Instruction: First, identify the target attributes from the provided list. Then, scan the product title, description, feature, and brand to extract the values associated with each target attribute. Finally, create a list of dictionaries, each containing the extracted attribute, its corresponding value, and the source where it was found.

Input:
Product title: Sony STRDA7100ES Black 7.1-Channel Home Theater Receiver
Product feature: Compatible with today's digital technology, Ideal for high resolution digital audio players, Provides outstanding Video up and Switching, Amplifier Relocation for Multiroom Audio provides sound to 3 Zones/3 Room Output.
Product brand: Sony
Target attributes: Number of Channels
Answer: attribute: number of channels
value: 7.1-channel
source: product title