The ML-6 preamplifier is a mono unit : you need two of them. The have an external power supply (ML-6 Power supply or PLS-154), and obviously lack of a balance button :-)
The ML-6 will be upgraded twice by model ML-6A and later the ML-6B.
They are of course modular. You can't imagine a simpler preamp with only two buttons on the facade, the input selector (3 positions, Phone, Off, Line, labeled SOURCE) and the volume (labeled OUTPUT LEVEL from infinity, then -23 to 0).
The ML-6 exists with white or black faceplate..
SpecificationsSee the brochures.
BrochuresML-6A Preamplifier [download]
ML-6A Monophonic Preamplifier [download]
ReviewsLa Nouvelle Revue du Son [download] (with ML-3)
La Nouvelle Revue du Son [download] (ML-6A alone)