To use a preamp with my Line Magnetic 805 integrated amp, or not?

I had decided on a Don Sach's Model 2 preamp to try. Unfortunately, due to some damage during shipping, I won't be able to give this experiment a try. Haven't even tried plugging it in due to fear of damaging it more. 

Just a quick update here. I did work with Don to get the preamp fixed and this was sent back to me to try with my Line Magnetic. After about a week of extensive listening, I struggled to hear a big difference between using the preamp on the pre-in vs just having the source go directly into the LM. It didn't make it sound any worse but it wasn't the large improvement I had hoped for. I can only think that the reason for this is due to the Line Magnetic's configuration where the preamp is not bypassed even when using the pre-in input. That is likely the limiting factor. 

Will it be any different if I used another preamp? Not sure. But I know that the Don Sach's didn't have the effect that I wanted to hear unfortunately. Don is a great guy to work with though! Maybe in the future I will go for his pre and amp combo but for now, I'll be returning his preamp. 

If the pre-in input does not bypass the LM's preamp circuitry, I doubt any external preamp will improve the sound through that input.  Does the LM have a tape input?  That bypasses the line circuitry in a number of preamps I'm aware of.  If it does, try that input.