MIX Amp differences between 4K,5K,6K and 8K

[Matt Sartori]

I have been asked this question today and I think the 4,6 and 8000 have the same mix amp architecture and even the same card 82026 but the 5000 is different,although I am not sure how.

anybody wants to comment?

Mattia.

[marcmozart]

I think it has more to do with the revision of the desk. Can't comment on the 5K, but the Cards in the Center Section have been updated on the G, and again on the G+. I have heard that the G+ Upgrade in the center section made a difference and would love to know some details.

[sintech]

Yeah, the 4,6 and 8K all share the same '26' card  set, whilst the 5k is completely a different architecture, in terms of pin-out and voltages.

Regarding the G '26' card has (C1,C2) 2200uF caps, much bigger than the 470uF fitted to the E series, this gives more subsonic action! and the 'Back to Back' Electrolytic's on the Pre VCA return are changed for single poly caps.

E series next to G, it would be interesting to see a G+ service manual, see if any very late changes were made to this card.

[kilmister]

I compared my G+ manual with G and schematics of the 26 seemed very same.

-Paavo

[brewery]

not entirely sure (away from the studio and schematics atm), but i think the main difference are the monitor cards, which are properly balanced on a G+. this doesn't mean that a standard G might not have those.
the older cards had the monitor trims in on top of the 651, G+ has them on the cards themselves. a 'proper' G+ doesn't even have the holes for the trims anymore. lots of older desks had their 651 cards upgraded to G+ though, as it was an easy (but quite expensive) upgrade.

[sintech]

The 8K G+ channels here, are only sending to the mix busses as usual, Unbalanced or Quasi-balanced selected by the jumper. So any changes to the summing input over the G (or E with Coat-hanger mod) would be pointless.

Looking at the G+ specs, I'm with Brewery, they balanced up the main and monitor outputs, could this be what your seeing in the MRAC?

[Helterbelter]

I have been asked this question today and I think the 4,6 and 8000 have the same mix amp architecture and even the same card 82026 but the 5000 is different,although I am not sure how.

anybody wants to comment?

Mattia.

The 5000 has balanced routingbuses for all groups, and all auxes. Check the schematic of the 552 mixamp, it's the same summingcircuitry as the 557 masterbusamp for the broadcast version 5K, and the 594 busamps for the filmversion 5K.

As a matter of fact, its summingcircuitry is pretty identical to the 9K, if memory serves me well (which can be doubtful, haha).