Vintage DD turntables. Are we living dangerously?

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

stethoscope. I use my to listen to my neighbours. She is
unbelievable beautiful and I am waiting to 'hear' any mistake he may make.

Ahh Nicola......what would we do without you? :^)
Yes Lew.....stethoscope is good for finding 'nodes' on a shelf however we have to be careful how we interpret these as.....on a wall-hung shelf....the only way to find these are by dynamic loading.......ie tapping.
There is....as far as I know.....no direct correlation between this and air-borne sound transmission?
The TT-101 (like all Japanese-only products) is designed to run on 100 volts.....not 110v as you have in USA. Could that be the cause of Gary's hum?
I have a 240v to 100v step-down transformer between the GPO and the TT-101.