All things Green Pre

[peterc]

I can replace the .1uf with smaller ones of less "quality" and put the 22uf Cerafine's in.....or keep the good .1uf's, and put in cheaper 22uf's.

Having gone to all the trouble of getting these special parts, it would be a shame not to use them......

I would use the Cerafines in the normal position & then solder the poly's to the underside of the PCB (trace side).

Peter

 

[khstudio]

I'm just finishing 2 SSL comp's & finished 2 LA-2A's & now I'm lookin at the GREEN PRE. What can it be compared to - sound/quality? I'm wondering if it would be worth building to add to my studio. The best mic pre I have now & use a lot is a Presonus M80 (8 ch w/Jenson Trz) & an MP20 (2 ch w/out...China or Japan copy's or something Trz)

How do you think the GREEN PRE would compare to the Presonus?

 

[matta]

Build it and see ;-)

I really like them, I?ve not done a side by side comparison with the
Presonus, but I have against the Focusrite Green Series Pres and my 002R,
samples can be found in the Green META.

Hope it helps.

Matt

 

[khstudio]

Thanks matta... anybody else?

 

[fum]

Sorry to re-hijack, but am redifining the term "should give up DIY" :wink: and am lookin for some troubleshooting advice, as I've for the moment run out of ideas as to how to narrow down the problem.

I'm still troubleshooting my 4 channel green pre.

3 of the channels pass the IC voltage checks, but 1 channel is down to a problem I can't figure out.

Pin 7 of IC one is sitting at 4 Volts ( which means pin 1 and 2 of IC2 are sitting at the same).

History: When I initially plugged this channel in, it smoked the power supply (due to confusing orange with red in a couple places (100K vs. 10K resistor thing).

Rebuilt the power supply, found the resistor problems in channel 3 and fixed those.

I've replaced quite a few of the components in the front end of this. All the electrolytics, and the BC550's.

I've resistance checked all the resistors, and compared against the known working channels, and everythings coming up equal.

Anyone else have troubleshooting tricks in their bag that might direct me towards where the problem might lie?

Regards

ju

 

[matta]

Fum,

Did you replace all your Zener Diodes?

Mat

 

[fum]

I did do a diode check using my fluke meter, and they all showed a forward voltage of .7V, with no reverse voltage, but not out of circuit.

ju

 

[fum]

*#$%##($#@@#@(#@*$%(#%

So I've totally stripped this channel down, and built it back up, and now it works correctly, but I've not a clue as to where my problem was.

I think one of the BC550's may have been a mess ( as I swapped out for new ones due to pin mangledness).

So in total, 12 hours spent beating head against desk, only to put it back together and have it work.

go figure. :roll:

I know, take what you can get.... =)

Press on, still have to work out metering, but that will be after I get them all calibrated.

where's my VO Gold?

ju

 

[Guest]

This might seem like a retro step back question
But I want to disable the metering on my Green PCB
reason is - I wish to use some of the new LED PCBs that are coming in the pipeline

Anybody any ideas whether the whol circuit can be taken out - or is it a really "bitty" oparation

 

[Flatpicker]

[quote author="John Hardy"]

Now we're talking about this let's set it straight for once & all:
is that O/0 in COG actually a zero or the 15th letter ?

I don't know![/quote]
It's C0G (number "0", not letter "O"), but don't ask me how I know that. :wink:

Funny, the Digi-key catalog list both COG and C0G, lol!

 

[peterc]

Anybody any ideas whether the whol circuit can be taken out - or is it a really "bitty" oparation

If they are not already built, you could just leave out the whole of the RHS of the PCB, except for the switches & pot......

Otherwise, just take out the TL074 & LM339.

Peter

 

[dissonantstring]

hi everyone (especially Peter C.),
i was finishing up my dual green pre and started designing a front panel (with the help of Frank's "wurst mic pre" layout - thanks again Frank!) and i was wondering... on the output attenuator what would the scale markings be?
it was mentioned that it might be: -infinity, -40, -30, -20, -10, 0. Is the output gain -6 to 0dB? any help would be appreciated.
-grant

 

[fucanay]

I just popped one of the 47uf caps on my second green board (backwards ) and I don't have anymore of the ones I used in here. They were 47uf 35V. I do have some 47uf 25V, but I don't want to pop the damned thing again and I don't know if the voltage rating it's supposed to be in here. Does anyone know if it'll be ok?

Thanks,

Matt

 

[jeroddumas]

25v should work no problem long as it is not one of the phantom blocking caps. the pre operates at 15v +/-.

 

[jeroddumas]

Can anyone tell me if the 4700uf cap has to be low esr type. I how I couple of these that are not low esr and I would rather use them than have to do a mouser order just for 2 caps. Would it make a major sound difference?

 

[fucanay]

[quote author="jeroddumas"]25v should work no problem long as it is not one of the phantom blocking caps. the pre operates at 15v +/-.[/quote]

Thanks for the info. Funny you should mention that. While searching the forum for the answer I found a post that made me realize that I had put the phantom blocking caps in the wrong place and with leads too short to put them in the right place. So now it's another 5 day wait and ordering other junk I don't need right now, just to get 6 caps. I've done this so many times now. It's getting old.

Hopefully, next weekend I'll have my own finished green pre thread.

Matt

 

[jeroddumas]

just use waste leads, or cut leads to make the ones on the caps longer.

 

[fucanay]

It doesn't seem like the most durable way to do it, but I guess I could. I'll see how strong they seem after putting the leads on. Thanks for the idea.

Matt

 

[Ptownkid]

Hey Fucany, you ordered my kit right....

If so, tell me which caps you need and I'll send em free of charge.

Cheers

Bryan

 

[fucanay]

Thanks for the offer Bryan, but the soldering the leads on worked out ok. Now I need to figure out this the grounding and the phantom power issues. Some strange stuff going on here, though I'm not sure what it is. I'll report back with some test numbers and behaviors.

Matt