With the SPL meter lying around after re-calibrating the HT setup I decided to play around with it.
I wanted to see if the speaker channels/outputs from my tube intergrated amp were equal.
First, I placed the SPL meter directly in front of the right speaker at exactly 2 feet away and played pink noise from the CDP. I turned the volume up until the SPL meter showed 70dB.
Next, without changing the volume control of the tube integrated amp, I move the SPL meter directly infront of the left speaker, also at exactly 2 feet away. I noticed that the SPL meter showed 69dB, and sometimes goes down to 68dB.
I tried reversing the speaker cables between left and right speakers, reversed the left and right interconnects, and even reversed the position of the tubes. But all the time I get the same readings from the SPL meter, which shows that the right channel is 1 to 2 dB louder that the left channel.
Based on the things that I have already done, it is neither the speakers nor the output from the CDP that is "unbalanced". It must be the tube amp then.
Is this normal or is there something wrong with the integrated amp?
Which components should I check or do I need to bring the tube integtrated amp for servicing already?