Problems with old flash gun

Hello.
I have got an old Prinz Jupiter 677 TCB flash that I got free from one of the other members on here, but I don't know how to use it. I dare not put it on my K-R as I'm afraid it will fry it but I've got an optical trigger (I don't really know what I'm talking about when it comes to flash) that triggers when the flash on the K-R goes off. The problem is that the Prinz seems to trigger too late, ie the shutter has already closed when it goes off unless I use shutter speed of 1/30th seconds or slower. Is this the only way it will work?

Any pointers will be appreciated.

Thanks

The optical trigger is fooled by the pre flash. You can either use wireless triggers, obtain a more advanced optical trigger that takes account of the pre flash (SY_5 type) or use a non p_ttl flash as your trigger.