hello.. i made a very good amplifier stereo tda 2003 with a preamplifier using a jrc 4558 and have good very good soun that i never heard in the amrket only the sansui is the measurement for this one , when a make it i don't believe that this amplifiers can work hi fi conditions but when i heard it i thing eureka, this is better thana kp500 ... now i had a idea the svr .. i wnt to maintain a good svr condition and a dont want to use a tda 2005 for a sub woofer or a woofer or for make another one in stereo with more power using the bridge on the utc 2003 tda for the diagram 1 for good svr .. or for make steroe using 2 bridges of utc 2003 but using tda 2003 with the same equalizer of 3 bands bass medium and high frecuencies but this one have more power.. now only i want to make a bridge with the first order or second order bass by pass filter for a woofer using this diagram on this site... http://html.alldatasheet.com/html-pdf/454032/UTC/TDA2003-TA5-T/324/5/TDA2003-TA5-T.html the tda 2005 develope high temperature and another thing is that use a simetrical source power. rather that the tda amplifier that only use a 12 volts 4 amp simple power source .. i calla the unifications source foer lower distortion low noise and dont need a fan for cooler the circuit also tha main troubble is the use of 2 electrical source , rather that one because the tda 2005 use +18 and - 18 volts for use it.. i want to use only 14 or 15 volts that i have and only 1 ground for 2 amplifiers... can you understand me,, call me please.. a can wait for days on this chat or a email sen. by you thank you i must be on line ,,,,