RADIO DESIGN LABS ST-PA6 RDL SIX-WATT UTILITY AMPLIFIER, FREQUENCY RESPONSE: 35 HZ-20 KHZ, THD: .35 %, INPUT: 10 KOHM, 400 MV (LINE LEVEL), POWER REQUIRE RDL SILICON X -WATT UTILITY AMPLIFIER, FREQUENCY RESPONSE: 35 HZ~20 KHZ, THD: 0.35 %, INPUT: 10 KILOHM, 400 MV (LINE LEVEL), POWER REQU