We have discussed this before, but I cannot get things to work right. 
 
Situation: Vocal track with Melodyne.  Trying to bounce it to another track.  Bounced track is consistently lower in volume, and the difference is immedateily apparent when looking at the wave forms.  
 
There is no automation on the source track.  I have tried pushing up the fader on the source track, but that makes no difference.  (I deally, you should be able to leave it in nominal position anyway.)

I get it louder. I've just been in the habit of setting the volume of the "tuner" track that I use (track I bounce FROM) to -2db or so.

My workflow is as follows:
Create a "tuner" track, place w/e vocals I'm tuning in there, and then do a straight up bounce to the real track. Simple and works for me. I agree tho, workarounds for leveling issues sucks.

I agree...a bounce to a new track with no level changes should render a new track with the same level.  Does Melodyne have any level adjustment with in the plugin?  I would assume it would default to 0 or nominal if it does.  But if everything else is set to 0, I can't imagine why your new bounced track would have less level.

I don't have Melodyne...but I'd be curious what you find out.

I'm pretty sure that in the bounce dialog box, the checkbox for "Track Automation" not only refers to envelopes but also on the level of your track fader.

So if this is set at anything less than 0dB you WILL get a level drop

I have noticed some time ago that one of my melodyne bounces was digitally clipping a section of the vocal track..... bad nasty sounding clipping after a bounce. Audibly, the two tracks side by side A/B in solo were about the same relative volume. 

The quick solution I came up with (successful experiment) was to select the entire original track with melodyne in it and use Audio Process, Reduce Gain, -3db.... and bounce it again.  No clipping. 

I have always had bounces that were about the same level..... and now..... 

I have adopted a slightly faster way to work with melodyne where, if there are any level changes, it will show immediately.   I still clone the track for safety reasons..... 

But...

 I work in the original track and I do a "PROCESS AUDIO" function with melodyne in the track. It prints melodyne to the track and removes the plug..... here's the other fast thing I do.... as I listen to the track after I go thorough it on a once over..... there are some little things I miss that first time..... so I insert melodyne again and ONLY let it grab a small snippet of the audio where the change needs to be. I process audio and move on. SO.... if it was not processing at the same level, that new snippet would be either louder or softer than the material around it and there is not the slightest bit of difference with the levels before, during , or after the new edit.

Thanks for answering, guys. 

1.  I started with the fader at 0 db and also tried moving it.  Automation was checked in the dialog box.
2.  Melodyne does have a way to increase volume:
• Select | All
• Select the gain tool (which looks like a hollow Melodyne blob)
• Put the curor in the box on the toll bar that says db and drag upward

Just not sure why this should be necessary.

The problem is not just with melodyne: I find bounce levels somewhat unpredictable.

I notice it mostly with Melodyne. I am sure konradh is not incorrect when he see's levels change with other plugins. I have not, as I don't bounce track much. I freeze, but not apply audio directly to a new clip inside a still "active" track.

And yes Melodyne does let you adjust volume. However, if you put a clip up, apply melodyne without even touching a single control, so basically rending the same exact clip, you get a level change. Fader at 0, pan at 0, etc etc. That is not the way things should be unless I'm mistaken.

fooman, Thanks for confirming that I am not imagining this.  For today, I am going to raise the Melodyne level 2-3 db and see if it sounds good when I bounce.

By the way, I need to bounce because this song has a couple of ritardandos (areas that slow down and then go back to Templo1) and one measure of 5/4 to make the pause at the end of one ritard sound natural.  This kind of stuff often messes up Melodyne and makes the vocal out-of-sync.  After I bounce, I will slide the pieces that are out of sync into place.  The Melodyne manual addresses this but I get mixed results and I don't want to redo all the tweaking I have already done—after which I may still have an out-of-sync vocal.

(Moving things in time is theoretically possible within the Melodyne interface, but I find it harder to get right than just slicing up a WAV.)