Hi Voyagers!
Can you safely reroute the headphone output into the external audio in to overdrive the Voyager?
Or is the headphone signal too hot?
Thanks in advance!
No it is not safe. The Voyager is not designed for this and it can actually cause damage.
Thanks MC 
What you can do is go get some cables: A. single male stereo–>dual male mono, and B. dual female mono–>single male mono. Plug A’s male stereo into mixer out/filter in, and dual male mono into B’s dual female mono. B’s single male mono goes into ext. audio in and then you’ll switch on ext. audio in your mixer. Turn the dial to about 75% and you’ll start getting some nice overload. This is safe, as far as I know. Been doing it since I got my Voyager about 6 months ago and it’s fine.
From “Kicking It Up A Notch”:
- Greg
Thanks Kenneth and Greg!!!
Why don’t you just try patching patching the left output back into internal? Watch out (no harm will come to the OS), with proper cut-off settings, you can get a wall shaking overdrive in the bass range that you can’t get any other way from the knobs alone. While you’re there, turn the filter switch to highpass-lowpass, that will get rid of some of the bass and make your OS sing like no model D can 
Very interesting textures this way.
Edit : oopss I meant the right output back to external in.
Yikes. In what way can running the headphone-out through the audio-in damage the Voyager? I have actually tried this, and though it didn’t result in the desired sound, I’m pretty sure it didn’t damage my Voyager. Lucky me I guess. 
What about Portamental’s suggestion of just running the right output back in to the audio-in? Is that dangerous? Or, just only desirable if your not using stereo?
Why NOT use the headphone jack back into external In ? Two reasons.
a) in two words : mismatched impedance. At max volume, the headphone level out is many orders of magnitude stronger (both in power and voltage) than that of line level.
b) when using a standard TS patch cable in the headphone jack, you are actually shorting one channel to ground. A TRS patch cable with the ring not connected would avoid that, but you have still to worry about a)
Why is the right output safe?
Because it is what is commonly called “line level output” and the external In is designed to accept line level input.
Without going too technical, line level of modern audio is +4 dBu (a dB is a ratio of power based on a reference voltage level). Stated otherwise, line level is .775 volts RMS or 2.18 volts peak-to-peak. That’s what makes it safe. That includes using line level audio in foogers and CP-251 without even worrying about using the attenuator. You probably will not get anything from the high end of the spectrum, but on the lower end, audio used as CV can give very interesting effects, particularly in the sub-audio range.
That being said, you still may want to use the level knob of the external In wisely. I have noticed on the OS that when you reach overload level (8ish), the overload led flashes, but when you go max, led goes off. Probably not critical on modern electronics such as the OS, but on a model D, the overload lamp runs hot and is more prone to burn off. I have changed a few.
Now go plug patch cables with peace of mind 
this is very good advice ~ THANK YOU!
Great thread. Thank you all for sharing.
Sorry for zombifing this thread, but I wanted to be certain.
If I’m running the voyager into my motu 828mk3 and using one of the analog outs to run back to the voyager to do the feedback overdrive trick or to route other audio through the filter quickly. When doing the feedback is there any risk of damage placing the motu in between with the DA conversion?
Thanks