Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
« Reply #1000 on: March 15, 2019, 11:12:28 AM »
Thanks for the quick reply! I tried pulling the line transformer and now I definitely need a new one. Not easy to get off the board in one piece. Anyway, it has to be the transformer so I don't think there were any hope for it even without me prying it off. Will order a new one asap and will report back.

Thanks again!

So, I got a new line input transformer and installed it. Now I get some sound, but what I'm getting is some 30-35 dB quieter than it is going out from my converters. I also see when running a white noise signal generator out from my converters that the low end rolls off quite a bit steeper than the digital signal I'm sending out from my converters. I'm a bit stumped for where to go with my troubleshooting. Does anyone have any tips? I'm getting the same frequency plot when using the mic input, so I'm guessing the problem lies elsewhere than the line input transformer, maybe? Hmmmm.

(In the photo I've compensated for the level loss by using the trim plugin in Pro Tools)


« Last Edit: March 15, 2019, 11:17:18 AM by bobtheninja »


Potato Cakes

Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
« Reply #1001 on: March 15, 2019, 11:49:04 AM »
First,  use pink noise and not white noise. There is a big difference.

Second, try injecting signal after the transformer and see if you get similar results. If the mic preamp is working then number of possibilities for the issue are extremely limited. Inject signal after the transformer and see what happens.

Thanks!

Paul

Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
« Reply #1002 on: March 15, 2019, 01:44:31 PM »
Thanks, Paul. I will do so Monday in a week. Left the studio for today and going on tour tomorrow.

Will report back, thanks again!

Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
« Reply #1003 on: March 30, 2019, 01:12:11 PM »
Hello,

Unfortunately my ez1073 doesn't work, no sound.
I generate a 1 kHz signal into the line input and  do I have to see on all the PL11 points the same sinusoidal (oscilloscope) as the input XLR or just some of them (which) ?
Thanks for help

Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
« Reply #1004 on: May 22, 2019, 09:01:12 AM »
Hi, just trying to understand the differences between 600Ohms terminated and unterminated on SW1 of the ez1073. Could somebody explain the reasoning behind?

'power good' circuit woes
« Reply #1005 on: May 29, 2019, 04:38:11 AM »
HOPING someone can give me a hand with this (??)

well i finished my builds (2) god - at least a year and a half ago now but ever since then i've been having troubles with the 'power good' light and circuit - never had a light turn on on my one unit and although it's not totally necessary - it would be concerting to know it's turned on etc since my rack is all but inaccessible from the rear or if there are any power issues with it.

so anyway i have it on the bench now - and here's the odd thing .... there is nearly 24V being fed directly to the LED post transistor .... the 24v and 48v power are FINE and within spec - resistors are FINE and within spec - but SOMEHOW i'm just NOT getting the voltage drop across the 10K resistor that i should be (it's not doing ANYTHING seemingly - but I dont' think that's the problem. Swapped out the 550BC transistor for a new one and NOPE - SAME problem!! Checked both the circuit board in fine detail for possible bridges and checked the schematic - and there's just NO WAY for 24V to feed into  the collector - it's driving me crazy - the transistor SEEMS to be working since the 23 point something voltage at the collector seems to be coming straight out of the emitter to the LED.

Can anyone give me a fresh pair of eyes on this?? It's driving me a bit nuts ... is there ANYTHING that could cause this condition??
thanks

Slenderchap

Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
« Reply #1006 on: May 29, 2019, 01:56:14 PM »
If there is no volt drop.. there is no current flowing...  is the LED in the correct way round ?.. or open circuit ?

Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
« Reply #1007 on: May 30, 2019, 06:41:10 AM »
If there is no volt drop.. there is no current flowing...  is the LED in the correct way round ?.. or open circuit ?

thank you for the reply Colin - will get back to you on that tomorrow when i'm back and can check - having the realization that maybe i'm maybe having a premature 'senior moment' - the original LED never worked in either orientation (tried reversing) but i measured 23.XX volts at the anode so i assumed it burnt out from an overvoltage but if I'm understanding you correctly once the circuit is complete and i just have one in there I SHOULD see it drop to something in the range of 2-2.5 v?  Sorry if that seems daft to ask but it doesn't make so much sense to me ... to see that happen

Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
« Reply #1008 on: May 31, 2019, 01:00:48 AM »
If there is no volt drop.. there is no current flowing...  is the LED in the correct way round ?.. or open circuit ?

ALRIGHT! THANK YOU!! it was just what i needed to hear!! sorry for the needless trouble (though i'm feeling more sorry to myself for having had the units de-racked for close to a year for something so stupid!). It's quite surprising the amount of time I waste on false assumptions about the way circuits work - it's something only experience and not theory can teach you apparently. For a good thirty years I'd had load of problems with capacitors based on the assumption they unload their charge explosively as soon as they got full (based on a demonstration my dad showed me when i was little with a large capacitor attached to two electrodes going into a cup with a poor hapless housefly inside!!) ...

as for what was going on the first time with the LED -hard to say what was happening. Could have been reversed though I doubt it - or it just could have been a bad LED - who knows ... anyway - i learned something new so thanks

edit: WOW - i just found the answer to that too! turns out the 1U enclosure i was using has a tab on the bottom that magically coincides with the underside of the solder pads and one or both of them were (it seems) grounding the bottom of the LED to the case! 

« Last Edit: May 31, 2019, 01:55:15 AM by leadpoisoning »

Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
« Reply #1009 on: June 13, 2019, 12:24:07 PM »
Could anyone confirm that the toggle switches are all in the engaged position when in the down position? For instance, phantom and EQ are on when down and signal is in phase when down, is that correct?


 

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