Mackie 808S preamp resistor wattage value

[Jerry]

I have a Mackie 808S mixer with a channel(#7,stereo) that has low output for the mic input and is noisy(crackles). The stereo line input gain is fine. I've replaced the 2 transistors and 2 opamps in the mic pre and haven't cured it yet. I have the schematic for the channels and it gives the resistance and capacitance values, but not the watt/volt ratings for the resistors and film caps. Would anyone know what these are?

Thanks! Jerry

[Enzo]

Does it make a difference if phantom is off? Does grounding pins 2 and 3 to pin 1 on the XLR make any difference?

The schematic doesn't specify wattage, nor does the parts list. I imagine this is one of those all resistors are 1/8 watt or 1/10 watt unless noted sort of deals. Note the input resistors are spec'd 1/4W. You have the parts to look at, judge by dimensions. The e-caps show voltages of 25v or 6v as I see it there. The other caps are little 150pf or 47pf or what have you, and I can't imagine finding them with too low a voltage rating. If the input caps are rated at 25v, the typical 50v ceramic caps ought to suffice.

If it sits there crackling, scope the stages. Is the noise there at pins 1 and 7 of U76?

Does the input level control have ANY effect on the noise?

Hit the circuit with freeze spreay, any reaction? Use a piece of cardboard or credit card, or something to shield some parts if you want to get down to specific parts.