Hi Panu21
Here is how I would hook up the Dodd Tube Buffer to your headphone amp if all have unbalanced jacks.
source audio output -> Dodd Tube Buffer Input -> Dodd Tube Buffer output -> Headphone amp Input. I wouldn't use the 1 recording output.
Also keep the volume on the Dodd tube buffer low at first. I don't know if your headphone amp has it's own volume control or not. Tweak the volume on both to see how you like it.
This is what I do with my Grant Fidelity DAC-09. The headphone amp I have is one from Einar sound that has XLR headphone outputs for my modified AKG 701s.
My source is a Sony CD595 that goes into the analog input of the DAC-09. The tube output is then connected to the inputs of the Einar Sound headphone amp. I adjust the volume of the DAC-09 to about 75% of the way up and then adjust the Einar sound's volume.
Best of luck and enjoy. I've always wanted tube stuff by Dodd but I never had the money. I hope Gary is ok. I remember reading he had health issues earlier this year.
