Thanks Unsound and Ngjockey. Unsound, at the time you referenced the Threshold it had a Sale Pending- I saw it before and it was Sale Pending for quite a while. I would likely have jumped on it.
Ngjockey:
From Stereophile's mearsurements of the SLP 05:
"The SLP 05's output impedance is specified as a usefully low 400 ohms. However, I got significantly higher values for the unbalanced output of 15001600 ohms in the midrange and treble, rising to 3400 ohms at 20Hz, with similar if slightly lower figures for the balanced output."
Ngjockey:
From Stereophile's mearsurements of the SLP 05:
"The SLP 05's output impedance is specified as a usefully low 400 ohms. However, I got significantly higher values for the unbalanced output of 15001600 ohms in the midrange and treble, rising to 3400 ohms at 20Hz, with similar if slightly lower figures for the balanced output."

