Serious Guess:
1. The name of the commodity - Monoblock Amplifiers
2. The number of them in the "Stack" - 2
3. Why they are a "Short Stack" - the amps are full width components but are short(about 2 inches) in height like the old Soundstream DA2 amps.

My lame attempt at a humorous guess:
1. The name of the commodity - exotic audio interconnects
2. The number of them in the "Stack" - 1
3. Why they are a "Short Stack" - Because you only need a short stack of credit cards in order to afford to buy one of these...



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Take Care,
merc