Vintage DD turntables. Are we living dangerously?

Halcro,
I'm glad to hear that someone else is crazy enough to buy a stethescope and go looking for trouble. I hadn't thought of it but you are right that the tech should have noticed that the transformer is humming.
The motor now is beautifully silent, and I tried with and without the ground wire attached to the phono pre-amp but no difference.
Today I am going to see if I can rubber mount the transformer. I might need to replace it. But if there is a way to power it via an umbilical cord that would be best. There is a good write up of this at the KAB turntable site and I sent an email to Kevin asking if he could do it.
Gary

A vibratory hum from the transformer is nothing to worry about, as long as it does not intrude on the listening experience. If you had an amplified hum coming thru the speakers, that is another story, but don't worry about the local mechanical hum. Why yours hums and Henry's does not is possibly only a function of the voltage and/or frequency of the current coming from your wall socket vs Henry's. (Don't know the voltage/frequency in Australia.)

Henry, are you using that stethoscope to identify nodes in your shelf? As a doctor, of course I was born with a stethoscope around my neck, and even though I never use one in my chosen field, I have always owned one or two.

It may be the case that you both wanted as kids to become
Doctor. To compensate you invented this excuse to buy an
stethoscope. I use my to listen to my neighbours. She is
unbelievable beautiful and I am waiting to 'hear' any mistake he may make.

Regards,

Lewm, my thinking is that the vibrating transformer adds to the general hash of noise we live in and that the stylus needs to decode. So, even though I don't hear it specifically, it can't be making things better. Also, the EMF generated by the transformer may be effecting various electronics including the cartridge and again, none for the better.
Gary

As this is a vibration / distortion hobby using a stethescope makes alot of sense to me. Yelling at your cartridge to see if direct sound pressure affects it - now that borders on questionable.

Lew /Gary /Henry – what brand of scope would you recommend. I figure I can also play doctor with my dog if I get bored. Before you reply Nikola - remember they are mans best friend.

Great info on this thread.

I have a question about an SP10 4 lb copper mat I own. Opinions seem divided over the years on whether these heavy mats do any harm to the DD Servo in the longer term with a SP10 MKII or equivalent other brand. Has anyone had any problems using them ?

I haven't used mine much as I actually like the sound from the stock rubber one. But am wondering ?

Cheers Chris