Firstly to be unbiased this preamp is not the best in the market but it still is a good competitor and can standup against other major brands. Considering the circuitry as mentioned in the review above mine, it is a bit cheap because you do get a thump (Which isn't a major issue to me). I have owned the Clarion EQS746 preamp before this and must say even though the clarion may have a 7 band Eq for frequency tuning and volume, I find this abit easier and very accurate. I use this in a setup with a Pioneer 3300UB headunit two amps, four 6"s and One Pioneer w307d4 12" sub and I've tuned everything to clarity for high volumes. With the Clarion EQS746 I struggled to tune my bass to get a defined sound but since I bought this preamp I configured my sub frequency very accurate. The Variable Subwoofer Low-Pass Crossover within this eliminates any non sub frequency from entering which is great. I'm impressed with this preamp's performance and I just love the blue LED lights illuminating. I recommend this for any system, you wouldn't be disappointed folks. Buy this or the Pwn19.