I have two of these plate amps for sale. They were used with Dayton RSS390 subs to very good result.
From the wayback machine:
This subwoofer amplifier is a conventional non-servo-based amp. Its high output make it a perfect match for the newest crops of subwoofer available today. These class A/B design amps provide far superior performance in terms of distortion, hum noise, and damping factor compared with digital amps. The highlights are (if you don't have a HT receiver, we recommend you to check out our Special Edition amp shown next):
1. 380W RMS@4ohm <0.1%THD, 245W RMS @8ohm<0.1% THD. Bigger power always bring in better bass, simply they use bigger transformer (ours is 600VA), bigger filter cap (ours is 4 of 6800uF/100V), and bigger heat sink (ours is one piece 3/16" thick back plate/heat sink construction for better heat transfer and rigid structure). Power rating is tested for 4 continuos minutes.
2. A defeatable extension filter with separate frequency and damping control. The extension filter can be bypass with 14hz and high damping setting. Frequency is adjustable between 14, 20 and 28hz. Damping factor is adjustable between high damping (Q=0.6, or bessel filter), medium damping (Q=1.07, or 1.5db boost Chebyshev), low damping (Q=1.33, or 3db boost Chebyshev). There are a total of 9 settings available. You can use this filter to boost the bottom end or do minor correction for room response. In case you don't know, our competitor has a 6db boost at 30hz which cannot be defeated. To defeat that, you have to unmount the circuit board and do some soldering, voiding the warranty if there is one. Incorrect rumble filter not only makes the bass sound boomy, it can even bottom out the woofer.
3. Damping factor: 160 @ 4ohms. (Note: damping factor is speaker wires dominated. Without speaker wires, the native damping factor is >800).
4. Signal to noise ratio: better than 107db (A-weighted).
5. Input impedance: 30k ohms.
6. Air tight by designed. No need for a back cover or separate chamber. It will give you an extra 0.15 cu ft enclosure net volume compared with those with back covers.
7. Auto ON/OFF on left channel input.
8. Accept both high level (from speaker) and low level (from preamp or processor) inputs.
9. Fixed highpass line level output for satellite speakers.
10. Continuous phase adjustment (0-180) and low pass filter adjustment (40-160hz).
11. Gold plated connectors.
12. Build-in thermal and short circuit protection circuitry.
13. Dimension: (W)10-3/8"x(H)12-7/16"x(D)4".
14. Cutout Dimension: (W) 9 1/8" x (H) 11 1/8".
15. Big power transformer with 650W max input power. Net weight is 16 lb.
Asking $100/ea OBO.
