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AMZ Power PCB

Started by Gordo, May 21, 2010, 11:42:07 PM

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Gordo

Just got Jack's new Power supply PCB in the mail today and am stoked to get it built up tomorrow. Anyone else seen this yet? 18V, +9, -9, 12, and adjustable outputs. Looks pretty slick.
Bust the busters
Screw the feeders
Make the healers feel the way I feel...

phoganuci

I just ordered one, along with all the parts to populate.  What size enclosure did you use?  I ordered the recommended wall wart adapters, how do I come across the dc satellite wires to power each of the boxes individually?

Gordo

Quote from: phoganuci on May 25, 2010, 10:26:09 AM
I just ordered one, along with all the parts to populate.  What size enclosure did you use?  I ordered the recommended wall wart adapters, how do I come across the dc satellite wires to power each of the boxes individually?

I crammed it all in a B size (small MXR) enclosure.  I ended up doing the full boat 18/12/9/-9/adj 9 build, which was total overkill but really, isn't that what we do? I was a bit worried about heat but it seems to run pretty comfortable.  I used an old HP inkjet printer power supply similar to Jack's.  I have a combination of a one spot multiple daisychain and then made up a bunch of cables using cable from an old power supply and a bunch of connectors from Small Bear.  I need to put together a bunch of right angled ones cuz the straight ones are too big and take a beating.  10 lbs of pedals on a 5lb pedal board... 
Bust the busters
Screw the feeders
Make the healers feel the way I feel...

Schappy

Is each output isolated on this power supply?

Where do you get the parts list?

chi_boy

Quote from: Schappy on May 26, 2010, 10:36:15 AM
Is each output isolated on this power supply?

Where do you get the parts list?

http://www.muzique.com/power.htm
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Pakaloabob

This certainly looks like a nice project to undertake!
Although I don't currently have a use for -9V, i will certainly make a PNP boost or fuzz at some point. The 9V sag is something I was going to do as a stand-alone unit anyway, so why not incorporate it into one project? I have a ROG Ruby Amp for which I like using 12V power supply. I suppose at some point I would also use 18V for something.
All in all, it seems to be perfect for all the power I might need!
That being said, I do have a few questions:
As Schappy asked earlier, are the outputs isolated? I thought that isolation was achieved using transformers on the back end of each output ala GEO Spyder, which the AMZ board does not seem to do.
Also, I don't see any Bridge Rectifier section as I have seen in two other projects I was considering. I might be mistaken, since I am not very familiar with power supplies. In the Small Bear "Small Wart" is see a Bridge rectifier right after the transformer, and in the Tonepad adjustable power supply, there is a diode network. I realize these are different animals, using the LM317 instead of 7809 fixed regulators.
Also, in comparing the Small Wart and Tonepad power supplies I see they are very similar except for a few extra items on the Tonepad one: two 0.1 uf caps and a diode, D5, across Vin and Vout of the lm317, and D6. What do these components do?
Sorry for the slightly off-topic and rambling nature of my post. Just wanted to clear some things up before I embark on the new project.

Cheers, Bob

Gordo

Quote from: Pakaloabob on May 29, 2010, 12:37:13 PM
Although I don't currently have a use for -9V, i will certainly make a PNP boost or fuzz at some point. The 9V sag is something I was going to do as a stand-alone unit anyway, so why not incorporate it into one project? I have a ROG Ruby Amp for which I like using 12V power supply. I suppose at some point I would also use 18V for something.

As Schappy asked earlier, are the outputs isolated?

Also, I don't see any Bridge Rectifier section as I have seen in two other projects I was considering.

Hi Bob, the outputs are isolated. If you're building on Jack's board you can just leave off the associated parts with the -9V stuff. The build docs detail this. If at some point you decide you need it, just add it later. The circuit doesn't include any rectification because it assumes that you're using a DC power supply. That's a slightly different twist on most other builds because it allows you to reuse a PS. In my case I'm a pack rat so even though I'd tossed an old HP inkjet I kept that PS thinking "I'll use this sometime". First time I can recall that it's ever paid off  :icon_biggrin:

I was hoping to use the sag supply for a compressor but in trying it out on a Dynacomp clone have been underwhelmed. Not an issue with the PS but the "mojo" sound I was expecting wasn't there. Not sure what the sag fuss is about so far, but by God when I figure it out, I'll have it on my pedal board....
Bust the busters
Screw the feeders
Make the healers feel the way I feel...

trixdropd

How are the outputs isolated if they share the same transformer? Not being an ass, I just don't get it.

Gordo

Quote from: trixdropd on May 30, 2010, 08:06:00 PM
How are the outputs isolated if they share the same transformer? Not being an ass, I just don't get it.

Not being an ass, my friend, honest question.  Isolated by being on different regulators.  The regulators are all seeing the same input (and by this point it's an "assumed" unfiltered DC voltage) and each regulates that voltage independent of the others, or is "isolated" from the others.  In my case I was having trouble with running my Boss Giga-Delay on a common power buss from a One-Spot with my other pedals.  I'd get a high pitched "whining" noise to the amp.  If I ran another One-Spot directly to the the Boss it would disappear.  Even if I dropped the ground from the Boss feed (figuring it was a ground loop) I'd still get it.  I'd thought about just putting another regulator on the Boss but would result in a voltage drop so this worked really well for me.
Bust the busters
Screw the feeders
Make the healers feel the way I feel...

Pakaloabob

Thanks for the info!
I think my confusion was that I assumed that in the other circuits the transformer puts out DC current, when actually it just steps down the 120V AC voltage to a lower AC voltage. I guess I really didn't understand the concept of a bridge rectifier, but it is becoming clearer now.
From what I understand, I think fuzz and distortion effects would benefit the most from voltage sag. I have read that Duane Allman requested used 9V batteries for his.
I too am a bit of a pack rat  ;) I am sure I have some sort of wall wart that I can use.
By the way, does anyone know if  the Visual Sound 1 spot is filtered or not. I suspect it is not because I seem to get more noise with it compared to battery usage. My tonepad Rat is very noisy, and when I tried my ROG Whisker Biscuit before putting it in an enclosure it was horrendous with the 1 spot, but fine with battery.



Hides-His-Eyes

Could I make a "semi-isolated" power supply with a high current 9V DC going in and a series of regulators coming out, or would there be no benefit?