8 Channel, 3U NEVE 1073 completed

[snipsnip]

Snipsnip, how are you doing?

Best,

M.

Like you, im under the cosh at work at the moment so not much progress. I did wire up the inputs using shield, but now im getting a really quiet signal on one channel. Im sure I just need to spend a bit of time on it.

I think using the shield has reduced the oscillation, but not removed it entirely. If this proves to be the case once both channels are running I'll try moving the transformer closer  to the PCB.

Thanks for following up.
Jake

 

[zachs]

Had my power supply working a while ago, just finished up the rest of my stuff today, turned it on, and now my fuse in the PS is blowing... any ideas why that might be now?

 

[pedroplanet]

I'm about to finish my 2ch Ez1290.
2 boards stuffed,  tranformers to be wired... waiting for the case so I won't make my usual messy wiring

I'll use siik screen for the painel. 2ch and JLM go between (pad, phase, phantom toggles..)

Can someone share a Panel design in JPG or .psd for 2U rack? I could change some things...

 

[SIXTYNINER]

Can someone share a Panel design in JPG or .psd for 2U rack? I could change some things...

HI
check here:

http://www.musiciansgig.com/neeb/
Front Panel Design for 2U, 2ch:
http://www.musiciansgig.com/ez1290/circuit_specialists_2u_panel.fpd
(to open this file, you need Front Panel Designer. Free download from: http://www.frontpanelexpress.com/)

 

[pedroplanet]

Front Panel Design for 2U, 2ch:
http://www.musiciansgig.com/ez1290/circuit_specialists_2u_panel.fpd
(to open this file, you need Front Panel Designer. Free download from: http://www.frontpanelexpress.com/)

I know, but this software does not allow me to Export a JPG or any image format, nor print...
:-\

 

[diyfanatic]

you can use this software, it's free.

http://www.inkscape.org/

you can export as jpeg but also as HPGL if you finally want to go the FPE way.

and this will ease up your life for the scale!

http://stiftsbogtrykkeriet.dk/~mcs/Scale.html

 

[SIXTYNINER]

nice project
there is way to add a meterled ?

8)

 

[snipsnip]

Hi Martin -

Im back with more problems : Sorry dude

My biggest issue is that im getting a really low signal on my right channel. Its the PCB that I previously had up and running, which makes me think it wont be anything on the board. Ive also swapped the input & output transformers over to see if thats where the problem was, but Im getting the same results. Ive adjusted the 5k trimpot and all my voltages are within .1v accuracy and ive reheated all the joints for the input and output wires. Is there anything you can suggest?

Also on the agenda, but not so urgent is the oscillation issue.  I have rewired everything using shield as intended, but am still getting the oscillation above 55db gain. I have also moved the input transformers close to the board so only very short unbalanced connection now, but no joy there.

Here is a pic of the new layout in case that helps.

Thanks a lot
Jake

 

[Carlos Lima]

Hi Martin,

Received the boards today. Let's the fun begin...

Thanks

Carlos Lima

 

[Nele]

@snipsnip: are your pcb's grounded? Although I didn't use plastic standoffs my pcb-ground wasn't connected to the case. I also had oscillation an humm. As soon as I connected pcb-ground to case, using one of the standoffs and a wire (instead of the prescribed 10 Ohm resistor) everything was solved..

 

[snipsnip]

Hi Nele - Thanks for the tip! 

I just did a quick bodge test on my working channel with a bit of wire to case and it did seem to resolve the oscillation issue! :-*

Thanks so much... its great to only have 1 problem on the go at any one time!  ;D

Now, just to figure out why the right channel is so quiet..........

 

[snipsnip]

Hi Guys,

I think Ive been really stupid  ;D

I was testing by running a line level sine wave into the pres using a line level to mic level pad.

It seems the pad is faulty, and my boards are fine!

I just didnt even consider the pad as the measurements with the scope all looked fine at the input XLRs, after the pad. I think maybe the hot & cold is wired up backwards in the pad.

Thanks so much for all your help.... I think a new pad should resolve everything.

Thanks again
Jake

 

[Gachet]

Hi there,

Just finished one unit and it sounds great ;D no oscillation no hum...
3 more channels and i'm done
The calibration didn't look like the assembly guide.Impossible to get the same distortion on both side of the signal.
But it 's not critical to me.Maybe it should?

I don't have enough 5K trimmers...Can i use 10K or 470R to do the job?(It's what I have in stock...)

By the way a great thanks to madriansee.This must be the best preamp I have ;D

 

[snipsnip]

Just finished one unit and it sounds great ;D no oscillation no hum...

Show off 

 

[Gachet]

 

[desol]

Just finished one unit and it sounds great ;D no oscillation no hum...

Show off  

Ha. I did eight, and they all worked first go!!   ;D

(fingers crossed)

 

[danjpiscina]

Just finished one unit and it sounds great ;D no oscillation no hum...

Show off  

Ha. I did eight, and they all worked first go!!   ;D

(fingers crossed)

Same here! 4 pairs. No problems. These pre's are the best, and for ≈$350/channel with Carnhill iron, you really can't beat it. Once again, Martin you ROCK!

 

[snipsnip]

Well, I had a proper play with these for a couple of hours and they are seriously classy!

Thanks for all your help martin (and others).. this is a great project! 

As everyone else seems to be posting pics of their 1290's... here mine. (my grounding of PCB to case is brutally ugly, but I wanted to get these racked!)

Thanks again!

 

[adam1176]

Hey guys, just read through this post today and I have to try this. I've done a couple small DIY projects but was looking for a pre to sink my teeth into. I think I'd like to try a 2 ch. My question is what has been the experience with the PSU inside the enclosure vs outside?

I noticed Martin prefers outside. Has anyone installed it inside? Pros/Cons?

Also what about 2U vs 1U regarding a 2ch?

 

[Whoops]

Hey guys, just read through this post today and I have to try this. I've done a couple small DIY projects but was looking for a pre to sink my teeth into. I think I'd like to try a 2 ch. My question is what has been the experience with the PSU inside the enclosure vs outside?

I noticed Martin prefers outside. Has anyone installed it inside? Pros/Cons?

Also what about 2U vs 1U regarding a 2ch?

I don't know about other people but I built two 1290 into a 1Unit rack case, with the Toroidal and PSU inside.
I didn't notice any noise.

You should put the toroidal inside the rack as far away from the boards as possible, I put it on the far corner.
Also you can rotate the toroid while listening the mic pres, and choose the position where you feel there's less noise. if there's any noise at all in the first place.

Anyway I totally respect Martin opinions, and I should let you know that having the PSU outside the box is always preferable if you can do so.
I just can't have that many external PSU's in my studio floor.

Neve 1073 DPA PSU and toroid is also inside the rack case.