Update and answers - thanks again Cyril - a great late afternoon out
600ohm Fader CircuitNot much different to a 10k one apparantly
PM me your fax number and I will fax the circuit over (I don't have a scanner)
EQ design/history/notes
The Concord came initially from a 10-4 mini mixer
The original series 3 mixers used coils in the mids and bass - the Concord was the first design using a coiless EQ - good headroom at +22/+23
Wein Bridge Circuit - sounded nice due to harmonics generated
However with a parametric you cut - thus no harmonics (he did explain - I glass over - sorry
Mixer design
All consoles designed at level gain - so always have 6db residual in hand - thus less noise
Other design criteria
Very wide frequency response
Plenty of headroom
Clean, clean, clean - no distortion
Noise - if you have doen the four above and your cicruits are clean as a whistle where is noise going to come from?
So design the 3 above and noise will take care of itself
Musicallity wil come from the coils and the caps