Hello,

I have TD 125 MK II set for 50 cycles and plugged into a UPS.

I use a KAB Speed Strobe to verify the speed, and when I do the Thorens strobe does not reflect the results. It drifts to varying degrees, faster or slower.

This is very confusing and frustrating.

I need to use a record weight for some of my records. If I do, I can't use the Speed Strobe. This is because I have to apply the weight with the table off. I'm not sure my table will be running at the right speed after I start i up even if it was correct before I stopped it.

I'm running the table on 220/50 electricity. The strobe is set to 50 and the table is plugged into a UPS. But local electricity fluctuations could be causing the strobe problem, right?

I wish Speed Strobe offered a 4" (label size) strobe for 33 that would fit under the record weight they sell.

Any suggestions?

Instability is often caused by the dirt in, or wear of, the adjustment potentiometer.

Ah, interesting.

I need to figure out how to clean it.

Gritto

What you need is called control/contact cleaner. It is sold in electronuics stores like Radio Shack.

It is a lot more likely that your turntable speed is fluctuating than that the line frequency is fluctuating (unless you live in a third-world country).

I live in Thailand. It is part way between third world and first world.

Short power outages are not uncommon here. That's why I think that cycle fluctuations could be affecting me. I do use an UPS, but I don't think that saves me from cycle changes.

The UPS has no effect at all until there is a power outage. It probably provides surge protection as well, but as long as there is power it just acts as a pass-through.

Well, it's been a while, but I want to update this. My UPS has an AVR, so it at least helps with the fluctuation above and below 220. But not cycles. Has some rewiring done to isolate my outlets from the air conditioner, but I still see fluctuation.

Time to clean it. The documentation I've seen isn't as user friendly as I'd like.

If your frequency is wrong, you should contact your power company. Most suppliers have a specification for the frequency range. If it is wrong, your top option would be an offline UPS (of the battery charger->battery->inverter type), which would completely rebuild the waveform. You would need to get a UPS with a good output waveform, though.

If the nominal frequency is fine, but there is a problem with "dirty power", the best option by far is a ferroresonant power conditioner. These are expensive, heavy devices which work much better than the cheap, small "conditioners" that the likes of Monster cable sell. They aren't cheap new, but I would imaging you wouldn't struggle too much to get a second hand one for a decent price in Thailand.

I've been using a UPS with an AVR for a while. Recently I changed UPS's to one that puts out a sine instead of square wave. It also has a built-in AVR. LED's report when the power source is lower or higher than 220. But I still see speed variations in the table when I test it using a SpeedStrobe.

Cabbagerat, thank you for your ferroresonant power conditioner suggestion. In theory my current UPS is reconditioning the output, but maybe I should run this by a tech at the UPS company. It would be nice if I be sure the table is getting electricity that is not fluctuating.

At this point, I'm clear that I need to get my old table overhauled (hoping the local Thorens rep can still do this kind of thing). If the table is reconditioned so that the strobe, etc., is working at spec, maybe the problem will go away.

But I'm still thinking about the electricity issue. Recently, I've learned that Rega offers a separate power supply that would obviate that.

If the table is just too old, and can't be repaired (parts availability, whatnot). I'll have to consider the Rega P3-24 - but I'm not sure how well it will work with the Grado Gold cartridges I have.

gritto,
Excuse me if what I say is a bit obvious and basic but a couple of things aren't clear to me.

1. How bad is the speed variation? Can you actually hear it or is it just the strobe telling you that it's not stable? If the latter why worry if your ears aren't also telling you something's wrong?

2. Have you done the basics like cleaning the belt's path around the motor spindle and platter? It's easily done with a Q tip and isopropyl alcohol. Or better still clean the metal parts then fit a new belt. You'll be able to get one mail order via the internet.

I have a TD124. I don't think it has much in common with the 125 but it does have a built in strobe (probably of similar design). I find that it needs to run for quite some time before it settles down. When I first got it I was forever fiddling with the speed control. After using it for a while I found that letting it run for 1/2 an hour or so before making any adjustment was better. These days I don't even bother to check as any speed drift seems to be over a long-ish period and I can't actually hear any fluctuation at all and unless you're blessed (cursed?) with perfect pitch or are wanting to play along with a fixed pitch instrument I doubt that you'll notice either.

Hope this helps

botface,

Thanks for your suggestions. I'm ready to have the machine overhauled, as I said. Cleaning the belt path is one thing. The belt is relatively new. Next I have have to find the correct oil for the spindle. Based on research, the strobe part may or may not be beyond my ability at this point, even though I've swapped arms, with all the hassle that entailed. So far, I don't trust the documentation I've read.

So, yes, you have a good point. It could be mechanical and not electrical.

I have let it run for a long time before testing, in between adjustments too. It got to me that I could test after one side and see a noticeable change.

No, I haven't really noticed the speed variations audibly (the heavy platter helps that way). But I'm archiving my records digitally, so I'm trying to get it right this time.