2. analog
  3. 159523-46

Getting him in my ARC PH3se phono pre

I use two isolation transformer to hook up all my equipment. 
One has the phono pre, TT motor (VPI Prime) and the speed controller equipment for the TT - 250w.  The other has the preamp, and amp - 1000w. 
I’m getting a hum when I turn up the volume when listing to audio through the TT. Here are the are the conditions it’s happening under:

1. Phono pre must be on for hum to occur. If turned off hum goes away. Obviously, so must amp and preamp Be turned at the same time to hear the hum. 2. Phono pre on, but TT motor off, hum is present. So no music playing. Btw motor is controlled by Eagle and Roadrunner. 3. Phono tubes are new and in good condition. 4. The Phono unit is an older unit, but when I had it connected to another system in another room I did not have a hum problem. 
Not sure where to go from here. Especially since I’m connected to isolation transformers. 
last_lemming
last_lemming OP
639 posts
 
Ok guys. I’ve been sheltered up for the last day due to Laura - I’m about an hour and a half away Lake Charles. 
I’m very lucky after the last week, puts my problems of humming in perspective for sure. 

I will look into the latest suggestions once I uncover all the equipment and plug everything back in. 
last_lemming OP
639 posts
 
Ok. Update. 
It’s not the TT, cart, stand, motor, and it’s not the phono preamp (since I changed phono pre and it still did it).

i just hooked up a different TT with a different cart set on the concrete floor, and ran it to the same preamp / amp and I’m STILL getting the pumping. 
So it must have something to do with the amp or preamp. 
They are both tube components, so what could be happening here? They are both old in the tooth, but what’s odd is they don’t do it with the CD player, just when the TT.

last_lemming OP
639 posts
 
The directly above post should have gone to my other post. 
Please disregard


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