Odd Trick? Amp input used as an output to another amp?

[DetroitBlues]

The guy I bought the Fender Blues Deluxe from mentioned to me that he connects the input jack from the Blues Deluxe into another small amp.  The smaller amp is used as a reference amp when he is playing live.  I've never heard of such  a thing before.  Anyone do this or know about?

 

[kbp810]

Also known as daisy chaining. You're basically using one amps set of inputs as a sort of "Y" cable to play through both amps at the same time. Guessing he's using one pointed at himself as a monitor. 

 

[DetroitBlues]

Also known as daisy chaining. You're basically using one amps set of inputs as a sort of "Y" cable to play through both amps at the same time. Guessing he's using one pointed at himself as a monitor. 

Yes, that's what he is doing.  I had no idea you could do that.  So I could effectively use a second input like a line out to another amp or a mixer?

 

[kbp810]

Yes, that's what he is doing.  I had no idea you could do that.  So I could effectively use a second input like a line out to another amp or a mixer?

It depends on the amp; but a good chunk of them it will work on; and can get some cool stereo and reverb like effects from it too. 

But doesnt work for all. Some may end up out of phase (sound waves will partially cancel each other out; having a detrimental effect on the Tone and volume); some may cause an oscillation (hiss, screech, bad feedback); and some may not have inputs wired in a way that will daisy chain (may send signal to ground). 

 

[ElNumero]

How do performing artists that use multiple amp heads (like Warren Haynes) on stage hook them all together?  Same way perhaps??