I have had to guess that you are using the Blaupunkt CDC-RF6 CD changer, so I have perused the installation manual for this device and find no output level adjustment. If this is not your model number, please post it as other models may have features the CDC-RF6 does not. Similarily, if you are using a Blaupunkt changer with a different manufacturer's modulator, this information would be helpful for troubleshooting as well.

To troubleshoot your low output level problem, I would first check for snug signal connections where the changer connects to the modulator, and where the modulator plugs into the back of your stereo. Also take a look at the ground connections to see they are free of corrosion.



If these connections are clean and snug, then I would change the modulator to its secondary frequency and see if that improves your sound level. The switch is located underneath the modulator module.



I hope that helps.