Looking for Technical help with Scan Tech (Spectral) Cartridge



I am hoping someone can help with an unusual problem that I am having with a Spectral LOMC Cartridge.

Last night as I was putting an album on and I was attaching the metal clamp to the center spindle a loud buzzing came from the left channel. It was the same kind of buzzing you get when the ground lead is not attached. The buzzing started the moment the metal clamp touched the center spindle. The right channel is ok and has no buzzing.

To make sure it wasn't the amplifier or SUT I used my other TT with no problems.

To make sure it wasn't the table i disconnected the headshell wires and attached them to another cart and had no problems.

My conclusion last night was I had fried my beloved Spectral cart with a blast of static electricity.

This morning I switched everything back on and there was no buzzing. I then played a quick track with no problem.

After returning the arm to the tonearm rest the buzzing came back but when I placed the arm back on the record it went away and played fine. When I then returned the tonearm back to the rest there was no buzzing.

I now have this intermittent buzzing that doesn't occur when playing but may or may not occur if I slightly touch the cantilever but doesn't occur when it is playing.

I should add that there is no sound degradation when playing.

All of this is very puzzling and it would great to know what I have done.

Any advice will be most welcome.

Thanks

Regards

Adrian






ateal
This erratic performance suggests some sort of problem with the pickup arm wiring. What kind or arm are you using? How is the pickup arm wiring terminated?
Hi Cleeds, the tonearm is a one year old Audiomods Series 5, so I am not sure that could be the problem. 

The buzzing started the exact moment my record clamp touched the center spindle. This is why I think it may be static related. 

The turntable is an oracle delphi. 

I used the turntable last night and the only time I got a buzzing was when I cleaned the cantilever with a brush. To stop the buzzing I simply put the needle into the groove and started playing. It also stopped buzzing when I brushed the cantilever in a certain way. 

My question now is....,.., is there a ground wire in the cartridge that may have been compromised. 

Adrian: There are four internal leads inside the MCR - left hot, left cold, right hot, right cold, and they correspond to the four output pins at the rear of the cartridge. Electrostatic grounding of the cantilever is accomplished by the act of using metal screws to mount the metal cartridge body to the tonearm.

I am also inclined to think that the problem is more likely to be the tonearm rather than cartridge. If the internal coil leads of the MCR were touching ground, chances are high you wouldn't have any output.

Nonetheless, if by swapping cartridges you can make the problem completely disappear and are confident that the MCR is the cause, you are welcome to send me a message through the forum.
Thanks very much jcarr, this is great info. I am out of town for the evening but will definitely send you a message and probably a short video demonstrating the issue as it is quite puzzling. 

The fortunate thing is that it still plays amazing when the buzz is not there. But how long this lasts I don't know. 

Thanks again 




Hi jcarr, I double checked with another cartridge and there appeared to be no problem. It only seems to occur with the spectral. 

I posted a short short video to see what happens when I simply either brush the cantilever or place the needle on the record. 

Hoping it helps to diagnose the problem as I really love this cart. 

The strange thing is the problem never occurs during play. Although the run out grooves can sometimes trigger the buzzing. 

Here is a link to the video. 

https://vimeo.com/257992356


I should probably reiterate that this buzzing started the instant the aluminum record clamp touched the center spindle, when I was changing the record over.