EZ1073 Build

[FelixT]

So just reflowed everything and gave another check to all the joints, and to make sure there are no shorts on lead ends etc. I also pushed the op tx connector all the way down finally. Still get no relay click, and while the sound is better through the unit it is still a bit quiet and crunchy, which I would assume would be sorted with proper biasing.

the worrying thing is that there is no relay click and the voltage between TP1 and TP2 is the full 16VDC. This has to symptomatic of the root of the problem.
Anyone have any ideas why the relay wouldn’t be clicking?

 

[Joeblutak]

I built the free standing version of this kit and found it relatively easy to signal trace audio through it. You’ve probably checked this but bear in mind that a low level and trebly output can be the result of connecting a transformer balanced output to an unbalanced input, but forgetting to earth the negative side of the transformer? I was caught out by that one!

Hey Stevie, I was just wondering how one would go about testing this? I can't seem to find where I would test the earth on the negative side of the transformer on the schematic!

 

[[email protected]]

G'day Felix,
I just finished building an AML ez1073 and I have the same symptom of low output and heavy, crunchy, distortion. Although, it's intermittent. I just plugged in a mic and it was clear and clean, changed the mic 2 mins later and it's distorted again.
Have you had any luck diagnosing the issue?

As a point of interest, I also noticed one time that it seemed to be clear in some gain positions, whilst distorted on other gain positions, however after playing around for a few minutes it was distorted in all positions. Got me wondering if there's something wrong with my switch.

Any tips on how to diagnose the issue would be greatly appreciated.

Regards,
Al

 

[[email protected]]

G'day folks,
I have another interesting observation regarding the distortion issue on my AML ez1073. When I first powered up the 1073 this morning with a condenser mic it's clear with a strong signal then 20-30 seconds later the signal fades and distorts.
I just switched off for a few minutes then powered it back up with same result. Smooth for a short period then fades in to distortion.

Any advice on how to diagnose the issue would be greatly appreciated.

 

[andow]

I just noticed that the 1073 kit is not listed anymore. Anybody know if it's just temporarily out of stock?
Also, a colleague said he's been trying to contact AML but got no response, any info on that?

 

[johnchantler]

Shows as available for me

 

[andow]

Shows as available for me

I realised this thread is about the 500 version, I was talking about the rack version...

 

[noiro]

Must be just out of stock...ask Colin direct then!

 

[dogma]

Yes it’s just out of stock atm, I was the same, about to buy 19” - he is waiting on pcb but have no gear - best bang for buck in audio is still around

 

[FelixT]

After taking the boards off again and narrowing down to the surge protection board (with the relay) I ended up taking that relay off the board and testing it off board. It wasn’t clicking until given around 25V so I chalked that up to a failed unit.

I bought a second kit (I want a pair anyway for outboard mix bus processing) and first thing I did was test that new relay. Sure enough it clicks on the dot of 16V and is a healthy sounding click. The old one was a squelchy unhealthy sounding click.

I am gonna do the new kit completely fresh and use it to diagnose the first kit and also buy a replacement relay for the first.

I’ll let you know how I get on!

 

[[email protected]]

Hi Felix,
Thanks for the update and well done on the root cause analysis. Sounds like you nailed down the fault. My issue is now intermittent. The unit started working for a few days, then the fault was back. Signal fades to almost nothing and it distorts if I yell in to the mic. However, last night worked flawlessly again. Got me stumped.
Sounds great while it's working, but.....

 

[FarisElek]

If you yell into it and it works that means it’s definitely means their is a weak connection in the audiopath. Can even be the xlr. I’d check solder around the opamps and try moving your 500 to a new slot as well. You never know l