Generally speaking it is preferable to connect a headphone amp to the tape outputs of a preamp, to keep the signal path that is used for headphone listening as simple as possible, **IF** the preamp's tape outputs can provide adequate drive capability. Which may or may not be the case with your particular equipment.
Two approaches to determining what is best in this particular situation occur to me:
1) It appears that your Teac deck has a line-level input impedance of 50K. You'll need to determine the input impedance of the headphone amp, which may necessitate contacting Klipsch. You would then determine the combined input impedance of the two loads by multiplying the two impedance numbers together and dividing that product by the sum of the two numbers. Then, since the output impedance of the preamp's tape outputs is not specified, ask Keith Herron if that combined impedance number is a suitable load for the preamp's tape outputs.
2) Try it both ways and see what sounds best. In doing so, for both approaches see if there are any sonic effects on what you hear from the speakers, as well as comparing results with the headphones.
Regards,
-- Al
Two approaches to determining what is best in this particular situation occur to me:
1) It appears that your Teac deck has a line-level input impedance of 50K. You'll need to determine the input impedance of the headphone amp, which may necessitate contacting Klipsch. You would then determine the combined input impedance of the two loads by multiplying the two impedance numbers together and dividing that product by the sum of the two numbers. Then, since the output impedance of the preamp's tape outputs is not specified, ask Keith Herron if that combined impedance number is a suitable load for the preamp's tape outputs.
2) Try it both ways and see what sounds best. In doing so, for both approaches see if there are any sonic effects on what you hear from the speakers, as well as comparing results with the headphones.
Regards,
-- Al