Garrard 401

[bob orbell]

Hi all, I require a bit of help with my 401 project, late 401 fitted into a home made solid oak plinth, looks nice, SME 3009 with Ortofon VMS20, OK, it plays very well, the problem is motor noise when playing very quiet tracks and very audible in-between tracks, the noise is only coming through the speakers, there is no sound at all from the turntable , I have just done a test whereby I removed the idler wheel and put the plater back on, placed a record on the plater and lowered the arm, switched on and the noise is there, so this rules out the main bearing, it sounds about 50 to 100 Hz, as soon as power is cut the noise stops, on returning the power there is about 1 second before the noise returns. The motor I have connected with 3 core flex, earthed at the plug top and the chassis, the arm is earthed only through the phono via a separate wire, as is normal practice, the phono is WD phono III, I have also fitted the arm with rubber washers, as in the SME instruction book, but this makes no difference, so I have returned the arm to solid fixing.PLEASE HELP BOB

[Richard]

Hi Bob,
Possibly a ground loop from having arm earthed via Phono and motor earthed to mains. Try earthing the arm to the motor unit so there's just one path to mains earth.
Also try it earthed to PSU instead of Phono and check Phono and PSU cases aren't touching as Phono earth post/case is lifted by 100R from PSU earth post/case which is at mains earth.

[bob orbell]

Thank's for the reply Richard, I will try that on Monday, the phono is some way from the PSU, and I have tried the earth at the PSU with no success, I do hope it is something simple like you mention, I will let you know. BOB

[Greg.]

Hi Bob,

I have my 401 and arm earthed exactly as you have with no hum problems. Could it be that your cartridge is unshielded and is being effected by the motor magnets. I have known this to be a problem with some cartridges.

For definitive help with this problem, can I suggest you join

http://garrardmatters.freeforums.org/index.php which has a specific section for 401's.

This site is run by Dominic and Natalie Harper of Northwest Anologue who are authorities on Garrard's and I have yet to see someone there with a problem not sorted out.

Greg

[bob orbell]

OK I have replaced the 3 core flex with 2 core with moulded plug top and connected the chassis earth to the arm earth post, so now only one earth wire, also tried both earth posts, phono and PSU, sadly no change, I now think that that the noise I am getting is motor vibration, I say this because of the 1 second delay when switching on, the motor is not touching the plinth as far as I can tell, and all the springs and rubber dampers seam OK. I have joined the forum, GARRARD MATTERS, that Greg posted, Thank you Greg, and will post my problem on that forum latter. If any one has any suggestions, please post. I also did a test on my LP12, whereby I removed the belt and ran the motor and there is no sound at all. BOB

[Shane]

Hi Bob, when you did your check with the idler removed, what happened when you lifted the stylus off the record? If you lifted it with the motor still switched on, did the noise stop the instant the stylus lifted out of the groove? If so, that would make it mechanical vibration from the motor, but if the noise carried on after the stylus lost contact with the record then it must be induced hum.

If it's mechanical noise, check that the motor is free to move on its suspension and isn't touching anything when the deck's in its normal operating position, and check that the lead to the motor isn't tight.

The fact that the noise took a second to come back when you switched the motor back on makes me think its much more likely to be mechanical, as that's about how long it would take the motor to spin up to speed. Induced hum would start again immediately.