Rangemasters and Power Supplies

[YouAre]

I was looking to build a rangemaster with an oc44 tranny (from smallbear) but i've read that the germanium gets a little noisier with power supplies, and work better with batteries.

Is there any way around this?

Is there another rangemaster-esque circuit out there that doesn't have any noise issues with power supplies?

[petemoore]

Is there another rangemaster-esque circuit out there that doesn't have any noise issues with power supplies? 
  I like the Omega, one hekuva boostager...
  You can try the RM with PS's, using a large filter cap across the supply rails, Gnd and V+ [or vice versa for PNP].
  Mine worked good with a VS 1Spot adapter, same as a battery AFAICT, until I used also an EZ vibe [and or wah I forget], then it got just a little bit noisy.
  But yupp, Ge stuff like RM's and FF's as well as wahs can be fussy about noise/power supplies.
  And AFAIK nothing puts out 'pure DC' like a battery, I just use batteries and a charger, RM takes very little current, with an input jack wired to switch the supply off [when plug is pulled], many months of good battery can be had.

[mac]

The RM sucks about 0.3mA from the a 9V batt. It should last a a long time. It's the best choice IMHO.

mac

[Elektrojänis]

Simple one transistor gain stages with no feedback are easily affected by the noise comming from power supply. The fix is to make sure your power supply will not put out any noise!

A good regulated power supply is a good idea if you want to get rid of the batteries.

You could also check out these:
http://www.muzique.com/lab/hum.htm
http://www.muzique.com/lab/filter.htm

You could even stick a regulator circuit in the pedal.

[Elektrojänis]

The RM sucks about 0.3mA from the a 9V batt. It should last a a long time. It's the best choice IMHO.

Good point.

One thing to remember though: A led status indicator will suck much more current than many of these simple circuits.

[Gus]

One thing that is often overlooked with 3 terminal regulators is that they "need" a few ma of draw to work correctly.  So use Ohms law

you have 9V and want 10ma    Well 1k across 9V is 9ma so even better make the draw more and use a LED.  Subtract the LED voltage drop (depend on color ans chemisty) from 9V.   Divide that voltage by .015A(15ma) and use the resistor value that is close.

A single small parts count effect often dose not draw enought current.

So the noise problem might not be a problem.

[YouAre]

I've got a godlyke power supply, is that sufficient?

Would adding the choke in that pedal be helpful with the godlyke?

[rockgardenlove]

It should be fine.  If you get noise in there, just use a BFC (to use RG's excellent term for Big Freaking Capacitor) across the power rails.  That helps a ton.  100Ω in series with the power supply also helps.  You could hook up a regulator too, but it's probably not necessary.

Hope that helped.

[mac]

The batt is best for me because I do not use leds. My setup is simple, the RM, the FF, Harmonic Percolator, some time-based fxs and the amp. That's it.
I have a diy PS I use for testing and debbuging, and for opamp fxs. It has a 317 adjusted to 9v. Very quiet even with the breadboard.

mac

[sfx1999]

The problem with the OC44 rangemaster is that it is positive ground, so you can't run it on the same adapter as negative ground power supplies.

However, you could build a negative ground version with an OC140 transistor. It should be listed on GGG as negative ground NPN.

[YouAre]

The problem with the OC44 rangemaster is that it is positive ground, so you can't run it on the same adapter as negative ground power supplies.

However, you could build a negative ground version with an OC140 transistor. It should be listed on GGG as negative ground NPN.

are you sure about the oc44? I called up robert keeley's shop today and asked about the oc44 in rangemasters, and one of the guys said that they work in daisy chains



so guys, am i going to want to build an NPN rangemaster? does the oc140 give a drastically different rangemaster tone? i see that its more expensive than the oc44.

~murad

[sfx1999]

A positive ground circuit has it's ground connected to the + terminal of your supply. The problem is, most pedals are negative ground; the ground is connected to the - side. When guitar effects are connected to each other, the ground is shared between the two effects. If you mix the two on the same power supply, you will get a short.

There is a PNP negative ground Rangemaster on http://www.generalguitargadgets.com/ that will work in daisy chains that can be used with the OC44.

If you wanted to go NPN negative ground with an OC140, certain components would need to be reversed, but it is a very simple change.

[YouAre]

A positive ground circuit has it's ground connected to the + terminal of your supply. The problem is, most pedals are negative ground; the ground is connected to the - side. When guitar effects are connected to each other, the ground is shared between the two effects. If you mix the two on the same power supply, you will get a short.

There is a PNP negative ground Rangemaster on http://www.generalguitargadgets.com/ that will work in daisy chains that can be used with the OC44.

If you wanted to go NPN negative ground with an OC140, certain components would need to be reversed, but it is a very simple change.

ideally, i'd like to use the oc44 cause its cheaper and more widely used as far as i know. So i'm going to want to build the negative ground version for use with a daisy chain?

[mac]

so guys, am i going to want to build an NPN rangemaster? does the oc140 give a drastically different rangemaster tone? i see that its more expensive than the oc44.

Most readers won't agree but in general yes, IMHO. Does not mean that this is the case, ie, the oc44 and the oc140. But a 2sb352 and a oc140 sound different.

mac

[YouAre]

sorry i'm a bit confused, is it possible to build the negative ground RM with an oc44?

[mac]

Yes. I never tried, but it may work.

mac

[hairyandy]

Here's a verified layout for a PNP Negative Ground Rangemaster:

http://aronnelson.com/gallery/album26/Rangemaster

Andy