Raph's alternate voice in Season 10 sounds like the OT Raph from Turtles Forever
 

Anyone notice how similar they sound? I hated the first alternate Raph voice in the two Season 3 eps and the Euro Vacation eps, but the one from Season 10 is actually quite good.

He may not be Rob Paulsen, but only a few of his lines felt off-pitch. He also sounded very similar to the Turtles Forever Raph, which I also liked very much.

I didn't think he was all too close in the earlier part of the tenth season, but as it progressed he tuned into his inner Paulsen a little.
Not great, but hardly worth complaining about. Even if the voice wasn't all that much there, the inflection and delivery definitely was.

The alternate Raph voice was probably the only thing that I didn't like about the red sky seasons. After several years I finally got the p'd off Raph that I always wanted. And then not only did season 10 feature a less likeable Raphael voice, but he kinda went back to being the silly Raphael.

He wasn't pissed off at all. He was virtually no different. If anything he seemed to crack even MORE jokes.

Now that you mention it, Michael Gough does sound a little like the Turtles Forever actor, I guess the Turtles Forever actor's voice sounds like it's mixed with Rob Paulson's and Michael Gough's voices.