# More Voltage Please!



## vadsy (Dec 2, 2010)

So I received Catalinbread DLS in the mail today and immediately noticed it could run 9 or 18 volts. I plugged it in using 18 as I already prefer my Timmy and OCD clone to run that way, aaaaaanndd.... guess what? The DLS is a killer pedal! I love it but after rockin' out for a while I switched over to 9 volts and was left disappointed. My question is; why aren't more pedals designed for 18 volt usage? It seems like a no-brainer with the huge quality of sound improvement, in my opinion. It can't be that tough on the builders, can it?


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## keto (May 23, 2006)

Well, those are all 3 op amp 'driven'. Of the HUNDREDS of types, not all op amps a) sound good in pedals b) can even work in pedals c) can take 18v.

Most typical transistor 'driven' units will be fried if plugged into 18v.

That's yer lowest common denominator basics, hopefully Mr. Hammer will be along in the morning with something that actually educates us


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## ronmac (Sep 22, 2006)

keto said:


> Most typical transistor 'driven' units will be fried if plugged into 18v.


The circuits need to be designed to operate at that level, but it can be done. 

Sometimes we struggle along using an old "standard" because, as Homer Simpson states it, "I dunno. It was like that when I got here..." We kept the NTSC colour television standard, developed in 1950, for decades, adapting every new innovation to conform to the old, limited system, with little true innovation or improvement as a result.

Using products that are engineered with high headroom in mind can be very revealing, even mind blowing. The first time I plugged a quacky piezo equipped acoustic guitar into a Pendulum SPS-1 preamp my jaw dropped. The difference in reproduction can be staggering. 

I say all controls should go to 18!


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## mhammer (Nov 30, 2007)

1) If the caps the circuit uses are rated at 16v (a common value), you do not want to run it at 18V. It tyhey are 25v-rated, there's a bigger margin of safety.

2) If the damn thing in biased in anticipation of 9v, then you don't want to run it at 18v.

3) If there is a CMOS chip ANYWHERE in there, then you don't want to give it more than 15vdc or you'll let the magic blue smoke out.

4) If your intention is to get more distortion, then providing greater headroom via a higher supply voltage is not your most strategic move.

Having said that, almost all op-amps are good to run at +/-15v or +/-18v. In some instances, however, a given pedal is designed to exploit the weaknesses of the chips used at the supply voltage. The Proco Rat and Distortion + come to mind here.

And having said THAT, the 9v convention is simply a byproduct of the commonness and compactness of 9v batteries, and nothing more. That's why we are seeing more pedals using charge pumps to turn 9v into something higher, and power bricks providing outputs higher than 9v.


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## vadsy (Dec 2, 2010)

Thanks for the education guys! I also just found out one of my longer term dirt pedals, the Lovepedal Kalamazoo can run at 18 volts, that's great news to me as I've been loving it at 9 so 18 should be like riding a rocket ship. Any ideas on the Wampler stuff, Paisley or Black 65? Quick Google but nothing obvious popped up. Maybe 12 volts, that way it's still only one power outlet on the PP2+? 

I understand the concept of lower voltage sounding good on some things, say fuzz pedals, but overdrives with some headroom and crisp, defined pick attack just improves it to me. Any pedal that can sound more amp like is a bonus.

Again, thanks for the walk through on pedal designs.


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## hollowbody (Jan 15, 2008)

vadsy said:


> Thanks for the education guys! I also just found out one of my longer term dirt pedals, the Lovepedal Kalamazoo can run at 18 volts, that's great news to me as I've been loving it at 9 so 18 should be like riding a rocket ship. Any ideas on the Wampler stuff, Paisley or Black 65? Quick Google but nothing obvious popped up. Maybe 12 volts, that way it's still only one power outlet on the PP2+?
> 
> I understand the concept of lower voltage sounding good on some things, say fuzz pedals, but overdrives with some headroom and crisp, defined pick attack just improves it to me. Any pedal that can sound more amp like is a bonus.
> 
> Again, thanks for the walk through on pedal designs.


Brian Wampler says his pedals are designed to sound best at 9v, but you can try them at 18v. The Triple Wreck's boost channel is out of bias at 18v (according to Wampler), but otherwise is fine. My Plextortion sounds pretty similar at either voltage, so I just run it at 9v to keep an outlet on my PP2 free.


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## sulphur (Jun 2, 2011)

Intersting thread guys.

At ILF, somebody put up samples of the Elements at different voltages.
I found a very slight, if any difference in the sound clips.
Ryan himself said that he prefered it at 9vs.

I keep hearing "more headroom" as a result of a higher voltage.
So what, you can just run it louder? Does it change the character of the gain much?

The biggest problem I found, was that it hogged out two ports on the PP2+.
I've only used splitters so I could run _more_ pedals!


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## mhammer (Nov 30, 2007)

Any audio circuit can only "swing" (ie., go positive and negative) as wide as the power supply allows. A circuit running off 9vdc cannot swing +/-5v around ground. So, if the gain the circuit is set for deliberately "requests" more amplification and "swing" than the power supply can provide, the circuit will clip. If the amount of amplification or gain in the circuit exceeds what the power supply can typically support, it will clip. Indeed, many distortion and overdrive circuits wehave come to know and love may look like they do all their clipping via the diodes or LEDs used for that purpose, but they also clip due to headroom limitations. Take the clipping diodes out and the circuit will still sound miles away from clean.

If the _intention_ of the circuit is to be clean, then increasing headroom via change in supply will improve performance. I remember shortly after he had finished designing the Truetone booster pedal for Visual Sound, RG Keen wrote me and noted that, due to the voltage tripler circuit it included (turning +9v into around 25.5VDC, given the various diode-related losses) "amplifier input stages quivered in terror at its approach". Where a clean booster with a 9vdc supply might clip the peaks of any power chords, a much higher supply voltage lifted that ceiling to allow even greater peaks to reach the amp. The Klon Centaur also ran part of the circuit off a higher supply voltage.

There are chips referred to as "charge pumps" that are used to take a supply voltage and increase them (they can also producer +/- from a + input but we'll leave that aside for now). Many designers (and the Truetone is one example) use charge pump chips on the circuit board so the user can power the pedal with a 9v battery or a 9v wallwart and still enjoy the advantages of a much higher supply voltage. That is, from the outside it looks like a 9v pedal, but on the inside its running something higher. This approach has its limitations, though. One is that charge pump chips are usually limited to supplying about maybe 15-20ma which is more than enough for some circuits, but nowhere near enough for some others. A second is that they produce that higher voltage by using a clock, and essentially storing up the pulses it produces. That clock is generally high enough in the frequency spectrum to not produce audible sideeffects in audio circuits...but not always.

The other caveat I should note is that folks can maybe take some chances on the basis of partial information that don't work out so well for them. So, person owns a decent well-regulated 9v power supply, and hears that 18v supercharges a pedal. They score themselves an 18v supply that is not nearly as well-regulated, or perhaps even has the same plug polarity, plug the thing into the pedal and whoops it don't work so good no more.


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## keto (May 23, 2006)

sulphur said:


> Intersting thread guys.
> 
> At ILF, somebody put up samples of the Elements at different voltages.
> I found a very slight, if any difference in the sound clips.
> ...


It's not just a matter of tone or headroom, sorta a combination of those for me - I run my Mooer Hustle (OCD clone) at 18v and I like it WAY better than at 9v. Doesn't really change the tone, ie, frequency response, but tightens it up and gives it a slightly different character that *could be* described as headroom but is something more than that, to my ears. Just works better for me in the context in which I use it. Same holds true for the Mooer Cruncher (Crunch Box clone), which is natively very compressed but somewhat less so at 18v, which again is a good thing.


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## vadsy (Dec 2, 2010)

I meant to post earlier with my take, in regards, to sulphurs question. Sorry but it's been a busy day. Its tough to describe sound or tone sometimes without using all the regular buzzwords but to me the one word answer is: clarity. Yes, it gets louder but it also, as keto said, tightens up and I notice it usually tends to sound a bit more defined responding better to pick attack. It clears up and fills out for me like removing a baffle or amp shield. If I go back down to 9 volts for some reason I almost always find myself playing with a presence or tone treble knob somewhere.


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## ezcomes (Jul 28, 2008)

its kinda funny this came up...i just got an MXR carbon copy...i plugged it into my board and it didn't sound quite right...i plugged the power supplu straight into it and BAM...it works like a charm...the power filter i built drops the voltage about 0.4V...so its sitting at about 8.6V...the CC repeats are quiet at this voltage...but up at 9V...perfect...i HEAR that 18V is supposed to be a lot better...but i don't have an 18V adaptor...

oddly enough...my tuner acts strange too...at 8.6V it won't even turn on...


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## mhammer (Nov 30, 2007)

Some pedals use +5v internally, particularly if there is anything digital about them. Not always, but often enough to mention here, they will use 3-pin regulators, like the LM78L05 to drop the battery or external supply voltage down to that regulated 5V. Now, the thing with 3-pin regulators is that they generally want to see at least 2 more volts at their input than they will provide at their output. So a 5V regulator insists on being fed at least 7V if it's going to put in a day's work. Another thing to consider is the manner in which you lowewred that 9v down to 8.6. Digital pedals want a lot more current than analog ones, and depending on whatyou did, perhaps you limited the current in a manner that ends up underpowering the tuner.

I don't know any of this for certain, but these are ideas to mull over and atthe very least, cross off your troubleshooting list.

I know that all the discussion in this thread has revolved around the sound of clipping/overdrive circuits. HIgher supply voltages can make audible differences in other types of circuits too. I have a couple of the old blue Boss BF-1 flangers. The chassis says to feed 'em 9v (they don't take batteries), but the _service manual_ says to feed them 12v. If you feed them 9v, they work fine but don't sound terribly different from anythng else. If you feed them 12V, like the service manual says, they sweep much wider and "higher". The 3V difference certainly doesn't turn them into A/DA flangers, but it makes enough of a noticeable improvement in the sweep that it stands out from a much larger share of the competition.


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## hollowbody (Jan 15, 2008)

keto said:


> It's not just a matter of tone or headroom, sorta a combination of those for me - I run my Mooer Hustle (OCD clone) at 18v and I like it WAY better than at 9v. Doesn't really change the tone, ie, frequency response, but tightens it up and gives it a slightly different character that *could be* described as headroom but is something more than that, to my ears. Just works better for me in the context in which I use it. Same holds true for the Mooer Cruncher (Crunch Box clone), which is natively very compressed but somewhat less so at 18v, which again is a good thing.


I felt the same way for the OCD (mine's a Fulltone). At 9v, it sounds a bit congested - still good, mind you - but at 18v it's a little clearer (while still being very driven), tighter and overall much better. The OCD and Fulldrive are two pedals in particular that I think sound much better at 18v.


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## seanmj (May 9, 2009)

I have a couple of different versions of the DLS and while I do like them a lot at 18v, I don't mind them at 9v either... they play a little looser and compress a bit more which I think can be cool for certain things.

I'd love to find a way to flip the voltage of the DLS on the fly. Any suggestions?

Sean Meredith-Jones
www.seanmeredithjones.com


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## greco (Jul 15, 2007)

seanmj said:


> I have a couple of different versions of the DLS and while I do like them a lot at 18v, I don't mind them at 9v either... they play a little looser and compress a bit more which I think can be cool for certain things.
> 
> I'd love to find a way to flip the voltage of the DLS on the fly. *Any suggestions?*
> 
> ...


This is a thought. If you have an 18VDC supply, you might be able to make a simple pedal that would drop the 18 VDC to 9 VDC using a voltage regulator for the 9 VDC. A standard stomp switch would be used to switch between the voltages and an LED could be wired to each circuit to identify which voltage is being used at any given time.

Hopefully, some of the pedal makers/gurus will chime in on the viability/practicality of my idea.

Cheers

Dave


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## keto (May 23, 2006)

Yes, Dave, I think you have it nailed. Run it thru a voltage amp, with a bypass via 3PDT footswitch. Haven't done it or seen it but in my head I can imagine it. Or maybe an 18v supply with a resistor to drop it to 9v on the footswitch?


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## loudtubeamps (Feb 2, 2012)

How about a variable DC supply? U can dial in the supply voltage and find the pedal's sweet spot.
Tekpower DC Variable Power Supply, 1.5-15 V @ 2A, HY152A: Amazon.com: Industrial & Scientific


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## mhammer (Nov 30, 2007)

seanmj said:


> I have a couple of different versions of the DLS and while I do like them a lot at 18v, I don't mind them at 9v either... they play a little looser and compress a bit more which I think can be cool for certain things.
> 
> I'd love to find a way to flip the voltage of the DLS on the fly. Any suggestions?
> 
> ...


Sure, get yourself a couple of suitable zener diodes and use a 3-position toggle to select between full voltage at the power jack, or two addition lower voltages. Assuming the zeners used are rated in a manner appropriate to the current draw of the pedal (and the vast majority will be) it should be easy to do.

So, for example, on the power input to the OCD, you should probably see a 1N4001 diode (black w/white stripe) going to ground. This is a protection didoe to prevent V+ going to where V- should go, should you have the wrong sort of wallwart supply plugged in. The diode will conduct anything over about 600mv or so, such that even if you use an 18V supply, that has the outside ground and inside V+ (i.e., the "wrong" plug polarity), the circuit would only see -600mv applied where V+ ought to go.

If you put a 1N4742A and a 1N4739A zener diode in parallel with the 1N4001, you could select between the 18v from the power jack (assuming neither of the zeners are connected to ground), OR 12V (with the 1N4742A connected to ground and the 4739 unconnected, OR 9.1v if the 4739 is connected and the 4742 not connected.

How to do it? Use a SPDT on-off-on 3 position switch. The centre lug of that switch goes to ground, and the stripe end of whatever two zeners you use go to each of the two outside lugs. In the middle switch position, neither of the zeners are connected to anything so you get whatever you plugged into the power jack. In one of the outside positions, you get 12V, and in the other you get 9.1V. Each of the outside positions drop the voltage coming from the external power jack down to whatever their voltage rating is.

The part number is not especially critical, but I went with one-watt zeners since we could be absollutely certain your current draw would not stress them. You can look through the list here - http://www.datasheetcatalog.org/datasheet/fairchild/1N4728A.pdf - to see a bunch of other zener values and associated part numbers that may represent other useful choices.

Personally, I think 3 choices is enough, and it's hard to get simpler and cheaper, but if a person wanted to go nuts, they could use a 12-position rotary switch , and connect any of 11 zeners of lower value than the supply voltage. Incidentally, should it come to a situation where you are forced to use a 9v supply, or battery, simply put the switch to the middle position and the zeners will be out of circuit.

Make sense?


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