All things Green Pre

[mhelin]

Regarding the Green Pre and the new R*N*D 5012 design, would it make any sense to use a tx (1:1 - 1:2) between the IC1(a,b) and IC2(a) stages to unbalance the signal (instead of the differential IC2a stage)? Better CMRR? More "iron" in sound?

 

[clintrubber]

Regarding the Green Pre and the new R*N*D 5012 design,

Not sure what you want to do... you want to get the sound of a BA283-like-circuit+gapped-TX out of the Green by inserting a TX ? :shock:

 

[Mendelt]

[quote author="mhelin"]Regarding the Green Pre and the new R*N*D 5012 design, would it make any sense to use a tx (1:1 - 1:2) between the IC1(a,b) and IC2(a) stages to unbalance the signal (instead of the differential IC2a stage)? Better CMRR? More "iron" in sound?[/quote]

You can probably improve CMRR a tiny bit with a transformer if that's really important to you. But I don't know why you would want to have iron in the sound of the Green Pre.
I have just started mine so I havn't heard them yet but as far as i can tell from the stories of others this is a really clean preamp. If you're looking for something with more colour there are other designs better suited for that, maybe stuff like the Neve or Api clones.

 

[Ptownkid]

Wouldn't putting iron in the sound of the green pre defeat the purpose of the green pre?

Either way, it may have an interesting outcome, but the green pre sounds fantastic as designed.

Let us know if you end up doing it.

Cheers

 

[Mendelt]

Another part sourcing problem..

The BOM i'm hosting for PeterC has 22pF and 150 pF capacitors specified. I saw that the two 10pF capacitors in the earlier version of the green pre had been replaced by more 22pF caps.
According to the BOM these shoult be film caps but all i can find are ceramics of these values.
And there are 14 47uF elco's in the BOM but i can only find 9 on the circuit board.

 

[Mendelt]

Never mind my stupid questions.. I should really learn to search the meta's first. :?

 

[clintrubber]

Ceramics for the 22pF was stated OK. Use NGO/CGO-types, those with the black top. And/or see the section on ceramics in the John Hardy/990-pdf & 'TC' (tempco) in
http://home.hetnet.nl/~chickennerdpig/FILES/ColourCode_RC_9399-269-00601.jpg

 

[peterc]

And there are 14 47uF elco's in the BOM but i can only find 9 on the circuit board.

Thanks for the heads up, BOM updated.

 

[OddHarmonic]

[quote author="peterc"]

And there are 14 47uF elco's in the BOM but i can only find 9 on the circuit board.

Thanks for the heads up, BOM updated.[/quote]


Wierd, I found all 14 on the PCB, although 9 were silkscreened with the large circle, and the other five were small rectangles. The smaller ones all seem to be tied to the IC power lines, and in pictures on Peter's site, look like Electros. I stuffed Electros as per the BOM and the pictures, but won't be firing up the first pre until tonight or tomorrow.

andrew

 

[Ptownkid]

Yeah, I got a little lost on the 47uf too, but i ended up figuring it out, it's just two different footprints.

If anyone's having a hard time finding a part or two I can help

Cheers

[email protected]

 

[T-Beam]

Can you Green Pre-buliders give some advise before I go for buying the parts?

- For the multiturn trimmers on the Green Pre, how many turns do you recommend to use?

- Also if you would like to add info about what quality, material, brand and model you use. As I been told it's more critical in the 1K then the other two. How do Bourns quality?

- What kind of 10Klog-pot do you use? ordinary or better quality?

I would be very grateful if I could get some answers on this, I havn't found so much on this before here.

 

[peterc]

For the trimmers I use 10 turn Bourns copies called "Baron"... They seem to be good.

For the 10k Log pots I use Meggit-Piher carbons, but there are many that will work.

Peter

 

[T-Beam]

[quote author="peterc"]For the trimmers I use 10 turn Bourns copies called "Baron"... They seem to be good.

For the 10k Log pots I use Meggit-Piher carbons, but there are many that will work.

Peter[/quote]
Thanks Peter....always to count on for help....don't you ever getting tired of all newbie-questions? :grin:

By the way, what brand/serie do you use for the elyts, do you think that is critical for the Green??? (I'm still looking for the best deal vs. quality for it will be needed).

 

[clintrubber]

Hadn't seen mentioned before, but sorry if it was: did anyone thrown a film-'bypass' of any value to that 4700uF-electrolytic yet ? I figure it needs to be several uFs to have an helping influence...

 

[peterc]

By the way, what brand/serie do you use for the elyts, do you think that is critical for the Green??? (I'm still looking for the best deal vs. quality for it will be needed)

There are some "best electrolytic" threads here at The Lab, they will give you a good idea of what to look for. I use Rubicon YXF(?) low ESR caps.

did anyone thrown a film-'bypass' of any value to that 4700uF-electrolytic yet ?

Tried a .1uF, no difference to my ears.

Peter

 

[clintrubber]

Quote:

did anyone thrown a film-'bypass' of any value to that 4700uF-electrolytic yet ?

Tried a .1uF, no difference to my ears.

Thanks for mentioning. Maybe I try some 2u2F Wima's I have around. But first completing the unit now, time the lid gets closed :wink:

Regards,

Peter

 

[cannikin]

Hey Guys;

Finally bought my Green PCBs. I've been looking around maybe I missed it.. has anyone put a DI in their green pre.. any suggestions?

 

[Ptownkid]

Yeah I was curious about this to

 

[peterc]

This has been discussed before, general concensus was that a stand alone DI box before the input is the best solution.

I've done this with great results before.

Peter

 

[matta]

I second Peter.

I did some Bass Guitar throught a Boss DI-1 (yeah, not the greatest, but built like brick for gigging) and I was very happy with the results.

Cheers

Matt