly hear the motor itself humming and you can feel the vibration on the plinth. It's quite quiet through the speakers, considering.

    It's the only niggle with the table...solve it and I'd be a very happy camper. I also wonder if there are any unintended consequences to look fowrard to. BTW shipping was only $8.15.
     
  10. Balthazar

    Balthazar Well-Known Member

    For the Pro-Ject, this may help:

    http://www.musicdirect.com/p-3094-pro-ject-speed-box-ii.aspx

    I found it very effective with my Debut III USB. My set up was was especially prone to noise sensitivity, as I was running it straight into my desktop computer and listening to it through Audioengine A2 speakers in an extreme nearfield position. I was not bothered by any hum with the Speed Box. Admittedly, I can't recall if it ever bothered me without the Speed Box. At the time, I think the added convenience of one touch switching between speeds was the main selling point for me. The sonic improvements were just icing on the cake. If you like the Debut III, it may be worth trying, because you will lose money on resale, if you decide to do that to get something else.

    I'm eager to hear more about this variable AC output device. Can't wait to hear the results.
     
  11. Art K

    Art K Forum Resident Thread Starter

    Location:
    Corvallis, Oregon
    Just received the email confirming the order and shipping. Should be here on Friday. probably won't get to test it out until Saturday (wife wants movie night this week).

    BTW with some cartridges the Speedbox can actually introduce motor hum.
     
  12. blakep

    blakep Forum Resident

    Good deal on the shipping-I paid at least 4X that but I'm in Canada.

    The variac will do nothing for cartridge induced hum at end of record-that is another issue entirely related to the positioning of the Rega motor relative to the cartridge at side ends.

    You should experience a significant reduction in motor hum though and you should actually be able to feel the vibration lessen on the plinth as you ramp the voltage down to between 70 and 85V. I'd recommend starting at the higher number and experimenting to see if you can work your way down lower. A friend had a P3 I believe that he ran with very positve results around 80-85-I'll check and post his number back later. I do run at 70V with my Gyrodec.

    Simply start up at 120V and then ramp down to your preferred number-once you've established it, simply mark the top dial to identify where you want to dial to (I'd go by the reading on the front meter as opposed to the dial itself) and then ramp back at the end of side or when you turn off to be ready to start up the next time.
     
  13. Art K

    Art K Forum Resident Thread Starter

    Location:
    Corvallis, Oregon

    You do this at the end of every side..do tell. I run a Rega. You leave it on and play records. I wouldn't want to mess with this beast at every side change...that would put in the category of way too much PIA. I have a simple setup for a reason. I guess I just don't understand. By preferred number what do you mean...is there a difference in sound based on the number?
     
  14. blakep

    blakep Forum Resident

    If you're leaving the table on constantly and not turning it off when changing records that will not present a problem. I use a table with a clamp so I'm not able to do that. No big deal really, adds another few seconds for me.

    So you may well only have to turn the voltage back up to 120 at the end of a session as opposed to between sides.

    Different AC motors will probably react slightly differently to the reduced voltage. I just checked and my friend ran his P3 at 90V with an Armageddon clone that he built. I would probably still try to go lower. The key is to reduce the voltage to an amount that will provide the motor with enough voltage to keep the platter spinning but maximize the reduction in vibration. At a certain point, too little voltage will result in the motor not providing enough power to turn the platter. No big deal and no harm will come to your motor from this so it is a matter of finding how low you can go, or what's reasonable on the voltage for you to achieve the maximum performance.

    Another option is to simply leave the table powered on at the reduced voltage all the time and simply stop and start the table by hand. I have a friend that uses a VPI SDS this way with his (non VPI) table and Nottingham tables essentially operate in the same manner. The lower voltage is not enough to get the platter revolving from a dead stop but if you "hand start" the table by giving the platter a bit of a push the motor is capable of keeping the platter revolving at the right speed.
     
  15. TVC15

    TVC15 Forum Resident

    Location:
    New Jersey
    You shouldn't have to buy workarounds for a noisy motor. I guess the RP1's motor control unit doesn't account for (or is adjustable for) motor vibration. Issue is also some of that noise is being transferred to your plinth, and therefore your noise floor.

    Since I'm assuming the RP1 isn't designed to be this way, I'd take it back to your dealer to compare against a demo. If the demo is quiet, but yours is not, you likely have a warranty claim, if not basis for a replacement. NOT some $50 work-around which may or may not work.

    Edit: Just saw you ordered the $50 thingy. Did you check in with your dealer? A vibrating plinth is a very bad thing, especially on a rega. All of that energy is being amplified. You shouldn't be able to feel the motor through the plinth. Unless the RP1 is "just that way" (which I seriously doubt is by design).
     
  16. KT88

    KT88 Forum Resident

    I don't believe that is covered under warranty... The Premotec motor isn't the largest out there and is already a low torque motor. It is easy enough to stall and that can be done for a few seconds but I don't know that leaving it in a stalled state for a long period of time would be a good idea. For instance, if you get the TT-PSU, you might find that trying to start the motor at 45rpm is slow or will not work at all without a "push start" ala Nottingham. Rega specifically advises against this in the manual and recommends starting instead at the higher torque 33rpm position and then upping the speed to 45rpm once the platter has come up to speed. They don't state that it will damage the motor or circuitry but do state that it can cause the motor to stall and that it may not reach full speed from that point. They also advise to turn off the supply when not in use for extended periods, even though the motor is not connected due to the power switch on the table being disengaged. Heat is not good for electronics and unnecessary heat is, well... dammit, unnecessary. :winkgrin: The Nottingham motor is much larger than the Premotec motor and can dissipate the heat more readily so direct comparisons are done at your own risk. It's a pretty silly mode of operation to leave voltage applied at all times in any design.
    -Bill
     
  17. blakep

    blakep Forum Resident

    Yes, makes sense Bill and I've always been a bit leery of using the push start method with the variac and my table which uses a Papst motor which is a bit of a beast. Your info on the Premotec motor being low torque may also explain why my friend had good results at 90V with his P3 as opposed to lower numbers (around 70) that seem to give great results with tables that probably have higher torque motors as well.

    The linked transformer that I'm using that Art has ordered throws off no heat at all so I've never had any concern about leaving it powered 24/7. That being said, I'd agree that you're best to start up at full voltage of 120 and then power down.
     
  18. xyyyy

    xyyyy Forum Resident


    A Rega RP1 with Premotec motor shouldn't require a work around to run address excessive motor noise. Can you simply file a warranty claim with Rega if there is a problem and cancel your order for the Variac? Rega's are supposed to be simple:agree: Good luck:wave:
     
  19. Quadraflex

    Quadraflex Forum Resident

    Location:
    Dallas, TX
    Would it be worth it to try other outlets for the RP1 just to troubleshoot?
     
  20. Art K

    Art K Forum Resident Thread Starter

    Location:
    Corvallis, Oregon
    I cancelled the order. I want to thank Blakep for the suggestions and the time he has taken here to address my questions, very generous sir. I love the sound of the table...I''m at a bit of a loss here.
     
  21. Art K

    Art K Forum Resident Thread Starter

    Location:
    Corvallis, Oregon
    If you mean other outlets in the home, I have. I'm currently using a dedicated circuit that was put in last year.
     
  22. TVC15

    TVC15 Forum Resident

    Location:
    New Jersey
    Simple. Take it back to your dealer. Shouldn't vibrate. Motors have unique vibration characteristics, even of the same lot, which is why Rega "hand trims" among those models with vibration control. RP1 doesn't have that. So seems you got a noisy one. Take it back.
     
  23. Closed on OP's request.
     
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