Is it possible to build a 2 box pre-power for under £400

Disclaimer
I'm afraid I have no electronic engineering experience nor any skills in DIY electronic audio so please excuse the following, possibly naive questions.


The goal

[Re]Produce a two box system similar to the late 80's Naim pre/power combinations. Try and recapture that "British" sound - please don't ask me to quantify that at this stage!

Cost effective, quality not necessarily esoteric.

Must have modest power and not be too fussy about the cable or speakers unlike it's earlier Naim cousins.

Must fit the old Naim shoebox size.

Why not just buy a second hand Naim system? Well the following:


Requirements

The Pre-Amplifier must contain a good quality DAC for digital inputs as well as a good quality phono stage. The inputs must be balanced to provide the same volume to the amplifier so you don't have to constantly adjust volume.

Is switching of inputs required? Surely no one uses several sources at once so is this required for electrical/sonic reasons?

The power amplifier must be of good quality and run reasonably cool if possible, to avoid use of heat sinks other than the case itself. Perhaps modest power of 30w - 40w per channel into 8ohms?

No fancy connectors or exotic cabling, just good quality.

I'm really interested to find out if anyone is willing to support this project? For my part I am happy to contribute towards material costs, the cases and the product design.
 
You need a switch. You don't want two inputs to "see" each other. If both sources are active one will act as a filter on the other. I can't help you with the build, but I think it's possible. There are lots of cheap constructions that sound really well. A good chip amp, A flexible phono stage from maybe RJM audio (he have a very small one). I'm not experienced with DAC's, but there are plenty out there. You just match the phonostage output and DAC. I don't think some fancy input sensing circuit is needed. Some recordings are louder than others of course, but that's life.
 
You need a switch. You don't want two inputs to "see" each other. If both sources are active one will act as a filter on the other. I can't help you with the build, but I think it's possible. There are lots of cheap constructions that sound really well. A good chip amp, A flexible phono stage from maybe RJM audio (he have a very small one). I'm not experienced with DAC's, but there are plenty out there. You just match the phonostage output and DAC. I don't think some fancy input sensing circuit is needed. Some recordings are louder than others of course, but that's life.

Thank you that's very helpful and really encouraging!!!