Updated: Jul 2
Generally we recommend to use linear regulators like the used LT3045 to <60% of their capability. Audio devices seem to benefit of that headroom, resulting in a better listening experience. Headroom should be available in all situations. That would result in 3A for an ALS-HPULN or 1,8A for the MS-HPULN power supply.
To decide for the right power supply, following questions should be answered basically:
1. Do I need one or two rails?
2. Which current does my device / application need?
3. Which is the available area for your new power supply?
HPULN Power Supplies are available with one and with two rails on one PCB.
Comparing the same category the single power PS uses the same number of regulators, for one rail, which are used for the rails in the dual rail version. This is why dual rail PS's current is divided in halve comparing to the single rail PS.
It's recommended always to use the biggest HPULN version matching your available area, it has to get built in. The reasons are following:
- Bigger heatsink = better heat dissipation
- More LT3045-regulators working in parallel = lower noise
- Linear power supplies should always be calculated with some "headroom" in any situation, so also under full load.