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

[jaymz168]

I've finally got some time off to get started on this build and run into a tiny problem:  I seem to have cracked to the outside of two resistors.  I was placing two different resistors with my multitool (don't ask) and I seem to have squeezed a little too hard and cracked the outside.  I'd like to replace them, codes are easy to read and all, but I'm not 100% sure on the wattage. 

Can you confirm that the  3k9 and 4k3 are 0.25W metal film resistors?

PS I really wish we could search within topics.  Also thanks for providing this kit and for the super fast shipping!

EDIT:  A little google-fu with the "site:" argument lead me to the answer of .6W metal film.  BTW, if I wanted to be weird and match the looks what brand did you use?

 

[Slenderchap]

http://www.rapidonline.com/vishay-metal-film-resistor-1-0-6w-box-of-1000-561947

Colin
www.audiomaintenance.com

 

[jaymz168]

http://www.rapidonline.com/vishay-metal-film-resistor-1-0-6w-box-of-1000-561947

Thanks, incidentally Vishay is headquartered about 40 mins from me.  Anyway, I had already ordered some 1% 1/4W metal film, they should be fine for R92 and R145, right?

It's coming along nicely, btw:

 

[jaymz168]

OK, while waiting for the replacement resistors to come in I've finished up as much as I can.  I've gotten to the output transformer and it looks like the leads don't match the pcb.  I've checked a ton of pics and it looks like mine has the blue and orange reversed compared to everyone elses.  Do you know if this is just an insulation color issue and the winding leads are the same?  Should I just go ahead and solder the orange to the blue terminal and vice versa?

 

[Slenderchap]

1/4 watt resistors should be fine.

Solder the blue wire to the blue contact and the orange wire to the orange contact......

[the order that they come out of the bobbin changes depending on which person made it].

Colin
www.audiomaintenance.com

 

[jaymz168]

1/4 watt resistors should be fine.

Solder the blue wire to the blue contact and the orange wire to the orange contact......

[the order that they come out of the bobbin changes depending on which person made it].

Colin
www.audiomaintenance.com

Thanks, I had a feeling I may have been over thinking the transformer leads haha.

 

[phaedra74]

Hi guys...
I have some little(???) problem with my unit:
1. for the first 7step, the mic gain work fine....on the other, no audio is present (except for a very very low signal lpf filtered)...for this 5step I have a high bump when I switch it; the spectrum analyzer software, marks a high signal in the low end (below 30Hz).
2. no phantom power (but the 48V is ok on the power supply)

All other sections is ok (line IN, mic impedance, polarity, eq IN, all the eq section).
The hum and noisefloor are very low, except for the 5 mic step with no signal (in this case is present some hum).

I have not much experience with circuits , anyone can give me some suggestions?

thanks..

 

[phaedra74]

OK, while waiting for the replacement resistors to come in I've finished up as much as I can.  I've gotten to the output transformer and it looks like the leads don't match the pcb.  I've checked a ton of pics and it looks like mine has the blue and orange reversed compared to everyone elses.  Do you know if this is just an insulation color issue and the winding leads are the same?  Should I just go ahead and solder the orange to the blue terminal and vice versa?

Hi,
control some welds on the resistor...
it seems be there to much solder:

I hope I was helpful...and sorry for my english

 

[phaedra74]

ok...
I find the problem on the 48V, now work fine.
I bought and used a little tip (0,3mm) for small reophore and I resolder some bad welds  :


I still have the problem in the last five step of the mic input...

 

[phaedra74]

I find a short in the gain stage1 on a transistor (soldering error).
I check the hfe (about 600), seems work fine; you think is ok or is better to change it?

 

[phaedra74]

Problem solved....
The unit now work fine!

No hum, very low noise and no bump when I switch the pots (except the pot of impedence 300/1.2, but it is normal).

The pre is very good and the eq is "special"...

 

[Daniel S]

Hi guys, first timer!  8)

I just finished the build but I'm not reading the correct value on R26, it should be 130mV regulating R20 but I'm not shure I did it right, I had no problem trimming the 48v.
Powered up the unit and transistor Q4 in the Stage 3 started smoking 20 seconds after... it did not happen at the first power up,  it happened after I plugged the XLRs for trying it out. No apparent short between the chassis and the pcb. 

 

[Daniel S]

Update, I made sure nothing touches the case below the pcb, replaced Q4 and R26 just to be sure they're working, no smoke now, the unit stays on but only with 200mA fuse, it blows 100mA everytime. I'm in Italy, 220V here.
In the measurements I read 23.8V, the 48V is ok but the damn 130mV on R26 trimming R10 doesn't show up... just can't get it to move plus the reading is really difficult, value keeps on jumping from 1 to random numbers.

Someone has an idea of what the problem could be? Please  :'(

 

[EstockAudio]

For those of you using the EZ1073 w/ the Collective case, what standoffs are you using?  I can't seem to find any that fit properly. 

Thanks!

 

[phaedra74]

Update, I made sure nothing touches the case below the pcb, replaced Q4 and R26 just to be sure they're working, no smoke now, the unit stays on but only with 200mA fuse, it blows 100mA everytime. I'm in Italy, 220V here.
In the measurements I read 23.8V, the 48V is ok but the damn 130mV on R26 trimming R10 doesn't show up... just can't get it to move plus the reading is really difficult, value keeps on jumping from 1 to random numbers.

Someone has an idea of what the problem could be? Please  :'(

hai usato un 100mA T?cioè timed?Magari lo spunto del toroidale te lo brucia se è fast...
è solo un'ipotesi eh....

 

[delichef]

For those of you using the EZ1073 w/ the Collective case, what standoffs are you using?  I can't seem to find any that fit properly. 

Thanks!

I'm curious about this as well as a couple of other things. I've built two already and the issues were minor enough that I didn't worry about them. Now that i'm building a few more, i'd like to take the time to finish them all off properly.

- To echo the question above, which standoffs did you use? Are they just providing support to the PCB or do they actually provide a ground of some kind? Some people have mentioned a nylon standoff with an adhesive bottom...could you just use these and not need to drill the chassis? Any links to what you used would be super helpful.

- Connection and ground wiring on the back XLR inputs and outputs...I used a hacked up mic cable for wiring...which was big and hard to work with. What's better wiring to use for this? Shielded vs. non-shielded? I've seen some pics that just have 3 separate wires going from the XLR to the chassis. Could I just use regular 18-22g solid core wire?

- One other question...I've seen some that have a switch added to the back panel next to the IEC power receptacle. Are people adding power switches or ground lifts to these?

thanks!

 

[EstockAudio]

I'm curious about this as well as a couple of other things. I've built two already and the issues were minor enough that I didn't worry about them. Now that i'm building a few more, i'd like to take the time to finish them all off properly.

- To echo the question above, which standoffs did you use? Are they just providing support to the PCB or do they actually provide a ground of some kind? Some people have mentioned a nylon standoff with an adhesive bottom...could you just use these and not need to drill the chassis? Any links to what you used would be super helpful.

- Connection and ground wiring on the back XLR inputs and outputs...I used a hacked up mic cable for wiring...which was big and hard to work with. What's better wiring to use for this? Shielded vs. non-shielded? I've seen some pics that just have 3 separate wires going from the XLR to the chassis. Could I just use regular 18-22g solid core wire?

- One other question...I've seen some that have a switch added to the back panel next to the IEC power receptacle. Are people adding power switches or ground lifts to these?

thanks!

I'm still stumped on these standoffs, too.

 

[EstockAudio]

Hi Guy/Gals,

I thought I just finished my first one of these and upon powering up I have no signal, so I'm trying to troubleshoot this bad boy before I start the second one.  Here's what I know:

- I get -24V across J5 and J6 and I get the proper voltage for phantom and output bias.
- I don't get any level of any kind out of the unit no matter how cranked the mic pre is
- Turning phantom on and off does generate a small pop and meter indication. 

Any recommendation as where to start?

 

[phaedra74]

If the power supply is ok (24V rail and 48V rail), check the audio signal path.

 

[EstockAudio]

OK guys.  Here's where I'm at:

- The mic gain, line gain, and EQ are all working and passing signal.  All frequency points seem to be working.
- Everything lines up with the calibrations steps. 
- There seems to be a low level hum/buzz that's present all the time. 
- 48V doesn't seem to be working at all.  When I engage it, I get a pop and some level into my A/D but it quickly dies off.  I went back to the 48V section of the board and checked all my solder joints.  Everything seems fine. 

Any ideas?

Thanks all!