New plate amp problems

[winggo]

A number of years ago I built a subwoofer using the Peerless 12" xls long throw woofer with matching passive radiator. I put a kg-5230 300 watt plate amp in that I bought from Madisound. The subwoofer work wonderfully for many years when a couple of weeks ago the amp gave out. I bought a SPA500 amp from Parts Express with 500 watts and installed it last week end. At 75% gain this amp is just audible. At that kind of gain my old amp would have broken windows. I've got a email into Parts Express about the problem but haven't heard back yet. Changing all the setting does not do much for the volume. Am I doing something wrong or is the amp possibly bad?

Any suggestions on how I can test this amp to see if it's bad or not?

Thanks

 

[Brian Steele]

"At 75% gain this amp is just audible"

Maybe the issue is with the source. Try using another source to drive the amp.

 

[zerokelvin99]

Try different source, interconnects, LFE only input, check all rear controls inc. Lowpass

 

[SamAnytime]

From the manual:
1.) Left/Right inputsRCA style jacks that will accept standard line level inputs from a pre-amp level source. They will accept a stereo signal and internally combine it into mono. Both left and right input jacks must be connected to the source in order to drive the amplifier to full output. The use of a “Y” cord is suggested if a mono source is all that is available.

 

[rabbitz]

Had a similar issue with a different brand sub amp and the amp was faulty so was returned. Checked it against a low power Class D amp as a sanity check and that provided heaps of volume.

You don't say the source or whether you are using the Stereo or LFE inputs.

 

[winggo]

Turns out is seems to be a problem with my Jolida inegrated amp variable outputs. I hooked up to the outputs on my head phone amp and got plenty of volume. Looks like I need to get Jolida amp in for repair.