Ah ok, thanks. Interesting so with the 18vac I will get 25.4vdc need to drop the rest and have enough current left.

35 minutes ago, mwl168 said:

Agree with cspirou that 13V drop for 20V regulated output is likely excessive.

How much current does your application draw from each rails? The GRLV's dropout voltage varies with load - the higher the load the higher the dropout voltage. 

For my balanced CPA2 amp which I set it up to draw about 1A each rail, I have to use a transformer with 22v secondaries to support 22VDC regulated rails from the GRLV.

Dynalo Mk2 

On ‎12‎/‎18‎/‎2017 at 4:43 PM, MrSlim said:

Hey Kerry, 

Are you making the Gerbers available for these boards, or do you happen to have a few spares you could part with?    I'm thinking that these might make a nice little +- 15V power supply for a DAC board I have on the way.  I would also thinking about a second + supply for 3.3V, if it could be configured that low.

I've been utterly swamped at work, but I can get the Gerbers over to Kevin in the next week or so.  I'd love for someone to do a group buy for assembled boards.  I don't have the time for that.

14 hours ago, Kerry said:

I've been utterly swamped at work, but I can get the Gerbers over to Kevin in the next week or so.  I'd love for someone to do a group buy for assembled boards.  I don't have the time for that.

Where would be a good place to get boards assembled?

Can I use opa445 instead of opa134 for GRLV for 30V output? It's necessary? Thanks!

yes but the opamps are wired regulated to ground so a opa134 is good for up to 36v output voltage

from Kerry, the gr78xx and gr79xx board files

I want a few of each if there is going to be a group buy

GR79xx.zip

GR78xx-v1-2.zip

Edited December 26, 20178 yr by kevin gilmore

What's the max voltage of these?

with the opa134 you are limited to 36v. you can certainly change that opamp to opa445 and then it would work up to higher voltages. going to check on the ratings of the transistors now

 

edit: subject to the voltage ratings on the capacitors, so probably 35v

Edited December 27, 20178 yr by kevin gilmore

I want to use GRLV for my new headphone amplifier. But I need 30V power supply with 3 sockets, and place for large capacitors in the filter (up to 35mm in diameter), and I want to use Elna Silmic II 220uf, 50V as output capacitors. And I spent two evenings to made my own GRLV pcb, simultaneously learning kicad. This is the first pcb in my life, which I have made myself. I also replaced the diode bridges with the fast diodes MUR820, and shunted them with ceramic capacitors. Perhaps someone will find this useful. But I'm not sure of the complete absence of errors ).

Gerbers: https://drive.google.com/open?id=15m6y5CElB4RjW0pRd9Lu47jA_6w2T-0V

Project: https://drive.google.com/open?id=1bV1xTn5Iw3sC_sxR5AL8iZZ5hN85-95U

Doesn’t sound much like a GRLV...

EDIT: doesn't look bad at all. Larger, but I for one could use the additional outputs. I didn't verify the schematic either.

Board is 116.8mm * 147.3mm

Edited December 28, 20178 yr by Pars

Looks close to the original dual board but bigger. I did not verify the wiring.

BOM for the GRxx boards

GR79.csv

GR78.csv

By the way, linear technology is now owned by analog devices, and you can buy these parts from mouser.

Edited December 28, 20178 yr by kevin gilmore

Thanks Kevin.

That's so nice that we can get the references on mouser too.

I would consider doing an assembled run of these, but we would need a decent amount of interest.

Is “a decent amount” closer to 50, 100, 500, or more? I want a few of each, but don’t want to spend more than a total of $200 or thereabouts.

I’m very much interested.

Interested too. 

Interested as well. Also fine with unpopulated PCBs

Interested also.

Definitely interested.

I'm down for a few

Is “a decent amount” closer to 50, 100, 500, or more? I want a few of each, but don’t want to spend more than a total of $200 or thereabouts.

Probably 50 of each.@Kerry, can you generate the pick-and-place coordinate file, or e-mail me the Diptrace files? I will get some quotes.

penciling in interest as well

15 hours ago, luvdunhill said:

I would consider doing an assembled run of these, but we would need a decent amount of interest.

Will have to change his custom title to:- "Will Assemble SMD Boards For Food"  

6 hours ago, luvdunhill said:

 

Probably 50 of each.@Kerry, can you generate the pick-and-place coordinate file, or e-mail me the Diptrace files? I will get some quotes.

 

Thanks Marc.

I'll do this tomorrow.

... and yes, I'm interested too