Thanks to Boby Joseph who mentioned Craig Utley’s SSAS videos to me:
Contents include Cube Sparsity, Query Performance, Perspectives, Translations , Storage Modes, ProClarity.
Craig Utley is a former SQL Server MVP. He is a mentor with Solid Quality Mentors and a former Program Manager on the SQLCAT team. He wrote Business Intelligence with Microsoft® Office PerformancePoint Server 2007.
There are quite a lot of videos in this web site. Probably about 30 SSAS videos and 5 ProClarity videos.
The other place where you can watch SSAS videos is SQLbits: www.sqlbits.com