Ideas on 18VDC power supply

[David]

When my Tiny Giant died last week, it took the 9VDC power for my pedalboard with it.  Since I have no choice but to go back to using a combo amp, I am planning to build the AMZ Super Buffer to drive a guitar cord long enough to run from my pedalboard into the closet where our church now puts speaker cabinets for isolation and miking up to the console.  I intend to run the buffer at 18VDC to get the maximum possible headroom.  I also intend to replace my Boss EQ with a DIY boost -- probably a Shaka Boost, again running at 18VDC.

This is going to require that I build a new distribution system.  There are a couple of ways I can go with this.  I own a Dunlop DC Brick which I sent to the minors after one outing on my pedalboard.  Its wall wart generates 18VDC -- perfect for what I need.  This would power the buffer and the booster.  I guess I could then use a regulator like a 7809 or LM317 (which might be preferable for current delivery) to deliver 9VDC to my pedalboard.

I have seen reviews that the strain relief on the Brick wall-wart seems to encourage premature cord failure.  Can anyone confirm or deny that?

Finally, I could also start with a 9VDC wall wart and use that MAX-whateveritis to deliver the 18 volts for the buffer and boost.  One possible advantage to this plan is that I have multiple wall-warts that are capable of delivering 9VDC at 1 amp or better;  unfortunately, more than one is pretty noisy.  I'd bet I could deal with that by using the old 100-ohm resistor and big capacitor across the inputs trick.

Any reason to pick one methodology over the other?

[Galego]

I usually just power my pedals all at 9VDC and use MAX1044 or ICL7660S to invert it and power the Opamps with +/-9V. You get the extra headroom and save on a few parts you'd use to get the Vref from the +18V. The Vref is GND.

[Brossman]

WELL~ I'm not sure what your price range is, but this is what the EE at my workplace told me is the best place for QUIET and "cheap" P/S...  So you dont have to deal with Rectifying/Filtering/RC-bridge, etc.

I compiled a list of possibilities for your application here: http://www.astrodyne.com/ecatalog/usa/encapsulated-power-supply/compare/ANC-5S12D%7C%7CANC-5S15D%7C%7CASC-12D%7C%7CASC-15D%7C%7CASC-5S12D%7C%7CASC-5S15D%7C%7C  ...PM me to let me know if it doesnt work for you.

EDIT, on second thought just surf Astrodyne for good PS... I've seen em as low as $20-30 - by the time you deal with AC>DC>filter>etc, you'll proly spend a bit over that for large PS...  Just now, I see those are almost or over $100 a piece... well, random Goodwill wallwarts with a little hum for $1 each kinda beats that, sorry.

[bhill]

The "old large cap and 100R trick" can bite you in the fanny, as it does not take into account any loading from the pedals. I just repaired an SKB pedalboard someone had tried that trick with a 6800uf 16v electro and 100R. With nothing plugged into the power jacks, it dropped the 9.54Vdc from a One Spot to 9.01 Vdc. Each pedal added to the chain dropped that voltage another .12V with the end result after 5 pedals (small board) of reducing the power available to 8.41Vdc, at which point the pedals with lfo's quit lfoing. Eliminating the cap and resistor and the same pedals are working happily at 9.51Vdc, a drop of a whopping .03V.

[David]

The "old large cap and 100R trick" can bite you in the fanny, as it does not take into account any loading from the pedals. I just repaired an SKB pedalboard someone had tried that trick with a 6800uf 16v electro and 100R. With nothing plugged into the power jacks, it dropped the 9.54Vdc from a One Spot to 9.01 Vdc. Each pedal added to the chain dropped that voltage another .12V with the end result after 5 pedals (small board) of reducing the power available to 8.41Vdc, at which point the pedals with lfo's quit lfoing. Eliminating the cap and resistor and the same pedals are working happily at 9.51Vdc, a drop of a whopping .03V.

Hmmm...  as I prefer my posterior region to be unmarked by the dentition of strangers, I'll take that as a warning.
In the meantime, I have decided to alter my plan slightly and firm it up.

One of the main reasons I was considering using a MAX1044 or something similar to do voltage-doubling is that I have at least 3 wall warts that supply 9VDC.  As I stated, two of them are noisy.  It turns out that these same two will also do 12V, and I have a third with 12V output.  This gets me right back to having redundant wall-warts like I originally wanted.  I could then use a 7809 to give me regulated 9VDC and at that point I could possibly stick in the cap and resistor duo.  Not sure how to deal with noisy 12V, though, in view of the above comments.  With the one wall wart, I don't expect a problem as it looks like a switching type of wall-wart.  The others, though, are those Rat Shack switchable supplies.