DualTriode
Addicted to Fun and Learning
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- Oct 24, 2019
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Hello All,
I have been eyeing this Benchmark ABH2 power amplifier for several months. This last week I went over the edge. The big brown truck delivered it yesterday. The APx1701 test amplifier is not going away just sliding over to make room.
The AHB2 is cooled without a fan which is a huge plus. The goal is to get rid of the instrument cooling fans that may be adding noise to my speaker measurements.
The plan is to share the literal ins and outs of all the connections, microphone placements and the like. There is an assortment of load resistors and heat sinks coming next week. Also still to be purchased are “sense” resistors to measure voltage drop and calculate driver impedance phase and Thiele Small Parameters (included in the APx500 software)
I have some accessory Speakon cables that need to be fabricated.
First off will be testing of the Benchmark ABH2 with load resistors, the idea here is to test the amplifier with an assortment of different types of load resistors. Perhaps there is a difference among the load resistors?
There are a couple of 500 Watt cheap elevator braking resistors of unknown thermal coefficient (ppm/degree C) that need to be tested with the amplifier. I am thinking that at 5 watts, the standard test around here to test the THD+N and SINAD, that I do not expect to see much heat caused distortion caused by the cheap 500 nominal Watt resistors. Any guesses about THD+N and SINAD?
Thanks DT