DIY a deluxe power supply for guitar fx pedals?

[mike_mccue]

Hi,
I just started learning a process of recording electric guitar that is popularly known as Reamping. I bought a Reamp impedance and level matching device to allow +4dBu lo-z signals coming out of my recording system to hook up to my hi-z guitar amp and stomp box inputs. The Reamp has a ground lift that seems to work well.

I own a few cheap wall wart type power supplies that come with extra leads. They are marketed just for guitar stomp boxes.

I'm having lots of trouble when using the cheap power supplies to power the efx boxes. I get all kinds of interaction. Some 60hZ and some higher freqs. It just depends on what combo I've hooked up. (I have a big box full of pedals) I don't think they are consistent with regard to grounding design so there's all sorts of weird interactions.

Because I'm currently focused on recording the specific sound of the effects I'm more sensitive than usual about the noise. The noise might be ignored in a jam session with a live drummer etc.

Today I pulled the power supply and restocked with batteries and most of my complaints just disappeared.

So I'm wondering, can someone here help me work up a design for really deluxe power supply that might power many pedals but keep each isolated from each other?

I imagine I could buy or build a basic 9vDC power supply and then isolate the distribution feeds?

best regards,
mike

[mike_mccue]

I was looking at Bob Bradshaw's website:

http://www.customaudioelectronics.co...and_power_.htm


And saw this quote:

"Sometimes it is necessary to isolate DC voltages from each other to eliminate ground loop hum in critical applications. At CAE, we use high quality DC/DC converters for this purpose. This device, when used properly, can eliminate many sources of noise and make a pedal think it is connected to a battery! Of course, this adds considerable expense to power supply cost, so we use them in only when necessary."

I think this is what I want... but I don't know what a DC/DC converter is in terms of a specific part. I reminded myself that an ISO tranny is for AC. So I guess I really don't know how you isolate DC.

Thanks,
mike

[rplovanich]

Check out General Guitar Gadgets "Regulated Power Supply". I built one and it works great. I purchased the PCB from them and my parts from Mouser. Easy build.

[mike_mccue]

Thanks,
I pulled out my Mouser catalog last night and found 40 pages of DC/DC converters, many with isolation.
They all seem to be designed for circuit boards so my DIY point to point experience is not readily adaptable.

I'll take a look.

best regards,
mike

[Mark Black]

R.G. has a very informative article here:
http://www.geofex.com/Article_Folders/Spyder/spyder.htm

[mike_mccue]

Thanks Mark,

That's great article.

best regards,
mike

[mike_mccue]

Mark,
That R.G. Keen article was a good read. I was searching out some ore info about the Spyder as a DIY project on some DIY forums and stumbled on the fact that the Voodoo Labs Pedal Power 2 plus was very similar in design. 8 Isolated 9vDC outputs.

I happened to find one in stock locally with one phone call... which for me is rare opportunity. I rushed down to the store and bought it.

Last night I plugged up 5 pedals in series and wow... I couldn't be happier.

Thanks to both of you for the great suggestions. Once I understood what I was looking for I was able to make a decision that worked ok for me.
I hope I didn't disappoint by not going all the way with the interest in DIY.

You guys really helped me out.

best regards,
mike

[Mark Black]

Glad to hear you found a happy solution!

I usually feel the same - if there's an "off-the-shelf" solution already existing and it saves me the time of a build with breadboarding and such I'm all for it.

Last single-source multi-output power supply I built took a while and some re-engineering of the ground plane to get the noise level down.