• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Marantz 1030 chassis voltages

Keith Baran

Keith Baran

Member
I have a Marantz 1030 amp, when I touch the chassis I very a very faint voltage, my meter measures five volts AC with the ground probe of my meter floating. Is this normal? Should I convert it to a three prong plug and ground the chassis? I just recapped the P700 because of an output problem but that didn’t change anything, still have five volts.

Any suggestions would be appreciated

Regards

Keith
 
Register to hide this ad
Keith Baran said:
with the ground probe of my meter floating
Click to expand...
That reading means nothing with the second probe floating. You want to ground the second probe.
Many of the european Marantz I saw have a three prong plug and ground connected to chassis. I added a three prong plug and chassis grounding to a few other amps/receivers, never had an issue, and I'm happy with more safety.
 
Thanks for your input Bert, Oh my, when I ground the other meter probe there is 107.0 volts on the chassis :eek:. So would I be correct if I install a three prong plug and attache the ground wire to the chassis? Is there anything else that could be causing this?
 
All you are feeling/testing is a tiny, high impedance to active via the 2.2M resistor to ground:

1030.JPG

If you rotate your two pin plug in the wall socket, it will disappear, your DMM will read it as 100v+ due to its very high input impedance.
 
Sometimes there is enough dust on the 2.2M Ohm resistor to raise the voltage on the chassis.
With the unit unplugged from the power outlet, try cleaning the resistor with alcohol. When it's dry, test again.

This is how I test for AC leakage on the chassis. A good battery powered DMM will work for the meter. Test with the power plug in both orientations in the wall outlet.
These were built with a 2 wire power cord so that the plug on the receiver/amp and the one on your turntable could be oriented for the least hum.

Tom
AC leakage.jpg
 
Pardon my ignorance, I've searched for R013 and I cannot find it, would you please assist in the location of this resistor.
Thanks
Keith
 
It is usually connected inside between one of the accessory outlets on the rear panel and the chassis. It may be covered in insulated tubing of some sort.

Tom
 
You must log in or register to reply here.
Back
Top Bottom