• 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

left channel 1,9V DC - Marantz 1152 DC

L

Luca6644

New Member
Hello. I got recommended to this forum, I hope someone could me with this problem.

I have the problem that I get up to 1,9V DC on both of my left channels of the 1152 DC. I think the problem existed a good 15 years, I just realized it IS a problem a week ago.


Back then the left channel would occasionally shut down, due to the relay reacting to DC voltage - I think. Turning it off and on again would get rid of the problem so I havent thought much of it. It turned off when the incoming signal was too low.

I already treated the pots and faders with Deoxit D5 and looked for some signs of a problem for 20hours. But I couldn't find anything yet.

What I already checked:

  • Temperature of the final stage transistors (all around 31°C - no abnormalities)
  • The two transistors (with the little coolers) both have similar temperatures (around 50°C)
  • What I did notice: At the power resistors (0.33ohms). One resistor got 15-20°C more then the others.
  • The DC Voltage on the left channel starts at around 0,9V and rises to 1,8V in idle after around 20minutes.
  • I tried the procedure for the DC offset - I am limited by the little resistor and can't get the voltage any lower. The resistors of both sides have the same Ohms.

I hope someone has a tip on what to look for, or what I could measure next to find the cause of the problem.
A solution without a expensive Hifi technician would be highly appreciated by me as a student.

Thanks in advance!
 
Register to hide this ad
You must log in or register to reply here.
Back
Top Bottom