Nakamichi Pa-7 Nakamichi CA-5 Noise Problem Input

I sold my old Nak CA7A to my bro in law and hooked it up for him in his system with a dvd and cable being fed into the preamp's inputs which are all connected to the TV as well. At first, I used a Mapleshade powercord feeding the Nak, and there is a nasty hum as a result. I switched to a Virtual Dynamics P3, and the problem went away.

My first thought is the Nakamichi pre-amp and amp in question are analog units. I don't think they accept a "coax" digital signal.

Also I don't think feeding them anything but a "Line Source Signal will work. Meaning no amplification of the signal before it enters the Naks.

Hope this helps.

Brad

You may be having a ground-loop caused by your cable. You can get an isolation transformer for it for a few bucks ($5 or $10) that will isolate the cable ground from the system but let the signal get through. Your tv service man can let in on the details.

I too had a similar problem. I floated the ground on the amp
(cheater plug) and the problem diminished. I also took two 75 to 300ohm transformers and connect to 300ohm sections together. that'll give you two 75 ohm f connectors to patch into your cable feed. This solved my problem. BTW this is a poor mans Magic Box & it works just as well & saves you $90.
Hope this helps.

Tim