Turntable Tweak

 

Upgrading a standard record-player by quick and simple means

I don’t play records that often; mainly for nostalgic reasons about once a month I will play some of my record collection. So I don’t have (or need) a very expensive high-end turntable. The turntable I will be modifying in this article is an old Sony PS-LX311 which only cost the equivalent of about €90,- ten or more years ago. Just your standard basic record player that can be found in most 3½-person-house-holds. The total tweak can be done in a few hours; I did this modification while I was waiting for the paint to dry on my equipment-rack. All you will need is a piece of 22mm thick mdf the same size as the base of the player, soft foam tape used for sealing loudspeaker baskets in cabinets and some good old 4mm thick self adhesive lead bitumen.

 

The recipe

First of all remove the bottom of the record player. The bottom of my Sony has a cheap 4mm thin hardboard base. This reveals the inside of the record player. The chassis is made of lightweight injection moulded plastic, the walls and top surface are about 3mm thick and there are some vertical supports that also are used for screwing the base to. Basically a rather flimsy construction. Now cut to size the lead bitumen so that it covers all the injection moulded plastic chassis (be careful that it doesn’t get in the way of the moving parts inside the turntable). Because I didn’t want to remove any parts inside the player I had to cut the bitumen up a bit so it would fit around and under the parts and the wiring. Some large areas got a double layer of bitumen bringing the total thickness to an extra 8mm.

 

  

 

Before and after: On the left the “empty” chassis, on the right the same but covered with lead bitumen sheets.

 

The second part uses the soft foam tape. Detach the mains transformer from the chassis so that can’t transmit its 50Hz vibration via the chassis. Cover the transformer and the bottom of the sheet metal motor support with the foam tape. Later on these will be pressing against the new turntable base, the idea being that the contact via foam will absorb some of the vibrations coming from the transformer and the turntable motor. Don’t screw the transformer back in place, just let it “float” in the foam tape.

 

  

 

Before and after: On the left the bare transformer and motor support, on the right the same but covered with the soft foam tape.

Note also the thick layers of bitumen on the side panels of the chassis.

 

The third and final part is to make a new base using a piece of 22mm thick mdf (one of those leftovers again!). Make the necessary cutouts in the mdf so that it fits over any protruding parts like screw-heads or bolts and drill the holes for so that the base can be screwed back on again. You will need longer screws this time! Glue the mdf base to the original hardboard base. For looks you can paint the base black to match the rest of the record player. I used matt black that makes a nice contrast with the semi gloss finish of the chassis.

Finally mount the feet under the mdf base. The original Sony feet were made from a sort of soft rubber in a plastic case. They absorb vibrations rather well.

 

 

Note the cutouts for the transformer on the left and the motor bolt in the middle.

 

The result

Basically I have done two things here: First of all the mass of the record-player is now about double what is was and secondly the thin vibrating surfaces have been covered with a nice dead material. The sound of the turntable has gone a few steps up the quality ladder. It has lost the cheap quality air it had to it. The result is more definition and clarity in the bass and midrange. Bass has more detail and sounds faster and dryer. The midrange has become more open. The differences are so large that even the untrained ear can easily tell the difference. It hasn’t transformed it into a Transrotor but it isn’t a Sony anymore.

 

 

The finished product. The mdf base can be seen below the original chassis.

 

 

NOTE: This design is strictly for the home DIY enthusiast and not to be used professionally without my permission!

 

Tony Gee

The Netherlands

 

April 2002