PSU issues with Aeros and Ojai

I’m powering a Beatbuddy, an Aeros and a couple of other standard pedals with an Ojai.

If I turn on the Aeros w/ the BB already on, it will only actually power up one time in three or so. Sometimes I just get audible clicking or static through the Aeros, and it never powers on.

If I turn on the Aeros without the BB plugged in, it will never power up.

If I power the Aeroes with it’s own PSU, it powers up every time.

How can I fix this?

Latest firmware is installed, and the Ojai is rated for 500ma 9v, so it should work.

I really don’t want to have to buy a new PSU - I’ve already had to buy a new looper to sync with the BB, so I’m out of pocket much more than I anticipated when I decided to pick up the BB!

Weird. Strymon has pretty good e-mail support. It could be that the Ojai is either malfunctioning or does not have enough power to support your pedals.

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Do you have any effects on the Ojai that draw more than 500ma? If not, I agree it might be a defective Ojai.

As it happens, I have a fresh Ojai because I’m putting together a bigger pedalboard than my Nano (because the Aeros is big!) so that helps to confirm the case. I pulled it out, plugged it in, problem goes away.



After some back and forth with Strymon, this is their response

"It looks like this particular issue has come up specifically with the Singular Sound Aeros. The reason is that our power supplies ramp up power instead of sending the full amount all out once. There are a few pedals that don’t react well with that, hence the reason it sometimes works and sometimes doesn’t.

Some people have more success if they have the Ojai turned on already, and then plug the power cable into the pedal.

If you were to send this in for repair, it most likely wouldn’t have any issues that need repair and would be considered functioning correctly.

You are more than welcome to reach out to the Australian distributor Noise Toys Imports if you’d like"

So I wouldn’t recommend using Strymon PSUs, given they either will or won’t work, but neither reliably.

Apparently the fact that I have one Ojai that’s reliable and one that isn’t doesn’t count as a fault!

Another factor (from experience with electronics rather than with these pedal power supplies, so apply salt) is that often electronics take their highest currents at switch on. Capacitors and inductors start out uncharged and need to “fill up” with energy, ultimately derived from the supply current.

So a pedal that takes, say, 300mA in normal operation would seem to be perfectly suited to a 500mA capable supply. But what if the 300mA device takes 700mA in-rush current for 50ms when it first switches on? Disaster, unless the power supply can also cope with delivering a higher peak current for a short burst.

The devil is in the detail.

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I have this same issue with either/both the BB and Aeros. Running each in isolation with the Ojai thinking it might be because the PS-124 that technically runs the show only outputs 1000mA max (so…unclear how it would actually power 4 pedals drawing 500mA?). Support at Strymon confirmed that the issue has to do with a self-protection scheme in how it distributes current; only wish I’d seen this post before purchasing this in May :confused:

One issue we’ve seen in the past is that some pedals do not like how our power supplies ramp up power as a self-protection scheme. Digital pedals that are then connected see the low power at first and do not power on. A reset timer tells the internal processor to re-try powering on after a period of time. If this is too short, or not done at all, the pedal will never realize that the current has ramped up and is adequate to power on the pedal.

We have found that running pedals that have this issue with a current doubler (NOT voltage) will provide enough immediate current to power our some pedals that have this issue. However, this does mean you would need 2 outputs to power just one pedal. We unfortunately have not been able to personally try it with your specific pedal, but it’s something you can safely try to see if that helps, as more current will not damage a pedal.

The reason that we think this issue happens with the Singular Sound pedals isn’t due to a lack of overall power. It’s a lack of initial current to the pedal. Like I said in my previous email our power supplies ramp up to the total output of 500mA per output. There are pedals that won’t work if they don’t receive the full amount of current right away. If they don’t have a way to recheck for that signal with a timer then they won’t turn on.

It’s rare that this is an issue, but there are some pedal manufacturers that experience this issue with our power supplies.

As for the total amount of pedals that can be powered by the Ojai, it depends on the pedal and the voltage.

At 100% efficiency, each of the outputs when maxed (9V, 500mA) uses 4.5W of power. Electronic devices are never 100% efficient however, so running at a lower efficiency could actually use more than 4.5W of power per output if maxed.

The formula for watts is amps x voltage. 9V x .5A = 4.5W.

We don’t offer any power supplies that output above 500mA per output.

Changing the 24V power adapter into the Ojai won’t change anything. The design stems from the Ojai, and not the external power adapter.

I wasn’t able to get the Aeros to start reliably using the current doubler cable; didn’t bother trying with the BB as I can’t use the Ojai the first anyway.