Total System Gain Question

The gain of the preamp is, I would expect, specified at maximum. So it will be less as you turn the volume down.

The gain of the power amp is typical of power amps I have used, as is the sensitivity of your speakers. I would think this would be fine.

Typically, home audio components have more gain than necessary in most situations. But if the units are quiet enough (most are) that is not a problem in the practical sense.

That’s a lot of gain, works out to around 2500W into 8Ω at full volume. A rule of thumb is that every 6dB of gain doubles the voltage, if you know Ohm’s law you can work out the rest.
If you ran a unity gain (0dB) preamp into that power amp it’d need to be capable of 150W into 8Ω, or with a preamp with 6dB gain around 600W.
Main thing to make sure of is your preamp output doesn’t exceed the power amp input sensitivity figure.

Edit... not sure if the OP changed or I just read it wrong. If your power amp has an input sensitivity of 575mA then you need 12dB of attenuation between the DAC and the power amp. If you use a preamp with 18dB of gain then your volume control will be at -30dB when the power amp is at max rated output.

pragmasi

That’s a lot of gain, works out to around 2500W into 8Ω at full volume. A rule of thumb is that every 6dB of gain doubles the voltage, if you know Ohm’s law you can work out the rest.
If you ran a unity gain (0dB) preamp into that power amp it’d need to be capable of 150W into 8Ω, or with a preamp with 6dB gain around 600W

You've confused gain (and input sensitivity) with power output. They are two completely different things. There's no way to calculate power output in watts from the information the OP has provided.

You’ve confused gain (and input sensitivity) with power output. They are two completely different things. There’s no way to calculate power output in watts from the information the OP has provided.

Input sensitivity, gain and power output are all related mathematically and you can work out one from the others if you assume a certain loudspeaker impedance.
I didn’t say the system would be capable, just that an 8Ω speaker driven by the maximum output voltage would need 2500W from the amplifier and need to be able to tolerate it.

Short answer: what this means in practical terms is that you'll very likely only be using your preamp's volume control at the lower end of its range.