Hello Jack,
There are no setting to change the output levels of SMPTE LTC port of TimeCore.
I have not head of people having a problem because of this.
As most equipment tries to decode the block wave signal by reading the high an low parts.
Because it only encodes two levels (high and low) the exact level is less important then normal audio.
Can you verify the signal which is received still receives a high an a low part.
Kind regards,
Guido Visser