I may be missing something here, but I don't understand why you need a splitter.
Here's the way a headphone amp typically works. You connect a source(s) to it, in this case your turntable / Puffin. Some headphone amps have more than one input, so you can connect another source. The headphone amp has an output and you run that to one of the inputs on your integrated. You're basically sticking the headphone amp in between your source and the preamp or amp.
Most headphone amps have a fixed output, so when you're not using the headphones you are controlling the volume of your speakers with the volume control on your preamp or integrated amp. The volume control on the headphone amp only controls the volume of the headphones.
You don't need a line out or tape out on the preamp / integrated.
Some preamps and integrateds have built in headphone amps, but until you move quite a bit up the price scale from where you're at now, they are basically an afterthought and a standalone headphone amp will be better.
In your case the setup would look just as you described:
Turntable -> Puffin -> Headphone Amp -> Integrated amp.
Here's the way a headphone amp typically works. You connect a source(s) to it, in this case your turntable / Puffin. Some headphone amps have more than one input, so you can connect another source. The headphone amp has an output and you run that to one of the inputs on your integrated. You're basically sticking the headphone amp in between your source and the preamp or amp.
Most headphone amps have a fixed output, so when you're not using the headphones you are controlling the volume of your speakers with the volume control on your preamp or integrated amp. The volume control on the headphone amp only controls the volume of the headphones.
You don't need a line out or tape out on the preamp / integrated.
Some preamps and integrateds have built in headphone amps, but until you move quite a bit up the price scale from where you're at now, they are basically an afterthought and a standalone headphone amp will be better.
In your case the setup would look just as you described:
Turntable -> Puffin -> Headphone Amp -> Integrated amp.