All things Green Pre

[metalb00b00]

You can replace the ferrite bead with a jumper wire and the pre will work just fine.

 

[peterc]

You can replace the ferrite bead with a jumper wire and the pre will work just fine.

I have also done this with good results. The ferrite would make a difference in high RF areas, I would think, if you were near a radio transmitter, for example.

I have never had any issues in pres without the ferrite.

Peter

 

[stitch-o]

Hi Forum!
I recently picked up a shabby rack of 4 of these.
I pulled apart the rack and have all the goods to rack them up nice on the way.
Put the PS in an external enclosure and have some LM6172's Im going to drop in.

Quick question though: I can not for the life of me seem to find all the build docs.
Anyone have a link?

Cheers!

 

[peterc]

Stitch, send me a mail and I will send the docs across

[email protected]

 

[stitch-o]

Stitch, send me a mail and I will send the docs across

[email protected]

email sent

Cheers!

 

[stitch-o]

Ok Thanks Peter!
Got info and sorting out now.
Here's some gutz shots for 'y'all:::

Interesting about the 6172: its a video amp and seemingly more noisier then a 5532 at input.
2134 seems to keep cropping up. Anyone play with amps?

Cheers!

EDIT: Everything seems to work except channel 2 VU isnt lighting up.
When I crank the trims I get to LEDs to light up so I think the VU circuit itself works,
its the feed that is an issue...

 

[dribro]

Ages to finish. All channels Calibrated and sounding awesomely good. Thank you Peter.

 

[rankot]

I am looking for schematic for V14 version of Green Pre. Found only PCB and layout file, but I need schematic 'cause I want to design my own PCB. Any help appreciated!

 

[gordcragg]

Hi All

New to the site. I am looking at building a mic pre and stumbled across the threads relating to the green pre. I have found a schematic but I am struggling to find other information (BOM etc) as most of the links no longer work.

Could anyone assist in providing me with some of the information?

Gordon

 

[pstcho]

Hello guys, i finished a 8 channels green preamp and i find it really mind blowing on drums, really incredible !!!!!  amazing project

one stupid question, is there anywhere the schematics including the vu meter, i would like to make a small modification but i cant find the schematics ??  ??? ??? ???

 

[scott2000]

Have you tried waybackmachine for any dead links?

Just right click,  copy link location, then paste into wayback search.....

I found this.....not sure if it's what you are looking for .... but there are other things.......

https://web.archive.org/web/20060815122105if_/http://www.mendelt.nl:80/greenpre_V14/_Green_trim_HPF%20CCT.gif

 

[pstcho]

thanks for your reply, on this one there is not the 6 led meter

 

[scott2000]

Another thing that is useful is to search groupdiy along with the topic

like in goofle window ...type..

groupdiy green pre led meter

like this comes up..

https://groupdiy.com/index.php?topic=2403.20

..looks like PRR linked something on last post??? may not be the 6  you want but.... until someone chimes in with it....searching may reveal something somewhere ???

 

[pstcho]

thanks for the reply, i had indeed searched a lot the last days and i didnt manage to find any info about the 6 led meter neither the power supply  V6a 1-3-7

about the power supply i found what i was searching for but about the meter i cant find info even by searching how the lm339 is working

 

[mhelin]

Seems some schematics are missing for this project. Here is the redrawn preamp section.

 

[mhelin]

Here is the LED meter. Found it from this thread:
https://groupdiy.com/index.php?topic=8605.0
Hope this helps

 

[mhelin]

Does anyone know what the 10k LOG gain pot next to switches does on the PCB, it is not shown on any schematics? Is it some additional trim or a point where the gain switch is connected (in which case you could bypass it or use as trim in series with the switch)?
Layout is here:
http://www.mhumhirecords.org/DIYpages/Green/_V14-All.gif

 

[mhelin]

There is also this mod for LED levels for more precise control of high levels (for DAW):
https://groupdiy.com/index.php?topic=6646.0

 

[scott2000]

Does anyone know what the 10k LOG gain pot next to switches does on the PCB, it is not shown on any schematics?

is it not the output pot on the schematic?

 

[mhelin]

is it not the output pot on the schematic?

Sure, somehow missed that...
And the gain switch goes to the 2-pin header on the left side of the board below the 10k resistor and on the right side of the 22uF capacitor.