Wayne's BA 2018 linestage

Buy one for every domicile where you might want to troubleshoot misbehaving audio gear. USD 699 , cheaper than a moving coil cartridge.
:rofl:
Mark, which scope are you referring to? I'd like to know what you would deem worthy.

Since I have become accustomed to the matched build, find it hard to listen to the stock sound ideal now. It's too harsh and brittle -- by a bunch.
Don't you dare do that to me! My BA2018 is not done yet!!!!!! (on the other hand I can still make changes....eek!)
 
Good news. Problem is solved and this matched, premium board appears to be fixed.
Did two things: removed the resistors surrounding the 4 SMDs and carefully reflowed their legs using special precaution to make sure their continuity was clean and immediate. Then, while resoldering the Rs, noticed there were issues with both Q16 and Q18 -- the legs were not firmly soldered.
Made these changes and have been playing the BA2018 for an hour now and the left channel is staying rock stable in its volume -- soundstage is nicely stable as well.
So, THANKS folks. Those who stressed cold solder joints are the winners but all the help is appreciated.
 
I have problems in my BA2018
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I'd sure like to see your offset lower. That seems a bit high. Mine, for example, is at 0V.

I do see a few things that could be related. The yellow circles are a few sockets that look like they may need to be reheated or have solder added. The best check, of course, it to check the back side of the board. The red circles on Q3 and Q4 look like you might have shorted a few connections. Or it could be just a photo anomaly and those are the existing traces. Let us know!

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Hi. I checked. The power supply is stable +-18 volts. I tested my equipment and the clipping is symmetrical with another preamp. In BA2018 offset goes up to 10 volts DC with sinusoid signal at input!!!
 

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