Can't create search service application in powershell

I'm working on creating a SP2013 search service application based on Todd Klindt's work (http://ift.tt/1CdVqjC). It worked down to the line New-SPEnterpriseSearchAdminComponent –SearchTopology $clone -SearchServiceInstance $searchServiceInstance. I've modified the $clone and $searchserviceinstance from what he has to:

$ssa = Get-SPEnterpriseSearchServiceApplication
$active = Get-SPEnterpriseSearchTopology -SearchApplication $ssa -Active
$clone = New-SPEnterpriseSearchTopology -SearchApplication $ssa -Clone -SearchTopology $active
write-host "we have a clone"
$searchServiceInstance = Get-SPEnterpriseSearchServiceInstance
write-host "we have a search service instance"

The two write-host commands print out fine, but when I get to the next line, New-SPEnterpriseSearchAdminComponent –SearchTopology $clone -SearchServiceInstance $searchServiceInstance, I get an error:

New-SPEnterpriseSearchAdminComponent : A positional parameter cannot be found that 
accepts argument 'â?SearchTopology TopologyId:
61b33981-a905-44f7-8000-eaa40e7b4676, CreationDate: 12/19/2014 2:18:35 PM,
State: Inactive, Components:  -SearchServiceInstance SearchServiceInstance