Hum question

analog97 · « **on:** 4 Feb 2006, 01:58 am »

I have learned just how exquisitely sensitive all phono stages are to hum. I just learned another lesson that is baffling. Why do I have less hum when I switch the Cornet2 to mono? I just did this 10 times, each trial unmistakeably unambiguous. Any ideas? I still have hum in my analog front-end. I do not think it is the Cornet2 simply because I have had this hum with each phono stage I've had. Don't get me wrong. The Cornet2 is heads, shoulders and logs (i.e. exponents) better than my previous phono stages, but SACD on my system is SOOOOOOO quiet and humless, I want to achieve that. Help sought.....

PatOMalley · « **Reply #1 on:** 4 Feb 2006, 05:36 pm »

what kind of table, arm, cartridge?
how do you have your equipment sitting. is the phono pre close to the table's motor or is it sitting on top of a tube preamplifier.

it could also be a bad ground from table.

analog97 · « **Reply #2 on:** 4 Feb 2006, 05:44 pm »

Rega P3-2000, Rega RB300, Denon 103 low-output MC, Denon transormer.

hagtech · « **Reply #3 on:** 4 Feb 2006, 06:42 pm »

The mono switch ties the inputs together resulting in a loading of 23k. If hum changes, then it indicates the pickup is with the cart or wiring. I would guess magnetic. So look for magnetic field coupling from a power transformer or motor.

jh