[bcwang]

I've got an XP7 which is very unbalanced at the very beginning of the volume control. Probably the first mm or 2 of rotation. There is absolutely no sound on the right at first and then it quickly catches up to be even with the left side.

Now, as I use more sensitive headphones and play at lower volumes, this is becoming more of an issue since the volume needed to get it to be even is higher than I'd like to listen to sometimes.

Is this a general characteristic that cannot be fixed, or a defective amp that should get repaired? The amp was like this when I first bought it but I didn't care too much at the time as I listened louder, but not it is a nuisance.

 

[recstar24]

Most traditional volume pots have that characteristic at the lowest volume setting, where the channels are not quite matched. This is typically not an issue with most full sized cans because most listeners need to bring up the volume to anywhere between 9-12, like the Grados and Senns. The mismatching of volume pots becomes an issue to listeners who use very sensitive cans like IEM's or who listen at very low volumes. Another issue is that if the gain is too high for the sensitivity of your cans, it restricts your volume pot setting very low, which is right at the spot where the pot is unmatched. Most amps that use traditional volume pots, even the really good ones, will have this issue, but some pots are better matched between channels at the low volumes than others.

You can try and ask Ray to see if he will mod the amp to have a lower gain, which will allow you to use the volume pot at a higher setting, thus making the channels more matched. Its an easy mod that requires changing the feedback resistor on the opamp, but will require shipping and time. That is why a lot of the portable amps nowadays have gain switches, that allow the user to switch to a lower gain for their IEM's, or a higher gain for their senns, grados, beyers, etc.

 

[hon]

It's a general issue for carbon pots.

If you don't want to tweak the gain or have it shipped to Ray. You may try adding a serial resistor to your earphone jack to lower the sensitivity of your earphones. I found etymotic P-S adaptor particularly useful for such case.

 

[bcwang]

Funny thing, I'm usually using them with Grado RS1s and I think it's louder than I like for long extended listening once the volume matches up. In fact, if I listen at 9 o'clock, it is way too loud other than to listen to for a short demo. The only reason I'm concerned is fear of hearing damage because I listen to headphones all day long at work and afterwards at home as well. If anything below 9 oclock is safe levels for any music on the RS1, then maybe I shouldn't worry so much. But it sure doesn't feel safe from the amount of sound it feels like.

I had another XP7 before Ray replaced it with this one. I could have sworn the other one matched up much better such that I didn't even notice it being unbalanced. Could a luck of the draw of the particular volume pot make a difference?

 

[hon]

Quote:

Originally Posted by bcwang /img/forum/go_quote.gif I had another XP7 before Ray replaced it with this one. I could have sworn the other one matched up much better such that I didn't even notice it being unbalanced. Could a luck of the draw of the particular volume pot make a difference?

It could be, some pots are better matched than others even if they are of the same model and in the same lot.