I have a vintage Marantz 2252B I used to checked for DC offset at it speaker outputs. Note I have not powered up the receiver for about a month.
The 2252B has two sets of speaker outputs, system 1 & system 2. I have a a pair of speakers connected to #1 so I used #2 for my first testing. system 1 set to off.
multimeter is a Fluke87. Set to dc mv range.
I followed the procedure outline by the guy in my previous post.
Powered up the receiver and allowed it to warm up for 10 minutes.
Initial test results.
L (Left) ch 1.4mv
R (Right) ch 10.5mv
I then checked again after the receiver had been power up for 20 min.
L ch 1.2mv
R ch 9.6mv
After 30 min I checked again.
L ch 1.4mv - 1.5mv
R ch 9.2mv.
All the above measurements were taken without any load connected to the outputs. I had read on one website to get a more accurate measurement a load needed to be connected to the outputs. The guy said to use an 8 ohm resistor.
I don’t have an 8 ohm resistor for a load. I do have the speakers that are connected to speaker system 1.
With the the Marantz you have the choice to power speakers outputs 1 or 2 or both.
(By now the receiver had been powered up for about 25 - 30 min.)
Here are the test results.
L ch without connected load 1.5mv. With load 1.4mv - 1.5mv
R ch without connected load 9.2mv. with load 4.0mv
Not sure how the measurements would be using an 8 ohm resistor connected to the same output terminals as the meter test probes.
.
The 2252B has two sets of speaker outputs, system 1 & system 2. I have a a pair of speakers connected to #1 so I used #2 for my first testing. system 1 set to off.
multimeter is a Fluke87. Set to dc mv range.
I followed the procedure outline by the guy in my previous post.
Powered up the receiver and allowed it to warm up for 10 minutes.
Initial test results.
L (Left) ch 1.4mv
R (Right) ch 10.5mv
I then checked again after the receiver had been power up for 20 min.
L ch 1.2mv
R ch 9.6mv
After 30 min I checked again.
L ch 1.4mv - 1.5mv
R ch 9.2mv.
All the above measurements were taken without any load connected to the outputs. I had read on one website to get a more accurate measurement a load needed to be connected to the outputs. The guy said to use an 8 ohm resistor.
I don’t have an 8 ohm resistor for a load. I do have the speakers that are connected to speaker system 1.
With the the Marantz you have the choice to power speakers outputs 1 or 2 or both.
(By now the receiver had been powered up for about 25 - 30 min.)
Here are the test results.
L ch without connected load 1.5mv. With load 1.4mv - 1.5mv
R ch without connected load 9.2mv. with load 4.0mv
Not sure how the measurements would be using an 8 ohm resistor connected to the same output terminals as the meter test probes.
.