[jakepro]

Newbie to DIY audio and this site.  I have just completed a Pass audio B1 preamp.  The unit powers up and plays, but one channel plays louder than the other and I am getting a lot of speaker movement in that same channel.  All sounds well otherwise.  Any suggestions to what might be the cause?

[Phil A]

Welcome to AC! - have you reversed the channels on the preamp/amp?

[brooklyn]

[jakepro]

Thanx for the fast response.  I don't think anything is reversed. I even tried reversing inputs, outputs, and speaker leads, the results are always the same.

[Freo-1]

You need to get a multi meter and compare the voltages between the good and bad channel.  A cold solder joint, or a misplaced wire often is the cause of these types of problems.  Once you see where the voltage readings take you, may need to check out components such as resistors to see if they are in tolerance or not.

One other thing you could do:  Log onto the DIY Audio website,  Pass section, and post your issues.  Papa Pass is really good about supporting the DIY community.  He helped me with a bias problem I had with a old Threshold power amp.

[I.Greyhound Fan]

Agree with the previous poster, check the DIY forum

http://www.diyaudio.com/forums/pass-labs/181552-b1-preamp-build-thread-27.html


Also, did you check all the values of your resistors before installing them?  Did you damage one by getting it too hot when soldering?  You may also want to check the Caps.  I am no expert though. 

Also, is the volume pot bad?  I built one and the Blue Alps pot was bad and had to replace it.