"The best value expandable pedal power supply out there right now": Harley Benton PowerPlant ISO-1AC Pro Modular review

Harley Benton PowerPlant ISO-1AC Pro Modular review: What it is?

Cards on the table time: Thomann didn't send me this pedalboard power supply to review. I bought it like any other customer would. In fact, it's the third one I've bought for two pedalboards (more on that later). I've been impressed enough to suggest a review on MusicRadar. So here we are and you've already had a spoiler by my return custom reveal; the Harley Benton PowerPlant ISO-1AC Pro Modular pedalboard power supply is very good.

Pedals are now both cheaper and more expensive than ever, depending on which end of the market you're focussing. On the upper branches of the effects tree, the current draw demands have certainly gone up in places – to as much as 400mA for pedals, including UA's UAFX full-size amp emulators and effects, while the big box Strymon effects like the Timeline are 300mA. A lot of budget power supplies simply can't meet some of these demands, and when it comes to safettly and efficiently powering your pedalboard, why would you want to be cheap anyway?

It's true that power supplies feel like a necessary presence rather than an exciting investment like an effects pedal. But they're essential and not to be scrimped on. If you want reliable performance, you need to know you're not overloading them and have solid build quality behind your effects power. There are other considerations too; can you fit them where you want? The underside of your specific pedalboard, for example.

Voodoo Lab, MXR, Truetone, Cioks, Strymon, T-Rex… these are the brands we associate with the pro-grade standards of pedal power supplies. Even Fender has joined the fray now.  But if you pigeonholed Harley Benton as a brand for affordable guitars and amps, but not giggable pedal power solutions, it's time for a revision. The Thomann brand has power supplies aplenty with its PowerPlant range – and the specs are as impressive as the prices.

But why have I chosen to buy three of this particular model with my own money? I think it represents the best combination for not just my needs, but most players. I was originally looking to buy a Truetone 1 Spot Pro CS7, a similarly spec'd power supply to the ISO-1AC Pro Modular. The Truetone reputation meant that was an assured purchase, but then I saw the Harley Benton offering and it was less than half the price. In addition, it had the capability to be joined to a second  ISO-1AC  if my pedal needs and 'board expanded in the future. It was enough to win me over the much more established brand in this field. 

Was the decision completely vindicated? Well, let's first take a look at exactly what the ISO-1AC Pro Modular offers for the £51/$54 asking price. 

Harley Benton PowerPlant ISO-1AC Pro Modular review: Performance

With five 500mA isolated outputs offering short circuit protection, this power supply can cover most of the hungrier end of the power draw scale (Universal Audio's full-size UAFX pedals are 400mA, for example). 

In the box you get a cable for each of the five outputs (one end right-angled) and a two-pole Euro power lead. Great for mainland Europe, but useless for the UK and USA. You'll have to provide your own 3-pole earthed 'kettle' lead in the UK – something any musician who owns an amp should have a few of already… hopefully. It's not ideal to have to provide your own but considering Thomann is a German brand and mainland Europe is much larger than the UK, I can see the logic here when it comes to keeping the cost down and not shipping an extra cable.  They're pretty cheap to buy afterwards if required with UK options online under £5. 

Though Harley Benton offers a wealth of options with the PowerPlant range (like the ISO-2) that use coaxial power plugs, I specifically chose the  ISO-1AC Pro Modular because of the 'kettle' power lead type it uses (it's easy to source from retailers in various lengths) and the fact it's modular; it has an output and an included female-to-male connector to allow expansion to a second unit if needed. You never know how your pedalboard size and power needs will change, so the scope for adding a second supply is great to have. Which is precisely what I did with my first two as you can see below. 

This decision to expand was a result of needing isolated outputs for more high-draw pedals I am reviewing for MusicRadar and testing in combination with my own pedals (including a 300mA Universal Audio Astra Modulation Machine). And it's worked like a charm, fitting snuggly under the fairly cramped space of the Rockboard Duo 2:3 'board. 

The build quality here is equally reassuring with aluminium casing and a robust feel that I feel confident enough fixing under my pedalboards to weather any environment I'll play in. At 130 x 88 x 35 mm it's deeper than the One Spot Pro CS7 but not enough to drag on the ground under my Rockboard 2:2 and 2:3 (I like single-tier pedalboards, ok?).

I've already gigged with one a few times, as well as practice sessions and it's held up well. At home I've even pushed the Harley Benton PowerPlant ISO-1AC Pro Modular to its limit by throwing isolated power caution to the wind and using splitter cables to share the outlets to power more pedals. Effects like overdrives and basic loopers tend to be lower mA ratings so I assembled them alongside some recent power-hungry review pedals we've had come in to see how many I could get on a Rockboard 2:2. And you can see the results below.

While I wouldn't gig using this many shared outputs (I'm even using the output of the TC Electronic PolyTune pedal tuner to power one of the overdrive pedals)  I've had no issues with it at home in terms of the kind of interference that can occur, and it's a reflection of just how solid the Harley Benton PowerPlant ISO-1AC Pro Modular can be. For my second 'board I've played it safer by linking two supplies and making sure every pedal has its own isolated output. 

Harley Benton PowerPlant ISO-1AC Pro Modular: Verdict

Reviewing the Harley Benton PowerPlant ISO-1AC Pro Modular has been a different process for me – more akin to a long-term test. But having used three in different pedalboard configurations I feel even more confident recommending it. Especially in light of it being similarly spec'd to models from other brands more than double its price. I think that kind of value proposition is enough for the lack of UK adaptor not to be a blight on the overall appeal here for those affected by its absence.

MusicRadar verdict: This is the best value expandable pedal power supply out there right now - and suggests this market might be one of Harley Benton's strongest suites. You shouldn't be cheap when it comes to what powers your pedals, but with the PowerPlant ISO-1AC Pro Modular, you can be! 

• Check out the Harley Benton PowerPlant ISO-1AC Pro Modular at Thomann

Harley Benton PowerPlant ISO-1AC Pro Modular review: Specifications

• ORIGIN: China
• TYPE: Five-output pedal power supply
• FEATURES: Short-circuit protected and isolated outputs each handling a maximum of 500mA current draw (total output max 22.5W), LED for each output, male-to female connector and five 60cm 2.1mm DC cables included, 1 x AC power (1.2m) EU plug cable
• DIMENSIONS:  130 x 88 x 35 mm ((W x D x H)
• WEIGHT: 400g
• CONTACT: thomann.com