Items are shipped when SOS receives payment. Many mailing list members have used SOS and noone has reported problems with expansion boards. A few purchasing synths reported no problems. Synths will work but you should get a power transformer adapter because incorrect voltage and power surges can eventually damage electronics. Also, you should know that you can run into problems when ordering sensitive electronics from other countries.
Shipment goes through several hands and presents many opportunities for damage.
Returning products to other countries may also be complicated and time consuming. Com Tons of info. Musician Store Sheet music. The Music Yellow Pages PG Music Midi stuff. Seldom Fed Productions Performance rights info.