Ami B hum

Hi Group (especially Ron and Rob) - I have an AMI B that's drving me nuts. There's a low hum only when a record is playing. As soon as the needle lifts off it stops. I've moved the ground wire to several spots and even removed it. That didn't work. I've replaced the 6L6 and 5U4 tubes. Still hums. I've just ordered a pair of 6N7 tubes. Will the 6N7's eliminate the hum? Any advice?

Do you think that there may be some form of rumble being picked up from the turntable or motor?

You say that the hum goes if the needle is removed. I would check the cable from the cartridge for any shorts etc and maybe try an input into the ampfifier from another source as a quick test.

I may be barking up the wrong tree because I have never worked on this mechanism.

Regards
Alan

Alan Hood
ami-man
UK

Hi Alan - Never thought about that. Good idea. I'll give it a shot. Thanks.

Guy's,
It would be my guess that it is related to the tone arm -- either its picking up "rumble" from the motor( check motor supports!), or the tone arm needs grounding/"un-grounding"--- ("earthing" to you Alan) Ron Rich

Hi Ron - I moved the ground wire to different spots on the box to ground and then completely removed it. No difference. I'm beginning to think Alan may be right. There isn't much else it can be.

I think so also---did you dis-connect the tone arm wire at the amp--
If no hum then--it's picking up rumble from the TT--Did you check the motor mounts ? Ron Rich

I bought the B from Freddy Bailey who restored it. It just ocurred to me that there's a dime stuck in between the cartridge and the tone arm (I'm assuming for added weight). Could this be the culprit?

Eurika!! It's the wire from the cart to the amp. I took the dime out and it still hummed. I just touched the wire and the hum stopped. YEA!

Funny-don't understand why you mentioned it, but I was just thinking of Freddy--have you seen/heard from him lately ?
Ron Rich

Hi Ron,

I used to buy video games off of Freddy in the early 80's when he had a company called Gameworld in the UK.

Regards
Alan

Alan Hood
ami-man
UK

Haven't heard or seen anything of Freddy for several years. He took down his website and I can't find any information. Don't think he went back to England.

Last I heard, he was in England--maybe 2-3 years ago--my memory does not work too well, on "past time"--
Ron Rich

Hi Guy's

The last time I saw any information for Freddie: he was still on your side of the pond, orhe was in June of this year.

Regards
Alan

Alan Hood
ami-man
UK

SON OF AMI B HUM - Still have the annoying hum. The tonearm wire has no breaks, all the tubes have been replaced, and the ground wire doesn't seem to make a difference. I contacted Denny at Victory Glass and he suggested switching the leads off of the cartridge which I did with no results. I'm going to order motor grommets and hope that the problem is solved. Other than that I don't know what else to do.