Monthly Archives: February 2014

February 25, 2014 by

Double Whammy

Acquiring a DigiTech Whammy is a rite of passage for most guitarists who get into pedals.

Hopefully most owners will do more than I did with mine – excitedly plug it in that first day, make it go “wheeeee-whooooo” a bit, play the riff from Seven Nation Army, then put it in a drawer.

Lots of them change hands secondhand (probably because of experiences like the above), so there are many of them floating around without a power adaptor.

This is where it gets a little tricky – there are versions that need 9 AC/AC and others that need 9V AC/DC.
Also, there are quite a few versions of the Whammy – WH-1, WH-4, Whammy DT, Whammy 5th gen and more! You’ve to be careful about this, as they all look rather similar. The model of yours will be written on sticker on the bottom – this gives the best information.

Here’s the model number on the sticker on mine, to show you an example:

whammy4v-uk

whammy4v-uk

You can look up your model in our power supply finder – we have most of them there (and we add power adaptors all the time).

If you’re curious, and want to know if your DigiTech Whammy needs AC or DC – look at the power input. It’ll indicate whether it needs 9V AC/AC or 9V AC/DC.

Here’s my DigiTech Whammy 4 – it states “9 VAC” so you can see it needs a 9V AC/AC adaptor:

Digitech Whammy 4 with 9V AC/AC power input

Digitech Whammy 4 with 9V AC/AC power input

Here’s a DigiTech Whammy DT – it states 1300mA (although not the voltage, rather unhelpfully) – it needs a 9V AC/DC adaptor (with centre negative polarity):

Digitech Whammy DT with 9V DC power input

Digitech Whammy DT with 9V DC power input

Of course, if you’re buying a replacement power adaptor from MyVolts, you can rest assured: power is our business, and we know all the devices, and exactly their power requirements, so when you buy from us you don’t need to worry – we get it right.

You can ask me if you’re not sure about your Whammy – email me at caroline AT myvolts DOT co DOT uk. Send me a picture of the power input and I’ll tell you exactly the power adaptor you need.

February 19, 2014 by

Check your input, before you wreck your input

If you’re buying a PSU, especially for an older device, you should be careful before you start trying random adaptors from your PSU Rat King.
Many secondhand and used devices on eBay are sold without a power adaptor, so I often get asked what power adaptor an older device takes – and my advice is to carefully check not just voltage, current, polarity, or if it needs AC/DC or AC/AC, but also the shape of the power input.

The Alesis Microverb and Alesis Midiverb series of digital signal processors have several different possibilities for power adaptors, so I’ll have a quick look at a couple of these.

Barrel-type
This is the normal, concentric shape we’re familiar with – a round hole, with a pin in the centre.
Here it is on the back of the Alesis Microverb III:
microverb III - barrel

Up close:
microverb III - barrel close

3.5mm jack
This power input looks like a headphone jack input – 3.5mm across, with no pin in the centre. It’s also called 1/8″ jack or 3.5mm monopin.
Here it is on the back of the Alesis Microverb II:
microverb II - monopin

So make sure you check!

You can ask me if you’re not sure about what power adaptor your device needs – especially older devices (I like the challenge)!
email me at caroline AT myvolts DOT co DOT uk – feel free to include a picture of the power input.

Of course, if you’re buying a replacement power adaptor from MyVolts, you can rest assured: power is our business, and we know all the devices, and the shape and sizes of their power inputs, so when you buy from us you don’t need to worry – we get it right.

February 12, 2014 by

What’s Watts?

Power is measured in Watts (W).

At this point, there’s usually an explanation of this in terms of some theoretical water rushing through an imaginary pipe, or over the side of an idealized cliff. I’m going to spare you the watery analogies and tell you only what you need to know.
If you know the watts W and the voltage V a device needs then it’s simple to figure out the required amps A:
Watts/Volts = Amps
So if you’ve a device that needs 12V and 24W: 24/12 = 2, so it’ll need 2A to work.
It’s OK if the power adaptor provides more than 2A – see my earlier blog post about this.

One more thing: Sometimes, especially on AC/AC power adaptors, the watts is expressed as VA, instead of W.

Of course, if you’re buying a replacement power adaptor from MyVolts, you can rest assured: power is our business, and we know all the devices, and exactly their power requirements, so when you buy from us you don’t need to worry – we get it right.

You can ask me if you’re not sure about your device – email me at caroline AT myvolts DOT co DOT uk.

February 5, 2014 by

AC/AC and AC/DC – Fly on the wall (wart)

How can you tell if an adaptor is AC/DC or AC/AC? It’s important to get this right – if you get it wrong, you risk damaging your device.

If you’re buying a replacement power adaptor from MyVolts, you can rest assured: power is our business, and we know all the devices, and whether they need AC/AC or AC/DC, so when you buy from us you don’t need to worry – we get it right.

99% of devices need DC – Direct Current – so they need an AC/DC adaptor.

An AC/DC power adaptor takes the AC voltage that comes out of the wall socket – and turns it into the DC voltage the device needs.

How you can tell from the label:

DC power supply

DC power supply


Circled in red is the Output: 9V, then a straight line with a dashed line under it. That denotes DC.

Also, DC current has polarity, so if there’s a polarity diagram on your power adaptor, it’s an AC/DC power adaptor. In the one above,the polarity diagram is circled in blue.

A few devices need AC – Alternating Current, so they need an AC/AC adaptor
An AC/AC power adaptor takes the AC voltage that comes out of the wall socket – and modifies it into the AC voltage the device uses.

How you can tell from the label:

AC power adaptor

AC power adaptor


Circled in red is the Output: 9V, then a wavy line. That denotes AC.
Also, there’s no polarity diagram.

That seems simple enough – but confusion arises when power adaptors are referred to as “AC adaptors” – in that they “adapt” the AC voltage that’s coming out of the wall.
That leads people to think an “AC adaptor” means an AC/AC adaptor, not an AC/DC adaptor, which, actually isn’t the case!
Clear as mud, I know.

You can ask me if you’re not sure about your device – email me at caroline AT myvolts DOT co DOT uk.