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

[chocorookie]

This what happened on my unit no.2:

check that the body of the 2N3055 is not shorted to the Agnd (screws are a bit big for the pads really so they can cause a short to the ground plane).... when you have removed the regulator to replace it just measure the resistance between the 24v tab and the Agnd tab.... if you get a very low resistance (say 1 or 2 ohms) then you have a short circuit somewhere

The 12E resistor began to burn and a lower 24Voltage. (see 15 posts ago) Everyone should take a close look to this when installing the heatsink of the 2N3055. I loosen the bolds and put a M3 for it, this did the trick. Ain't having a 12ohm resistor arround, I checked the old one and it reads 9.1ohm with some burn marks, but good to go for testing, allthow no good voltage drop to 24 V.

Result: non smoking working unit!

The new 12-er is allready on the bench, didn't have the time to interchange it. Also I do a check layer on for all values in the "3-rd section" where the trouble with the screw shortage began.

Good to know 4 all you guys still in the building and troubleshooting stage.

Regards Patrick.

PS, also my 48V voltagesupply mic switch is up-side-down in switching. have to mark it on the chassis before people are starting frying microphones ;D

 

[sr1200]

Just wanted to find out if there is a substitute for the WIMA MKS2 caps, there are 3 I cant find as MKS2's but found them as MKP2's.  (One is the polyester and one is the polypro)  Is there a tonal difference between the two, are they interchangable?

Thanks much

 

[sysexguy]

Thanks Colin, package arrived yesterday and ebay was kind to me....

Andy

 

[dgoszillai]

hi
i have 2xez1073 1U
i have problems with 2 rotary switch. one is the LF Freq of unit1 and the other the HPF Freq of unit2
i put the Adjustment Pins at 12oclock and 5oclock but when i turn the knob i get 7 positions
any idea ?

also a question about the 220-240v Transformer Wiring.
what do i do with the grey and violet wires ? i sold them together ? (i noob)

 

[Slenderchap]

i have problems with 2 rotary switch. one is the LF Freq of unit1 and the other the HPF Freq of unit2
i put the Adjustment Pins at 12oclock and 5oclock but when i turn the knob i get 7 positions
any idea ?

also a question about the 220-240v Transformer Wiring.
what do i do with the grey and violet wires ? i sold them together ? (i noob)

You have either "viewed" the switches upside down (ie your 12 o'clock is actually 6 o'clock)... or more likely, when you put the pins in, the switches had already been turned so they are now in the"wrong half" of their rotation. When you fit the pins, the "D" of the shaft should be in the position shown in the colourbook (flat pointing toward the 7 o'clock position).

The grey and violet wires need to be connected together for 220-240 operation.... but BEWARE... they will be at 110-120volts !... so must be insulated properly from everything.

Colin
www.audiomaintenance.com

 

[Brotastic]

I finally got my two ez1073 preamps working.  I used to much solder on some resistors and I didn't not properly mount the Voltage regulators so they touch the heat sinks.  Here are some pics with Chuck of Cathedral Pipes knobs.  They sound really stunning on vocals.  I will be testing them on some guitars soon.....can't wait.

Thanks Colin.  I know I annoyed you with all my newby questions...hahaha, but thanks.

Dan

 

[Brotastic]

here is another one.  Now if I can figure out that dual 1176 it will go in the empty space!

 

[saxmonster]

Looks great Dan, good to hear you have them up and running.

-Scott

 

[Brotastic]

Thanks man.  I am glad too.  Now I just need to work on my dual 1176

 

[dgoszillai]

thx Slenderchap i'm almost done !
about the DC FEEDS gould said :

unless you want to hook up some other device you don't need to use them

can someone explain me what "other device" he means ?
i have nothing set on these DCFEEDS. is that ok if i power up the unit without anything here ?

 

[Slenderchap]

i have nothing set on these DCFEEDS. is that ok if i power up the unit without anything here ?

Yes.... you can just ignore them if you are using the power supply which is on the circuit board.

They are only there if you want to power the PCB from an external power supply.... the PCB was designed with "making a mixing console" in mind.... in which case you would have an external PSU feeding all the channels with DC voltages.... which is also the reason that the XLR's can be fitted to the PCB.

Colin
www.audiomaintenance.com

 

[mulletchuck]

Finished build of the rack version after doing a pair of the 500-series version last october/november.  This thing is SIIIIIICK.

But, upon doing a comparison of the two versions, this rack version sounds a bit sweeter than the 500-series version.  It's just a little bit more open.  Any ideas what might cause that?  I made a little audio test if anyone wants to hear the two preamps back to back on identical settings.

 

[dgoszillai]

hi again

for C53 i miss a 1n5J100
the only thing i found in store next to me is 1n5J63 or "1500 400- P9" (i write what i read on the thing ) the sellor says last one should work ..

 

[sr1200]

Colin, this thing is a work of art!  Used it for some bass tracking for a couple sessions this past week... one word... WOW. Thanks much for the great project!

 

[dgoszillai]

IT's DOOONE

haha my very first DI projecy  8) i'm so happy it's "nearly" working" yeah nearly because i have to check some hum on the mic .. but maybe it's my mic cable or setup because i have the same thing on both units.
but Line is 100% perfect. (missing some catherdral knobs coming soon)

the mic sounds so great (dispite that little hum)! i used my fireface for years and it's night/day compared to the sound coming out of the ez1073 
regarding forward to do some more !

 

[tmuikku]

dgoszillai: Use shielded cable for the input / output connectors to PCB connections. Now you have cool loops in the cable for the magnetic fields inside the chassis to induce hum to the cables

 

[dgoszillai]

;D right ... i wonder how i can do such mistakes and got this think up without burning all the building.

 

[kante1603]

dgoszillai: Use shielded cable for the input / output connectors to PCB connections. Now you have cool loops in the cable for the magnetic fields inside the chassis to induce hum to the cables

......or twist them and cut them to proper length!
You've built some nice "antennas" there....

Udo.

 

[dgoszillai]

hahaha  caman guys please stop laughing at me  ;D
tell me if this version is better
that's right the hum is totally gone now it sounds huge clean musical i love it !
thx for the help

 

[kante1603]

Well done!

Udo ;D