Headphone amp between source & amplifier - how to passthrough?

[redal]

I'd like to put my headphone amplifier (Rod Elliot 113) permanently between the source selector and amplifier so that I don't have to mess with cables to either listen through speakers or headphones, :

Source selector -> Headphone Amp -> Speaker amp

I'm thinking that the simplest way is to have 2 sets of input sockets on the back of the headphone amp:

Set 1 - Externally connected to the source selector (phono cables) and internally connected to the HA circuit

Set 2 - Externally connected to the speaker amp (phono cables) and internally wired to set 1 (in parallel)

I don't know if this is ok, or if I need to do anything else, any thoughts much appreciated.

Andy

 

[blueskull]

If the sources' impedance are low enough, and the hp amp and the power amp both have a big enough input impedance, and you have a low distributed capacitance cable set, I will say yes, you can parallel 2 signal sink to one signal source.

 

[redal]

Thanks for the reply

Source impedance to the headphone amp could be either:
Pioneer DVD (565a),
Hifime diy sabre ES9023 DAC,
Xonar D2x sound card

Unfortunately I don't know the output impedance of these

Headphone amp has a 10k stepped attenuator followed by a 1k resistor into the opamp stage

Speaker amp is a chip amp's 1875 which has a 10k stepped attenuator into the PCB.

Cheers,
Andy

 

[blueskull]

The DAC seems to be unbuffered according to its photo, while the DVD player's output impedance is unknown. If you are using an active source selector, you can confidently connect in this fashion. If not, I suggest an extra buffer to be used either in the hp amp's set 1, or in the output stage of the selector.