Do all vibrato plug-ins phase at zero Depth?

Hi -

Can someone check me please? Running a vocal through the two vibrato plug-ins I have (Melda MVibrato and the stock Cubase vibrato), they each sound as if it may be adding some kind of delay, so that it sounds a bit phasy.

Repro:

  1. Route some audio to the master out. I used a vocal with a fair degree of sibilance.
  2. Send it at unity gain to an Group that has the vibrato plug-in inserted on it (Depth = 0.00%), in turn routed to the master out.
  3. Listen while toggling the Vibrato plug-in on/off while looping the audio.
  4. Then render the master track twice, once with the Vibrato plug-in bypassed, once not. Reverse phase on one of the rendered tracks and play both.

What I found on my system:
Step 3: Toggling the Vibrato plug-in in/out made a definite difference in how things sounded. Especially prominent in the “Ssss” of the vocal track.
Step 4: The vocal tracks didn’t null (the backing tracks did, as expected).

Can anyone else reproduce that please?

Thanks much - Alexis

(PS: The application I was trying to use the Vibrato plug-in for: In the Group Channel, inserted just before the Vibrato plug-in, I had a reverb plug in. I was trying to apply a modulated pitch shift to the reverb. Things didn’t sound right - with the Vibrato plug-in inserted/not bypassed, there was noticeable phasing even at Depth = 0.00%; when the Depth was turned up to around 30-40%, the phasing was very obvious. So I wound up simplifying, and getting the results as above).