My latest lovely journey with external PSUs

[The Elf]

Guitarist arrives with a Line 6 HX Stomp XL... but no PSU.

In the past hour I've been through my entire collection of PSUs and can find not one that is the right Voltage, Ampage, or physical connector - and I have many. The ones that fit refuse to power up the pedal - most likely since they all have too low Ampage.

So this afternoon I'll be using my big Helix, with it's mains plug and internal PSU, and we'll just have to build some new presets.

[Hugh Robjohns]

Doncha just love artists turning up for a recording session well prepared....

And yes... external PSUs... joy!

[The Elf]

Hate the sin, love the sinner. I can forgive losing the PSU. It's happened to all of us.

It made me think...

I'm willing to bet that there as many pieces of gear languishing, or heading for land-fill, for lack of a PSU, as there are misplaced PSUs languishing or heading for landfill.

Most 'normal' people haven't the first clue about PSUs - if they don't have the exact PSU an item arrived with they consider it unusable (this from experience of family and friends). Even the thought of trying to decypher those tiny numbers written on the PSU is never even considered - and wouldn't mean anything to them, even if they did.

So how about a PSU exchange scheme? A place where PSUs can be saved from land-fill and find a needy home? Maybe this is something that re-cycling centres could take up?

And then I thought of all those law-suits from people blowing up their gear, electrocuting themselves and setting their property on fire... It was a nice dream while it lasted.

[Sam Inglis]

Thankfully, at least when you buy something with an external PSU, that PSU is always clearly marked and identifiable as belonging to the relevant item...

Not.

[The Elf]

Thankfully, at least when you buy something with an external PSU, that PSU is always clearly marked and identifiable as belonging to the relevant item...

Not.

.

[amanise]

Coincidentally.. I have only in the last couple of days had a really unexpectedly positive external PSU experience! Ray of sunshine!

For the last 15 or so years I've been backing up all my files, photos, sounds, music library - everything - to an external USB hard drive. I have never filled it up it was so unimaginably spacious when I got it. However.... On Sunday it went missing. No reassuring spinning noise, no alluring glow. NO DATA!! Gaa!! Sysadmin hell!

Anyway; ray of sunshine point 1 - I managed to find someone in Oakham who ACTUALLY REPAIRS STUFF yesterday morning. He works out of his shed. He confirmed the power supply was dead with a meter and Amazon was the place these days.

Ray of sunshine point 2 - Amazon did indeed have a generic 'Amazon's Choice' power supply of exactly the right specs and 4 ADAPTOR PLUG END PIECES for different things! It was £11.99 I now have all my tunes and holiday snaps back since the dawn of digital media. I have renamed myself El Smuggo.

[OneWorld]

Guitarist arrives with a Line 6 HX Stomp XL... but no PSU.

In the past hour I've been through my entire collection of PSUs and can find not one that is the right Voltage, Ampage, or physical connector - and I have many. The ones that fit refuse to power up the pedal - most likely since they all have too low Ampage.

So this afternoon I'll be using my big Helix, with it's mains plug and internal PSU, and we'll just have to build some new presets.

Goodness me I have the equivalent of a landfill pile of them in a corner of the attic, the box I had for them soon filled up.

There was a charity shop nearby that took them in, but stopped as they couldn't do the PAT testing.

"Power to the People" yep, I can go with that, but as long as it's not in the form of a WallWart

[DGL.]

Guitarist arrives with a Line 6 HX Stomp XL... but no PSU.

In the past hour I've been through my entire collection of PSUs and can find not one that is the right Voltage, Ampage, or physical connector - and I have many. The ones that fit refuse to power up the pedal - most likely since they all have too low Ampage.

So this afternoon I'll be using my big Helix, with it's mains plug and internal PSU, and we'll just have to build some new presets.

Goodness me I have the equivalent of a landfill pile of them in a corner of the attic, the box I had for them soon filled up.

There was a charity shop nearby that took them in, but stopped as they couldn't do the PAT testing.

"Power to the People" yep, I can go with that, but as long as it's not in the form of a WallWart

Joke is that for all "wall-warts" that I know of and all "line-lump" supplies that I know of without a removable 3 core mains lead all that's required is a visual inspection, and with a removable three core cable (so cloverleaf/mickey mouse or "kettle" style) you only need to test the removable cable. This all only needs someone competent to do it.

As for wierd PSU's try Roland's R8 and R5 drum machines, centre tapped transformer (18-0-18 I believe) and a custom DC connector, basically if it fails you'll have to hope the connector is still good or you'll have to replace the connector on the machine itself to something else. Stupid design.

[The Elf]

Well if anyone has a 9V, 3A, centre negative, with a 2.5mm connector, needing a purpose in life, I could use a spare here!

[merlyn]

There's more to power connector specs than just the diameter. There's inside diameter, outside diameter and barrel length. If you're intending to solder a new connector on, there's also the maximum cable diameter the connector will take.

[MarkOne]

Which is why there should be international pressure to standardise.

Even Apple caved to the EU to put a USB C on the iPhone.

With the cheap access to buck/boost circuits with wide input/output voltages and USB-C PD being spec’d right up to 240W, there is really no reason you couldn’t power anything in a studio from a standardised USB PD supply.

And the consumer pressure to reduce e-waste is growing, and as so many of us have box loads of badly identified wall warts that will find their inevitable home in landfill, I can’t see a good reason not to standardise.

[zenguitar]

I recently received the email that the Tone Dexter II was finally available. I ordered it from Andertons but when it arrived it wouldn't boot up.

The manual described the PSU rating for the minimum requirement and also the ratings for the included PSU.

The PSU actually supplied only provided half the Amps required and didn't meet the minimum spec.

An email to Andertons quickly started the process, and couple of photos of the PSU enabled Audio Sprockets to establish that their supplier had applied the wrong part to them. They immediately sent a replacement to Andertons who couriered it to me on receipt.

It took less than a week from start to finish.

Andy

[amanise]

Well if anyone has a 9V, 3A, centre negative, with a 2.5mm connector, needing a purpose in life, I could use a spare here!

It sounds daft - but it's really worth looking on Amazon for that. There's loads of them really cheap - mine was a 12v one, but they had tons of other ones. I bet there was a 9v one. The really cool thing was the set of different adaptors that came with it for different sized plugs. £11.99 and free next day delivery with Prime.

[The Elf]

Already bought one - a MyVolts (who I trust). I like to have this kind of thing available, as it won't be the last time this happens. It comes out of my income, though, and it also brings yet another damned external PSU into the world, which makes me grit my teeth.

[amanise]

..It comes out of my income, though, ...

Know what you mean. I'm going to need about 13 million streams on Spotify to pay for mine

[Aled Hughes]

Already bought one - a MyVolts (who I trust). I like to have this kind of thing available, as it won't be the last time this happens. It comes out of my income, though, and it also brings yet another damned external PSU into the world, which makes me grit my teeth.

I just bought a MyVolts Ripcord for my HX Stomp, and I also ordered another for ‘standard’ 9v guitar pedals.

Turns out, they’re both the same! Both seem to fit the two different socket sizes. Very handy, I do hope they’re reliable.

Using this, I’ve powered my Stomp off a high-current USB charging block for the past two gigs without issues (though my Sennheiser wireless guitar receiver was noisy when powered off the same block with the second Ripcord)

[Stratman57]

I can also recommend Amazon for odd power supplies. I got a spare 15v supply for my Tascam Model 12 from the MyVolts brand. OK, it doesn't have the safety screw of the original, but it powers the mixer. I also bought a power supply for my Line 6 Firehawk FX pedal board directly from MyVolts.

Regards, Simon.

[The Elf]

Already bought one - a MyVolts (who I trust). I like to have this kind of thing available, as it won't be the last time this happens. It comes out of my income, though, and it also brings yet another damned external PSU into the world, which makes me grit my teeth.

I just bought a MyVolts Ripcord for my HX Stomp...

I have a few of these cables for 9V- 9V+ 12V and 15V with various sized connectors. I also have a MyVolts adapter kit and I tried various connector sizes and polarities, but couldn't find any combination that worked. Maybe it's the mains power board USB socket I was using.

I didn't hold out much hope, though - USB is 500mA, isn't it? The Stomps take a 3A supply. All this Volts, Amps and Watts stuff is completely baffling to me.

[Folderol]

As far as I'm concerned 'they' have totally lost the plot.
Originally your wall wart could supply a relatively low voltage and current (hence low power) from a totally enclosed unit. This was safer for users, and cheaper for kit makers as they no longer needed to go through extensive (and expensive) certifications.

USB 1 followed along the same track, 5V, 500mA, which is just 2.5W. Then the current rating got bumped up to 3A - 15W which raised a few eyebrows as this could do some real damage. Now while starting fairly low, via a negotiation system, that can go up to 48V @ 5A, which is 240W. Regardless of the current, under some circumstances 48V is potentially lethal. You could also make a mini welder with that @ 5A. In any case faulty kit could very easily catch fire. Oh, and a DC arc is far more dangerous than an AC one.

[Aled Hughes]

Already bought one - a MyVolts (who I trust). I like to have this kind of thing available, as it won't be the last time this happens. It comes out of my income, though, and it also brings yet another damned external PSU into the world, which makes me grit my teeth.

I just bought a MyVolts Ripcord for my HX Stomp...

I have a few of these cables for 9V- 9V+ 12V and 15V with various sized connectors. I also have a MyVolts adapter kit and I tried various connector sizes and polarities, but couldn't find any combination that worked. Maybe it's the mains power board USB socket I was using.

I didn't hold out much hope, though - USB is 500mA, isn't it? The Stomps take a 3A supply. All this Volts, Amps and Watts stuff is completely baffling to me.

Well, I ordered the one they specifically said works with the HX, and then added the other one to my basket. The two that arrived were the same, and they both work with the Stomp and with regular pedals, despite them requiring different sized barrel connectors.

It doesn't work with all USB blocks - I ordered high-current ones off Amazon, and can confirm that the following two does work with the Stomp:

https://www.amazon.co.uk/dp/B00PK1IIJY? ... ct_details

https://www.amazon.co.uk/dp/B016LPMFUA? ... ct_details

[ef37a]

Home
> Test Equipment
> Bench Power Supplies, Sources & Loads
> Bench Top Power Supplies

Single Output DC Bench Power Supply 0-30V / 0-3A - 72-10480

For a relatively modest 60 quid you can get one of the above (I thought they would be £100s?) and Amazon will provide you with an adaptor for every DC hole on the planet for a few quid. If I have a duff supply or YET another 5V one I don't need I cut off the DC cable with plug. This can be spliced onto the one you need.

When not saving some keyboardists arse the supply will be useful in the workshop. (err, CPC BTW.)

Dave.

[tea for two]

All this Volts, Amps and Watts stuff is completely baffling to me.

I'm trying to think of a way to say how Voltage and Current work together.
I'm unsure whether what I'm writing is clarifying or muddying, if muddying please delete my post as it is a matter of safety.

A spin bowler bowling at 50mph, a fast bowler 90mph-95mph are let's suppose signify different Voltage levels.
The Current level is let's suppose whether a grape or a cricket ball is being bowled.
If the fast 90mph (high voltage) grape (low current) hits us it will hurt, butt a cricket ball (high current) hitting us at 90mph (high voltage) is going to do lot more damage even kill as has happened couple years earlier on an Australian cricket match.
If the spin 50mph (low voltage) cricket ball (high current) hits us then it will hurt but it won't kill.
If the spin 50mph (low voltage) grape (low current) hits us it won't hurt as much.

There's another important factor : how long in seconds the current is flowing, the longer in seconds depending where it's flowing in our body the more damage even lethal.

Wattage is the outcome of the spin or fast bowling (voltage) multiplied by grape or cricket ball (current).

::

Specs say Helix HX Stomp XL requires 27W as 9V x 3A.
So the plug Aled linked to which outputs 60W as 12V × 5A more than suffices.

::

I have a GAN power plug charger 20V x 3.25A = 65W to deliver thru a usbC port to my laptop usbC port.
Then there's such as Dell 150W laptop charger 19.5V x 7.7A.
These GAN power plugs and laptop charger are Class II devices shielded with plastic still they are not to be trifled with.

48V x 5A = 240W is the max that a usbC port power delivery can handle this would concern me if I had such a power plug charger.
I already unplug my 65W GAN plug when not in use.
A 100W = 20V x 5A GAN plug is the most I'd purrchase.

[The Elf]

Already bought one - a MyVolts (who I trust). I like to have this kind of thing available, as it won't be the last time this happens. It comes out of my income, though, and it also brings yet another damned external PSU into the world, which makes me grit my teeth.

I just bought a MyVolts Ripcord for my HX Stomp...

I have a few of these cables for 9V- 9V+ 12V and 15V with various sized connectors. I also have a MyVolts adapter kit and I tried various connector sizes and polarities, but couldn't find any combination that worked. Maybe it's the mains power board USB socket I was using.

I didn't hold out much hope, though - USB is 500mA, isn't it? The Stomps take a 3A supply. All this Volts, Amps and Watts stuff is completely baffling to me.

Well, I ordered the one they specifically said works with the HX, and then added the other one to my basket. The two that arrived were the same, and they both work with the Stomp and with regular pedals, despite them requiring different sized barrel connectors.

It doesn't work with all USB blocks - I ordered high-current ones off Amazon, and can confirm that the following two does work with the Stomp:

https://www.amazon.co.uk/dp/B00PK1IIJY? ... ct_details

https://www.amazon.co.uk/dp/B016LPMFUA? ... ct_details

Thanks.

I did suspect that the reason the RipCords weren't working was because of what I was plugging them into. By this stage I'm better just getting a PSU - which is what I've ordered.

[The Elf]

All this Volts, Amps and Watts stuff is completely baffling to me.

Specs say Helix HX Stomp XL requires 27W as 9V x 3A.
So the plug Aled linked to which outputs 60W as 12V × 5A more than suffices.

Err...

So are we saying a 12V PSU would be OK with a device expecting 9V? Surely not? Or are we saying that the RipCord cable is sorting all that out? In which case why doesn't that cable suffer by being given too much V? What would happen if I plugged a USB device expecting 500mA into that 5A output?

Nope, I don't get it. Many have tried, but I have a mental block with this stuff.

[Hugh Robjohns]

It's all determined by Ohms Law: V = I * R ... or to use algebra to put it another way, I = V / R ...and R = V / I

I is current in Amps, V is voltage in Volts, and R is resistance in Ohms.

The same basic formula works for both AC and DC, by the way.

The other useful formula is Power (Watts) = I * V

Most devices need either a specific operating voltage, like 9V or 12V, etc... or can accept any voltage within a defined range, such as 9-12V or 18-24V etc.

But either way, they need the specified voltage and they generally won't work with too low a supply voltage. Too high a supply voltage may result in damage or destruction!

It's also usually critical that you don't feed DC into something expecting AC, and vice versa. There are exceptions that can work with either, but most need one format only and damage may result if fed the wrong format.

Also, with DC power supplies, be aware that some are regulated while others are not. The difference is that regulated types effectively guarantee to provide the exact stated voltage regardless of the current supplied.

In contrast, unregulated types will only deliver the correct voltage when supplying the specified current.

So use regulated supplies whoever possible for peace of mind (and no nasty surprises).

When it comes to current, there will be a maximum current rating that the power supply can provide, like 1 amp, 500mA or 100mA etc. However, the actual current that flows from the supply depends only upon the resistance presented by the destination's powering circuitry— as calculated by Ohms Law. I = V / R

So, if the device's has a 9V supply, and the power input resistance is 90 Ohms, say, the current must be 0.1 Amps or 100 milliamps — even if the power supply could provide up to 500mA (or whatever).

In other words, the device determines the current it needs, not the power supply — as long as the latter can provide at least as much current as needed.

So, when matching power supplies to devices, you need to match the AC or DC format, and make sure the voltage is correct (or within the specified range). You also need to match the connector polarity, where coaxial plugs are used.

But the current rating just needs to be more than the device's stated minimum requirement because the device will only take what it needs.

In the same way, provided the voltage is right, you can use a higher wattage supply, as the device will only consume the power it needs.

That said, its best to choose a supply which is no more than two or three times the stated rating because the output voltage of very lightly-loaded supplies can rise above its stated value in some cases.

So... right format (ac/dc), right polarity (connector), right voltage, but any higher current or wattage (within reason).

I hope that clears things up.