The Studer A80RC as designed stops only when both tension sensors lose tension. When using fragile archival tapes, especially at slower speeds, this creates some difficulties as the tape end weaves through the head block. Here is a modification which makes the A80RC operate like an A810, stopping the tape when either tension sensor looses tension. The mod is completely done on the 1.081.393 Command Receiver board and involves adding two parts and removing one.
Here is the circuit diagram for the modification:
Use this at your own risk. If it doesn’t work, breaks a tape, or blows up the machine, I am not responsible. Please be careful, the +24V trace is under the likely area to add the parts.