Hey there, I recently got my hands on a defective D6C (rev 2) for a great price and managed to fix most of the problems but I still have a problem where the highs don't sound the way they are supposed to. I have already replaced the mute and EQ switching modules so I'm guessing the problem is a failing capacitor somewhere but I haven't got the slightest idea where to look. Below are examples of how it sounds and how it should sound.
Sounds like flutter to me. Have you measured the W&F figure with WFGUI ? Does the same problem occur when speed tune is turned on (PLL disconnected) ?
Hello and welcome to Stereo2go. @Valentin has beaten me to it. I think the problem is flutter (fast variation in speed) as well. I suggest checking to see if the flutter is still present if the Speed Tune is turned on. If the flutter goes away with the speed tune switched on then the problem may be that RV601 needs adjusting.
