Hey hey,
Had the weird experience to record percussion on a recording of ALWs Jesus Christ superstar that a friend of mine is doing and they had almost entirely used Mellotron and Chamberlin sounds for Strings, Oboes some voices but it really sounded flat and weird. Still had that weird ambience to it but didn´t have the right Kapaooww feeling. I think for instance the sampled Chamberlin stuff sounds great due to Harry Chamberlins great recordings of the instruments but when they are so clean and Hifi they just turn into weird Cellos sounds with the vibrato in the wrong places. Couldn´t help putting on some Fiona Apple when I got back home just to check that I wasn't all wrong and all of a sudden all the spinetingling came back.
I think the most important thing is when you use Mellotron samples is to get some of the original grittiness in there...pull it through an amp and mike it so it has some sonic framing to it. I do that a lot with my 400 pulling it through a Guitar amp with just a bit of Spring (no...not the band) reverb and it just sounds...right at least to my ears. If you doubletrack it ( if it is strings for instance) and pan hard lef/right and then add root notes on the Cello....you are home.
Slight sidestep...I once used a Optigan drum loop on a pop track and when I showed up at the studio the next day...the exhausted engineer proclaimed proudly that he had spent the previous night cleaning up the loop getting all the scatchiness and clicks and cracks out...A difficult discussion followed.
I don´t want to be lengthy about this but another thing is...If you are using samples. One should try to play the sample in a original-sound manner. If you listen to the big Mellotron players it sounds great because they are adapting the playing to the instrument. Some notes are out of tune...so don´t play em et.c et.c Big massive chords didn´t always work out so you break it down into parts. John Paul Jones talked about approaching recording Mellotron parts as in viewing it as a String section. Everyone plays more or less one note interacting with the others creating chords and melodies.
What I am trying to get at is I think the samples are pretty decent. But the Mellotron isn´t a perfect instrument. If you play incredibly fast runs on a sample of the 3 violins it won´t sound like Tony Banks, King Crimson or Rick Wakeman. And it won´t have anything to do with the sample.
An interesting thing is also the fact that all of a sudden there must thousands upon thousands of people with samples of the weirdest Mellotron sounds available and I have so far (to my knowledge) never heard anyone use any of the Mark II organs or the electric guitar. It is still the same old strings and choirs... Seems like a terrible waste of opportunities.
Best regards,