General Specifications
Inputs: balanced mic <-65dBu (1kOhm)
           balanced line <-30dBu (50kOhm)
           aux return <-15dBu (10kOhm)
Equaliser: Bass ±15dB @ 45Hz
           Mid ±15dB 330 - 6.5kHz sweep
           HF ±15dB @ 11kHz
L&R Outputs: +4dBm 600 Ohm min load
                    max output +21dBm
Aux Outputs: +4dBm 1kOhm load
                    max output +21dBm
Fader type: 110mm sealed carbon track
S/N Ratio: All outputs at max, -84dB
            All ch to mix, unity gain, -74dB
Unterminated equiv input noise, -127.5dB
T.H.D: <0.03% @1kHz,<0.04% @10kHz
Headphone Out: mono mix, 1.7W max

Click here for Seck support and spares, salvaged / reclaimed parts

Seck 8 bus mixing console

12 channels for mic (XLR) or line (jack) inputs plus independent tape return on each channel, each with phantom power, gain, insert, 3 band EQ (with mid sweep), 4 auxiliaries, pan, solo, 110mm faders. 8 group.
Left and Right XLR outputs, 2 FX returns, LED meters, two headphone sockets, external power supply (PSU), hinged handle, all aluminium housing. 

18.8.2 model has identical layout and specification to the 12.8.2 but with 18 input channels.

Free schematic diagram for the multitrack recording 12 or 18 channel 8 bus mixer section.
Free data sheet for the Seck 6.2 Mk1
Free data sheet for the Seck 6.2 Mk2
Free data sheet for the Seck 12.2 Mk1  
Free data sheet for the Seck 18.8.2