How balanced is balanced?

[Sleigo]

I have a Mcintosh c2600 tube pre-amp. I have noticed of late that the output gauges occasionally vary between left and right; is this a feature of the source (ie the record or CD) or is this a problem with my pre-amp? Sorry, newbie question with no tech savvy

 

[kward]

Rig up or purchase a Y adapter and drive both preamp channels from the same source. That will tell you if it is the preamp or the source.

 

[triode17]

If you are monitoring a stereo signal, then the signals will vary from each other on the meters.

 

[Yamaki]

The frequency production is not the same across both channels.

You'll notice the needles "bounce" at varying levels. That represents not only the the volume level of the music in that channel, it also reflects what is being produced at that moment on that channel.

It's called "separation" which provides the distinct sound of each instrument and voice reproduced by the music. Those levels are separate and they vary as the material was mixed to place certain instruments on specific channels during the recording process.

 

[Sleigo]

Thanks. This is what I thought... some confusing info from someone.
It is just variation from the original recording.
Appreciate you.

 

[kward]

Just understand it could be possible there is an issue with the preamp. Driving both channels from a single source would identify that. But yes, apologies for not being clear. stereo signals are not supposed to be identical.

 

[Sleigo]

Thanks kward, if anything looks crazy off I will try your method with a Y

 

[4-2-7]

Thanks kward, if anything looks crazy off I will try your method with a Y

You don't have to go through any cable changes from the source. Both channels should be different as Michael said above in stereo. However if you want to see if both channels operate the same, you have a mono switch on the preamp. If you set that to mono it should show the meters moving the same output at the same time.

 

[frahengeo]

As a sanity check, you can always swap the left and right to see if the lower VU follows. Of course, this assumes that there are particular passages or sections of a song/album where the differences were observed.

 

[crispycircuit]

The Vu meter circuit may have an adjustment & need to be calibrated it self. A repair service manual would have the info.