I’m working on a TD-115 that belongs to friend Richard. It was pretty hammered, looked like it had been living in a shed for years. I’ve stripped it down, cleaned every contact, lubricated everything that moves and tested most of the components on the circuit boards. It’s strangely constructed, I read it described as being ‘high tech done cheap’. I don’t think it’s highly rated among Thorens enthusiasts, but I’ll finish it and get it running – why not?
The foam in the suspension ‘pods’ had rotted away, well, crystallised would be a better description. I cleaned it all out and looked for new foam inserts on ebay, but there were none that I could find. I made some today – I marked out circles on a piece of quite thick foam – my friend Mike had thought thicker (and denser) was better, and any foam was better than no foam – and cut it using a foam cutter I constructed from plywood, nichrome wire and hot-melt glue. I powered it with my DC supply – 1.2A, 2.8V produced about 100 degrees according to my multimeter’s thermocouple. Cut the foam into discs, made holes in the centres with a craft knife and reassembled the pods. Seems OK!
Here are some pictures of the shemozzle. As I’ve said about other projects, if I can do it, you can!
Today I realised, while trying to cut replacement temple pads for my Koss TNT/77 headphones, that the wire needs to be under tension to make an even cut, so I rigged up a clothes peg spring to provide same. It’s probably unnecessarily complicated, but I feel quite proud…here are some pics:
Also added banana plugs to make hooking it up to the power supply easier. It sounds like a koto or banjo if you pluck the string!
So the next thing I did wrong…broke the bobbles off the ends of the stupid plastic speed selector linkage rods. I really don’t get the way they’ve designed this thing! I reconstructed them with JB Weld, plastic tubes from Q-tips and new bobbles from an old style of cable tie that I’d saved. I didn’t expect it to work, but it did! You can see the linkages in the picture below. Friend Mike used to work at the Thorens importer years ago and said the linkages were a popular part – “Technicians were always breaking them”. Glad it’s not just me…I suppose I should have bought replacements from ebay, and I looked, but the only two listings which contained the parts didn’t have all the linkages, had a lot of other parts I didn’t need and would have been reasonably expensive, so I just made some new ones up. Tsk.
I’m on the final stretch with this, but it’s a long stretch: today I spent two hours or so reassembling it. I realised there are adjuster pieces on the ends of each suspension pod, so levelled them and took the opportunity to tighten and Loctite all the nuts in the pods themselves. I got the turntable running, adjusted the speed control pots (the cutouts on the top edge of the platter are for 33rpm, the ones on the bottom edge 45rpm) but there were some grinding noises as the platter revolved. I realised the height of the bearing housing can actually be adjusted – there’s a circular spring-steel washer that sits underneath it, and the three screws holding the housing in place can be adjusted, and the spring tensions the housing against them. I used my Vernier calipers to set them to about 5mm and all the grinding stopped. I’ll Loctite the screws in place. The arm lifter doesn’t work properly, but I found that if I lifted the arm and swung it inboard of the label edge, the platter stopped. The service manual has instructions for setting the auto-stop so I’ll follow them – tomorrow!
Auto-stop set: I just undid the securing screw and moved the shutter until the arm lifted at the appropriate point in the lead-out groove. THEN…I tested continuity from the audio plugs to the cartridge pins: none in the right channel. I isolated the problem to the connector the arm wand plugs into. Oh, great: I’ll have to remove the tonearm to access it! I just unscrewed the cups the arm pivots up and down in, then removed the top cup in which the arm pivots laterally. I unsoldered the tonearm wires from the terminal board under the arm and removed the tonearm base. A screw held the shaft in place, I removed it, removed the shaft then tapped the connector out with a small drift. I soldered new wires to the connector pins, heatshrunk each connection and reassembled the connector. I’m not making this very clear, but you’ll see what I mean from the photo.
Each pin has a small spring around it so when the arm wand is installed, the pin retracts and is held against the contact pad in the wand by spring tension. Soldering wires to the pins (they had originally been crimped) heated the pins (even though I clamped them in an alligator clip as a heat shunt), must have melted the plastic slightly and made the pins move less freely in their holes. I tried freeing them up with contact cleaner and tweezers, but with limited success. However, when I reassembled the arm there was continuity all the way from the cartridge to the ends of the tonearm wires, phew!
So, on the home stretch (I know I’ve said this before!) – acrylic cement arrived, I glued the crack in the dustcover and fitted a small aluminium plate at the rear of the cover to reinforce the repair. Did some more polishing and waxed the plinth. I found that the arm wasn’t lifting very high at the end of the side, so I shortened and reformed the spring responsible for that. Had to have another go at setting the auto-stop shutter, but finally everything is working as it should. I’ll listen to a record tomorrow, take some photos and list it. I think this has taken me about a month, off and on. Quite a project!
Abiding impressions of this turntable: ambitious, convoluted design which has been cheaply realised. Takes an absolute age to set everything up. I doubt that this could hold its own against any of the Japanese turntables of the same era and price point. Why didn’t Thorens stick to making high-end ‘tables? Actually, I take that back – the TD-280 is an underrated deck. Very simple, well-executed. THAT’S the one to buy if you’re on a budget and absolutely must have a Thorens (IMHO).