One more "Green Pre" born!

[WaxLex]

Hello everybody,

im the proud father of a GreenPre Twin. Yeah!

First of all i want to say thanks to all the people here around to run this DIY-thing. Special honor goes to the forum maintenance and peter. :thumb:

It takes more than one year to finish my assemble of a dual channel green. But maybe things they take long time becomes good. This is my first DIY build and i want to give the community back a little bit, in frame of my possibilities.

My PCBs
I redesign the boards. I try to make it a little smaller, because i have to pay per square cm! I used "sprintlayout" for this job. With the Amp PCBs it worked well, but with the PSU PCBs i was to stingy. They are to small for all components. Next time, better time.
The manufacturer of my confidence: http://www.mme-pcb.de/

Stuffing
I worked out a own BOM on the basis of the Bratwurst Amp http://www.nrgrecording.de/green_pre.pdf.
All parts i have ordert @ Ms. Reichelt's mailorder. http://www.reichelt.de/
The transformator i bought at Segor a local store here in Berlin. The only i know, cus i dont like to go to Conrad. :?

My iron was made for fixing holes in a gutter, but with some feeling in the finger tips everything is possible. As first step i draw all components with a maker in right place, to be shure that i dont forget something. Maybe u spent the money to print your boards! :wink: Then I mount all parts in classes, first resistor, then caps... and so on.

After stuffing, i power up the PSU and measure it, there is a small difference with and without load. Then i connecting the boards an controlling the voltage at the sockets. http://www.groupdiy.com/index.php?topic=5235 At last step i touch the heating element in my room and put the ICs in place. Then calibrate the minipots. http://www.mendelt.nl/greenpre_V14/_Green Pre Setup.txt Without a scope.

The Amp
Here it is! Bling!
The trimpot knobs are not installed, cus i decide to remove the pot soon.

- I run my system without fuse?! ( I dont know how much mA they consuming?)
- I hate my cheap rackcase, but where i can get a quality one in germany without to pay a monthly rent?
- I have recorded with some M-Box2, GoldMike, Liquidchannel, 1604, DM-3200, SSL 4000 E & G and Neve 88RS. But after recording some "Cajon" and Vocals with my Green i got GooseBumps! It sound awesome, not sterilely! Analog gear rules.

Gimme a small hint
Something is wrong with the amplification! Im not able to drive the amp im the distortion! The red LED never lit! Thus i have a bad Noisefloor/Headroom Ratio while recording quite signals! What i have to do, changing the input impedance or the gain pot resistors?

greezy :sam:
Alex

 

[Greg]

First off... very nice work !

[quote author="WaxLex"]- I run my system without fuse?! ( I dont know how much mA they consuming?)[/quote]
No, no, and no. A 500mA fuse is fine for these preamps.

 

[vertiges]

As you said : "yeah" ! :green:

Nice work ! :thumb:

eD

 

[WaxLex]

Ok Greg,
i add a 500mA fuse. Thats done.

Can someone give me a hint to the amplification problem, how i get more "Brat" in my green?

 

[dissonantstring]

hi alex,
did you do the set up according to Peter's set up text document found here?
that might help to calibrate the the gain to the overload indicator/meter.
regards,
grant

 

[kato]

Let me get this straight:

This is your first DIY and you sourced all the parts yourself,
redesigned the PCB, and had boards manufactured. Talk about hitting the ground running! I predict you will accomplish great things here.

I don't know about your distortion problem but you may just be overloading the front with a hot mic and loud source. (?) Perhaps turning down the trim or engaging the pad is all you need. (?) just a guess.

Glad to have you onboard! Kato

 

[WaxLex]

did you do the set up according to Peter's set up text document found here?
that might help to calibrate the the gain to the overload indicator/meter.

Yeah, i did. Not exactly because i have no own scope, and my test signal comes from a D/A output. :?
But to calibrate the LED Meter is not my problem. It runs fine, maybe not exact 40,20,0,+20. But both channels match close, like its possible with my tools.

This is your first DIY and you sourced all the parts yourself,
redesigned the PCB, and had boards manufactured. Talk about hitting the ground running! I predict you will accomplish great things here.

thx. next things are comming. but how i can decide... its feeling like a kid in a candystore.

I don't know about your distortion problem but you may just be overloading the front with a hot mic and loud source. (?) Perhaps turning down the trim or engaging the pad is all you need. (?) just a guess.

hehe, this is what i like to do, overload it. I got diffrend Mics (i talk about the Phantoms) no matter wich one, AKG, Georg or Shure, i plug in the signal is to low. Its not possible to get some clipping. (And i dont mean in my eyes (level-LED's) i mean in ears. So i cant go hot as possible in my DAW.

If i rec some Vocals i insert a comp so i gainriding it out. But there is a diffrence, maybe only a small one, between something good and something perfect. :evil: I can work with it, and it sound anytime better then my 1604 or Digi Tascam Pre.





P.S.: Sorry, how i do that there stand "Wrote Name: " and not "Quote" ?

 

[natek]

Looks Great! You definitely did a good job, especially if you sourced all your own parts! I cant wait to get going on my pair of green pre's (patiently waiting for the boards from Peter C) :green: keep up the good work!