Pioneer Exclusive M5
(1982 - 1988)
Pioneer Exclusive M5a
(1988 - 1991)
Pioneer Exclusive M6
(1989 - 1991)

While the vast majority of Pioneer's Exclusives was NOT exported, the M6 was.
Probably more as a test : to see if there could be a market for well-behaved but ultra-high-end japanese powerhouses outside Japan. It seems there wasn't in the end because the C7, M7 and ultimate M8 (a monoblock version of the M7) only saw brief and often unofficial appearances outside their homeland.

I believe the M6 to be the export-only version of the M5 bestseller - with the added XLR input of the M5a... As potential proof, the image below was printed around the M6 in a rare european catalog but it isn't the M6 : it is the M5a ! However, the basic circuit for all three versions (M5, M5a and M6) comes directly from the M-Z1 and C-Z1. Furthermore, Pioneer's technical papers for the M6 describe the latter as an M5 - so this post can therefore count as covering both the M6 and the M5. The differences between the M5 and M5a are centered around the upgraded caps (see below) and the XLR input.

Anyway - the M6 is a 300W in pure Class A powerhouse of the non-NFB kind, with Pioneer's SLC (Super Linear Circuit) in upgraded form - the circuit in detail you can read about by using the "more" pop-ups below.
The chassis, first, is carbon-coated aluminium (!). The two big transformers are rubber-damped and housed in internally damped resin cases for no no no vibrations.
The three polycarbonate/polypropylene caps are shielded by a resin case and tube. The PC boards are of glass epoxy and the tracks of 99,99% pure OFC copper, eight times thicker than usual.The PNP and NPN transistors in the SLC are matched pairs for common-mode non-linearity which remain mirro images of each other ; reverse-connected, they make linear amplification possible by eliminating distortion due to non-linearity.
As for the M5a, the input is doubled with either balanced XLR or RCA terminals, wih a ground post just in case. Speaker terminals are gold-plated and e x t r a large. Special feet, special power-cord, ultra-select componentry etc - of course. Dynamically, the M6 can output 700W at 4Ohm and 1000W at 2Ohm - in pure Class A !

If we judge by the astounding amount of M-Z1, MZ-1a and M5 that sold in Japan, Pioneer's Exclusive amplifiers must have been also a bit... supreme.

This post was made possible by Yves Braeckman who provided the nice images you see here and Pioneer's own french division which has kept in storage most of the literature related to Pioneer's long history in high-end audio.

Click below for the entire circuit descriptions !!!