TD145 mkII Motor Noise

Hi all

I recently purchased a Thorens TD-145 mkII which is my first foray into the world of turntables and vinyl. So far I'm enjoying the experience, however I am finding the Thorens a bit of work. I have enjoyed modding so far, although I haven't gone too far with the unit. I have replaced the base with 16mm MDF, replaced the stock feet, replaced the power cable, and added some newer RCA cables.

I am having some humming/buzzing coming through the speakers, and these noises come and go depending on the position of the tonearm and other factors which I couldn't quite nail down so I decided to add an external ground wire as per the service manual. The hum got worst until I eventually found a ground strap attached to the left channel (blue pin) of my Stanton 681eee cartridge. So with this removed, the noise on the TD145 is at a level that I am very happy with.

That is until I turn the motor on. I get a buzz through the left speaker, that is usually faint, but not always. This buzz does get loader as I move the arm to the centre of the deck (or towards the motor in other words). When I tap the cartridge or tone arm it sounds just like tapping a microphone (the noises come through the speakers) - is this normal?

I have the earth running to my Rega A2D phono stage, but I also get the same noises if I run through my Sony ES amp phono stage. I have checked the pins on the cartridge to make sure they are tight, and the stylus is firm on the cartridge. When I remove the wand (I have a TP62) I get a loud hum, not sure if that is normal either.

Any help with this would be greatly appreciated as I have searched the forum and I am now lost!

I inherited my TD 145 and had the same problem and did exactly what you did and still had the hum. It turned out to be the RCA jacks, I simply replaced them with some others. Search around on this site, it's documented as an issue.

Here is my old thread: http://www.audiokarma.org/forums/showthread.php?t=368680

good luck.

milanomike said:

I inherited my TD 145 and had the same problem and did exactly what you did and still had the hum. It turned out to be the RCA jacks, I simply replaced them with some others. Search around on this site, it's documented as an issue.

Here is my old thread: http://www.audiokarma.org/forums/showthread.php?t=368680

good luck.

Click to expand...

Good suggestion, I would suspect cables first. I would recommend replacing them with good quality ones. It is a little fiddly soldering in new leads to the Thorens tonearm. I would recommend either running wire to dedicated rca jacks that you can mount to the back of the plinth, or if you want to keep it simpler attach a barrier strip to the inside of the plinth and run your tonearm leads and new interconnects to it. Will be easier and keep the stock look if that is important to you.

Hopefully you don't have a wiring issue inside your arm, does the noise vary when you move the tonearm back and forth? And yes, hum would be produced when you remove the wand.

Good Luck!

Thanks Mike and Sandstrom for taking the time to help. I have attached RCA jacks to the back of the plinth and I am running a couple of nice rca cables to my phono stage. I am still using the original Thorens wire from board under the tonearm inside the box to the back of the plinth, but this is all hardwired (so no RCA connectors inside). Could this short run of maybe 6" be the issue?

Yes the hum increases as I move the arm towards the motor.

So I still have a slight buzz/static in the left speaker. However, I have found that when I remove the ground wire from the phono stage, it hums (as you would expect), but when I take the end of that ground wire and touch it to the blue pin on the cartridge, I get complete silence. I have removed the little earth tag from the blue pin, however when I reattach it (without reattaching the earth wire to the phono stage) I get the same buzzing in the left speaker. Has anyone got any ideas how I can solve this?

You could try some alligator clip test leads to experiment with connections. Are the motor ground and audio ground segregated?

Thanks cdk99, the audio ground is separate to the motor ground.

Try it to find original cable from some old TT and replace yours. When is buzz the motor - in the begining of use or after few time? May be you needed to oil the axis of bush ( sory for bad english) with light oil from sewing machine.

Best luck.
Vicky

Vicky, the buzz is constant from first switch on in the morning. I have oiled the motor from above with paper clip, and removed base and oiled the bottom.

I'm not sure which cable you are referring to, however I have changed both rca leads, and also replaced the original power cable.

Needed to know why you was changed original cable from TT to amplifier? Not every connection cable is good for TT's. That is why i was tell you to find (if possible) original TT's connection cable (from TT to amplifier) from un old TT. I was have the same problem with one of my TT's and that was my happy solutions. Trust me.
About buzz - check around motor for rubber... The motor must be touch the frame of TT only by rubber. This is just a glue, if you don't it check already.
Can you give me pictures of your motor and all grounds, and also your cartriges and arm pls. Out of your arms you need to see 6 pieses of cable - white, red, blue, green and two dark. I needed to see all grounds. Hard to resolve problems from distance, but you must help me to resolve it.

Best regards from Sofia.
Vicky.

Vi my, I'm travelling interstate at the moment but I will be home tomorrow. I will put some photos up then. Great tip re. the motor. I will be checking that first thing.

here are the photos as promised. I cannot see any rubber on the motor mounts.

O'k, thank you for your pictures and i see that unusualy missing rubber between spring and frame of the motor. Did you have service manual? If not have it, look in vinylengine (http://www.vinylengine.com/library/thorens/td145.shtml) and you can see where to put the rubber.

Next for wiring cables inside - too bad choice for cable's inside TT and very badly soldering... Must change it at all with new cables from old TT exept cable's of arm. All new cable's must be soldering!

Good luck and take me information what you do.
Vicky.

Setting up brand new interconnects on these decks is a must. Eliminates so many potential issues.

I have the manual Vinny, but I am not sure where the reference is to the rubber for the motor. Which wiring are you referring to in my pictures - the tonearm wiring going to the interconnects, or the wiring coming from the motor?

Sance, I have the original interconnect wire running to the plinth, and from there I use Van den hul cabling. Are you suggesting that the short run of original Thorens interconnect from the base of the tonearem to the plinth should also be changed?

So I opened her up again and rerouted some wires, double checked my interconnect mounts against the metal chassis, and then hooked her up again. I still have a buzz, but I notice now that when I grab the metal chassis with both hands, with my feet touching the ground, the hum goes away, and the table is silent. Does this give any clues?

This cable must be grounded into frame on TT.

okay, before that was just sent through one of the rca leads. I assumed it was ground through the screw (indicated as "A") in the service manual and then earthed to the outer chassis through the earth strap pictured. I'll run another earth lead to the the earth strap.

So I have added another earth strap but it has made no difference. I think I am stuck with the buzz

Did you try a different cartridge? Ground problems are one of the toughest to solve. You have to get a multimeter and check every connection from the headshell back. You have to check all wires for continuity. All solder joints and make sure no wires are touching each other. Clean headshell pins and where they connect. I would start by trying a different cart. But don't give up. There is something wrong YOU have to find it.