It's time to discuss the hacks output. What can you do with it?
Headphone out
Step one: Get the right kind of headphone jack.
Line out
Our main goal in designing a line output is to avoid damaging the equipment we're plugging in to. Now, most competently designed audio equipment should be impossible to damage because it will have overvoltage and short-circuit protection built in. Sadly we do not live in a world of universal competence, we live in reality, where cost cutting managers and accountants will yank out or neuter perfectly good protection circuits just to save a few pennies. So we are going to make our line output as safe as possible because Murphy's law is almost certainly out to get us. Even so, I am not guaranteeing that you will not damage your receiver somehow. I have no control over how this kit is assembled, nor do I have any control of or knowledge of the condition or internal workings of your receiver's line-in circuitry. Do not swim for one hour after eating a balanced and healthy meal. Do not eat the Stella amp.
Alright, here is our schematic:
[schematic]
The signal goes through R14, which forms a voltage divider with the 10k trim pot. Rpd2 will help reduce pops when we plug our equipment in. Our trim pot is going to tame the signal before it gets to D1 and D2 (it needs to be a trim pot because hey, I don't know what voltage you're running this at.)
D1 and D2 look a lot like clipping diodes. Well, they are clipping diodes, except in this case it would be better to say that they are clamping diodes. This is a line out signal so we want it to be around 1 to 1.2 volts peak to peak. Those diodes are going to ensure that our signal never gets above 1.4 volts peak to peak. The basic idea here is that we will adjust the line trim pot until the peak
That's the main idea. Now, [tone control]
Step one: Fiddle with the amp to give you the loudest possible clean tone.
Step two: Turn your line trim pot all the way down, and the volume pot all the way up, and plug your Stella amp into your receiver.
Step three: Turn up your line trim pot until you get the tiniest bit of distortion, then back off just a little bit. (If you have a scope, dial that line trim pot down so your signal is 1 or 1.2 volts peak to peak.)
Step three: Crank your Stella amp and make sure that the distortion and the sounds you're getting are coming from the Stella amp distorting and not the clipping diodes. It's one of two things. Either your speaker is naturally rolling off some of those harsh harmonics, and you're used to that sound. A line out will give you the full signal, unfiltered. Or, it might be the clipping diodes. With everything cranked on the Stella amp, if you find the distortion to be too harsh with your line out, you can turn down the line trim pot to see if that helps.