Balance leaning more towards the left. [resolved]

[jlizaso]

Hi,

Just finished the Moreplay Pre and all Resistance and voltage completed with expected result. Fire it up and sound good except that the Stereo balance leans stronger to the left, like I have to put the balance a bit more to the 2 o'clock position to get imaging centered.

I tried changing tubes but still the left side is louder than the right.

Please help.

 

[Paul Joppa]

The first stage is to make sure the problem is in fact in the Moreplay. I assume that changing tubes means you swapped left/right the stock tubes? If so, then we know it's not the tubes  It is easy and helpful to also swap the inputs left/right, and then swap the outputs left/right, to be sure it's not anything external.

The next steps would be to trace the signal by inserting a known constant signal voltage at the inputs and measuring the  AC voltage level at the balance control and level control. PB usually suggests getting an app or website on your smartphone/tablet or whatever you have that is battery powered (to minimize grounding issues) using a headphone to RCA adapter cable. (He may have  other/better ideas though!)

 

[jlizaso]

Yes, I have swapped the stock tubes and it wasn't the tubes, I tried swapping the input and its the same, so is not the source, but when I swap the output the problem swaps to the right channel.

 

[jlizaso]

I tried measuring the AC from the output RCA and the right measures lower voltage then the left channel, a difference of about 20 volts (ex. right channel measures 30.7 and the left is 51.2)

 

[AB2KH]

Hello,
cheque your balance pot to make shure that it is a LINEAR 100K and not a LOG 100K . Should be marked 100KB. Please read - (Moreplay/Ballance pot)  (on page 2) AB2KH. Hope this helps!
If you have a analog meter you can measure the tracking,it will be quite obvious which one you have.

Chris/AB2KH

 

[jlizaso]

Hello,
cheque your balance pot to make shure that it is a LINEAR 100K and not a LOG 100K . Should be marked 100KB. Please read - (Moreplay/Ballance pot)  (on page 2) AB2KH. Hope this helps!
If you have a analog meter you can measure the tracking,it will be quite obvious which one you have.

Chris/AB2KH

Thanks a lot! That was my bad, I mistakenly used the B100K as the Volume pot and the A10K as the Balance pot. I swapped and it now plays with good imaging, punch and detail.

Again thanks!