Absolutely, that is the fastest way for it to stabilise fully.

With or without signal is OK but connect an input, many recommend connecting a tuner.

It will be a few weeks before it settles into its final sound and will go through "phases" during that period - do not give up on it - give it time and it will repay your patience.

Enjoy 

1 - Yes,

2 - yes,

3 - connect a source and leave it powered on - listen as often as you wish or not,

4 - not AFAIK but if you prefer to be on the safe side connect a pair.

My Solo is some years old and is only turned off if I need to move it or re-arrange power leads.

Hi EDMCR, good question!

I suppose the obvious answer is upgrade the Solo and add a DAC later. That is if course if adding a DAC at all will improve the sound.

I would agree with that choice - I do think that will offer the best "sound for the pound".

Although you mention that your Solo is connected to the tape out of your amp I see no mention of your source - one assumes a CD player? and that the connection to the tape out is a convenience that allows use of source with either the Solo or a speaker system.

FWIW - I have messed around with a number of DACs and read many reports on many different DACs as well as listening to many on friends differing systems - many of these use their DACs to interface computer based systems, my feeling is that it requires a fair investment in a DAC to significantly outclass a competent CD player.

In that respect, if the objective is to improve on the ipod dock or access computer sources, then the Dacmagic might prove quite acceptable (the Audio GD products receive very good press out here and a number are price competitive with the DM), if however, the objective in the longer term is to improve on a decent CDP, then the bar might need raising somewhat - the new Rega DAC is receiving rather good press.

I do not own a DAC or CDP that betters my analogue setup, but the investment is not as great either.  My preferred DAC is a DIY job with many mods and is now sounding quite good, the total investment in that is now a deal more than the cost of a DM and a number of parts used are now virtually unobtainable so it would be difficult to recommend it.

For a memory refresh, I have just now done a quick comparison between the analogue out of a modded Marantz CD 52 SE and a modded Beresford Caiman (the mods would take its cost to around the DM and have received significant following elsewhere), I also compared it to the analogue out of a semi-pro soundcard that uses the Envy 24 chip and AKM hard codecs.  While I might have felt that a slight edge went to the Caiman v the soundcard, (depending on the digital cable used and the output board selected - I tried the "Gator" discrete board and the modified stock board with changed caps and THS 4032 opamps) the difference v the CDP were largely of slightly differing "flavour".  Testing was done using both inputs on the Solo to allow quick switching and I reran 2 different tracks, one classical, one pop.  The only significant advantage of the DAC was multiple inputs and the possibility of using the variable output as a preamp or for level matching.   There was no appreciable benefit in SQ over the standalone player. 

Reverting to my preferred DAC, there was an obvious step up in SQ, though it OTOH, does not offer the same flexibility WRT inputs and volume control.

Hope some of this is helpful.

Salt and vinegar and printers ink for chips (they used to wrap them in old newspaper in days gone by).

While your arrangement is best for convenience, I would at least try connecting the CDP direct to the Solo to see if it made an appreciable difference, but then I am happy to swap cables for best sound.