I'm considering a 7500.

Are both of the transformers and power supply in the 7500 shared across all 5 channels?

Reason I ask is because I'm wondering if their are any advantages to using specific amp channels for L and R for 2 channel music (something different than the channel designations on the 7500).

All the channels are the same. We designated them on the back panel for your convenience during set up. They easily could have said Channel 1 , 2 , etc. So, no extra advantage for using one set of channels vs. another. They all sound great with 2 channel and multichannel sources. To see more specs about this amazing amp, feel free to download the manual from the product page.

Thanks for the quick reply.

Per the manual - "Each output module has 12 discrete output devices, 30,000 uF total filter capacitance" - does this refer to each channel?

Also, does the power rating increase with just 2 channels driven?

Based on the way it's worded in the manual and the way the amp is designed, I'm 99% sure that these values relate to each individual amp channel.

They don't list output ratings for individual channels, so I don't know how much output might be possible. Practically speaking, I bet it would be at least somewhat higher.

Whether an individual channel would get more power will depend on whether it is the channel components or the transformer which hits max first. Knowing that the transformer is capable of 1500 watts total to 4 ohms gives me some idea that the transformer is not the limiting component. Remember too that the 7500 is conservatively rated at 200 WPC. I have seen a review where it put out close to 260 wpc at .05% THD. Most amps are rated at lower wpc and at a higher THD spec. I also think that 3 channels go to one TX and the other two go to the other TX. This thing is a beast and will drive anything.

You are correct about that last part - the two channels closest to the power jack connect to one transformer, and the other three channels go to the second transformer.

Thanks for the replies.

So based on gonk's last post, one would be using separate transformers for the L and R channels when using the designated channel indicators.

However, there is no indication that this would have any advantages vs. having the L and R channels running off of a single transformer.

The only time I could see that making a difference is if the power supplies were poorly designed and could not handle the peak load that the amp put on them. Given the beefyness of the power supplies I would not expect any performance difference.

If using it for a two-channel application, I agree with EEman that the benefits of spreading the load across both transformers is probably mostly mental. Those are two very stout power supplies. If you were running some really, really inefficient speakers in a really, really large space, there might be reason to take every possible measure to maximize available power, but that's a pretty atypical situation.

In a surround sound installation, it makes sense to spread the load out evenly across both power supplies, which is likely one reason that the left and right channel labels are at the left and right sides of the amp (putting each on a separate transformer). Of course, that layout also makes sense from the perspective of wire management, as it lets the wires start to distribute toward where the associated speakers are most likely located.

Bottom line: it's not a bad idea, but it's not likely to offer any meaningful advantage.

Each identical amp module gets its transformer secondary feed from one of the transformers. These feed the power supplies of each amp module. One reason for the particular layout, at least in HT applications, is to evenly disperse somewhat greater heat, generated by the more fully driven channels, like the center, and the left and right main.