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Lenco P77 tonearm restoration

Just over a year ago I managed to get my hands on an a rare and iconic piece of Lenco history, the P77 tonearm. Fortunately the arm was in excellent cosmetic condition and was only missing the anti-skating weight. However, when I tried to setup the tonearm I had a lot of trouble getting the arm to float. The vertical movement was not as smooth as it should have been, and on closer examination it turned out the vertical bearings in one side of the arm were missing. In their place were a couple of small brass disks, and a lot of grease. The solution to the problem was to replace the bearings in both sides with ball reaces.

P77 with ball races

This solved the problem and the arm now be balanced perfectly and, once setup, worked wonderfully.

This quickly became my main tonearm, and proved a perfect match for the Denon DL-103 cartridge. So, a few months after replacing the vertical bearing I decided that the arm would probably benefit from a complete restoration. One particular item that needed attention was the arm lift damping which was almost non-existent.

The arm pillar and housing was completely disassembled, removing the horizontal bearing races and spacers. The lift mechanism with damper and piston was removed, and all parts were inspected for wear or damage.

P77 breakdown

Despite being 40+ years old, close inspection of the parts showed no damage and very little wear. All parts were cleaned to remove the old lubricant and accumulated dirt using a good solvent. The ball races were given a good oil bath, after which they ran as smooth as the day they left the factory.

Next up was the tonearm lift and damping mechanism. In all the P77 arms I have come across the damping in the lift mechanism has been non-existent. The damping in this arm is provided by the brass block with the see-saw lever mechanism on the botttom right of the following photo. This is a sealed unit and, although it provide some damping, was no longer adding sufficient resistance to counter the weight of the arm when lowered. The solution was to use a ´sticky´ grease on the plunger shaft, and to reduce the spring tension on the assembly to a minimum.

damping assembly The re-assembled pillar assembly turned out to be much smoother running, and the tonearm lift now provided the necessary damping to allow the stylus to descend gracefully to the record surface.

pillar assembly

The counterweight was given a quick clean to remove the old grease. On inspection I couldn´t see any reason to completely disassemble this. Movement of the geared weights was smooth and there was very little dirt inside. What there was cleaned off easily, along with the old grease, with a little solvent.

counterweight

The arm, once back together, was ´dynamically´ balanced as per the instructions and then setup on a turntable. The difference was quite surprising. I had originally thought that the arm was free moving but the restored version proved just how much an old tonearm can benefit from a good restoration.

One item I didn´t touch on this arm was the wiring. The wiring from the headshell connector to the mini-DIN socket on the pillar shaft can not be removed without permanently damaging the connector. As this is a rare arm, and in good condition I felt that keeping it in original condition was more important then any gains that could be had replacing this wiring. However, it is possible to replace the cabling from the mini-DIN plug to the phono connectors. I haven´t done this with this arm, but may do so in the future. Since this restoration I have had the opportunity to restore two more P77 arms and in both cases have replaced the cabling from the small round circuit board to the phono plugs. Both have used shielded Cardas cable and, having had an opportunity to compare, I think there is an audible improvement.

completed arm

The benefits to be had from carrying out a proper restoration, or refurbishment of the P77 tonearm are well worth the efforts. This is a great high-mass tonearm and a perfect match for the Denon DL-103 cartridge.  I have a number of tonearms mounted on different Lenco turntables but find myself using the turntable with the P77 for most of my vinyl listening. It sounds great and is a joy to use.

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