Left channel 1dB louder than the right

[m00dawg]

I spent a couple of hours now trying to figure this one out and I think I'm out of ideas. The left-channel output of my turntable (or phono-amp) seems a tad louder than the right. It's small - about 1-1.5dB if the VU meters are correct. It was around 2-2.5dB off but after adding another rubber mat to increase the height of my platter, adjusting the tone-arm height, switching out the headshell, re-adjusting everything as if it was a new setup, I seem to have improved, but not eliminated the bias.

Is that just a fact of life or does anyone else have any ideas? Oddly enough, the bias seems worse on a mono 7" I have than on stereo records but it's still there no matter. I thought it might be the anti-skate but no setting of that (in spec or otherwise) seems to really affect that much.

The cartridge (a Shure M97xE - my first), is about 9 months old. My DJ cartridge (an M44G) also has the problem, albeit to a lesser degree. Since my M44G is almost brand new, I assume it's not an issue with stylus wear but that's the only thing I can come up with at this point (unless my phono amp is flawed).

Anyone have any thoughts or suggestions?

[aardvarkash10]

I'd put some opaque stickers over the VU meters...

[m00dawg]

I'd put some opaque stickers over the VU meters...

Well it's more for recording. Normally I listen to the real thing but I do like to keep digital copies around just in case and for occasional portability (I still prefer the mastering of vinyl over the brickwalled digital counterparts available). The bias can be fixed in post, but I don't really like to muck with the original sound if there is a fix outside of that.

[Alec124c41]

Is your azimuth good? Put a small mirror on the platter, and look from dead ahead. The mirror will seem to double any error.

Cheers,
Alec

[Conrad Hoffman]

Long ago I had VU meters and obsessed over this. Best solution is to get rid of 'em. Cartridges are often different by 1 dB and unless you go through all your electronics and match the gains, there will be an error there. I doubt any given mix will be balanced, in fact I doubt an average of many mixes will be balanced. As Alec says, check your alignment, but that opaque tape might be the best solution.

[m00dawg]

Is your azimuth good? Put a small mirror on the platter, and look from dead ahead. The mirror will seem to double any error.

Cheers,
Alec

Hmm I'll try that. I had to look-up exactly how to do that but I think I have it now. My table is an SL-1200 which does not have an azimuth adjustment (I thought that was solved by tonearm height, silly me). I assume I'll need a headshell that can be adjusted or I need to get a shim.

Sounds like I'm barking up the ugly tree though according to the other folks on this thread so maybe I should just fix it with panning

[jake]

I went through this imbalance problem one year, turned out to be the speakers. I had them re-built, and now I can sleep at night. Until you get this solved , it will bug you no end.

[m00dawg]

It's generally so small that on a stereo record at least I don't notice it usually. I have ruled out the speakers and phono amps as the source of the bias so it's definitely coming off the table. It sounds like azimuth but I haven't found any good suggestions on how to fix that given my turntable.

[abril]

Very often there is 1db balance error on cartridges anyhow,and given the reputation that the M97 is getting I would not be surprised that it is worse than that from the box new.
The only way to get a real idea of any balance error is with a test disc as normal music recordings often look like that on meters.

[m00dawg]

Indeed! I'm hoping to pick up a test record this weekend if I can. Otherwise I will order one (good things to have anyway). I'm debating on buying a Sumkiko HS-12 headshell but the thing is $90! It's the only headshell I have found that offers and azimuth adjustment, however.

I'm trying to upgrade both my cartridge and phono amp from the M97xE and TCC-750 to a Denon DL-110 and Cambridge Audio 640 but having to add the cost of a $90 means something would have to give there. I don't think the 750 is going to really make the DL-110 shine so I really should upgrade my phono stage. But, on the flip-side, buying a new cartridge that's arguably a step up would be a good time to try and adjust azimuth as best as I can.

*shrug*

[Alec124c41]

There is often enough play in the standard headshell mount, that a bit of inattention can lead to the azimuth being a bit off. Check it first, and see if you can straighten it if it is off, by loosening the collar, straightening it, and retightening while holding the headshell level..

Cheers,
Alec

[keiko5]

Maybe you already checked, but are you sure your meters are calibrated accurately? Most VU and power meters have an adjustment that is used with a calibration signal to balance them. You will need to have a calibration signal generator that sends an equal signal to each channel. My tuner has a built-in calibration signal generator.

You can determine if the problem is with the source (cartridge, the azimuth or cartridge leads) by switching the left and right channel cables at the phono input. If it is source related the VU meters will read 1db louder on the right channel after switching the inputs.

As others have said, I wouldn't fret over it.

[Aural Addict]

From what I understand the smallest db difference that is audible to the human ear is 3... If you are showing less than that, are you sure you aren't having a "placebo" effect from seeing a measurement difference of 1/2 that on a meter?

[Aural Addict]

Indeed! I'm hoping to pick up a test record this weekend if I can. Otherwise I will order one (good things to have anyway). I'm debating on buying a Sumkiko HS-12 headshell but the thing is $90! It's the only headshell I have found that offers and azimuth adjustment, however.

I'm trying to upgrade both my cartridge and phono amp from the M97xE and TCC-750 to a Denon DL-110 and Cambridge Audio 640 but having to add the cost of a $90 means something would have to give there. I don't think the 750 is going to really make the DL-110 shine so I really should upgrade my phono stage. But, on the flip-side, buying a new cartridge that's arguably a step up would be a good time to try and adjust azimuth as best as I can.

*shrug*

Go down to the Cambridge 540p. I sell Cambridge and the only difference on the two is the 640 can do MC....