Hallo.I fond an Alembic F2-B preamp.The guy that sell this one says that he has change the 110 V(american) to 220V(european). Maybe this is a problem?Is this problem for the sound qualit or something else. I know that is not very good to change something from an amp or preamp. I hope to understandmy question

Here's instructions for changing the voltage:
FAQ ? F-2B Stereo Tube Preamp

Thanks.Actually he says : Since I bought the unit from years in the U.S., it was rebuilt here in Europe in a Fachwerkst??te of 110 V to 220 V -.

Looking at the ebay picture, to me, it seems to be of a vintage that will allow  
you to do the transformer tapping as described above.
If the transformer has already been modded by the above method there are no problems.
If the mod is by some other method such as step-up transformer  
Alembic will sell you a correct transformer.
 
BTW what is a Fachwerkst??te?
 
slawie
 
(Message edited by slawie on September 09, 2010)
 
(Message edited by slawie on September 09, 2010)

Fachwerkstatt (pl. Fachwerkst?tte) means specialist workshop.
 
(Message edited by adriaan on September 10, 2010)

Ok.Thanks.Do you believe it's ok to buy this one?Or it's a problem that the ownerhas change the transformer with a non original one.

DAFFY,  
 
Changing the voltage from 110v to 220v or 220v to 110v only requires moving two wires inside the unit.... It isn't a hard task, and it's a bonus if the owner is willing to do this for you. I don't think that any actual component was swapped out of the unit.  
 
If this is your only concern, then I'd say that it's a safe buy! Good luck!!!