Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500

The polarity shouldn't effect level as far as I know, should just make + into - and vice versa in respect to the audio coming in.  Used for things like micing the top and bottom of a snare for instance where 2 mics or signals are out of phase, you flip that and put them in phase.  You're sure you have the inputs wired correctly now?  Also, make sure you didnt accidentally make a solder bridge anywhere, esp. on the greyhills.

Sounds a bit like one of the input or output connections is no connected ... try connecting it to a completely different piece of balanced gear using different cables...just in case you have some sort of wiring oddity....... if it is the same then it may be an open circuit inside the box somewhere.... maybe the molex pins are connecting to the cable sheath instead of the wire core... seen that a few times.

Colin
www.audiomaintenance.com

Been pointing around with the multimeter in the patchbays and everything is wired correctly. Been doublechecking the connections in the 1073 and it seems correct. Molexes are fine, but when checking the ones soldered to the board hot and cold is getting connection on both inputs and outputs, is that normal? Been looking around with a magnifyingglas but cant find any bridges and i've resoldered everything that could be a cold joint.

It's odd because when thinking back the mic input worked perfectly in the old studio, not the line though but now both act the same...
I'm gonna try and set up the mobile rig to see if i get any changes there but i need to solder some patch cables first.

Hey guys - see if you can help me out with something. I got my 1u EZ1073 put together a few months ago.  Everything appears to work correctly with the exception of two things:
  - when I touch the mic gain knob, I get a sudden jump in hum.
  - The mic side has a low hum(kind of sounds like steady wind actually) that I can't seem to figure out where it's coming from.  You have to crank everything to hear it, but it's pretty noticeable with all gains stages maxed out.  The hum does not exist when I switch to Line input.

Any ideas where I can look or how I would go about troubleshooting that?  I admit to being a little green so any bit helps.  Thanks!

WNS, I recall you miswiring the XLR connectors a while back.  Is it possible that you have a solder bridge on the actual XLR connector somewhere?

sr1200 said:

WNS, I recall you miswiring the XLR connectors a while back.  Is it possible that you have a solder bridge on the actual XLR connector somewhere?

Click to expand...

Yeah i've quadruple checked every connection i've made since then, no bridges, it's on the PCB part of the molex when the XLR's are unplugged. I am borrowing a scope today for an undecided future, hopefully i'll be able to figure it out.

Dont need a scope to see where thats happening. Just set your multimeter to beep and see where its open.  Keep in mind that solder can work its way UNDER the molex header if you really globbed it in there, Remove the header all together and wire it directly... see what happens.

Apparently the entire Mic/line switch is connected to ground? And in turn same with the Line switch...

Check near your relays.

sr1200 said:

Check near your relays.

Click to expand...

There are no relays....

WNStudios said:

I am borrowing a scope today for an undecided future, hopefully i'll be able to figure it out.

Click to expand...

Did you figure it out ?

Colin
www.audiomaintenance.com

Slenderchap said:

sr1200 said:

Check near your relays.

Click to expand...

There are no relays....

WNStudios said:

I am borrowing a scope today for an undecided future, hopefully i'll be able to figure it out.

Click to expand...

Did you figure it out ?

Colin
www.audiomaintenance.com

Click to expand...

No it's even worse now...Apparently hot and cold are connected to ground now, aswell as most points on the mic/line switch and line gain...I've been checking both top and bottom of the board and cant see a single bridge, even resoldered the switches just to see aswell as took away the molexes and soldered the leads directly to the board. I'm not getting any continuity between input and output except for grounding...

Dont think you would get continuity btwn in and out.  Is it possible you mixed up the line/mic trafo mounting boards!  Also. There might be a solder bridge on one of the pins for the trafo connections. Either on the main board or one of the mounting boards. Bit of a pain to get em off with all those points. Did you test the xlrs with nothing conected to them?  Bridge might be IN the xlr chassis.

Hey, just finished my 2nd unit.  Got a question, cause I dont remember running into this the first time through.  My 48V trimmer is only allowing me to get to about 45.1v.    Seems the trim pot needs to be turned multiple times for there to be a change in a tenth of a volt.  (possible i either got the trimmers mixed up or got a bad one?) or did i put a wrong resistor somewhere in the 48 v section)  Im putting in a mouser order in the AM, perhaps I should order one just in case.  The bias voltage section worked fine btw.  Other than that... Unit sounds amazing (as expected!)  You made this kit WAY too easy man... (not a complaint )

EDIT.  i opened up my "good" unit and i have identical voltages up to the VR (so the recitifiers and torroid are good.  Im thinkin bad pot for sure now) double checked all the resistors and caps in the area, everything was correct in respect to values.  Im gonna order a new one tomorrow from mouser, that should take care of er.  I was also quite impressed withmyself in that I drilled out my own front panel for the thing and it actually fit!  (im aweful with measuring and cutting... im cut 5 times measure nonece) lol

NEW EDIT: yep bad trimmer, works fine now!!

I'm recording all week so i wont be able to work on it for a while but i know the trafoboards are right. I have however not tested the XLR's yet but i will do as soon as i have some free time.

Did you figure out the problem yet ?

Colin
www.audiomaintenance.com

Mines been up and running and have already tracked with it.  Was a bad trim pot.

I see that Dan (Collective cases) has now started making metalwork for the 1U version.

http://www.groupdiy.com/index.php?topic=41963.0

Colin
www.audiomaintenance.com

glimmertwins said:

Hey guys - see if you can help me out with something. I got my 1u EZ1073 put together a few months ago.  Everything appears to work correctly with the exception of two things:
  - when I touch the mic gain knob, I get a sudden jump in hum.
  - The mic side has a low hum(kind of sounds like steady wind actually) that I can't seem to figure out where it's coming from.  You have to crank everything to hear it, but it's pretty noticeable with all gains stages maxed out.  The hum does not exist when I switch to Line input.

Any ideas where I can look or how I would go about troubleshooting that?  I admit to being a little green so any bit helps.  Thanks!

Click to expand...

I Got the same problem, I have checked all solders. Big Hum with Mic, No hum, when i switch to line...
Anyone have an idea?
Yannick

I have rechecked all solders and now it works!!!

Very good sound as expected  ;D

Hi!

First post on this forum.

I've just finished my EZ1073, but I can't seem to get it running. Every time I connect the power, the fuse blows. I've looked for solder bridges and cold solderings as well as comparing it to pictures of some of your finnished projects, and I can't seem to figure out where the problem is.

Do you guys have any idea what I could have done wrong?

I'm kind of a noob, so probably it's something very obvious.