Hmmm...... what value resistors are in your potential divider ?

75K in series with both the live and the shield and 560 Ohms across
them. These figures (and configuration) were arrived at with the help
of the folks over in rec.audio.pro.

Using a mic input is a really bad idea. Performance is limited by the
noise figure of the " PA head's " own mic amps.
It is easy to show using theory that this will *always* be worse than
just using the PA head's mic amps on their own ! No matter how good
the mixer is.

I know, I know... :-( We're not gigging at the moment (band reshuffle
!) and have spent a bit on other gear recently, but a separate PA amp
is next on my shopping list. I can finally run in stereo then ! (I
just want to hear my stereo chorus pedal through the PA :-) )

I really don't think the desk is to blame.

Perhaps it's not. I will do some more testing on Friday. I'm only
really basing my accusations of the desk on the fact that when we plug
into the PA head directly (mics and guitars), there's almost no hiss.
Bit of mains hum (diabolical electrics in the place we practice in !),
but no hiss. When we bring the mixer into play and plug into that,
there's a noticeable increase in hiss from the PA speakers when we're
not playing. I'm also presuming that this hiss will be 'polluting' the
sound when we are, - I can't hear it then, but I know it's there! We
have nice guitars and good mic's and I want it as clean as I can get it
:-)


Doesn't the PA head have a line level - ish input ( like a stereo
input for example ) ? Or an insert point. That would produce far
better results.

Yes, but none that I can route via the internal reverb of the PA head.
I need to use two mic inputs on the PA head, one with a bit of reverb
for the vocals & rhythm guitar, and the other one dry (I have a better
quality reverb in an effects pedal) for my guitar. I can't see any way
of routing a line level input on the PA head through it's internal
reverb - that would solve everything if I could !

http://homepage.ntlworld.com/anengin...7%20Manual.pdf
(though sadly it's not a schematic).

Incidentally, the mixing desk has it's own 'reverb'. Possibly the
worst I have ever heard though ! It's a simple delay, more an echo
than a reverb (unless it's faulty and not supposed to sound like that
!). Once again, it's stuff I plan to sort when funds are available - a
decent outboard reverb unit - eventually.

But until throngs of adoring fans start throwing money at us ;-), we're
stuck with this mish-mash setup :-).