Gyro SE suspension problem...
I have a Gyro SE MkII with a SME 309 tonearm (purchased 12/2009) and was finding that in order to get the platter level I was having to raise the spring opposite the motor considerably higher than the other two suspension springs. The spring ends up being elongated more than the other two and this affects the “bounce”; that is, I was unable to get a perpendicular bounce because the one spring, because it’s elongated more, does not have the same springiness.
I thought maybe it’s because the one spring had lost some elasticity over time so I ordered a set of replacement springs. Today I replaced the springs but the problem is still there. The one spring suspension “nut” (nylon insert that seats into top of spring) is about 3.5mm higher on the post than the other two in order to level the platter. So the problem wasn’t the spring. Rather, it seems like the weighting of the chassis isn’t correct; as though the wrong weights were used in the chassis, especially the weight located at the motor opening. The problem is present when 1) only the chassis is in place, and 2) the platter is in place; the problem worsens when the platter is installed. This is both discouraging and irritating, since I paid $139 USD for the replacement springs and the problem is still there.
Some background:
- I ordered the turntable with a SME arm adapter plate and assume that I received the correct plate with the correct weight for the SME 309.
- The acrylic “plinth” was leveled prior to installing the suspension towers, chassis, and platter.
- I was careful inserting the nylon inserts into the springs, making sure I did not stretch the springs.
- I checked that all the suspension tower thrust balls were in place in and in the correct position.
- I checked that the white spacers were in the correct position and the spring assemblies were correctly seated into the chassis.
- I kept the suspension towers at their lowest settings for the initial installation, only raising the one suspension spring to level the platter.
- I tried rotating the spring assemblies to different positions but the spring opposite the motor opening is still the one that is more elongated.
My impression is that the weighting of the chassis is incorrect, rather than the adapter plate or spring being at fault. It’s based on my observation that the two suspension springs located on either side of the motor opening are extended fairly evenly and the spring opposite the opening is over-extended, indicating that the weight located at the motor opening is not heavy enough. It appears that additional chassis weight is needed under the motor opening ring to correctly balance out the weight of the tonearm and weight at the front of the chassis.
Anyone else experience this problem? Thoughts? Suggestions?
Regards,
Tom
PS: I contacted Artech Electronics (US Distributor) and Michell Engineering to see what they say and will post their response when they get back to me.