EZ1084EQ NEW BATCH COMING - SEE MY MARCH 27 COMMENT ON PAGE 38

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
I started building mine last night.  I got the AML kit and the TAW kit.  Super easy! 

Obviously I will be using my case which I have plenty of!  Just need to get some resistors and this will be ready to go in my rack.
 
dandeurloo said:
I started building mine last night.  I got the AML kit and the TAW kit.  Super easy! 

Obviously I will be using my case which I have plenty of!  Just need to get some resistors and this will be ready to go in my rack.

Hi Dan,

Glad you like the "EZ" part of the project. Yes please post pictures and especially tell us what you think about the sound !

Cheers

Jim
 
I put in one of my tant capacitors backwards.  It was c70.  Did I wipe out a bunch of my transistors.  I have some pretty major gain loss and it sounds like bandwidth loss as well.

Thanks for any help.
 
Ok, I got it going and sounds good from the simple test I have done.  I need to Bias it but don't have a scope.  Can someone who has biased theirs please get me a few voltages.  I would like to have the voltages of the emitter, collector and base of the 2N3055?  Thanks

Some inspiration for everyone.  My cases and ChuckD's knobs!

EZ1084-Side-Chucks-Knobsweb.jpg
 
Just beautiful Dan! Nice work.

Jim

dandeurloo said:
Ok, I got it going and sounds good from the simple test I have done.  I need to Bias it but don't have a scope.  Can someone who has biased theirs please get me a few voltages.  I would like to have the voltages of the emitter, collector and base of the 2N3055?  Thanks

Some inspiration for everyone.  My cases and ChuckD's knobs!

EZ1084-Side-Chucks-Knobsweb.jpg
 
Okay, I'll start by saying this EQ sounds GREAT!!  And it was an easy build..

BUT

After some use, I began noticing that my HPF seems to amplify/create hum.. Kind of ground loop hum but not..
The unit is fine if the HPF is set to "off". 

So, I took the unit out of the rack (switched on) and as I did so, the hum disappeared... Naturally I thought it must be some interference from a neighbouring unit so began switching units off.  Now everything in the rack is switched off except the EZ1084 and I still have the same problem!!
It's almost like proximity is the problem.. I swear I can hear a change in the hums level just lifting and closing the lid!!

How is this possible?!

btw - I have 2 boards in a 2u case..
 
Dubka if the EQ sounds good out of the rack.
try to check your ground wiring first.
Try to sand the all the parts of the case that touch so they make better contact for grounding.

Thanks.
 
Cheers mate.
I should probably point out, the hum begins before the front panel touches the rack rails and grows in volume as the unit moves deeper into the rack.. It's more like psu interference from another unit (except nothing else is switched on!!!)

Once again - ONLY WHEN HPF IS ENGAGED
 
Dubka said:
Cheers mate.
I should probably point out, the hum begins before the front panel touches the rack rails and grows in volume as the unit moves deeper into the rack.. It's more like psu interference from another unit (except nothing else is switched on!!!)

Once again - ONLY WHEN HPF IS ENGAGED

First off congrats on your finished unit! Nice to see my babies growing up and doing good work throughout the world.  ;D
Second I assure you these EQs are dead quiet. Quieter than the original design. I spent many hours making sure everything is well isolated and grounded.

Unplug the other racked gear one by one until your hum disappears. If the hum only disappears when you unplug the last unit start plugging back one unit at a time so that there is only one unit plugged in. In other words plug unit 1 in and see if hum appears then unplug it and do same for unit 2 and so on. If it happens you get hum on every unit you must have a ground loop inside the EQ somewhere.

It is possible that your case is flexing as you put in the rack and then making contact or cutting contact with ground. Does moving the EQ to another position help?


Let us know.

Cheers

Jim
 
But that's just it - nothing else is switched on!

And what's the connection with the HPF?  The unit sounds fine if I don't use the HPF...

The hum gradually decreases as I lift the unit out of the rack and steadily increases as I slide it back in... So odd..
 
Dubka said:
But that's just it - nothing else is switched on!

And what's the connection with the HPF?  The unit sounds fine if I don't use the HPF...

The hum gradually decreases as I lift the unit out of the rack and steadily increases as I slide it back in... So odd..

Yes but did you unplug the other units?

There should absolutely be no connection with the HPF section. The few people that have had problems with their unit have always found the problem. It was always something simple that was overlooked. Not saying that is what is happening but....

What about your power supply. Is it the Fivefish one? What enclosure are you using. How is it grounded? Is it also mounted or touching the rack? Does the unit have any hum if away from rack (sorry if you stated this before. I may have wisked through your previous messages). We'll find the culprit by process of elimination.

Try and see if there are some cold solder joints in the HPF section. You can email me at [email protected] as discussing here is distracting (unless someone else has a solution).

Hang in there.

Cheers

Jim
 
Ok, so I bought one of these boards from the first run, and another from the second run -- and this morning I finally got around to finishing the first channel (after what, about two years?) :-[. Finished, sans enclosure, that is.

First off I've got to say this is a great project, super easy build, awesome sound. Big thanks to Jim and everyone else involved who helped make this happen. Now on to my problem:

Upon completion I ran some pink noise through the unit and into an analyzer to check what the controls were actually doing. Everything checked out fine except for the LPF. It seems that it is acting not as an LPF, but I am actually getting a narrow notch filter at the selected frequencies, nothing rolled off above it. Any ideas?

 
Just finished my second one.  Sounds great!  Thanks for the project. These turned out stunning.  Now to get them biased and in the rack!
 
Still troubleshooting over here, still getting weirdness with the LPF.

So far I have reflowed all solder joints, checked continuity between all components and traces, double checked all component placement, even swapped out the 9044 inductors. Everything appears to be fine, and everything besides the LPF is working properly.

I still am getting a just a narrow, deep cut at the following frequencies starting from the off position: 12k, 9.5k, 6.6k, 5.7k, 4.2k

Am I missing something? Is everyone else's LPF functioning properly? Perhaps my switch is bad, or maybe a cap? This is a bit past my comprehension so if anyone could offer some advice I would greatly appreciate it.
 

Latest posts

Back
Top