All things Green Pre

[warpboy]

hello,
i've just finished my green pre, and i've a problem.

When i speak in the mic, my voice seems like a robot . each time i speak highs frequencies of my voice seem satureted....it's not a buzz or power supply problem
can someone help me please :?

 

[matta]

Can be a grounding problem, I've had a similar thing before, grounding doesn't always mean it doesn't have to hum. How are you grounding the unit? Starground?

List how you have all your ground tied together, including at the PSU.

Cheers

Matt

 

[warpboy]

thanks Matta , i look at all the ground setting

 

[warpboy]

finally i have checked all the connections and it works great :grin:
the output of the green pre is directly connected to a joe cheep comp using a vactrol vtl5c9 and it enables to have mic pre+compression for a voice
:thumb:

 

[matta]

Awesome! Congrats on your new build. May you have MANY great hours of recording on them.

Cheers

Matt

 

[warpboy]

Yes completely agree with you , it's really pleasant to do his own pre amp, comp or anything else....but really necessary to recognyze the time past to develop these machines (neve,ssl, tubetech.....)

has soon on prodigy forum :thumb:

 

[lofi]

sorry, dont know where to post this, so here goes...

i have only gone and paid for the boards for 4 pres and a power suply!!!

life is good

i love this place

will find out where i should post and keep you informed of my progress

:thumb: :guinness: :guinness: :guinness: :guinness: :sam: :sam:

Iain

 

[capnspoony]

I had a question about the green pre layout PDF

In the lower right hand corner there is a resistor on end that is not marked.
Directly above the pair of diodes.

Is that the 220R resistor?

thanks

richie

 

[bluezplaya]

Is that the 220R resistor?

I believe so. I have had my Green's finished and racked for a while, but I do believe that is the 220R.


Adam
:sam:

 

[peterc]

220R is correct.

Definitely marked on my diagrams...

Peter

 

[capnspoony]

thanks .. the pdf i have is not marked .. but it was on the board although the holes make it hard to read sometmes .. just double checking!


thanks!

im enjoying this project
:thumb: :thumb:

richie

 

[capnspoony]

I had a question:

My voltage for the phantom power is coming out at 77v dc

At the zeners im running about 10v hot at the three places to check the voltage.

My plus and minus 15vdc is perfect...

Can I just drop a load on the output of the regultor on the 220R resistor to bring the voltage from 77 to 48vdc?

-richie

 

[peterc]

My voltage for the phantom power is coming out at 77v dc

Sounds like the 48v reg is blown. It is very sensitive to being shorted out.

Peter

 

[capnspoony]

thanks peterc :razz:

hooked up all four of the green pres last night without phantom and everything else was running smoothly first time!

thanks for such clear instructions

best

richie

 

[Freq Band]

It turns out, I am able to fit some (big) Axon MKP 47uf input caps in my box, replacing those 47uf electrolytics.
Is this do'able? Do I need to adjust anything else because of the non-polarity??....i.e. to keep phantom power under control ?


=FB=

 

[imo]

I have had my Green Pre's up and running for a couple of months and they have been a wonderful addition to my studio. Thanks to Peter and everyone who contributed the effort to put the project together.
A hooked up a condensor last night, switched on the phantom and..nothing. The LM317 had a heatsink, but sure enough i checked and the reg was blown. This led me to do a bit of backwards research on the 317 specs<g> I know the 317 is used on a number of different 48v phantom power supplies, but the max input voltage is 40 volts and max regulated is 37v. Is there something i'm missing or are we just using the regulator beyond spec?
Thanks
Ian

 

[Freq Band]

......voltage is 40 volts and max regulated is 37v. Is there something i'm missing or are we just using the regulator beyond spec?

This comes up often. In the 117/317 datasheet it also says:
"Besides replacing fixed regulators, the LM117 (317) is useful in a
wide variety of other applications. Since the regulator is
?floating? and sees only the input-to-output differential voltage,
supplies of several hundred volts can be regulated as
long as the maximum input to output differential is not exceeded,
i.e., avoid short-circuiting the output."

=FB=

(ok, now somebody answer my Q above..... :grin: )

 

[imo]

Thanks. I think i read that a few months ago, but couldn't find it in the search.
Lovely!!
I guess the regulator must have shorted out then. Replaced it and back up and running. Nice pre's..I really like them on clean, powerful guitars. I always used my 312's as a first, but these really work well with my AC30, focused and clean, tight, nice top end..

 

[3nity]

Hi everybody.
I just powered up 1 channel of a Green and IT SOUNDS!!! :grin:
But then there was some hum but i did a quick grounding and hum went down a lot. but still remain a little, i tought that is maybe my SM58 or the cable.

Now i use my cheap condenser ( audio technica AT2020) and apply phantom...and it'starts to make some synthetizer noise...what that means??

read every post and not an answer.

BTW: this pres is amazing! i'll power the other one maybe tonight i feel some lazyness! :green:

 

[Freq Band]

[quote author="Freq Band"]It turns out, I am able to fit some (big) Axon MKP 47uf input caps in my box, replacing those 47uf electrolytics.
Is this do'able? Do I need to adjust anything else because of the non-polarity??....i.e. to keep phantom power under control ?


=FB=[/quote]

????

=FB=
-------------------------
3nity

but still remain a little, i tought that is maybe my SM58 or the cable.

Is your Green sitting on your workbench, opened up?
Some hum/noise will occur if it is, until it's closed up in it's case, and becomes sheilded. I sometimes scratch my head when hearing noises.......then I realize I have a flourescent swivle work-lamp near the circuit..... :?