9V to +-14v

[nickbungus]

Hi guys

NJKMonty has been grafting away with Eagle designing a layout for a CE-1 clone.

Heres the schematic we are using.

Due to the size of the of the board and our view to make it in a 1590bb we're struggling with the power section. 

In a nutshell, we are trying to get a +/-14v supply from 9v.

I was looking at doing something like this but with different diodes to get us closer to +-14v.


But I'm sure theres a better way.

Any suggestions would be more than welcome

[njkmonty]

one fellow member here suggested something like this however  i think they only handle low amps?

https://www.rapidonline.com/mornsun-wra0515s-3wr2-3w-dual-o-p-sip-regulated-isolated-dc-converter-15v-dc-84-1561

[rankot]

This will bring you to +14.5/-13.7 V:

[rankot]

Or you can use  Mornsun A0915S-1WR2, it is 2W Fixed Input Isolated and Unregulated Dual Output DC/DC Converter.
http://www.acalbfi.com/uk/Power-supplies/DC-DC/PCB-mounted/p/2W-Fixed-Input-Isolated-and-Unregulated-Dual-Output-DC-DC-Converter/0000005BDY

[armdnrdy]

This efficient DC/DC converter runs in the MHz so....it's way out of human audio range
The output voltage can be changed with a couple of resistors.

https://obsoletetechnology.wordpress.com/projects/studio-electronics/dc-dc-bipolar-power-supply-for-effect-pedals/

[nickbungus]

Cheers guys.  That's excellent.

Thanks as always Larry

[njkmonty]

would those smd capacitors voltage rating be adequate?   

[armdnrdy]

would those smd capacitors voltage rating be adequate?

If you are referring to the supply that I posted....yes.
You would be surprised at the voltage ratings of tiny SMD parts.
Miniature ceramic caps are rated for 1000V!
I have a BOM of parts that I sourced from Digikey...I can PM you the list if you'd like.

[njkmonty]

Thanks heaps

[digi2t]

You had me at CE-1. 

Any plans for public boards?

[nickbungus]

Yep.  Thats the plan.

We're looking at getting some boards made and then selling them with an MN3002.

Aussie Nick (Njkmonty) has done most of the work (actually pretty much all of the work), and from what I've seen its really coming on!

[njkmonty]

yeah its point to point    but  turrets arent cheap, so not sure what it will cost

[thermionix]

A point-to-point Ce-1 clone on turrets?  Well this I gotta see.


I currently have in my posession a Multivox CB-1 Chorus Box, which I've read is an exact CE-1 clone (not sure of that, but it's definitely close).  I fixed it for a buddy who lives in a neighboring state, so it's here with me until he comes to town and gets it, along with a few other items too big to ship.  If you hit a snag and need voltages, I'd be glad to fire it up and try to help, assuming it's still here.  Can also take some gut pics, quality limited by my crappy camera, if that might help you in any way.

[njkmonty]

sure! why not


turrets   was me taking the piss out of my limited eagle cad abilities in making a good small layout!

[thermionix]

Here ya go, let me know if you want anything more specific or zoomed.



















I'm not generally a big fan of chorus, but this thing does sound really nice.  Think "Feeling Gravity's Pull" by REM.  Gotta keep the speed pretty low (here labeled "intensity" for some reason).  Best below 1Hz I'd say, otherwise it sounds more like your guitar's going out of tune rhythmically, make you seasick.  The vibrato function is pretty useless IMO, doesn't sound very good, but it's neat that it has an independent speed control.

[njkmonty]

that looks like the same board as the original!!!

fantastic

[thermionix]

Wow, holy crap!

https://medias.audiofanzine.com/images/normal/boss-ce-1-chorus-ensemble-672952.jpg

Exactly the same board, stuffed with different brands of components.  I guess Roland sold the PCBs to Multivox.  Both MIJ, but unrelated companies AFAIK.

About 20 years ago, another buddy of mine had a Multivox tape echo, with a built-in chorus.  That thing sounded amazing, otherworldly.  It was cool just to watch, the tape wasn't on reels but just snaked around in a shallow chamber on top that had a smoked plexiglass lid.  I'd love to find one, but I wouldn't want to have to work on it.

[njkmonty]

Hey Armdnrdy,, if we implement the smd bipolar power supply into the ce 1 circuit,  would we need to use all the 220uf and 47uf power capacitors?   or do you think what you suggested would  not need any more capacitor filtering?

in pic there are 2 examples,  would the bottom be ok,  diodes are just to drop voltage

[nickbungus]

We dont need to use diodes to get down to + and - 14v, we need to use the values of R1 and R2 to get us the 14v (as per the webpage linked by armdnrdy).  We just need to also get the +/-13v after that

[armdnrdy]

Hey Armdnrdy,, if we implement the smd bipolar power supply into the ce 1 circuit,  would we need to use all the 220uf and 47uf power capacitors?   or do you think what you suggested would  not need any more capacitor filtering?

in pic there are 2 examples,  would the bottom be ok,  diodes are just to drop voltage

I would say....additional power supply filtering isn't going to hurt anything but...
I don't see the need for the size used in the original.
The original circuit used larger caps to smooth the PS after conversion from AC to DC.
I would use 100µf after the 3467 supply, and 47µfs for the 13V.