DigiTech’s Vocalist series are made with chips and algorithms from IVL Technologies. So is the Voice Prism. For all intents and purposes, TC Helicon is the new high-end arm of IVL, while DigiTech is the midrange and low-end. (IVL also makes the technology behind Yamaha’s vocal harmonizers, whether built-into a PSR-8000, 9000, 9000 Pro, Clavinova CVP-107, MU-100R, etc., or plugged in via a PLG100-VH card. They may make some of the others as well.)

TC Helicon is a new partnership between TC Electronics (known for very high-end outboard effects gear), and IVL Technologies.

The Digitech Studio Vocalist EX was discontinued months ago. Consider the Voice Prism as its replacement. The Vocalist Workstation is now the top of the DigiTech line, and anything higher than that will be coming out from TC Helicon.

The Voice Prism has more modern DSPs than the older DigiTech stuff, so it has more raw power. This power is put to good use, for things such as more effects (Phasers, Flangers, EQ, etc., instead of just the basic harmonizing, Gender [Studio and Workstation only], Vibrato, and [Workstation only] Digital Reverb and [Studio only] Timing/Delay of the DigiTech line), and more importantly, 24-bit I/O and processing. The flanging-type artifacts noticeable in most harmonizers including the DigiTech line are caused by integer round-off errors in the DSP math, and having 24 bits instead of 16 bits reduces the audible results of these errors by 256-fold!

Also, the Gender of the two Gender-capable DigiTech products is limited to two separate Gender settings at a time. If you have four voices, you can assign two to Gender #1 and the other two to Gender #2, or three to one Gender and one to the other, etc., but you can’t have three or four distinct Gender effects at the same time (well, three if you count the unprocessed Lead voice as a null Gender setting distinct from the up-to-four generated harmony voices).

The Voice Prism, on the other hand, has four distinct Gender settings per program, so each of the four generated voices can have its own vocal tonality setting. This helps them sound more like four distinct singers instead of copies of the same singer.

I personally own a Vocalist Workstation (pre-EX), and am considered something of an expert on both the Workstation and Studio series on the Vocalist mailing list. I get into the nitty-gritty of programming, having made my own User Programs and Songs.

Note: the Song Feature of the DigiTech units is woefully underused in the factory demos in ROM. My Workstation only has two demo Songs, and both merely use the Song Mode as a chord sequencer. It’s far more than that! It lets you sequence program changes as well! Because of this, I can (and have) easily perform, live, with all vocal effects intact and switched instantly via footswitch, songs as vocally complex as “Along Came Jones” using nothing but my Yamaha PSR-7000 and DigiTech Vocalist Workstation, a headset microphone, and my normal voice!