But the OP was using a completly resonable buffer, If you get crackles at 256 on a computer that is capable like the OP's and he even ran Latency monitor it sort of rules that out. And that leaves us at 32 bit VST's. 
 
And Roger I was to understand that jbridge is a process that runs in the background like bitbridge? 
I didn't know it was a convertor. If it works then why don't the vendors of 32 bit plug ins use it? 
 
OK I was right, it is a background app and so the same as bitbridge and looks like you have to purchase it. 
Only $15 so that's OK and there's a demo. But myself I'm done with 32 bit. Mr Tramp has been replaced with a few others I found like Air's Velvet and even SI Eletric Piano and Lounge Lizzard are doing fine.