Buying new pre-amp

Years ago I moved up from an IC-150 to an AR SP-4, another solid state unit. There was very noticeable improvement. Now have a First Sound Presence Deluxe and will never go back. Have fun in your quest for your favorite, but do not hesitate. It is easy to improve on the Crown.

I know S/N ratios will probably be much better, but will it sound any better through say the CD input which is basically a straight through connection anyway.

Op amps have improved a lot since the 70's. The power supply caps will probably be dried out and need replacing too. Chances are that you will get a significant performance improvement with a modern equivalent SS preamp - what power amp and speakers are you using - is it a Crown 300?

Try, try before you buy. Find a dealer that has a business model that lets you try, try. That is the only way to tell what difference thee is.

The IC-150 is of course an IC (integrated circuit) based design. It was a decent component in its' day, but yes do move on.
If your cabling is also of that vintage you should also experiment with upgrading there. Your interconects & AC cord (which are now detachable, so you can try out different models of cords).

Well I did buy an Emotiva RSP-2 pre-amp. Yes I have in fact replaced the RSP-2 three times, and am awaiting my fourth unit!

The first one had a noisy phono stage, and very sticky volume control when operated by remote.

The second had half the logo come of when I peeled off the protective shipping strip.

The third one had an even worse volume control than the first, which was really immaterial anyway, because the unit went completely nuts with the front panel lights flashing through all the dimmer values when any input was switched on the front panel. The next morning I was greeted to alien gibberish on the front display. The only way to shut it down was using the back panel switch.

I'm now patiently waiting for the fourth unit to come. Lonnie claimed that the third unit was checked out completely before being shipped. I'm sure something just failed when I got it. It can happen.

Now I spoke with Dan the owner, and he promised me the next one will be perfect, as it will be going through a 2 day burn in.

If this unit proves to be bad, guess the Parasound P3 is my next step. I have already checked it out. Seems like a nice unit, but I will loose one input, and I prefer full height components. Well see what happens.
I will admit the RSP-2 did sound a bit better than my IC-150., but for now my 37 year old crown is back in the saddle again.