Home Forums Ask Ted Impedance balancing 828 outputs? Reply To: Impedance balancing 828 outputs?



Are the schematics posted on the website somewhere? I’ve been unable to find them using google, could you email them to me?

I ended up using 100R resistors to impedance balance the direct outputs. I was going to do some measurements and try using trimmers, but this was a quick fix and allows me to use the balanced jack loom that I have to hand!

The version of the 828 that I have doesn’t seem to have the discrete mic pre, it looks like the transformer (a belclare) goes straight into a 5534. Sounds better than the preamps on my soundcard either way. It also seems that four of the channels direct outs are taken pre-fader, and the other four are taken post fader. I noticed a resistor on the channel PCBs that was soldered into a different position that correlates with this. Would the desk have left the factory like this or was it modified afterwards? I like the extra flexibility it provides, given that the mic amps don’t have a pad.

I have noticed that with phantom power switched on, the power transformer acoustically buzzes. The phantom supply still works, and measures correctly, but I take it that this isn’t normal. I intend to recap the desk soon, and will take a closer look at the PSU then.

Many thanks,