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Speaker Impedance: 4 Ohm or 8 Ohm

Speaker Impedance and amplifier design

 

There’s been a lot of techno speak on the various forums to readers about the advantages of using loudspeaker impedances of specific values, some even discussing the merits of 4 Ohms as only being used in very high end systems. The question here is based on another question:  If a great sounding system works well driving an 8 Ohm why would you then think a 4 Ohm would make it sound better?

2 Way loudspeaker crossover
2 Way Loudspeaker crossover – Wiki Commons German Wiki Frank Klemm

Certainly car audio is often found with 4 Ohm speakers, sometimes in parallel to get 2 Ohms.  Does it sound better than 4 Ohms?

Is a system designed to drive an 8 Ohm speaker then  inferior to that which can drive a 4 Ohm speaker? Continue reading “Speaker Impedance: 4 Ohm or 8 Ohm”

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Vintage Audio Vs Modern Technology

Is vintage audio better than modern releases?  (post 2000)

This reminds me of the first argument I had regarding the merits of mechanical VU meters over LED.

Yeah, we like vintage stuff, especially with those big VU meters. Hell, I was looking at the specs of the Pioneer SX-1980 the other evening and thought  what a beast this must have been in the 1980s. At 270W this is certainly by no stretch of the imagination much in modern times thanks to PWM, Class D and mounted on a one inch square heatsink.

McIntosh_MA6800
McIntosh MA6800

en:McIntosh Labs MA6800 amplifier. *Source:  *Credit: [http://www.flickr.com/people/ux/ Akira Kamikura] *License: cc-by-2.0 {{cc-by-2.0}}

Continue reading “Vintage Audio Vs Modern Technology”

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Repairing the Sony TA-F444ESX – Regulator failure

Sony TA-F444ESX PSU

The Sony vintage TA-F444ESX – protector and regulator failure

As a follow up to our previous article on speaker protection we thought it pertinent to look at this classic vintage amplifier, the Sony TA-F444ESX. Good in looks, solid in build and of course exceptional audio.

The Sony TA-F444ESX is similar to the TA-F700ES with international supply voltages 100 – 240V. Continue reading “Repairing the Sony TA-F444ESX – Regulator failure”

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Electric Motors in low current Circuits

Induction Motor

Electric Motors, Trends over the last 50 Years

For those born after 2000 and electric motor is seen as just another product of technology, just like the cell phone.  Electric motors have been with us for the last 200 years, personal handheld phone (Motorola and Martin Cooper) about 50. There is a link of course, that being switching devices.

Universal Series Wound Electric Motor
Universal Series Wound Electric Motor

Although it is an accepted fact that inverters and variable frequency drives are with us to stay, older technology relied on some pretty innovative ideas to increase and/or lock an electric motor’s speed.

Continue reading “Electric Motors in low current Circuits”

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Innovation in South Africa

This steam evaporator aboard HMS Belfast distilled up to six tons of fresh water per hour for the boiler and for drinking

Innovation in South Africa steps up a notch!

Much must be said about our not so dearly departed prez, J.G. Zuma. He may have reversed the good in this country under his tenureship but he also turned the citizens into a bunch of aspiring entrepreneurs, innovators and budding scientists.  In times of hardship innovation always comes out tops.

It was not that long ago that our country switched from the bankrupt supply commission, Eskom to solar panels, inverters, batteries, gensets and methane gas. Our neighbours became experts in renewable energy,  domestic wiring, preventing backfeeds and LED lighting.

Electric stoves went from power gobbling electric elements to gas burners, electric geysers became gas, heat pumps and solar. Continue reading “Innovation in South Africa”

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Electronic Circuits for Beginners

Electronic Circuits for Beginners - Prototyping

What to look for when starting out – Electronic circuits for beginners

What is the attraction behind electronics?  This is a sore topic in many South African circles chiefly because the architects of education are failing the academia, the principals and the teachers.  This in turn fails the learners, our future. This article, “Electronic Circuits for beginners” was written for grade 8 learners and in subsequent articles will hopefully add some value and direction to your schooling.  Education does not stop when you leave the classroom.

Electronic Circuits for Beginners - IoT
Electronic Circuits for Beginners – IoT – the spares box

Anybody whom loves reading should get a copy of the book “Elon Musk – How the Billionaire CEO of SpaceX and Tesla is shaping our Future” by Ashlee Vance.  Musk has all the makings of not just a great scientist and entrepreneur but a great leader.  He is regarded somewhat as an opportunist. Ditto Bill Gates and the gone but never forgotten Steve Jobs.

Electronic circuits for beginners – making a career choice Continue reading “Electronic Circuits for Beginners”

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The Maker Community – The CNC Machine

CNC Lathe

The CNC Machine – a positive influence on our lives

An interesting topic gathering momentum is that of the CNC machine or Computer Numerical Code machines, machines driven by computers and becoming increasing popular within the DIY Maker community.

Here we will look at the basic CNC machine and suppliers in South Africa.

The CNC Machine Forums

There are endless forums on the internet covering CNC and we’ll look at this as well.  We don’t seem to have a dedicated forum in South Africa so we’ll put this under a category on these pages. Continue reading “The Maker Community – The CNC Machine”

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Soldering and Rework Stations and other Kit

Magnum Rework Station 3005

The best soldering iron and rework stations for the job?

Of course this is a commonly asked question and the reply will always be to get the best one can afford.  Most home users are now spending a lot more money on getting better quality soldering and rework stations to complete projects. Cheaper irons, the home store DIY project types are not designed for intricate electronic circuitry.

Weller WSD81
Weller WSD81

There is no thermal control, the stupid tips wear away after ten minutes of use and after an hour one can hardly pick the thing up because it is radiating more heat than Koeberg. So bottom line, get one for an emergency – it will only last a day.  Do not use it on CMOS or static sensitive devices, just for simple home wiring.

Weller, Antex and Magnum Continue reading “Soldering and Rework Stations and other Kit”