As per the above post, please note that Soulution has no repair facilities in the USA and that any units needing repair, etc. must be shipped to Switzerland at your expense. For example, my friends Soulution amp stopped working and he had to paid the freight, both ways, plus the actual cost to repair his amp.
If you decided to purchase any preowned unit (any brand), please confirm the company has repairs facilities in the USA. I also suggest you call the company to confirm repairs are possible on the preowned unit and that they will do them. Independent audio repair shops are another option.