Dual 1226 hum

[MKG]

Picked up a new to me Dual 1226 today. It’s been about 12 years since I’ve had turntables, and back then I was a wannabe dj so I was more interested in how well it could stay in the groove while I was abusing the hell out of a record. Anyhow, it came with a shure m91ed cart, looked pretty damn dirty so I took it off and hit it with some rubbing alcohol. I’m guessing that was a mistake because now it has a loud hum- the hum changes in volume if I touch the arm, platter, or any other metal bit.
I’m planning on opening it up and cleaning out the old grease and relubing everything (it holds a steady and appropriate speed, yay! But, automatic function doesn’t work- it just raises and lowers the tonearm and thinks it’s job is done), but first I’d like to figure out what’s causing the hum. Is the cartridge shot? Did I kill the stylus by cleaning it with alcohol? Is the ground wire not properly grounding?
Also, if I rotate the tonearm clockwise it comes up and out of its seat, is that normal?

 

[MKG]

Hum is there even if the cartridge is removed.
Hum is there even when turntable is unplugged.
Maybe it’s my preamp?

 

[Tim D]

When you say unplugged do you mean the rca plugs aren’t connected to your amp?

 

[MKG]

When you say unplugged do you mean the rca plugs aren’t connected to your amp?

No, I mean rca & ground wire plugged into phone pre, phone pre plugged into preamp, preamp plugged into amp. Turntable unplugged from wall outlet.

 

[likebike23]

Ground wire connected? If yes, I'd clean up all the connections at the headshell and tonearm. I use a soft pencil eraser to clean the sled contacts and tonearm contacts that the sled mates with. If you are feeling motivated, clean the inside of the cartridge clips with a toothpick soaked with deoxit.

 

[Tim D]

I’d check for bad connections. The rca’s on these tend to be a source of trouble. Also the connections on the sled might give trouble.. Don’t use sandpaper on the contacts though. A pencil eraser or alcohol with gentle cleaning might help. Also try flipping the AC plug. They aren’t polarized.

Do both channels have the problem?

 

[Tim D]

The way you describe the auto function isn’t working hints that it needs a good cleaning, lube and a fresh Steuerpimpel. There is a guy on the bay that sells the grease, instructions and the steuerpimple. That might be the ticket if you are handy. (No affiliation).

 

[Tim D]

I wouldn’t suspect your cart right away. If it was working and you were doing external cleaning it may be ok. Even if you damaged the stylus it probably would not cause the hum.

 

[Tim D]

I wouldn’t twist the tone arm.. No purpose to that and you could put stress on the wires that run inside.

 

[MKG]

Hum wasn’t there before, hum suddenly appeared after I cleaned the stylus.
Tried cleaning the cartridge sled with a q-tip & deoxit. Started with just the right channel and now it’s in both- if I touch or adjust the cart just right it goes away, but once the main hum goes away there’s still a different, lower volume, higher frequency more ear piercing noise. The louder hum does sound very similar to when an rca cable is going bad so I’m leaning in that direction. About to try flipping the plug to see if that makes a difference.

 

[MKG]

Flipped plug, hum still there.

 

[Tim D]

I’ve got a 1226 with an M91ED. It’s a sublime combination. Hope we can get you through this.

BTW, I’m not an expert but I can share what I’ve learned. The real experts may come along and add more and better ideas soon.

 

[MKG]

I’m leaning towards either bad rcas or a bad phono pre, but the hum wasn’t there until I took alcohol to the stylus and removed the cart, so maybe I’m jumping to conclusions.
I looked on eBay for a new Steuerpimpel and found lots of options from China, but none that included directions or grease. Not really an issue as I can get white lithium grease & machine oil from Home Depot and directions are available online.

 

[Tim D]

I’ll check tomorrow to see if he’s still selling his kit. Hmmm

 

[Tim D]

Seems he's only selling the instructions right now. His handle on the big auction site is mrow22. If you are interested you could send him a message on the big auction site.

 

[tedgerto]

he is selling the kit with lube, LARGE pdf, and Steuerpimpel - i just got one last week, PM to mrow22 on ebay, and he sent a paypal invoice. slick option, very appreciative of all the help

 

[Hajidub]

Please do not use alcohol on your stylus, it could affect the glue that bonds the tip. Use a magic erasure.

 

[mhjmhjones]

No, I mean rca & ground wire plugged into phone pre, phone pre plugged into preamp, preamp plugged into amp. Turntable unplugged from wall outlet.

Try unplugging the ground from the phono pre.

 

[mhjmhjones]

Did you recently remove the cartridge sled from the headshell? Could be that the sled isn't connecting with the traces on the PCB on the back of the headshell.

 

[MKG]

Ordered the kit from mrow22. Won’t have time to fiddle with the TT until tomorrow evening when I’ll try removing the ground wire, cleaning the shell contacts, and double checking that it’s properly seated.