# Truetone 1 Spot PRO switching power supplies



## Greg Ellis (Oct 1, 2007)

Anybody using one of the new(-ish) 1 Spot Pro pedal power supplies? How's that working out?

They seem very capable and rather inexpensive when compared to some of other options.

I'm not sure of the implications of using a "switching" power supply for this purpose.

Truetone mentions that it's more space-efficient than a transformer-based design and able to handle more current as well. They don't really mention and potential downsides. Yay marketing!

Any thoughts about this series?


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## bzrkrage (Mar 20, 2011)

Love it. I have the CS12.
I use all except the 9vac (meant for Line6 M series style pedals)
Noise wise? Nothing. Fits pedaltrain & my Temple.
Wished it had the daisy chan for external power like the Voodoo.
Not enough 500ma for a full swag of Strymon.
But, excellent value & power.
Can change to 220v if you travel.
The new CS-6 is slimmer.


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## mhammer (Nov 30, 2007)

If you have ever used a wallwart that wasn't heavy, it was a switching supply. My long-time (does 25 years count?) friend RG Keen was a hardware engineer for IBM before he became chief engineer for Visual Sound/Truetone. As far as I know, he was responsible for the design of the various 1-Spot products. At the very least, I know he actively solicits feedback on any and all technical issues encountered with the supplies, for the purposes of improving them or providing any needed advisories.

The downside of switching supplies is that they use high-frequency clocks. Depending on the age of the supply, and the age of any digital pedals one might be powering, there is a risk that the clock spikes on the power line, whether coming from the PS or the pedal (which also has internal clocks), will result in "heterodyning" I'm not enough of an electronic engineer to go into the theory (thank goodness), but the gist is that such clock-produced spikes can generate something similar to ring modulators when they clash; i.e., the sum and difference of the two frequencies. The clocks in switching supplies and digital pedals are both very high frequency, but even when they are ostensibly the same high frequency, they can differ by a smidgen. If the PS produces hash on the power line at 2.0001mhz and the digital pedal produces similar power-line hash at 1.9999mhz, both of those clocks are pretty damn close to their spec. And although one could never hear the _sum_ of those clock frequencies (4mhz), their _difference_ falls well within human hearing range.

Historically, we have lots of instances of people having a nice quiet pedalboard, with a single digital pedal and a bunch of other analog pedals. When they bring home a second digital pedal, all of a sudden they encounter disgusting noise like a buzzing hornet's nest. They assume the new pedal is defective. It isn't. What they hear is the clash_ between_ the two digital pedals. When the new pedal is the only digital one sharing the same power source, it is every bit as quiet as the first one.

So, since the more widespread occurrence and purchase of digital pedals, and such instances frustrating consumers, more pedals have been designed to prevent spikes from "leaving" the pedal, more power supplies have been designed to not provide any themselves, and more power bricks have been designed to more effectively isolate the various outputs, such that, even if used with multiple older digital pedals, there will be little risk of heterodyning.

The original 1-Spot wallwart is fine for powering an all-analog pedalboard, or perhaps a pedalboard with a single digital pedal.


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## Greg Ellis (Oct 1, 2007)

bzrkrage said:


> Wished it had the daisy chan for external power like the Voodoo. Not enough 500ma for a full swag of Strymon.


When you say "daisy chain for external power", do you mean an AC courtesy outlet? Like on the back of an old tube amp? I saw they had an adapter for that which splits off an extra AC plug where power enters the 1 Spot. Clunky maybe, but I'm thinking I might be able to use that for the one pedal I have that needs 12V AC. I do wish they had included more voltage options (besides 9V) on their AC out.

All of their models seem to have only 2 x 500mA, so yeah I guess if you've got SEVERAL high current pedals this might not cut it. Two is probably enough for me, I think... for now...


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## Cups (Jan 5, 2010)

Because it’s a switching supply you can power higher ma pedals. I power an 800ma pedal with my CS6. As long as the total current isn’t exceeded


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## cboutilier (Jan 12, 2016)

Greg Ellis said:


> When you say "daisy chain for external power", do you mean an AC courtesy outlet? Like on the back of an old tube amp? I saw they had an adapter for that which splits off an extra AC plug where power enters the 1 Spot. Clunky maybe, but I'm thinking I might be able to use that for the one pedal I have that needs 12V AC. I do wish they had included more voltage options (besides 9V) on their AC out.
> 
> All of their models seem to have only 2 x 500mA, so yeah I guess if you've got SEVERAL high current pedals this might not cut it. Two is probably enough for me, I think... for now...


I love the courtesy outlet on the old amps.


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## Greg Ellis (Oct 1, 2007)

I bought a 1 Spot Pro CS6 today at L&M.

That's the low profile model that can fit underneath a small flat pedalboard like a PT Nano or PT Metro.

I don't really need that feature right now, but it might be handy down the road.

Power looks good for most of the applications I can imagine. There are six isolated outputs:

2 x 500mA @ 9V
2 x 200mA @ 9V or 12V
2 x 100mA @ 9V or 18V

Apparently, each output is able to handle considerably MORE than its rated current, as long as I don't exceed the total available power (1600mA).

It has a fair bit bigger footprint than my old DC Brick, but it's also lighter and offers a lot more power. Uh.. no, i take that back. Not lighter.

BTW, I googled the specs on my DC Brick (the original one, not the more recent reboot model) and it only outputs a TOTAL of 375mA at 9V (spread across 7 output jacks) and 625mA at 18V spread across 3 more output jacks. My (original version) Holy Grail is labeled for 500mA. No wonder they didn't get along, lol.

Some of the power leads on the 1 Spot are just ridiculously long for the applications I'm intending, but I guess they're trying to accommodate very large pedalboards too. They do include a range of useful adapters for non-standard pedals that would normally cost about $10 each, so that's very nice of them.

I'm looking forward to trying this out.


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## sambonee (Dec 20, 2007)

Cool. Good power guarantees the best possible tone.


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## mhammer (Nov 30, 2007)

Greg Ellis said:


> I bought a 1 Spot Pro CS6 today at L&M.
> 
> That's the low profile model that can fit underneath a small flat pedalboard like a PT Nano or PT Metro.
> 
> ...


Once upon a time, a pedal might come with an onboard transformer and power cord. Heck, I've been running my EHX Hot Tubes clone on a 9V battery for years, but the original had an onboard transformer and power cord, simply because the unit went through 9V batteries a little too quickly for some tastes.

Eventually, more manufacturers began using onboard* regulation *(usually indicated by wiggly lines legended beside the power jack, to signify AC), but a wallwart as the external supply. both to save on space inside the enclosure, to make tear-down a little easier, and also to keep a hum source away from the audio path. But as more and more pedals came to rely on external power, pedalboards could get cluttered with wallwarts sticking out of power bars.

The next logical step was to have a centralized power source that could be distributed to individual pedals, via power cords. What has happened over the last 10-15 years is that the power needs of pedals kept changing, in anticipation of power bricks, and supply capabilities, while the power bricks had to keep changing inanticipation of the ever-greater, and more diverse power needs of pedals. Once upon a time a player might have a single digital pedal, requiring more than 100ma @9VDC (usually downregulated to 5VDC inside the pedal), and a bunch of analog pedals seldom requiring more than 15ma each. But then pedalboards grew and grew in number of pedals on board, and pedals grew and grew in their power requirements. What might have been a small brick with 7 or 8 nine-volt outlets, with 100ma capacity each, now had to be something that also had to provide 12V, 18V, and 9V, often at more than 100ma per output. (For the uninitiated, *why* 100ma? Here's why: http://www.ti.com/lit/ds/symlink/lm78l.pdf ).

So there has been a jockeying between pedal design and power-supply design. Supply designers have to anticipate what might be required in the near future, in order to make the product sustainable. Pedal designers predicate their designs around the ability to be able to sell the pedal _sans wallwart_ (or with one, assuming that it might eventually get lost or broken), with the knowledge that something out there is able to properly power the pedal in a noncumbersome manner.


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## troyhead (May 23, 2014)

Here is an informative white paper from Strymon about linear and switching power supplies and more.

Effects Pedal Power Supplies - White Paper - Strymon


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## DavidP (Mar 7, 2006)

I have the CS12; according to the TrueTone folks, it should power pedals as big as the HX Effects unit! Each outlet can produce well beyond its rating but the big issue is the overall draw on the unit (2200mA total).


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## mhammer (Nov 30, 2007)

I think one should note that the _stated_ power requirements on the chassis of owner's manual of many pedals is often well above what the pedal _actually_ draws. In some respects, that's simply more insurance for the manufacturer, intended to avoid complaints, and in the same ball park as when they used to say you MUST use their power supplies. If a pedal actually draws 53-72ma, depending on settings, the manufacturer will say it requires a 100ma supply, or maybe even a 200ma supply, just to be on the safe side.. If the end-user provides that, then the manufacturer knows that a) the pedal won't be underpowered and result in the consumer grumbling that "the frigging thing doesn't work properly", and b) the end-user is not going to overtax the power supply and potentially fry it. They do the math for you, and leave a wide margin for error.

That said, the end-user is entirely at liberty to do the math themselves (based on solid information about current-draw), and stretch the power-supply in reasonable and safe ways. Of course, the safest route is to simply abide by the recommended power consumption on both the pedal and the power-brick.


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## Greg Ellis (Oct 1, 2007)

1 Spot recently came out with a milliamp meter which can be used to measure the actual power draw of pedals during operation.

DC only, 9V to 24V and up to 999mA

It's not super expensive, maybe $40? 

I thought about buying one, but I think I've got things covered for now.


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## mhammer (Nov 30, 2007)

I asked RG Keen if the current reader was his idea, but he told me it was Bob Weil's baby.


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