What should be removed


Where should I start?
 today I use Accuphase E-206 with Cub Wilson Audio speakers. Have also Audio Research preamp Sp4.Also own a Hitachi HCA-8300 preamp.
What parts should I sell? Accuphase and buy an amp to Hitachi HCA-8300 / AUDIO RESEARCH Sp4?
Any suggestions?
titus1
Get rid of all 3 and buy something like an Ayre AX-7. I have a pair of Cubs myself that I use in a 2nd system. They're pretty good speakers. But if you don't pair them with modern, high quality electronics, you'll never hear them at full potential. 

Do you have any more suggestions on the amplifier?
What should I consider when I'm looking for amplifiers
Recently bought my Wilson Audio Cub.
" Do you have any more suggestions on the amplifier?"

Did you have something else in mind? The Ayre has a very good price/performance ratio. You can definitely use something else, but you just need to be careful with regards to your other components gain. The Cubs are something like 95db, and like any high efficient speaker, they're not forgiving when it comes to gain. If you're not careful, you can get a hiss.

If the Ayre is too much, maybe look at the Parasound Halo integrated. It goes for around $2500 and it has a dac. The Halo gear has a good track record when being paired with Wilson. Also, having the dac, preamp and amp in one box should eliminate any chance of gain issues. You probably won't like it as much as an Ayre, but it should still be a huge upgrade from what you have now.
titus1 your question and setup are both confusing. First thing, why do you want to change? Second question, the Accuphase E-206 is an integrated for what purpose are you using the  Hitachi and AR preamps? I would imagine the E-206 is a nice integrated Accuphase makes nice stuff, so if you are really looking to upgrade it may take a fair bit to improve on it.
The impedance drops down to around 3 ohms over the 200Hz–1kHz region. A good deal of the power in typical program material falls in this range, which suggests that the CUB will not be particularly easy to drive.
http://www.stereophile.com/images/archivesart/wilCubfig1.jpg
To get the very best from these Cub's.
This is from Stereophile’s review/measurement results, pick the right amp that can do it easy into a 3ohm load and with current ability.

Cheers George