8 Channel, 3U NEVE 1073 completed

[briomusic]

Best would be to tap the VU meter from the L-P connection (this is either a jumper or a out-level pot on the EZ1290 board). I don't know if a buffer amp is required. I guess you could connect BEFORE the trim pot, to see how hard you are driving the pre-amp, before you are attenuating the level with the trim.
AFTER the trim pot would once again be the same signal that the DAW sees.

 

[sr1200]

Yes i have a VU buffer build and in there.  And Ill have to try that... I completely forgot about that! Thanks

On a side note: As Im getting closer to finishing this thing, ive noticed a couple of odd things.  First, the grayhill rotary switch for the input gain is positioned really strange.  Any knob i use puts the lowest setting at around 10 or 11 o'clock on the front panel.  The set screw for the knob would have to be in line (on the same side) with the indicator.  Is there a way to reset this or did i mess up putting that stop pin in.  I believe i put it in a 12:00 if you're looking at the board with all components facing up (laying flat on a table).  I found possibly the most disgusting knobs ever created for this thing which i think i may have to put a set screw in anyway so, might not be a huge deal, but if those knobs dont work it might be a little awkward.

second is what im going to do with looming the wires with all the crap i added to this thing, but thats more of a personal battle for now.

 

[sr1200]

Sir:  You have brought a tear to my eye.  I just finished the 2 pre's and I cannot believe the sound.  My crappiest dynamic sounded pretty good... my crappiest condenser sounds like GOLD... unreal man!  Thank you so much!  Ill post some pics after i get the real front panel done.

 

[herrmann]

Hi all,
Just finished my dual pre. All is working fine and sound good, but in the last 2 positions (70 and 75) I have no sound... Voltages are all good. I've this issue on both channels.
Are the grayhill non-shorting ? Because I've a pop sound when switching.
Have some ground problem too, some hum when I touch the case. As I read in the assembly guide, 0V should not be connected to the ground/case. Will work on this.

 

[briomusic]

Hi all,
Just finished my dual pre. All is working fine and sound good, but in the last 2 positions (70 and 75) I have no sound... Voltages are all good. I've this issue on both channels.
Are the grayhill non-shorting ? Because I've a pop sound when switching.
Have some ground problem too, some hum when I touch the case. As I read in the assembly guide, 0V should not be connected to the ground/case. Will work on this.

Have a look at R20 (3k9), does it have the right value and is soldered in properly?
Have another close look around the rotary switch for any solderbridges etc.
I think you are meant to connect 0V to the case via a 10 Ohm resistor if I remember correctly.
Did you connect pin1 of the XLRs to the case?

 

[herrmann]

Ok, problems gone since I've connected case. Thanks for the tip !

 

[ilfungo]

apologize for the stupid question ....
is possible for a rock voice to saturate the input stage of the  EZ1290?
Thanks

 

[briomusic]

apologize for the stupid question ....
is possible for a rock voice to saturate the input stage of the  EZ1290?
Thanks

I would say this is exactly what's been happening on a daily basis since the 70s  ;D

 

[ilfungo]

but if you do not want to saturate the input stage?
pad?
thanks

 

[briomusic]

yes, i find that sometimes even the lowest gain-setting is too hot.
this obviously depends largely on the signal and mic, but does happen to me a lot with a snare drum through an SM57, so conceivably also with rock voice.
I have a jlm go-between on one of my Dual-EZ1290s which includes a pad (-20db i think).
the other one doesn't have a pad, so I am using an XLR-pad-adapter like this one:
http://www.karmamics.com/shop/Karma-In-Line-XLR-Microphone-Pad.html

 

[MicDaddy]

:-[  nearly had a heart attack

http://www.mouser.com/Search/ProductDetail.aspx?R=225P10394XD3virtualkey61320000virtualkey75-225P400V0.01

 

[benlindell]

:-[  nearly had a heart attack

http://www.mouser.com/Search/ProductDetail.aspx?R=225P10394XD3virtualkey61320000virtualkey75-225P400V0.01

That's a fair price if you only getting one of them

 

[Chrome Heart]

Just finished the front panel. Now on to number 2
Thanks Martin

 

[sr1200]

Congrats! Nice build!

 

[MicDaddy]

Here's a question..

What transformer are Vintech now since they've gone away from the Carnhills and why? 

Whose transformers are they using, I suspect they cost less than the Carnhill?

 

[dutu]

Hi!

Martin, what are the gain positions that are switched by the red gain switch?

Starting ___ dB (first position),  Ending ___dB (12th position)

On your faceplate you didn't specify. Either goes until 75dB and starts from 20, either starts from 15 and ends with 70dB... which one? Or is it different?

Thanks!

Ovi

 

[SimonB]

Hi!

Martin, what are the gain positions that are switched by the red gain switch?

Starting ___ dB (first position),  Ending ___dB (12th position)

On your faceplate you didn't specify. Either goes until 75dB and starts from 20, either starts from 15 and ends with 70dB... which one? Or is it different?

Thanks!

Ovi

The FPE file shows the gain positions. Starts at 20 and goes to 75.

 

[dutu]

Thanks, Simon!

My problem was with the position in between 20 and 70. Didn't know if it was a 15 or a 75. Thanks for clearing this for me!

I have another question.. Souldn't we use a fuse for the preamp unit? Or more?

Sould we put 2 fuses? One right after the mains plug and one in the 24 circuit? Should we also use one for the phantom circuit? Or it's not that necessarry to use so many?

What fuse values shall I use for a 2 channel preamp? I'm using the JLM Audio clone power supply (cloned by me - I posted the pcb & bom earlier). It's identical to the JLM Audio one but costs about 10$ to make.

The transformer is a 2x24VAC 40W one. I'm also using 220V mains power.

Thanks!

Ovi

 

[NannerPuddin]

I have been lurking here for a couple of months.  I think I am ready to build one of these.  Time to order the boards.  Thanks in advance for so much good information that will help......

Thanks,

Doug

 

[deuce42]

Ok I am stumped with my build. Connected a switchmode 24vdc power supply to the board, (just for testing it - I intend to use a JLM once the boards is up and runnin), and my output carnhill makes a terrible hissing sound from its bobbin !!!! - Cant be good.

I am measuring my transistor voltages and am getting something like 24v across their legs when the chart indicates most of them around the 3-6v range. Clearly I am way off here. But I have cross checked all my components and have correct value resistors and caps, and the caps polarities are the right way round.

I am totally stumped. Anyone offer any ideas? A squeeling output transformer cannot be a good sign  Funny how more straighforward circuits like this can humble ones abilities