Friday, 14 July 2017

Make a Portable Speaker with PAM8403 Amplifier

Make a Portable Speaker with PAM8403 Amplifier - Intro


Do you have an old speaker or two hanging around in the garage or loft? Would you like to make a kick @$$ portable speaker for just £3 / $6? Left me show you how.

Lets get real here, you are not going to save lots of money you can probably buy a portable speaker, for you iphone or android phone direct from china for £6 / $12, but this way you get to save a trip to the dump, and get some satisfaction.

Old Speaker + £3 = Disco


Make a Portable Speaker with PAM8403 Amplifier - Ingredients


You will need the following ingredients:


  • An old speaker (4, 6 or 8 ohm) lower ohms = more volume.
  • Some wire (door bell, lead from old adaptor. . . )
  • Battery Holder to hold 3 x AA or 3x AAA batteries  
  • PAM8403 amplifier board
  • A drill 
  • screw driver
  • Soldering iron
  • solder
I have gone in to detail regarding the battery holder and the PAM8403 amplifier below.


Make a Portable Speaker with PAM8403 Amplifier - The Amplifier


You can buy the vanilla PAM8403 board on ebay for next to nothing but for a few £/$ more you could get hold of a blue tooth variant. This is useful if you want to use a phone without the 3.5mm jack socket.

There also variants with a volume control, and a smoothing capacitor. This may be worth getting if you do not have a spare capacitor

Bluetooth . . . . . volume control . . . . . or vanilla (normal) the choice to yours.

Make a Portable Speaker with PAM8403 Amplifier - Power Source


The amplifier run on a any voltage between 2.5V and 5.0V. This means you can power it with:


  • 3 x AA batteries
  • 3 x AAA batteries
  • USB power lead from PC or Wall Adaptor
  • 1 x 18650 Battery
  • A USB power bank
I have tried with a USB power lead, and then 3 x AA batteries both worked very well. 

The amp have two channels (left and right) and as far as I know you have to use both channels. You cannot splice the two channels together to make one. 

Make a Portable Speaker with PAM8403 Amplifier - How To

So the old speaker I have had a tweeter (small high frequency speaker) and woofer / midrange speaker. I used one "channel" from the amop for each. I cant remember which way around I put them. 

You will need to remove the cross over if there is one, save the capacitors for re-use.


In order to do this you will need to open up the speaker and, take a wire from either the woofer or the tweeter, you may find that you have a cross over unit in there, you will need to by-pass this so you can create two separate channels. Keep the cross over and carefully remove one of the capacitors for reuse, in a moment. You will need to solder this in to the positive wire of the tweeter. Like this:

Adding a capacitor as above will improve sound quality.

I first tried the amp and speaker together without this capacitor and the tweeter sounded distorted. However, after adding the capacitor all was well. 

The amplifier is tiny. . . note pinky (little finger) for scale.



Next up we need to start soldering all the bits together, if you do not have a soldering iron just buy one. They are useful for all sort of mending and fixing and making. As you can see the PAM8403 amplifier is tiny. And this makes for fiddly soldering, you can only use thin wire as the holes are too small for thick wire. 

Wiring is simple. . .but fiddly!


So for simplicity I house the wiring in a surface mounted junction box on the rear of the seapker, I had one of these spare in the garage. But you could actually just put all of the wires inside the speaker if you wanted to. Although it would be more fiddly to work on. 

3 x AA Battery Holder - £1.99


This cheap battery holder from ebay has a built in switch (counter sunk). I screwed it on to the rear of the speaker. With 3xAA batteries in side in produced 4.5V, good quality rechargeable batteries are preferable to disposable, as they hold a higher charge for longer, so voltage stays are close to the optimum (5V) as possible. 


Toggle switch. . . if you like.


I also added a toggle switch that I had as it is a nicer switch to use, than the one on the battery holder. You can also use a piece of cord, rope or strapping as a carry handle. 

Carry Handle


Make a Portable Speaker with PAM8403 Amplifier - Performance 


The sound level of the finished speaker (4 ohms / 4.5V ) is approximately 60 - 70 decibels. You cannot really have a normal conversation in the same room. As a 35+ year old man, I find it unpleasantly load at full volume.

There is quite a lot of midrange and high pitch sound, and perhaps some more bass would be a good, but overall for a piece of hardware that cost 99p, and is the size or a postage stamp it is amazing . . almost alchemy in terms of its performance. 

This is a fun, low cost project that I have enjoyed doing, and I would urge you to do the same if you require a speaker of this type rather than buying some other hard to recycle item from china.


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Thursday, 13 July 2017

Living with iOS 9.3.5 on an iPhone 4S

Living with iOS 9.3.5 on an iPhone 4S  - Intro


I have been avoiding upgrading my iOS since iOS 7. However, on wednesday night I drank too much red wine and upgraded, because an app I wanted to use requires iOS 9 or higher.

What a mistake to make. My snappy adequately fast phone was rendered sluggish and virtually useless. So what can I do?

Living with iOS 9.3.5 on an iPhone 4S  - Down-Grade - NO WAY


Apple must know that older devices will not run there newer iOS properly, and hope that the performance of iOS 9 on older devices will force people to upgrade. For this reason they do not offer a way to downgrade your iOS. 

There is one exception, and that is 6.1.3 which is still "signed" for use on the iPhone 4 (not 4S). There is 3rd party software avaiable to do this, if you have iOS 9.3.4, but not for iOS 9.3.5.

So this is impossible for 9.3.5.

Living with iOS 9.3.5 on an iPhone 4S  - Jail-Break - NOOOO WAY


This is also not possible, iOS 9.3.5 is not jail-break-able.

Living with iOS 9.3.5 on an iPhone 4S  - Re-Install and Performance Mods - WORTH A SHOT


This is the only way left for people, and I think by following the below steps you can claw back the usability of you iphone 4S.

9.3.5 Reinstall

  1. Back-Up Your Iphone (Use iTunes)
  2. Reset (Settings > General) Choose (Erase All Content and Settings) 
  3. Restore from Back Up when Done.
Note: This freed up a lot of storage space for me. Despite having most the same apps and music on the phone after restore. Perhaps the old iOS is not deleted from the phone when it is upgraded?

9.3.5 Performance Mods


Do the following:
  1. Turn Off Animations (Settings > General >Accessibility)
  2. Turn Off Transparency (Settings > General >Accessibility)
  3. Turn Off Back Ground App Refresh (Settings > General)
  4. Enable Low Power Mode (Settings > Battery)
  5. Delete All Unwanted Apps (Hold Down Any App Icon Until Wobble)

Living with iOS 9.3.5 on an iPhone 4S  - Conclusions


APPLE! It should not be like this, serve the customer please. If I want to install Windows 3.1 on my PC I can. . . . this means I do not have to send my old PC to india, for kids to dismantle, and go to early graves with lead poisoning. . . there is a moral element here!

Every time you make a new iphone there is also a carbon cost, it is no good prattling on about how considerate you are in you CSR reporting if your belligerent attitude towards legacy hardware is causing mountains of E-Waste, and unnecessary Carbon Emissions. You know global warming, that thing that Trump Ignores. . . but then he is a pretty good guy after all.   



Illustrator Devon



Tuesday, 11 July 2017

Daphon GA-1 Amplifier Review

Daphon GA-1 Amplifier Review - Intro


WHo wants a new blue tooth portable speaker when you can use a chunky black box, attached to your phone with a cable? I appreciate that this is a guitar amp, but I also thought it might be good for playing music through. . . . .turns out NOT. It is not even a very good amp, and yes I am considering the fact it is small and runs on batteries.

Daphon GA-1 Amplifier Review
A nice looking amp with a quality feel. . . . 

Daphon GA-1 Amplifier Review - Battery


This GA-1 takes a 9v power pack (LR6) what a faff that is , why not 6 xAA? That would be so much cheaper and easier. So that is a really annoying feature. Considering the amps performance (low) then you need to keep the battery in prime condition to deliver good sound, otherwise more distortion, and there is PLENTY of that any way.

Daphon GA-1 Amplifier Review BAttery
Really? That is the best battery option you could think of?

Daphon GA-1 Amplifier Review - Sound Quality

Terrible. There is something to be said for it small size, and if you are playing in your bedroom or maybe at a BBQ in the woods. . . . but the sound quality is so so poor, its hardly worth having. Using it a speaker for say music from an iphone is a terrible idea, as the sound distorts at an incredibly low volume. 

The Insides let this amp down. . .badly


Daphon GA-1 Amplifier Review - Insides

Inside the amp we see the board is centered around a panasonic (AN7142) 0.9W chip. This is well below the advertised 2W output, or leagues away from 5W max output touted.

Now I am not a electronic guy, but you can get amp chips that support 5W. So what have they done in there? Whatever they are doing it certainly looks as though the internals could be better.

A low power chip may be to blame for the terrible sound?

Daphon GA-1 Amplifier Review - Manufacturers Blurb

This is the blurb straight from daphon:

Portable Performance Amp

A perfect beginner guitar amp or a busker's best friend. Because of it's battery power you can have amplification wherever you are. The amp has the capacity to produce decent volume and you have control over your sound through tone control. Flick the drive button for a crunchy overdrive. Also suitable for microphones, though an impedance transformer is recommend for best performance.

Hours of Fun on a Single Battery

Runs on a single 9 volt battery (the rectangle type) that can last many hours depending on volume, can also be powered by a 9V ac adapter. The amp is 20cm / 16cm / 8cm in size and a headphone output is included for silent playing.

Music On-The-Go

Also a great portable music speaker. Just plug in your Mp3, Ipod or Discman via the input and you can have access to music wherever you go.

Daphon GA-1 Amplifier Review - Dimensions


Dimensions: 20cm x 16cm x 8cm
Weight: 1.2kg
Maximum power output: 5W
RMS power output: 2W

Daphon GA-1 Amplifier Review - Conclusions

A well built case a solid feeling controls, let down by very poor quality internals.

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