Mackie 808S No signal from L/R Mixer out

[chunkitup]

I just bought this unit off of craigslist and there was no way to check if everything was in working order. Perhaps i am missing something. I bought the BBE Max-X3 2-Way Stereo/3-Way Mono Crossover so I could use subs. Page 11 in the manual
http://www.mackie.com/pdf/ppm_om.pdf
is how I am connecting it but I am not getting signal out of the L/R mixer out jacks. I plugged my headphones into each jack and there was nothing. I also checked the signal for the monitor out and there was nothing. If I need to open her up does anyone have the schematic and advice on what to check first.

Edit: When plugging into the mixer out jacks, shouldnt the signal be cut off from going to the output and sent out to the crossover then the high signal would be returned to the mixer? Because it doesnt.

[Jazz P Bass]

Is the Main / Monitor switch set to the out position (Main/ Main)?

Other than the sub & monitor issues, do both of the amps work in the Main/ Main setting?

[Jazz P Bass]

Oh, the schematic is available here: MACKIE 808S MIXER SCH Service Manual free download, schematics, eeprom, repair info for electronics

At the bottom of the page, wait until this:"This file is downloadable free of charge. ...processing"
Says this: "This file is downloadable free of charge Get Manual"
Click on Get Manual.

[chunkitup]

Is the Main / Monitor switch set to the out position (Main/ Main)?

Other than the sub & monitor issue, do both of the amps work in the Main/ Main setting?

Yep, the switch is set for Main/Main and yes both main power amps are working properly. Perfect stereo sound.

[Jazz P Bass]

Edit: When plugging into the mixer out jacks, shouldnt the signal be cut off from going to the output and sent out to the crossover then the high signal would be returned to the mixer? Because it doesnt.

Page 19 of the schematic shows that the Mixer Out is in parallel with Power amp In.
Mixer out will not break the signal chain.
Power Amp In will. After the Mixer jack.

The signal level at the Mixer Out jack is not strong enough to 'drive' a headphone.
Instead, use your DMM or a scope to verify that there is signal at the jack.

The idea behind the hookup in the Mackie manual is to use the Xover to split the HF & LF signals.
The HF gets returned to the Power Amp In & on to the mains outputs.
(I would imagine the HF frequency range is selectable at the Xover)
If you want full signal in the mains, simply do not return the signal to Power Amp In.
The LF from the Xover will then go to the subs.

[chunkitup]

I thought that perhaps the line level was too small of a signal so I measured and I get no signal. I do want only the hf going back into the amp in jacks.
So when I had it correctly wired I still had the full signal going to my hf tops and no signal to my sub amp.

Edit: I had 5 minutes to run home at lunch and check whether the audio stopped when I inserted cables into the power amp in. NO! Then I remembered the drawings in the manual regarding the cables and jacks. So I pulled out the cables til they clicked, like using a mono cable in a stereo jack and holy crap the connection was severed. Now when I get more time after work I bet everything will work when the cables are inserted only to the first switch. I dont remember reading that was what you were supposed to do but the schematic of the plug and jack is what worked in my brain.

[Jazz P Bass]

Then you have a jack circuit problem.

I don't know that it's a line level signal.

If you insert a 1/4" mono plug into either Mix Out jack you should be able to read the two resistors to ground.
120 ohm in series with the 20K.
Chances are that the 120 ohm is open.

[chunkitup]

Hey Jazz please read my edit. Could you look at the manual and see if I am on the right track.

[Jazz P Bass]

The Power Amp in jack is a Tip, Ring Sleeve setup.
The Tip is the signal, The Ring & Sleeve are at ground.
So I don't see why going in 'one click' would work at all. (one click is ground)

At any rate, the set up as described in the manual is correct.
But you have to correct the Mix Out no signal problem.

As I said, the Power Amp In is only needed if you do not want the full signal going out to the mains.
Get the Mix Out working for the subs before you put anything in the Power Amp In jacks.

[g1]

This is quite odd. The schematic shows unbalanced 1/4" for mix out and pwr.amp in, but what you are finding implies TRS balanced.
Some of the spec sheets also call mix outs TRS.
So perhaps there is a schematic error, or they have updated the circuit but not schematic.

[Jazz P Bass]

The manual does specify an unbalance jack 'connection' for the MIX & Power jacks.
The type of jack itself is not specified.
Mackie may have simply used a common jack to the preamp inputs (Insert)

[chunkitup]

Mackie - 808S

I had to type in address. My phone is having trouble pasting.

Skip down the page and it explains they are 1/4 TRS jacks. Yea I dont have to open it up!!

[chunkitup]

Obviously the 6 TS 1/4in plugs will not work for this application. What a bummer. I have no other need for all these patch cords.

Please help me with the proper cords. The BBE has either XLR balanced or TRS unbalanced in and outs while the Mackie has TRS unbalanced in and outs. Should I just get TRS to TRS patch cords? or how can you go from XLR balanced to TRS unbalanced.

This is probably a really stupid question but I cant put my brain on it. Ive been reading about XLR balanced and unbalanced as well as TRS balanced and unbalanced and I feel like I am on a merry go round and getting dizzy.

[Jazz P Bass]

The mix output is indeed a TRS jack, although it is not being used in that manner.
TR is all you need.

Have you measured the resistance to ground from the Mix Out jack Tip to chassis ground? (Post #7)
For that matter, prove out that the Ring is common to the chassis.