stupid pedal tricks: the (charge)pumped tonebender

[pinkjimiphoton]

[video:youtube]

[Caevan O’Shite]

NIIIIIIICE FUZZ.

 

Sounds much better than many fuzzes do on chords, too.

 

Could you design and build a voltage-browning "sag" control with that charge-pump power-supply, so that reducing the voltage while maxing-out its controls and hitting it hard would generate sagging, dilating sounds with blunted attacks and blooming envelopes? (At least, I think that would be the result- ?) THAT would be COOL.

[pinkjimiphoton]

cake, bro...just add a pot wired as a voltage divider in line between the charge pump -9v out and the b= in of the circuit.

would have to cut a trace and add a couple wires, but no problem at all.

 

this thing already blooms some when thru a GOOD amp.

 

i love that dead battery in a big muff pi sound, too.

 

 

just curious, which did ya like better, the pumped one, or mine? don't worry about hurting my feelings if ya like the commercial one better...i kinda do...

 

but mine has probably twice as much balls.

 

also...you can run a dieing 9v in the pedal, too...but, BIG BUT, too...if you sag the voltage BEFORE the charge pump, it sounds like poo...when the battery gets soft, forget it. but a sag control AFTER is probably fine.

[Caevan O’Shite]

Oh, Idunno, it's not so much a matter of either one being "better", they're different in character, almost to the point of being an apples-and-oranges comparison, or at least Macs and Red Delicious. Your own characteristics from your touch, style, technique, etc. yada yada comes through with both. Maybe I'd like the charge-pump version better for me, but as you see, I also wondered about a further idealized version (with a "sag"/voltage "browner") to better still suit myself. I like its bold, robust character all-around, but would enjoy some sag and bloom.

 

 

Yeah, I'd assumed that any such voltage-sagging would need to be done post-pump.

 

I have an octave-fuzz pedal that employs a charge-pump internal power-supply that runs the pedal at 18v whether you use a 9v battery or a 9v external power-supply ("wall-wart") to feed it. It's very consistent and predictable in both excellent and somewhat disappointing ways- that is, while it runs quiet and quietly excellently, it doesn't sag and get chaotically weird the way a dimed old relic of an Octavia might. It's almost too polite and modern!

 

 

If all of the new/'2nd version' Dunlop "Jimi Hendrix Octavio" pedals are like the one I tried in a store a while back, then they really hit it out of the park! I don't know if they are consistently like the one I tried, or if I ran across a "magic" combination of tolerances and providential happenstance.

[pinkjimiphoton]

Oh, Idunno, it's not so much a matter of either one being "better", they're different in character, almost to the point of being an apples-and-oranges comparison, or at least Macs and Red Delicious. Your own characteristics from your touch, style, technique, etc. yada yada comes through with both. Maybe I'd like the charge-pump version better for me, but as you see, I also wondered about a further idealized version (with a "sag"/voltage "browner") to better still suit myself. I like its bold, robust character all-around, but would enjoy some sag and bloom.

 

if you'd like, i can probably build you one, or if you're ok with soldering, send you a "kit" you can build yourself.

my take is definitely louder and has more bite...part of that is cuz in my circuit, the emitters of the transistors are grounded directly instead of using emitter resistors, to get the most gain possible from the trannys. this way, pretty much no matter what trannys you use, it's gonna fuzz like a mofo. unity gain on the toneblaster is about 8:30, on the tonebender about 1:00..quite a substantial difference. the tone is very similar, but the germanium is warmer. it really is apples and oranges, for sure..or like you said, different species of apple.

 

 

Yeah, I'd assumed that any such voltage-sagging would need to be done post-pump.

 

it sounds bloody HORRIBLE when the battery starts to go in this thing...it's really designed for them guys that use a wart for everything. i am intrigued about the idea of adding a sag control to it, and also taking the internal 20k bias trimmer and mounting it as another knob to vary the bias...that's a similar effect to browning it out...the more you starve the tranny, the more fuzz and bloom, the more you feed it the louder and cleaner it gets. the original toneblaster was so clean at unity gain, it sounded more like a compressor than the fuzz it is now...if you check the old videos, the difference is nite and day.

 

I have an octave-fuzz pedal that employs a charge-pump internal power-supply that runs the pedal at 18v whether you use a 9v battery or a 9v external power-supply ("wall-wart") to feed it. It's very consistent and predictable in both excellent and somewhat disappointing ways- that is, while it runs quiet and quietly excellently, it doesn't sag and get chaotically weird the way a dimed old relic of an Octavia might. It's almost too polite and modern!

 

adding a "sag" control to the circuit after the charge pump may help...which model octave fuzz is it? (reminds me, i have one of them old dunlop "jimi hendrix octave" pedals i'm gonna add to my live board for tonite, thanks for reminding me...MY octavia is too big to stuff on the board!!). have you tried running it with a 9v adaptor? halving the voltage should change the quality somewhat, depending on whether they have voltage regulators onboard the design.

caveat: having a lower power supply may make the pedal draw more current, which COULD overheat and roast the charge pump!!!! some charge pumps can't handle it and will smoke..most aren't good for more than maybe 100ma of current draw.

 

in this case, best bet would be to look at the output of the charge pump, which would be pins 5 and 8 (looking at the chip with the "notch" on top, that would be the bottom and top pins on the right side respectively)....i bet your pedal uses a bipolar power supply (+9/-9v) rather than 18v ...it's still 18v, for all intents, but alot of chips want a bipolar supply of pos and neg...that's why alot of 9 volt pedals will have about 4.5 v feeding the different sides of dual opamps, etc...

you could try using an undersized adaptor, but the charge pump is gonna wanna see 9v and will probably not function right. the voltage drop has to be after it.

 

if it's bipolar, to add a sag control would require a dual-ganged pot, so you can adjust each side of the power supply from the pump simultaneously....if you turn down one side or the other, it plain won't work right.

 

i'd be happy to research it for you if you need me to bro!

 

 

If all of the new/'2nd version' Dunlop "Jimi Hendrix Octavio" pedals are like the one I tried in a store a while back, then they really hit it out of the park! I don't know if they are consistently like the one I tried, or if I ran across a "magic" combination of tolerances and providential happenstance.

 

the one i have is one of the original issues, it still had a battery with a date stamp of 97 in it...the thing sounds great!!

i prefer my homebrew, it's a little more musical (ie, you can turn the guitar way down and get great crunch rhythm tones with a lot of second harmonic...sounds almost like an electric 12 string thru a dimed marshall...also, can bypass the octave section by un-grounding the transformer and use it as an overdriver) but the dunlop one is hard to beat for it's size.

 

here's some linkage for ya bro, to make more sense of it than i can probably give.

 

note: on YOUR pedal, pcb would need some trace cuts and some modification to put a stacked dual pot in line after the charge pump, so be careful!!

 

http://www.beavisaudio.com/Projects/DBS/

 

http://www.beavisaudio.com/techpages/PoweringPedals/index.htm

 

hope this info helps bro... dano beavis (yes, the REAL beavis exists, and he's a diy-aholic)'s site is a treasure trove of great info, and worth a few days of surfing!!