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

Talking to Jim, I have now made an unbalanced cable out of a balanced one  :
Because of the short lenght it probably won`t matter, so I`ll leave it as is, and solder the shield pins on the XLR`s together. Just thought I`d post if anyone else was wondering on the same.

audiophreak said:

My PT and PSU are in the box so I guess thats a posibility -  but the low and hi frequency select switches are fine - and as I said , when the mid frequency select is set to the Off position the noise goes away - the unit is dead quiet.

Click to expand...

Exactly the same problem here with an ez1073.  Everything is dead quiet but the 380hz and 700hz mid frequencies create a hum tuned to these 2 frequencies.

Have you found a way to fix this?

Dyonight said:

Exactly the same problem here with an ez1073.  Everything is dead quiet but the 380hz and 700hz mid frequencies create a hum tuned to these 2 frequencies.

Have you found a way to fix this?

Click to expand...

Ok got it!

It's the power transformer of the ez1073 that's leaking a +/- 320hz hum in the midrange circuit.

I placed a random steel plate in front of it and the hum dropped by half.

I ordered a sheet of mu-metal and will warp the transformer in it, should make a good improvement!

This is one of the reasons that I recommend putting the power supply outside the EQ case. The other is you can power more than one unit with 1 power supply. Those inductors are susceptible to "induced" noise from nearby stray fields.

A few builders have reported successfully installing power supplies in the EQ case but I believe a lot of time was spent orienting the power XFR and using some mU metal as well.

Cheers

Jim

Yeah I totally see the point of opting for an external psu.

That being said Collin said he never heard of this effect with an ez1073, I probably just got a power tx which is a bit off-specs or maybe my particular scenario causes this.

It was pretty faint I must add but I'll go the extra mile to have it as perfect as possible!

Just grabbed the last 2 ez1084s off eBay, can't wait to start on them. Im gonna attempt to build a stereo unit with dual concentric  switch/pot combos, probably the  BE switches from aml.  Trying to make it look as neve as possible. Wish me luck

So... what kind of electrolytic 470 caps did people get from WIMA? I have a 6.3V 470 that Jim told me to wait to install (compared to the 25V ones), and contacted TAW, who in turn said that the kit has been the same since the start. Anybody else used 6,3V 470uf electrolytic?

I have a replacement that can handle 25V on the way, but anybody can tell me what`s up?

Nope! My bad, I was looking at the power section. There are 4 at 25v in that section but  1 (C83) at 6.3v is in amp section, so all is right.

Sorry for confusion.

Cheers

Jim

fragletrollet said:

So... what kind of electrolytic 470 caps did people get from WIMA? I have a 6.3V 470 that Jim told me to wait to install (compared to the 25V ones), and contacted TAW, who in turn said that the kit has been the same since the start. Anybody else used 6,3V 470uf electrolytic?

I have a replacement that can handle 25V on the way, but anybody can tell me what`s up?

Click to expand...

Just got lucky and grabbed 2 neve 1084 face plates off ebay, this thing is gonna be killer. I think I might start a thread for it if you guys think that we be ok. Should be able to have all the parts and have it built by june.

Finally got the High-Q switch, so here`s the first of the two running beautifully! No smoke no funny business just pure neveness at first listen! Everything seems to work just as it should. Notice the output knob squeezed in there  8)

Another healthy baby born!

Congratulations!

Cheers

Jim

fragletrollet said:

Finally got the High-Q switch, so here`s the first of the two running beautifully! No smoke no funny business just pure neveness at first listen! Everything seems to work just as it should. Notice the output knob squeezed in there  8)

Click to expand...

...and the brother joined the party:



Loving the looks of these, real happy how it all turned out. Second unit fired up just as nicely as it`s older brother.

Input shields are floating on both units, outputs have neutral to ground at the source (pcb). Forgot to link the shields from input to output on the second unit, but can`t pick up any noise or differences between the two units so I guess it`s arbitrary in my situation.

They sound awesome! Love the ability to drive the input and back off the ouput, so many nice levels of saturation to be had. A beast on low frequencies! Makes the 808-bassdrum sing  8)

So... what`s your next project planned?  8)

Twin brothers born this week!

Enjoy the frequencies frequently!

Cheers

Jim

fragletrollet said:

...and the brother joined the party:



Loving the looks of these, real happy how it all turned out. Second unit fired up just as nicely as it`s older brother.

Input shields are floating on both units, outputs have neutral to ground at the source (pcb). Forgot to link the shields from input to output on the second unit, but can`t pick up any noise or differences between the two units so I guess it`s arbitrary in my situation.

They sound awesome! Love the ability to drive the input and back off the ouput, so many nice levels of saturation to be had. A beast on low frequencies! Makes the 808-bassdrum sing  8)

So... what`s your next project planned?  8)

Click to expand...

Ok got the second set of transformers and wired it up. Everything works great except the unit will not BYPASS a signal. Is this relay problem?

Bonsaimaster

You either have faulty relays and I doubt you would , or you have wired the bypass switch wrong. Middle position is EQ engaged. Up should be Hard Bypass which engages the 2 relays near the XLR input and XLR output. Down position engages the small relay on right side of PCB (looking at front side). Also check that your diodes for the relays are in the correct orientation.

Cheers

Jim

Bonsaimaster said:

Ok got the second set of transformers and wired it up. Everything works great except the unit will not BYPASS a signal. Is this relay problem?

Bonsaimaster

Click to expand...

Diodes are correctly positioned. The Switch seems to be wired correctly and confirmed with channel 1. Which relay would be at issue?

The EQ is working so that is a good thing. Bypass circuitry is easily traced if faulty.

I assume both bypasses are not functioning? I also assume that you used the relays as designated in the BOM?

Start with Hard Bypass. The 2 relays in back of board between the I/O XLR area.

The Hard Bypass relays are very simple. Input XLR to output XLR. Both relays must operate. Make sure you are getting the +24v from switch going to them. use VOM on connector for Bypass switch. If the +24v is there then turn board over (remove bottom case cover so you can work while unit is operating) and verify voltage is reaching the relay. Check your soldering if it does.

If all checks out, pass a +24vdc to the relay without using switch. Why you ask? Because the relays will make a very low "click" sound when engaged. It's so low in volume that the sound of the bypass switch will disguise it usually. By applying (bypassing the bypass switch! There I've said it) power to the relay silently you should hear a "click".

Get that one done then let us know progress.

Cheers

Jim

Bonsaimaster said:

Diodes are correctly positioned. The Switch seems to be wired correctly and confirmed with channel 1. Which relay would be at issue?

Click to expand...

Both the IRON and EQ switches work fine  just no BYPASS. will check tomorrow. Switches are the ones in the BOM.

Did you mean relays instead of switches? I was wondering about the relays.

Cheers

JIm

Bonsaimaster said:

Both the IRON and EQ switches work fine  just no BYPASS. will check tomorrow. Switches are the ones in the BOM.

Click to expand...

Sorry relays and switches are from the BOM