I've mentioned a couple of times that an old friend of mine had troubles with his Linn Axis and has replaced it with a Linn LP12 Majik. He bought the Axis new in 1988 (according to the inspector sticker on the PCB, when I had it apart). His usual high-end stereo shop "couldn't" repair it (read: they knew he'd buy a new one if they "couldn't"). So, he gave it to me, using the Friends On Vacation delivery technique to get it from Texas to Virginia. I picked it up yesterday (and had a lovely afternoon with said friends).
I had already investigated the possible causes of the problems he was having--the motor control board would not maintain the correct speed--and had prepared by buying a bag full of replacement capacitors, etc. So, yesterday evening, I worked on it. After testing and confirming that the speeds were variable and very slow, and that it was unrelated to the belt, which was not slipping at all, I pulled the PCB and replaced all the electrolytic capacitors on the board.
One key design fault of the Axis was that the control board is always powered, and for no particular reason. But because the power supply is doing quite a bit of regulating, it gets hot and those caps just sit there and bake. A whole swathe of the PCB was darkened from heat. Solution: Put the turntable on a freaking power switch, fer cryin' out loud. I'll plug mine into the switched outlet on the back of the Holman Preamp.
Two of the larger bulk capacitors were toast--one was open and the other showed about 20% rated capacitance plus ESR about ten times higher than it should have been. Of the 8 or so smaller electrolytics, half were well out of spec. Only one did not show elevated ESR. So, unlike a lot of prophylactic capacitor replacements that accomplish little, these really did need replacing. The reinstalled control board now works perfectly, though I may still tweak the speed slightly.
The turntable came with a Basik Plus tonearm, which was an improved version of the original Basik. The improvements included a fixed head shell, better bearings, and (apparently) a higher price tag. When he bought the turntable, he bought a K9 cartridge to go with it, which was a rebadged and reportedly hot-rodded Audio Technica AT95. But he must have replaced the cartridge at some point--it now sports an Adikt, which is apparently a rebadged improved (?) Goldring 1000-series.
So, is this an improvement over my restored Thorens TD166II? Probably, but it was a lot easier to manufacture. The Thorens has a fixed top plate with a floating steel sub-chassis that houses the main platter bearing and the tonearm and is suspended on three steel springs. The motor is mounted to the plinth, and is a 16VAC synchronous motor that derives its speed from service power frequency. It uses a derailleur to change the belt on a stepped motor pulley to change speeds. The cueing it built into the plinth with a bowden cable to the lift. The Axis mounted the platter bearing and the tonearm on the main top plate, which is suspended separately from the plinth using three elastomeric shock mounts which also serve as the feet. I think it's probably a toss-up as to which would be the more effective, and probably the floating spring suspension is better in come cases and not as good in others. But the Axis is most assuredly suspended. The motor is mounted on the motor control board which is fastened to the bottom floor of the plinth. The top plate is a thick piece of some heavy composite material, so there's no separate steel sub-chassis as with the Thorens.
Where the Axis is much more sophisticated than the Thorens is in motor control. The Axis starts the platter with high voltage and once speed stabilizes it drops the motor voltage down to just enough to keep it idling at speed. This means the motor is putting out much less EM field when running. This was the forerunner, supposedly, of the Lingo power supply for the LP12. The problem was that the control board kept dropping the voltage too much and the platter was repeatedly stalling. It was
not the bearing, which is smooth as glass (and which is the same bearing as was used by the LP12 Sondek).
(Pics on the bench, and before I finished wiping old dust off of it.)
And, as a bonus, my friend also sent me the turntable he had before the Linn Axis, a Yamaha YP-D6 which is direct-drive and seems to work. I need to service the auto-return mechanism which is, I'm sure, glued together with gummy old grease. Once back in a state of good repair, it will be finding a new home.
Rick "too many turntables" Denney
orangessentials.com
