Velodyne ULD 18 questions / help

I was under the impression the series 1 amps are the same for the series 1 ULD 15 or 18 and same for series 2
Series 1 have the DIN cable between the amp and sub
Series 2 have an RCA connection from the amp to the sub
This third wire is how the amp interacts with the subs servo control
Both series are 400 watt class D amplifiers

The ULD 12 had the built in amplifier with a separate crossover/servo control

I never changed the frequency crossover in the amp. Its a matter of changing a capacitor on the circuit board in side the amplifier. Its not a plug and play change out but a solder job.

I got rid of mine years ago when Velodyne refused to support the product line anymore. Not many techs want to deal with them because of the servo control. A simple re-foam is not going to work like a conventional driver.

The ULD 18 was one of the best subs ever made for music and so many of them are unusable because Velodyne will no longer service them

Too bad

There is a ULD 18 amp for sale on ebay now,
All the best,
Mark

From what I understand the only dif b/w the amps supplied with the ULD 15 and 18 is that they were tweaked differently so as to operate optimally with the respective driver. Mine does work with the 15 amp but it would be nice to have it closer to perfect. For that matter it was said that each amp was individually tweaked to perform best the the specific specimen of each driver it was paired with...don't know how much that mattered though.

The biggest thing for me would probably be the ability to change the xo point. 85Hz is just too high for me. I currently favor my Infinity SSW210 most of the time because I can adjust the xo point to blend more seemlessly with my speakers. I use my system for music. Don't really care about how explosions in movies sound at all.

The one on ebay was a series II -- not compatible with series I unless there is a way to convert the amp to work with series I (hence my question).