I'm cross posting this here as well for my banned brethren
"The Goal"
I have a little pile of amplifiers at my disposal(some A/B, some class D, some large, some small, some old and some new, and some expensive, some middle of the road) and I want to determine first if I CAN hear a difference between them, and then, which I prefer and for what reasons.
I want to do a blind test so that I am not influenced by anything other than what my ears are hearing. Below I will detail the equipment and what I'm planning-please point out anything that could be a potential issue and advise of any easier methods you might recommend. One caveat- The process has to be fairly simple and not require much outside expensive gear other than what is available at my disposal already.
"The Gear"
TPS 75amp DC powersupply
Pioneer P99RS Source
Alesis Monitor Two studio monitors (10"/4"/1" configuration)
OWON Oscilloscope and true RMS DMM
Xtant X604
Diamond Audio D7054
JL Audio HD900/5
Phoenix Gold Ti800.4 (2011)
Arc Audio XDi804
Zapco Z-150.6
Soundstream REF4.920
"The Configuration/Setup"
The amplifiers will be powered by a TPS 75amp dc power supply. DC from the supply will then run through a circuit breaker to control power on/off for the whole system, and then off to fused power and ground distribution blocks to supply the amplifiers. For signal, a single pair of rca outputs will be supplied from the P99 with no crossovers or processing applied. These RCA's will plug into an rca "patch panel" where the source inputs are tied to each of the 8 RCA output pairs. This means the same signal is shared to each of the amplifiers being tested. Each amplifier will have it's own pair of RCA cables to supply its signal from the patch panel. All of these cables will be the exact same model and length and impedance will be measured of each to ensure they are in close tolerance. On the output side, each amplifier will output 2 channels (L and R) to a patch panel of binding posts. We will use one pair of speaker wires with banana plugs to "plug in to" the amplifier we wish to use to power the mains.
"The Method"
The source unit will be measured for clipping point and will be kept at a volume point a few notches below to ensure a full, clean signal. All filters and processing will be disengaged. The source volume will not be changed during the listening tests.
All amplifier gains will be set as close as possible to equal output voltage at the speaker terminals. I will aim to leave plenty of amplifier headroom so that the larger amplifiers do not gain a significant advantage over the smaller ones and output is relatively consistent.
The speaker patch panel will be hidden from view, leaving the listener unable to see which device is currently powering the speakers. The assistant will keep a list and assign a number to each amplifier randomly so that the listener has a basis for notes. To change the "source amplifier", the assistant will swap positions on the patch panel.