idahodewitt Posted November 24, 2009 Share Posted November 24, 2009 Anyone here know how to set the DC offset and bias on a B&K EX442? I need to know which pot is used to adjust the DC and which is the bias pot and the proper setting and procedure for setting the bias. Yeah, that's alot to ask, but I'm having trouble finding any info on the web so I thought I'd give this forum a try. I found that my DC offset is way out of spec (around -200mv, both channels) and figured it would be best to check the bias while I'm at it and adjust if necessary. I know this forum is mainly for speakers, but I thought I'd try. Thanks. Quote Link to comment Share on other sites More sharing options...
djk Posted November 24, 2009 Share Posted November 24, 2009 You already read my response to you in AA. "The top pot is bias. Unless there are four fuses near the power supply, you are going to have to pull the red wire at the bottom and wire your ammeter in series. If there are fuses, pull one and wire in your meter. Let it warm up for about 30 minutes, then adjust DC to 0V, bias to about 450mA. Then do it for the other channel. " Do you expect a different answer? You came back with: "Which pot is used to set the bias and which is for the DC offset? " What part of "The top pot is bias." don't you understand? If you can't figure out that the only one that is not the top pot, must be the DC off-set, then you have NO BUSINESS being inside this piece. Quote Link to comment Share on other sites More sharing options...
idahodewitt Posted November 25, 2009 Author Share Posted November 25, 2009 djk, Yes, I read your response, but I missed the short sentence "The top pot is bias", at the top of your reply to my question. If I had seen that then I would have totally understood all that you had said. I wouldn't still be asking the question if I'd seen that you'd already answered it. Too early, not enough coffee, and glasses in the bedroom don't make for a productive morning. Thank you so much for the information and putting up with the mistakes some of us ocasionally make. Quote Link to comment Share on other sites More sharing options...
JohnA Posted November 26, 2009 Share Posted November 26, 2009 Why don't you call B&K and get a service manual? Quote Link to comment Share on other sites More sharing options...
idahodewitt Posted November 26, 2009 Author Share Posted November 26, 2009 I called B&K and they will not sell a service manual to anyone who is not an electronics repair shop due to possible litigation (if I were to hurt myself while adjusting the amp). Sounds totally lame to me, but that's where the skewed legal system has gone......thanks to greedy lawyers and judges with an agenda. Larry Quote Link to comment Share on other sites More sharing options...
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