[pddjsteve]

I'm going to be getting the basic sonic impact T-Amp and modding/recasing it (removing pot, better jacks) for my girlfriend as part of a combined headphone amp/small bookshelf speaker amp for her dorm room. I'm going to use a headphone amp (I'm thinking cmoy) as a preamp for the T-Amp and add an Alien DAC to connect to her laptop.

First, I'm wondering if I should be going with a 50k pot on the cmoy since I'm going to be removing the volume control from the t-amp?

Second, I have a switch question. I want to have 2 sources (RCA and the AlienDAC) and for the speaker amp to not get input when she's just on headphones. I'd need a 3PDT?

 

[Polaris111688]

Well, the RCA and Alien DAC need one DPDT switch and the CMoy will need two output jacks hooked up to a DPDT switch, if I interpreted what you want correctly.

 

[pddjsteve]

Quote:

Originally Posted by Polaris111688 Well, the RCA and Alien DAC need one DPDT switch and the CMoy will need two output jacks hooked up to a DPDT switch, if I interpreted what you want correctly.

Yeah, I mistyped when I rearranged the last sentence of my post. I meant to say a 3PDT for each. Essentially what I want is:

RCA | Alien DAC -> Switch -> Cmoy (or other) with Pot -> Switch -> Headphone jack | input of SI amp

So your suggestion is that I only need to go DPDT and I should be leaving the grounds from everything connected all the time?

 

[Polaris111688]

Just hook up left and right to each "pull." Leave the ground connected to center lug on DPDT, since there's nowhere for current from the left and right to drain to if it's not connected to ground, hence no sound if the switch is not selected for the given output. Take what I said with a grain of salt though, because there are a ton of people here who know more about this than I do.