2. amps-preamps
  3. 184231-172419

Variac noise

Hi all. Not sure if this is the correct place for this question but here goes…

I have a Marantz model 8 from Japan running at 100volts through a variac. The variac hums while under load and it’s (just) loud enough to be annoying. I have a friend who uses the same variac for a similar setup and his is dead silent. Thought it might be a bad variac so I ordered another and set it up and still the same problem, so could it still be the variac? It’s a brand sold through Amazon and quite a few buyers complain about quality control problems with this product. I’ve looked at buying an American made variac but they cost more than $700. Could the amp be causing the variac to hum?


Any thoughts?

ccogopher

Showing 4 responses by ccogopher

ccogopher OP
26 posts
 

The amp is 50-60hz

 

if by “bypass the variac” you mean nothing plugged in to it, then yes, and it’s completely silent.

ccogopher OP
26 posts
 

Also possibly worth noting: when I power it on (amp plugged into it) it produces a very soft acceptable hum, but as the amp warms up over about 20 seconds, the hum starts taking on a buzzing quality.

-sorry, troubleshooting electronics is not something I’m good at…

ccogopher OP
26 posts
 

Not disinterested in your method. I’ve been trying to reach a tech friend who could try your idea. Also looking into a step down transformer as a possibility. 
I really appreciate your input as well as the others. 
thanks!

ccogopher OP
26 posts
 

Ok, I’m very interested by this. I still need to speak with my tech friend about maybe creating one of these for me. You’re right about step down transformer cost. Was eyeing one for $187… it’s huge and ugly as well

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