The Version 9 Green Pre

[peterc]

:grin: :grin: :grin: :grin:

Yeah, nice try. I dont actually want to lose money on this deal.


:grin: :grin: :grin: :grin:

Monday Pete

 

[Mbira]

Peter,
What is the current draw of these new cards? How many amps will my PS need to be for a 4 channel pre? Thanks!

Joel

 

[mesmer]

What will the total parts cost be? Sorry if it was stated previously, I haven't been able to find it.
Peter

 

[Kat]

Well, I'm interested even if it isn't free :? Is it possible to get one to feed four boards?

What will the cost be ?

 

[peterc]

The current draw of the audio part of the pre is under 50mA per rail, 100mA in total. I generally allow 100mA per channel.

The LED meter will draw about 30 - 40 mA. So in total not more than 140mA, usually about 120mA.

I'll check this tonite, I cant remember the exact figures.

If I were to do a PSU, my current design is one that uses 2 x LM 317 & 1 x 337 regulators. I'll have to get a quote, but it does depend heavily on quantity. With small clip-on heatsinks, it will feed 4 channels. The heatsinks get slightly warm to the touch, but I have used it in this configuration before with good results.

If there is any interest, I have a contact that will do them without solder mask or silkscreened legend & very small setup costs. I have used them before & the boards are good. The copper will be sealed with a flux spray.

Let me know.

Peter

 

[Mbira]

Hey Kev,
Would your previous Green power supply work with 4 of these new boards? I seem to remember it could do a 6A load, right? Just need a bigger fuse, I think?

Joel :guinness:

 

[peterc]

The previous supply used 7815/7915 regulators which are rated at 1,5 amps each, but will only handle this with large heatsinks. I would not recomend more than 4 channels on that PSU either.

I really like 2 supplies in an 8 chan pre in case one fails. There would be at least 4 channels still running. Could be a Redundant Array of Inexpensive PSU's?

Peter

 

[peterc]

Hi all

I have set up an order post in the Black Market, have a peek here :

http://www.groupdiy.com/index.php?topic=25692#25692

Peter

 

[Mbira]

OOps,
I didn't realize the regulators were only rated at 1.5 A. Hmmm... Let me look at this a while... When you say 2 power supplies, do you mean one transformer with the power going to 2 seperate circuits? (the 7815/7915's) Or would you use 2 transformers? The tranny is rated at 6A.

Joel :guinness:

 

[Kev]

At a continuous 1.5 amps you will probably want some permanent heat sinking on those regs.

I don't think you will need that much for 4 Green-Pres ??
The mkII will have more IC's so it will need a little more current.

My guess is that a 30VA trafo and 7815/7915 will still be fine.
As long as you don't go putting in HUGE meter lamps. :roll:

 

[peterc]

When you say 2 power supplies, do you mean one transformer with the power going to 2 seperate circuits? (the 7815/7915's) Or would you use 2 transformers? The tranny is rated at 6A.

Yes. I ran the mains transformer secondaries to both the PSU pcb's. Can be seen on my site here :

http://1176neve.tripod.com/1176/id15.html

The transformer was a 30VA unit.

Peter

 

[Mbira]

Very nice...

:guinness:

 

[frob]

dose this mean that even if we have expresed intrest( in the form of hay i want four, witch i do :wink: ) we still need to email you?

 

[Consul]

I think this is the longest a thread I started has ever gone. Should I be proud or something? :wink:

 

[peterc]

Here is a teaser.... :grin:

I will build it up tonite to check the workability.

Peter

 

[Kev]

:green: :green: :green:
... make Pete's DIY

:thumb:

 

[peterc]

Another teaser (or 2) :

What I've done is to make up a "photo essay" showing the board at each stage of assembly. The pics are BIG, so builders can zoom right in on the pics & see the components. I'll make the site available to those who get the PCB.

Peter

 

[orson whitfield]

Thank you Peter. This is forward thinking on your part. Newbies really benefit and appreciate this kind of visual.

 

[frob]

have they been sent out yet im drooling over here

 

[Category 5]

I got my boards today in Florida, and the package said it was shipped on the 22nd. WOW was that fast!

Now I am certaibly going to need help putting togather a parts order.

How many people plan to order from digikey? Would you mind sharing which components you got any why. Since I am so new at this I am a bit overwhelmed at which switches, caps, etc. to buy. I would like to match the pictures of the finished board, but DigiKey doesn't have pictures on the site.

The boards look awesome and I am simply drooling over here. I can see myself ordering more...maybe an 8 channel box is in my future. I bet these things would be great for live use too.

Shane