Jerry's TV
Active Member
Hi all - I picked up an original condition 800 receiver. The inside looks to be very original, un-touched. It sounds great. I'm trying to decide if i should leave it alone and just enjoy it or if i should restore. I don't want to re-start the "repair vs restore" debate here, but i do have a question which might lead me that way.
My question is regarding DC offset measurement. I need to place a resistor dummy load on the speaker terminals to get the DC offset to measure ~ 0mV. When i have my test speakers connected (mid-90's cheap bookshelf speakers) the DC offset will drift to ~+10V and above. I place the 8 ohm resistive load on B speaker channel... the DC offset drops to 0mv. When i switch back to A speakers only, the DC offset will start to slowly drift up (20 min = ~1V ; 2 hours = 10V) .
Both Channels L&R will drift at about the same rate and measures about the same. When it is playing with 10V background voltage it still sounds good, no distortion.
I suspect I am up for changing the coupling capacitors... but thought i'd ask.
thanks
My question is regarding DC offset measurement. I need to place a resistor dummy load on the speaker terminals to get the DC offset to measure ~ 0mV. When i have my test speakers connected (mid-90's cheap bookshelf speakers) the DC offset will drift to ~+10V and above. I place the 8 ohm resistive load on B speaker channel... the DC offset drops to 0mv. When i switch back to A speakers only, the DC offset will start to slowly drift up (20 min = ~1V ; 2 hours = 10V) .
Both Channels L&R will drift at about the same rate and measures about the same. When it is playing with 10V background voltage it still sounds good, no distortion.
I suspect I am up for changing the coupling capacitors... but thought i'd ask.
thanks