Velodyne ULD 15 mk II Help with servo amp

Isn't that how they usually sound??? Just kidding :)
Hmmm... I would call Velodyne Service about that and describe the symptoms. They probably can give you some diagnosis over the phone. Whether or not they still do this I don't know - but a few years ago, if you had a Kaput ULD series and they couldn't repair it, they would cut you a very good deal on a new DD series. And I mean VERY VERY good deal - like flat out wholesale - about half or less $$$ of the List Retail.

Thanks folks. I appreciate the input. The amp is working, the volume is beat and the sub sounds very slow and muddy.

If I recall correctly, Velodyne is not servicing these models any longer - though obviously, check that with them - they are a very friendly company. The most common issue with those amps is a blown output transistor. If the amp fuse keeps blowing when you turn the power on - that's very likely the problem. It's a mildly tricky job, but if someone local can test and replace transistors, you don't really need have Velodyne do it. My guess is that Velodyne probably used to just replace the whole circuit board rather than the individual transistor(s), and they may not stock them any longer.

Do not use the woofer without the servo control wire hooked up. The accelerometer on the woofer cone sends info to the amp via that little wire. Sending the amp back to velodyne is your best bet. They often do little upgrades when changes were made mid year on amps. For instance I had two uld 15's purchased many years apart. The volume controls tracked differently, and they matched them up for me when I sent in the earlier model I had. The velodyne factory is very helpful and their customer service is terrific.