a simple solution to low power pedals and adapters

[caress]

i realized how stupidly simple this is yesterday...

i was building a few univox squarewave fuzzes, which by the way, sound pretty great - tons of feedback!  so, while testing them, i realized that the fuzz sounded a lot better with the battery than with the 1spot adapter.  it wasn't hum or noise, the fuzz just sounded a bit fuller and a little less "pinched" with the battery.  so i opened up a squarewave and used a voltage starve pot to find the sweet sopt, then simply inserted a resistor in series with the dc jack in the pedals.  now i always have that particular fuzz sound, regardless of whether i use a battery or adapter...

might be useful in other fuzzes, too...

[R.G.]

Good bit of detective work there! Some distortions, especially, are sensitive to the size and impedance of their power feed.

[caress]

i'm sure some people practice this already, but i'm surprised that no one adds it onto schematics, layouts, etc...

it's definitely something to think about if you want a pedal to sound consistent...

[ambulancevoice]

fuzz factory uses a starve pot (stab)
most bias controls are just basically starve pots
also, Dano from beavisaudio has some notes on his findings with them, and he also adds them to his fuzzes

[Solidhex]

That's funny since I did the same thing the night before last night. I was checking transistor voltages on a Super Fuzz clone and was curious about voltage/ sonic differences between a 9volt wall adapter and a fresh battery. I experienced the same thing. Noisy blown out compared to the battery. I rigged a dc jack to a batt clip and plugged it into the adapter and was reading way over 13 volts with my multimeter off it. Adding the resistor sounds good to me. Trying to think where I'd put the resistor so it would affect the wall wart but not the battery.

--Brad

[George Giblet]

There is a reason why people use regulated adaptors.

[Zben3129]

I like to run some fuzz pedals at around 5v or so,

but I have found that a dying battery actually sounds different than a "simulated" dead battery of the same voltage. Maybe there is a different internal resistance or capacitance, or maybe just less current?


Zach

[caress]

There is a reason why people use regulated adaptors.

the reason i added the resistor was to get lower than 9v by using an adapter.  mid-high 7v-low 8v sounded best to my ears on the squarewave...

starve pots can be fun, but sometimes you just want the pedal to sound good without the options...  on most fuzzes i've built, i've tried out a starve pot and while you can get some subtle changes in tone, it's not always worthwhile to add it on.  a bias pot usually gives more tonal range, imo. 

Trying to think where I'd put the resistor so it would affect the wall wart but not the battery.

i would set it up like this:

adapter+ ---- board ---- trimpot/resistor ----
                                                              } ---- 9v+
battery+  ---- board ---------------------------

i think that's right...  you could make a little board for it or just save a few holes on your build to add it on.

[GravityRobert]

My Boss hm-2 also sounds better with batteries. What value resistor did you use? I'm thinking of trying this as well 

[caress]

place a xx value pot in series with the power supply, turn and listen!  when you reach your desired sound, measure the resistance with your meter and pop that resistor in.

OR just use a trimpot and set to taste...