All things Green Pre

[louder]

alo
excuse my ignorance,but where can i find the ferrites to the green pre?.
also,what is the rating for the bridge rectifier in the psu?.
best regards
pedro

 

[peterc]

Pedro

Any small ferrite will do, the ones I use are 5mm long by 3mm diameter.

BR should 1A for 4 chans, 2A for 8.

Peter

 

[louder]

alo
thank you peter for the answer.
now,another:can`t seem to find the right switchs both at digikey or mouser.
could you point me the correct part number?.
best regards
pedro

 

[clintrubber]

[quote author="louder"]alo

now,another:can`t seem to find the right switchs both at digikey or mouser.
could you point me the correct part number?.
best regards
pedro[/quote]
W.r.t. the switches, the info is here in one of the threads... somewhere.

 

[louder]

alo
do ferrites have any correct way to be mount,i mean,like any special direction?.
another question i have regards to the psu:in the layout there seems to be missing 2 electros just ahead of the 47mfd/100v, and that have no value specified.that is strange, because i saw a photo of this psu with those same electros mounted.
sorry for these dumb questions.
best regards
pedro

 

[Ptownkid]

the ferrites are NOT polarised, so there is no correct way, and those caps you're talking about are unecessary.

Cheers

 

[peterc]

there seems to be missing 2 electros just ahead of the 47mfd/100v, and that have no value specified.that is strange, because i saw a photo of this psu with those same electros mounted.

The PSU started out as a general purpose supply, so there is space for more voltage doubling, thats where the extra space in the 48v section comes from.

As you can see in the pic, there is a link in there to bypass the extra holes.

Peter

 

[HappyTom]

I don't know if this will be of any help for anyone but since I've done it I think I have to make it official.
Along the build of my 4 latest Greens I've shot some pictures for an homepage. I've seen one covering a sslclone I think.

Anyways here it is:
http://www.rollingthunder.se

I dunno how to make a directlink to the page so, left frame look for DIY.
Pm me if the language i wrong.

HT

 

[peterc]

Cool pics :thumb:

I think any resource like this helps immensely, thanks Tom


Peter

 

[matta]

Great site Tom,

Added it to the GREEN META, keep it up.

Cheers

Matt

 

[Yoannv]

Thanks HappyTom for this pictures :thumb:

I read in your webpage that you suggest to use heatsink on the regs, when using the PSU with four Green Pre.

I'm planning to build a QuadGreen, but I didn't think about this... So is this really necessary to use heatsink, or just a precaution?

You say you've used a "DIY heatsink"... Can I use a simple piece of metal to do this ?

yoann

 

[peterc]

If you run 4 pres with no heatsinks on the regs, the regs get quite warm to the touch, but one can still keep touching them without getting burnt.

Having said that, it does make a lot of sense to keep them as cool as possible for a longer life.

Regards
Peter

 

[HappyTom]

[quote author="Yoannv"]Thanks HappyTom for this pictures :thumb:

I read in your webpage that you suggest to use heatsink on the regs, when using the PSU with four Green Pre.

I'm planning to build a QuadGreen, but I didn't think about this... So is this really necessary to use heatsink, or just a precaution?

You say you've used a "DIY heatsink"... Can I use a simple piece of metal to do this ?

yoann[/quote]

Maby not really necessary, more of a precaution.
Better to be safe than sorry.
But as Peter says they won't burn your fingers they just gets kinda warm.
I always use heatsink on my regulators, as a precaution.

I use a piece of aluminium 4-5mm thick and it does the work quite fine.

Thanks guys for the kind words, I'll keep the site up and will probably fill it up with more of my DIY-projects.

HT

 

[fum]

Ok, gotta question.

The middle lug of the high pass filter connects to a jumper point. where does that jumper point connect to?

I see that it should go straight down to some of those other jumper points, but Peters diagram doesn't show what should it should be doin.

I wired it exactly as the diagram (with no connection), and the 10R down and to the left of the 3rd 5532 (from the left in the diagram), immediately started smokin (so I powered off right quick)

Sorry if this is covered allready somewhere.

Regards

ju

 

[HappyTom]

Hi!
This file shows the metering options and you can read about it in the greenpre setupfile.
http://www.nrgrecording.de/green_pre.pdf
Recheck the wires from the psu.
I messed up the wires on mine and smoked some resistors to.

HT

EDIT: added the link

 

[fum]

Hey Tom,

Yes, I've got that one printed out, but it confuses me =)

So that top one is either not connected at all, and the jumpber goes straight across( the "b" option), or if you want metering after the 10K pot, then you take the wire from above, and hookup to the 100nf cap( "a" option)?

If that's the case, I've got some other badness goin down, and will have to give things a once-over again.

Regards

Jon

 

[peterc]

So that top one is either not connected at all, and the jumpber goes straight across( the "b" option), or if you want metering after the 10K pot, then you take the wire from above, and hookup to the 100nf cap( "a" option)?

That is exactly right.

I dont think the smoke has anything to do with this connection, this conn. only applies to the meter section. The 5532's are in the audio core.

Check the voltages without the 3rd 5532 plugged in & make sure they match the voltage chart I sent. Is there still an issue with the 5532 removed?

If the 10R resistor smokes like that, it sounds like a dead short from the -V supply to Gnd.

Peter

 

[fum]

That, or you have the 5532's in backwards :roll:

The diagram referenced above has the names of the chips turned around the wrong way(only on the 5532's), but the cutouts are facing the right direction. Same on Peters original document (only the other way round =) )

So pay attention to them there pin one indicators, and not the orientation of text!


All appears to be disco now

Regards

ju

 

[Freq Band]

Hey all, I picked up (2) v14 boards and am starting to collect the parts.
I am using some stuff I have on-hand, and will be ordering the rest.

I acquired the boards without the acompaning info, but from reading threads here, I have found Pererc's FTP site documents, and the above mentioned PDF (which I have not examined closely yet.) I have not found a numbered parts (designations) on a schematic diagram (I only see the #designations on the parts list).

As a novice builder, I do have some initial questions though.

1) PARTS LIST:
I only found 8 .1uf ("good" quality)...and found 6 100nf ("any" quality).
The list has 10, and 4 respectivly..... Since these are really the same values, expressed different ways....two caps/sizes are switched???...what goes where? (edited today)

2) PICOfarads:
What is a good choice for the five 22pf's and one 150pf's ? I am having trouble finding these, and a source. Does voltage make a difference?

3) WIREwounds:
I have some quality Shallcross 100k .15watt wirewound resistors. Would these find a nice home in this pre?.....I am fairly ignorant about ww's in general.

4) ALPS pot:
I happen to have some 20k Alps Black Beauty's. Is there a way to use that instead of the 10k pot? (I realize they'll have to be wired "off-board").

5) POWER supply:
A friend suggested I gut an older Digigesign converter box and keep the PSU. It has a +15v, -15v power supply, but what do I do about the 48v ?...(I know.....it's a switching supply, but he assures me, he has used those gutted boxes for headphone preamps with excellent results).

Thanks for your patience.

=Freq Band=

 

[fum]

Peter,

another question.

I've got two channels up and happy now (two more to wire up). I'm having a problem with the metering. It's working, but I can not adjust it to set the clipping point.

I've done the first two setup steps with no problem.

Following the instructions, feeding 500 hz into the input, with the gain adjustment at it's lowest setting, with a multimeter on the output sitting at 7.75 V AC RMS

I can adjust so that I get no leds lit. As I turn up, one green, then the other comes into play, but yellow and red will not light.

If I take both the metering chips out and turn the unit on, all LED's light up.

Both channels are behaving the same way.

Thoughts?

Regards

ju