.
The E Cards seem to work well anywhere . A friend has 2 on his Linn Lp12 at irregular and unusual angles he said it made a nice improvement.
At another house I placed 1 E Card over the breaker in his box that feeds his audio wall..very noticeable and immediate increase in air and resolution. I really think the placement of the cards and the mats on a single chassis is not that crucial. The effect of the cards and mats is almost fluid like and in a short time fills the chassis with many musical benefits. I have over time placed more than 1 card or more than 1 mat on all my component parts and there has always been another benefit to soundstage and density. Tim thought there was a benefit in sound when the mats or cards were stacked. If you have just the 3 then I would put 1 on each component. This has been my experience. Tom