Promotions Catalogue

DIY Class A 6J5 HIFI Headphone Amplifier Vacuum Tube Preamplifier Kit

DIY Class A 6J5 HIFI Headphone Amplifier Vacuum Tube Preamplifier Kit


Size: 77mm * 75mm (L*W)
Weight: 79g
Frequency: 16 HZ - 28.5KHZ
Headphone impedance: 16-600Ω
SNR: > 108db
Channel separation: <-100db
Distortion: <0.003% (distortion noise but not all, of the second harmonic modified sound)
Input and output: standard 3.5mm headphone jack
NE5532 or MC33078 op-amp
6J5 low voltage power supply pre-made cushion, the sound is very warm.
Power supply requirement: ±12-15V DC power supply 10W above transformer, filament require 12V more than 2A
Default op amp NE5532 or MC33078 random delivery.

Package includes:

1 x Headphone Amplifier DIY Kits


This is DIY Kit need you solder it by yourself, and many component is very small,so need you have some DIY ability, the unsuccessful DIY making is beyond the scope of our warranty.
We do not supply you with a manual, please note before buying.

DIY 100W HIFI-Class Mono Amplifier Board Kit


1. Audio input: Mono audio signal input;
2. Audio output: Mono 100W audio output;
3. Operating voltage: DC ± 35V ±10%;
4. Input impedance: 39K OHM
5.Output impedance: 2-8 OHM
6.PCB size: double-sided FR4, 50x90x1.6MM

Package included:

1 x Amplifier Kit

100W Audio Amplifier Kit - note Mono only, buy two for stereo

TDA8950 2x170W Digital Subwoofer Class D Audio Amplifier Board AMP Module


This version can choose differential input, the effect is more good, need is equilibrium output level before to pick up.
The board with rectifier filter circuit, save yourself the trouble collocation rectifier filter, using 30 a new original rectifier bridge with South Korea.
Sanhe high-speed electrolytic arrays, the effect is very good.
Bring their own trumpet protection circuit, installed substitution of DIY is more convenient.
Can be convenient for BTL output, need very strong beginning ability, if you don't have a real master, please don't try this kind of connection.
Reserve a plus or minus 15 v voltage potential position on board, convenient DIY ability strong buyers with myself, can give the front-end power supply.
Adopts SMT process, more stable than hand soldering product.
Match: the amplifier board can be used directly as pure power amplifier You just need to plug in transformer, also can be used with tones ,or made subwoofer amplifier with low pass board, price is very high.


Name: TDA8950 Amplifier Board
Size:10 x 10 (cm) (Excluding potentiometer handle and other bulge)
Work: Class D
Efficiency: 90%
Rated output power: 2 x 170W
Operating voltage: AC16-28V
Maximum output: OCL = 170Wx2 BTL = 300Wx1

Package includes:

1 x TDA8950 Amplifier Board
1 x 3PIN Line

AC20V-28V LM3886+NE5532 68W+68W 4-8 Ohm Amp Power Amplifier Board

This is a Stereo 68W*2 LM3886+NE5532 Amplifier Assemble Board. Use 2pcs of LM3886&NE5532 and 2 X 10000 UF NOVER audio-specific capacitors, you can control bass treble and volume adjustment.

1. Supply voltage: AC dual 20V-28V, recommend use above two 26V / 150W
2. Output Power: 68W * 2
3. Speaker Impedance: 4-8 Ohm
4. Potentiometer center spacing: 25mm
5. Dimension: 15*9.3*5cm
Package included:
1 x LM3886+NE5532 68W+68W Power Amplifier Board

LM3886 and NE5532 Preamplifier
LM3886 with NE5532 Preamplifier
John Linsley Hood PNP Class A (note schematic incorrect - uses NPN driver)

DIY PNP Version 6 Transistor Hood 1969 A-Class Power Amplifier


- 1 set includes 2 boards, mirror design
- Transformer voltage range: AC12V to AC28V / DC18V to DC36V, 2 lines
- PCB size: 139MMX73MM
- 6 transistor design, 2 transistors are used to buffer filter

Click to download diagram  (Note that schematic is incorrect - the driver stage is an NPN: 2N3055)

Package included:

1 x Amplifier Kit

Board Kit

DIY TDA7293 2.0 100W+100W Dual Channel Digital Amplifier Board Kit


PCB size: 100X60MM
Voltage: AC 15-32V X2
Impedance range: 4-8 ohms
Distortion: <0.05%
Power: rated 100WX2

Online Parts International

A very big trend for some time now is for the home DIYer to build his own switched mode power supply.  These power supplies when run from the mains electrical supply if not designed by a professional company which specialises in mains switching circuits can be downright deadly. Why not try a few circuits already built which can operate from a 12V battery supply and boosted to the rail voltage you require.

Another, possibly a bigger reason is if the DIYer has transformers which he or she has collected over time but the secondary voltages are too low to get the necessary supply rail voltages.

In comes the step up converter, more commonly known as the boost converter. (to drop the rail voltages we would use a step-down converter or buck converter.

Here are some exceptionally good value ready built circuits from a supplier in the East.

600W DC-DC Boost Converter Step-up Module Mobile Power Supply


600W high power Boost module
Wide voltage input: the 10V - 60V
Output adjustable 12V -80V wide voltage
Adjustable output current
Ultra-low dropout


Input voltage: 10V-60V
Input Current: maximum input current 15A
Output voltage: 12V-80V continuously adjustable
Output current: maximum output current of 10A (adjustable)
Output power: effective power P = input voltage V x 10A
Conversion efficiency: up to 95% (input voltage and current; conversion efficiency of the output voltage, current impact)
Short-circuit protection: fuse

Package included:

1 x   DC-DC 600W DC IN 10-60V OUT 12-80V Boost Converter Step-up Module Mobile Power Supply

For a photographic list of products please see next page....

Promotions Catalogue

This is an affiliates page which hopefully will pay for the maintenance of this website one way or another.  Having personally tested the Dc-DC 10-32V to 12-35V mobile switcher it works very well - note though that the power supply does not have isolated (-) and (+) poles.  The input (-) and output (-) are bonded together. Those wanting to do a little bit of DIY can wire wrap a separate secondary but I have not tested this - it is a work in progress.

We used two of these modules on a transformer with 0-12V 0-12V secondaries through two bridge rectifiers to get a split rail supply of +32 0 -32V rails. It is used to power two TDA7293 modules running at about 50W into 8 Ohms.

Parts-ring concentrates on the DIYer and in what better manner than playing around with some pretty cost effective boosting switcher supplies.

The company that sources and supplies these products also sells a 480W adjustable 48V supply. This makes these highly affordable SMPS a very good solution for those wanting to power their +/- 50V supply amplifier kits.  We have not tested them yet but watch this space.

DC-DC 10-32V To 12-35V 150W Boost Adjust Module Mobile



Input voltage: DC 10V-32V.
Output voltage: DC12V-35V(adjustable).
Output current: 10A (MAX).
Input current: 16A (MAX) (more than 10A please strengthen heatsink).
Output power: natural cooling 100W (MAX), strengthening cooling 150W (MAX) real power.
Conversion efficiency: 94% (when Output 19V 2.5A Input 16V, Reference).
Output ripple: 2% (MAX).
Working temperature: industrial (- 40 ° c to +85 °c) ( environmental temperature, more than 40 degrees, please reduce power to use, or - enhance cooling).
Full-Load temperature: 45 degrees.
No-load current: 25mA typical.
Voltage regulation: ± 0.5%.
Load regulation: ± 0.5%.
Dynamic response speed: 200uS 5%.
Short circuit protection: No (Please installs the fuse or protection circuit at input parts).
Input Reverse protection: No (please comply with a reverse protection or connect a diode at input parts.).
Dimension: 65mm x 35mm x 23.5mm.

DIY an adjustable on-board power supply, you just input DC 12V, then you can get output DC 12V-35V (adjustable), But the output voltage can not below the input voltage.
DIY a booster charger.
Provide power for your electronic equipment.
Use Solar battery charging for electric accumulator.

Package included:
1 x Power Boost Module 150W Laptop Car

DC10-60V 30A 1500W To 12-90V Boost Converter Step Up Power Supply Module


Module properties: non-isolated step-up module (BOOST)
Input voltage: DC 10V~60V
Input current: 10~30V input voltage, maximum current 30A
                   31~60V input voltage, maximum current 25A
Quiescent current: 15 mA (12V liter 20V, the output voltage, the higher the current will increase too quiet)
Output voltage: 12~90V continuously adjustable
Constant] range: 0.8~20A (±0.3A)
Temperature: -40~ + 85℃(ambient temperature is too high, please enhance heat dissipation)
Operating frequency: 150 KHz
Conversion efficiency: 92% ~ 97%
Low battery protection: yes
Input reverse polarity protection: yes
Enter the anti-reverse protection: yes
Short circuit protection: yes
Installation: 4 x 3 mm screw holes
Module size(L*W*H): 130 x 52 x 85 mm
1. DIY a power supply, 12V can input and output can 12-50V adjustable.
2. The power supply for your electronic device, according to your system can set the output
3. As the car power supply for your laptop, PDA or a variety of digital products supply.
4. DIY a mobile notebook power supply: 12V coupled with high-capacity lithium battery pack, so you can go where light where books.
5. Solar panel regulator.
6. To the battery, rechargeable lithium batteries.
1. Thickening of the radiator and intelligent temperature control cooling fan.
2. Have input MOS meter protection, don't worry about input after burn out the power supply.
3. When used in battery input low battery protection avoid battery discharge damage power supply module and a battery.
Package included:
1 x Boost Constant Current Module

200W 7A 6-35V To 6-55V High Power Step Up Boost Converter Charger Module With Aluminum Case ME3L


200W 7A 6-35V To 6-55V High Power Step Up Boost Converter Charger Module With Aluminum Case ME3L


1, Input voltage: DC 6 - 35V
2, The output voltage: DC 6 - 55V ( Note: This is a step-up board , only the output voltage is greater than or equal to the input voltage)
3, Conversion efficiency: 97.6 percent ( input 32V output 45V / 3A when measured, the efficiency with input voltage and output voltage and current related)
4, The maximum input power: 200W (30V when input voltage is greater than the maximum power)
5, The maximum input current: 10A (Working long hours, please leave a certain margin)
6, The maximum output current: 7A (long hours, please leave a certain margin)
7, Module size: 70 x 39 x 32 mm (length x width x height)
Package included:
1 x 200W Boost Converter

AC 110-220V to 0-48V 10A 480W Adjustable Switch Power Supply Driver LCD Display For LED Strip Light

Short circuit overload, over voltage
on/off switch, or screws
LCD display

Input Voltage:110VAC/220VAC
Output Voltage:Adjustable 0-48V DC 
Output Current: 10A
Power: 480W
Frequency Range:47 ~ 63Hz
Cooling Fan Start Temperature:45 degrees
Over Heat Protection


Temperature:70 degrees
The Working Environment:10 to 50 DEG C; 20% ~ 90%RH (no condensation)
Size: Approx 215*115*50mm

Package Included:
1 X  Power Supply Driver

Analog Ian – “The more it changes, the more it’s the same thing.”

We have a sister website call Analog Ian – please go there and support us.

The Analog Ian website

Plus ça change, plus c’est la même chose – Jean-Baptiste Alphonse Karr (24 November 1808 – 29 September 1890)

“The more it changes, the more it’s the same thing.”

Pulling apart the Dixon PM121USB mixer

The VCF or Voltage Controlled Filter

The VCO or Voltage Controlled Oscillator


The Akai M8 Crossfield Head Recorder


Those who were around in the 1960s will remember the furor caused when this machine came to market. I dedicate this article to my late father Chris whom had one.

Akai M8
Akai M-8 – Vintage pre-1970

The Akai M8 was not the best machine out there, neither was it supposed to be at the price point it was released. It certainly wasn’t cheap but more to the point, those that had the test tape will remember that it’s fame was not around the tape quality at 15 i.p.s. but rather 1 7/8 i.p.s. and the Cross Field Head, licenced by Tandberg. Many audio enthusiasts unfairly compare this machine to professional machines at the time which came out with three motors.  The point here is that a machine with one motor is often more difficult to design compared to one with three motors. These motors can be very expensive and in order to mass produce at an affordable price point there was usually quite a bit of sophisticated engineering involved. (a case in point is that many enthusiasts in the 50s and 60s used to design and build their own mechanisms – often with three motors. Solenoid and switch control is easier to design (and build) than manufacturing cams, linkages and gears).


The M8 has made its appearance again over the last 5 years, not for it’s marvellous deck but for it’s audio amplifiers. I recently purchased one and will be restoring the deck and the audio section. A good price is usually around 100 dollars for a working unit. I paid about 65 dollars for mine. I do not know whether the amplifiers work because I should run them up through a variac first (which I don’t have) but the deck does need some maintenance. Strangely enough the pinch roller is not in bad nick although the belts will need replacing. This unit must have been kept in storage for some time gauging by a look at the casing.

Wow and flutter, hum and noise and cross talk may not have been perfect but I do recall on the new machine recordings of piano playing were usually exceptional – I recall this because I was ten at the time. When my hearing was still intact. A ten year old doesn’t know what wow and flutter may mean but will certainly complain if it was audible.  The other thing, at 15 ips these machines were very capable. Most RTR of the time were only 3 3/4 ips and looked their age. The M8 in comparison looked like a space ship. No, it’s not a Zoom H6 but in capable hands and with good quality tape some pretty damn near professional recordings could be had.


This deck will be restored because I do believe the transport mechanism is not in bad shape (which we will come to later). Quite often on the forums we have the vintage collectors pleading for owners not to cannibalise or modify these decks for the amplifiers but personally speaking if the deck is in bad shape it may just not have any value to the owner in any event. Many of the students of tube technology have absolutely no interest in the deck – only the sound of the amplifier.  My recollection is that the amplifier quality was not bad,  a fairly flat response and the reproduction of vinyl was crisp. This was also in the 70s when transistorised amplifiers were making their mark. Not knowing much about audio quality I do recall the solid state amplifiers as being powerful and crystal clear, the tube amplifiers were just lost in all that power and “perfect” imaging of the program source.

I do not believe that tube amplifiers are better than SS. I do believe that they sound different and depending on their use tubes can be superior. I do not believe that tubes should be used for home theater and in my own experience if one needs a tube microphone preamplifier it should be all tube. Power amplifiers are cheaper in SS format and we shouldn’t be clipping them in any event unless that’s the desired sound required. Tubes are remarkably resilient and for those that now claim they have a lifespan of two years then I wonder how CRT manufacturers got away with for so many years. My personal favourite is Mullard. Tube biasing is a personal cringe I have. We have so many different types of biasing now available today one must wonder if the engineers of yesteryear were just plain stupid. No, it’s all marketing hype. I have worked on transmitters delivering thousands of Watts to the load and the only advantage we have in modern times is that the critical safety circuits have all gone the SS route. Because it’s cheaper and more compact.

The EL84 output stage of the M8 is nothing unique. The design was very popular and of course the EL84 was definitely one of our more popular tubes. In the USA we have other permutations and audio engineers had their own preferences, often very valid. Compare USA and Brit guitar amplifiers for instance. The more popular “Hi-Fi amp” was the push pull version of the EL84 amplifier. In the 70s I rarely came across any tube amplifier reproducing more than 15W and the El34 was seen as an extravagance – quasi-complimentary and complementary transistorised amplifiers were becoming popular, didn’t smell as much and were way more efficient. I mention “smell” here because anyone not familiar with tube equipment will think there’s something wrong when first powering up their vintage piece of equipment.

Something to remember:

Tube amplifiers use in most cases dangerous voltages on their anodes (or plates) and screen grids. The supply rails can be anything above 250V DC and in high powers 750V or more. This will cause serious burns and God forbid, your early demise if you are not careful. Ensure the equipment is switched off and unplugged. Discharge all smoothing capacitors either across their terminals (better) or across ground and + rail.  Do not use your multimeter probe to short out the capacitors if you value the probe. Tube circuits use high impedance and it’s not advisable to “probe” around on the control grid circuits unless your meter has a very high input impedance.

This Akai deck is often compared to decks costing very much more.  Indeed the M8 does not have a boastful spec compared to modern equipment but then again neither does Tandberg, Teac and Revox/Studer. The Akai GX series were funky looking and the quality on spec often superior to the older tube amplifiers and single motor decks. They can be obtained off eBay for fairly realistic prices. Magnetic material (composites) used on tape for recording and the biasing also plays a remarkable role in the end product.

Interesting article here:  The Roberts Akai relationship at the museum of magnetic sound recording. (we include this because there has been a large amount of nonsense written about these two brands in the forums).

Part Two – the restoration process

Tape Recorder bias

The triple B factfinder’s column – Bullshit Breakfast Club

Google has unwittingly inspired many armchair wannabes to become experts in most fields, specifically dominating the IT, mechanical and electrical engineering industries but having its origins we believe in politics.

The ability to write well, stick a bun on the back of your head and behave with an air of confidence is fast becoming the norm, a frightening thought if one understands the phenomena known as the Dunning-Kruger Effect. Society has become full of it, possibly driven by the relatively new lack of standards in the IT industry. Now we smell the fresh aroma of cow dung at every gathering, party or pub visit.

Bullshit Anon – The fresh smell of manure in the air

On a recent visit to Orlando I had to chuckle to myself when I overheard an aviation expert persuading his many listeners in the smoker’s lounge that the reason why smoking on aircraft had been banned was because the authorities had calculated that over 200 kg of tar had accumulated in the passenger cabin of a 727 after only one year in service. The mind boggles.

Has one noticed that oft a geeky, pimply youth would wrap a nerd-like set of specs around his scrawny head, create or attach the bun hairstyle, drop the trousers to the knees plumber style and transform into a potential Bill Gates. Or the guy with a multi-meter becomes a Carver or Voltaire. In recent times I have come across real mechanic donning a clean pair of jeans and golf shirt but the dodgy around the corner auto expert puts on a dirty pair of overalls. It’s all perception folks.

My GP come medical practitioner come doctor does not wear a white coat and stethoscope, some of the best IT boffins look normal and yes, because you wear a suit doesn’t make you an honest individual fighting for the cause. A friend of mine whom holds two degrees, one in electrical engineering and one in computer science tells me when he is stumped. He is also very intelligent.  The typical anti BBB candidate.

Is the reason for Donald Trump’s many recent successes because he is anti BS. He is certainly not politically correct, indeed possibly even blatantly sexist. I’d love to see an unbiased listing of the demographics of his voters. I think we may be surprised. But yes, maybe this is what we need – someone who calls a spade a spade. I personally don’t like bullshitters. Even more, people that don’t even know they are bullshitters. I don’t want to walk into a shop which only sells high end audio gear thinking that the more I spend the better it’s going to be. I want auto manufacturers to build a car without frills so when I buy it second hand five years later I can fix it without breaking the bank. I want to buy anything based on the transparency of the sale. I want to see a website showing all the flaws in products. I do not want some geeky, pimply dude with a bun hairstyle telling me this is how it is.

Can you imagine a politician becoming a salesman? The bad news is that good sales people are as close to dammit as politicians.  From Wiki: “Politics (from Greek: πολιτικός politikos, definition “of, for, or relating to citizens”) is the process of making uniform decisions applying to all members of a group. It also involves the use of power by one person to affect the behavior of another person.” Note that there is no reference to “the advancement or betterment” of “another person”.

I like musicians. They understand politics because many of them write about it. They do more than politicians to serve the poor.  Musicians practice what they preach (mostly) and have very little tolerance for bullshit. Tracy Chapman, Roger Waters, Stevie Wonder, George Harrison, John Lennon, Ed Kowalczyk, etc – 99% of them. Real musicians. Often politically incorrect but mostly not suffering from the Dunning-Kruger Syndrome.  You will never become famous if you are not good. A musician cannot tell you how good they are until – they have to prove how good they are.

An international airlines pilot is a rated professional. They have regular tests to check competence. Whether all the tests are relevant is immaterial. We have to learn to trust this individual or individuals. In most industries this is not the case. A Bsc graduate in auto engineering may be totally incompetent in his field whilst the highly competent artisan is sidelined. This happens very often – Bullshit Baffles Brains.

In years to come we will reflect on the old artisans, long since pensioned off and deceased whom did what they said they could. We live in an age where the voice of authority is expert. Every single car manufacturer out there vies to have the best technology available whilst the roads collapse, where drivers cannot drive and there are no trains or buses. We live in an age where we sell curved TV, have 8K cameras and where the cheap Atom processor outperforms high end processors of ten years back. We have millions of computer languages, compilers and translators. We have multistandard TV systems, mains voltages of 100, 110, 120, 220, 240V.  We can read up on this and more.

But that doesn’t make us a real chef, real technician, real mechanic, real artisan or trusted doctor, attorney or accountant. And that’s what makes Steve Jobs, Bill Gates, Voltaire, Marconi, Flemming, Sinclair, Ford, Wright Brothers, Prince, Jackson, Benson, Bono, Madiba, Rooseveld, Churchill, Bosch, Stanley, Livingstone different. Because they did it.

Actions speak louder than words.

Einstein said:  “Two things are infinite: the universe and human stupidity; and I’m not sure about the universe”.

(Ed’s note: Eduan was forced to write this article after an office braggart told everyone how he had changed the idling speed of his car to make the engine run slower to get a higher top speed.  Also the same guy with a not seen helicopter license and “designer-engineer” part time for a manufacturer. What we do know is that has made two girls pregnant in the office and is employed as a “marketer”).

Autonomous Cars – embracing the inevitable

Let’s face it, we all dream about it but know it can’t happen – a self driving car! Yet, this is on the cards. Mercedes, Kia, Toyota, Ford, Audio, BMW, Volvo, you name it, they all have a car which can drive autonomously. “Not on our roads though” say the authorities.

It wasn’t that long ago that our great-grandfather was told never to drive faster than 100 m.p.h. because the blood would leave his body. In those days 40 m.p.h. was classified as breathtaking. Now we have Andy Green in his ThrustSSC breaking the sound barrier. He might have been white as a sheet when he cruised to a halt but his blood flow was normal and his body parts were still intact. Of course we digress but isn’t this what science is about – proving it wrong!

Autonomous or rather automated vehicles which require external and environmental assistance through usually magnetic strips and road navigation transponders is not something new, in fact was on the drawing board in the early 1980s. However, with smaller, faster and more reliable computers, highly sophisticated sensor systems and state of the art electro-mechanical output devices we have come to a cross-roads – cars which are driven near autonomously and when to mass manufacture? Only time can tell although major manufacturers already talk about the latter part of this decade, some as near as 2017. Unfortunately all of this will come to a nought, we believe, because of the road traffic authorities. Actually more so, the fraternity of global electronic engineers all shake their heads in disapproval. The thing is, we can fly an aircraft totally unmanned only because there are critical backup and redundant systems in place, not many obstacles to bump into and even less corners to negotiate. Motor cars are on land, they rely on absolutely accurate input data at all times and last but not least, the critical thinking aspect to this entire exercise, no errors or hardware failure. And this is where we have a problem. Imagine driving merrily along at 70 m.p.h when a sensor fails, the radar decides to stop working or the computer decides to reboot (unlikely but who knows).  The global think tank may be right.

Control freaks will never let go of the steering wheel. They are also some of the world’s worst drivers. Every year hundreds of thousands of people, pedestrians, drivers, occupants, (animals too) are killed on our roads. Traffic authorities have all but given up. What percentage is caused by driver failure?

Partially automated vehicles already protect the occupants of a vehicle when crossing lanes inadvertently, applying brakes when needed, stabilising a vehicle which may be on the verge of rollover and preventing unnecessary skidding.  So why can’t they be made to drive the occupants to a destination without driver intervention?  Because it cannot. It’s called the unknowns. What happens if?

Interesting to note that driverless cars use the cloud but flight MH370 didn’t. Losing communication to the driverless car may make it pull over to the side of the road and stop. What happens if the side of the road happens to be a cliff, dropping 300m to the sea or a rocky outcrop? No thanks. Although the same electronic engineers designing the workings of your trusty four wheeled carriage will swear to the reliability, they are the first to banish the notion of driverless cars. Quite rightly.

Autonomous Cars – if the roads allow it

Just as one was told that you may drive safely but not necessarily the “other” driver so it just so happens to be the reason why driverless cars may be on the drawing board and even successfully tested, it’s the “other” car that remains the problem. Just because the roads in Sweden and Germany are better than most third world countries makes the very idea of driving the Yungas without a steering wheel a frightening thought.

But no, as a matter of fact we do believe that driverless cars are here to stay. We do believe that if the road is not safe the driverless car will stop and tell you that you are on your own. If a machine which has proven to have more powerful thought processes than the driver’s brain pulls over because it is not safe then believe me, you are not safe.

Many years ago most drivers took to the roads because of the pleasure of it. Nowadays it’s a case of whether you will make it back alive. We cannot blame the authorities neither can we blame the electronic, automotive and mechanical engineers. Unfortunately scientists and engineers alike know that we can no longer rely on the human element, there has to come a stage where there is forced intervention. We can only blame ourselves. The authorities and engineers shouldn’t put a ban on it but embrace it.


On the Edge – amplifier design

Isn’t it frustrating to shop for the ultimate sound system on a limited budget. You see one, you hear one and that one on the next rung up always sounds that little bit better.  Fortunately we have good news. It’s all in the mind.

Anyone being an avid reader of any electronics and audio magazine that does comparison tests will often get overwhelmed by the amount of products on sale, let alone by the costs of these high end pieces of equipment. It’s almost like playing chess against a grand master – no matter the move, there is always one better. So it is with audio gear. The problem is, we often fall foul of the marketing machine and sales personnel pressure. Don’t. Whatever you do, never buy a sound system based on whatever someone else tells you.  What we do know is that power output is no longer directly linked to pricing, semiconductors are cheap.  Even Chinese manufactured toroidals are no longer the price it was ten years back. But what should one know?

Inputs and more inputs, all with the same output

Most audio amplifiers brought out over the last few years have surprisingly good build and sonic quality. For movies one loves the idea of being able to set up the sound stage through a microphone and an automatic process. However, audio installers complain about most users not setting up their systems properly even with electronic assistance Read up on this in the manual. If you are only buying the integrated amplifier like most of us do then ensure you have sufficient inputs. This seems to be the most important thing in the designs found currently on the market – millions of inputs. On a practical level these inputs should be HDMI and one or two for legacy use.

Marketing trends push for big power and in our experience this is true, go rather for overkill.  Pick up the amplifier, weigh it if necessary. Most of the weight is transformer and cooling based. A Class D amplifier is light – that’s a design advantage. Class AB will be heavy – that is also a design advantage. If it’s Class AB, delivers upwards of 60W x 5 or 7 channels it will be heavy. How heavy is heavy? We have our own estimations but do look at manufacturers such as Marantz and NAD. These guys don’t skimp on components least of all quality of the mains transformer. The importance of this is multi-fold. Read up on how tests are done and in this case, specifically output power measurement. Transformer secondary (output) voltages sag when under load. Power supply regulation is critical and to compete with the best there should be no compromise. This is where most budget systems cut costs.

Purchasing an amplifier which lacks oomph will cost more in the long run – you will be disappointed. If it’s a headphone amplifier you want then one needn’t be looking at killing your ears in one sitting. And no, you cannot put audio amplifiers in series to get more power. What you can do is purchase separate pre-amplifiers/processors and power amplifiers. It will work out cheaper in the long run if you need to upgrade for higher power.  This a more expensive solution but possibly a better long term plan. A well looked after, carefully selected preamplifier/processor may even prove to be a lifetime “investment”.

Six channels or more, two is best

Two, three, four, five, six, seven or ten channels? Here the choice is yours. There are many audiophiles passionate about their movies but only use two channels or stereo. The home movie expert may prefer the most amount of channels he can afford. 5.1 is still rated about the most common.  Quantity over quality? A good quality stereo setup beats a multi-channel movie theater setup for music anytime. (of course this is bias).

Tubes versus semiconductor?  Dollar for dollar there is absolutely no equaling the transistor or semiconductor. (I will add this though – my own opinion is that early transistorised amplifiers lacked the musicality of tube amplifiers. If transistor amplifiers were first on the market maybe I would have rewritten this and in all likelihood battled to justify the rationale. The fact remains though, musicians on a whole tend to prefer tube sound. So there!).

Why on the edge?  The objective of any audio amplifier is to faithfully reproduce the input signal as an exact image except for amplitude at its output. Through the years scientists and engineers have near perfected this art. A bench tested audio amplifier which reproduces with clinical precision the input program material to its output will sound good through a quality loudspeaker system. Most amplifiers today, except for cost cutting in the power supply will do exactly that. So where to now?

Digital is Doomed

Although we are living in the digital age man and machine will never be the same. Our logic is often irrational and therefore biased. We cannot live in peace with each other because of this exact reason.  With audio equipment we take a very sophisticated (in scientific terms) analogue signal, convert to binary, we then read the binary and convert to analogue. We them chop the analogue at a high frequency, modulate with a sawtooth wave, switch at a high voltage and finally filter out the high frequency component. We then feed the analogous high amplitude signal to a transducer which is an analogous device. Then the marketers come along and tell us vinyl is back!

We have fine tuned the Class D amplifier for home use but yet it’s true advantage is when used in cellular technology. We have lowered the cost of high powered audio amplifiers through this technology but yet loudspeakers have always been the obvious weakness, both in cost and efficiency.

It is time for manufacturers to look at cheaper and more efficient methods to reproduce this amplified signal.  The fixed magnet, moving coil paper or synthetic cone speaker *aka dynamic driver) should be cast to the ash heap, audio amplifiers have been re-looked at so many times that it’s run out of steam.

How it works… further reading:  Loudspeaker types


NCAP Vs Driver Safety Vs Safest Cars on the Road

Although there is no doubt that cars with high safety standards are a feather in the manufacturer’s cap it can also be said that many argue about the reliability of some of these cars and indeed, gauging by the number of comments posted by readers on some of the safety reviews, whether statistics are biased or somewhat ambiguous.

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We don’t believe that these stats are wholly skewed though as cars with a higher safety spec, often the German marque, do reflect a lower incidence of drivers and passengers succumbing to injuries in the event of an accident. The argument is often more about the vehicle size than safety. The argument is based on smaller cars causing more injuries. Our argument is that it is very seldom the car but always the driver – cars don’t cause accidents, drivers do. Guns don’t shoot people – people do. A driver is not legally entitled to drive a vehicle which is not roadworthy, neither under the influence of narcotics or alcohol.

Safest Cars Vs Safest Drivers

Not wearing a seatbelt is considered illegal in most countries and provinces. A question arising here is whether seatbelts and airbags are interlinked. Of course they are. This question comes up quite often and here we have another dilemma – why aren’t learner drivers taught this at driving school? Any person taking to the road for the first time should have been taught about the differences between AWD, FWD and RWD vehicles, stability and traction control, ABS,  wet weather driving, gravel roads, speed, under and over steer, overtaking and HP versus torque. Not just where the pedals, horn and indicators are located. We know that talking and texting over a cell phone is not a legally entertained practice but what about eating and drinking in a moving car? We need to get this right first and then can talk about what can happen in the event of an accident.

Motor cars are dangerous beasts and the faster one drives the less chance occupants of a vehicle will get out alive in the event of an accident. Which accidents are worse, head on collisions, side or T-boning, rear-ending, overturning or landing in the drink? Most accidents can be avoided by taking the defensive driving approach which then of course includes driving within the speed limit and thinking ahead. Ever notice how some drivers speed up when it rains? Often AWD vehicle drivers are the worst transgressors. And small pickups (empty) with very little traction on the rear wheels.

Driving the Driver

According to the more technical, modern motor cars are driving the driver – the driver becomes reckless knowing that his car can pull him out of a tight spot. This is a dangerous take on any situation.  Motor cars all have a safety margin of safety and a head on collision at 100 mph is not one of them. Braking hard at 100 mph may be fine in a Mercedes AMG but not in a 1995 Ford Escort. Driving under a truck with both vehicles will not leave much behind even at 50 mph. NCAP ratings don’t necessarily expect one to drive under a truck.

Safest Cars - Volvo
Volvo S90 – Manufacturers making a difference

The safest cars on the road today are often the most unreliable. Well this is a view from many armchair critics and gauging by the amount of negative publicity that certain cars have produced it’s an easy conclusion to come to but truth be told we don’t know how often the car gets serviced, how it is driven and neither the condition of the roads.  What we do know is that if one specific car can get 300 000 miles and another of the same type only 20 000 then we need to look at the driver and of course, the old theory about Monday cars. The fact is that modern cars are more reliable than older cars.

Feeling safe with AIDS

Stability control is a proven life saver for countless amount of drivers in SUVs but we’d rather know that the driver is aware of the risks of driving a high center of gravity vehicle at speed rather than him or her relying on an aid. Because that is what it is, an aid. An airbag may save your life but it is useless without a safety belt. Which brings us to the last point: driver safety.

Cars do not lose control, drivers do. Stick to the speed limit, don’t drive intoxicated or suffering from fatigue, adhere to the road traffic signs, keep off dangerous roads, slow down in the rain, ensure that your car is roadworthy and yes, checked by the AA once per year, play by the rules, be courteous, be watchful and alert and then you may be surprised to find that NCAP doesn’t really mean much at all.

The world’s safest cars are only as safe as the driver.






How to become lazy by doing things!

“We often miss opportunity because it’s dressed in overalls and looks like work” – TA Edison

Loading the latest piece of freeware that looks like AutoCAD but isn’t I was enthralled by the complexity, the genius of the software engineers and the ease of use. Much, much later I realised with dismay that we had friends coming around for dinner. Why is it we always friends around for dinner when I am testing out new software? Interestingly enough I am not a design engineer but this software had me enthralled. One month later it still had me wrapped around it’s finger of bits and bytes.

In that month I could have built a bird cage, rebuilt my old Ford engine, gone to the movies, reconnected with old friends and even re-landscaped my garden. I didn’t though because I was stuck behind the screen, as my brother calls it, in “Crouching Tiger, Hidden Dragon” mode.  Computers are interesting that way, they make us damned lazy. Unless you are using your computer to make money like many do most of us are captivated by the ease of use,  games and other novelties. We use it to “Google” and “Wiki”, we use it to paint, draw and write. We use it to communicate and write blogs, post pictures and troll. All of this at a price.

A computer is a very useful tool in the right hands. It was designed for the user to capture and manipulate data, it was designed to be a tool. Now we have become the tool. We communicate less effectively, we no longer write and we certainly don’t feel the urge to do something constructively once we sit down to jot our memoirs on Facebook. In short we have become freakin’ lazy.  Instead of using time at work constructively, as one is paid to do, we What’sApp friends and family. We “Google” for easy fixes – as if the page will jump out and fix the kettle. There are three things a person needs to know about your common and garden kettle – it has an on/off switch, it heats water and it will make a noise when the water boils or switch off automatically. How many people “Google” for a rapid fire response when their kettle fails. I do! Most probably so do you.

I recently watched a technical video on how to strip and repair an automatic gearbox. I learnt a lot and now when we talk gearboxes I can with absolute authority maintain my own in any conversation. How many people out there are like that?  Those same people have never wielded a spanner nor know the difference between metric and imperial. If ever there is an industry which has been most hard hit by the internet it must be the IT industry. There are now so many computer technicians floating around I wonder often whom is growing the beans? With a few key-strokes and a click of a button we find out which university degrees are hardest to get, read up a little and then become experts.

A few years back I needed some forms to be printed. The lady doing the job dropped the completed forms off and told me with a voice of authority that I need to check my grammar in future. I felt my stomach drop through my butt. She used spell and grammatical usage with what Word had decided and used that instead. One thousand forms written in Computer English.  How many times does one read of the word “loose” being used instead of “lose” and the other favourite, “witch”. Writing a blog now has become rather simple nowadays because most people reading the content will only read one paragraph. I do this with emails, skip over most of the content and think I have enough information to generate an accurate reply.

One wonders how much the use of a computer, the switching on of a TV receiver or the playing of games on a tablet has lead to diabetes and heart disease?  We sit behind a computer these days and do things. That’s what I do. Each and every day. I thought I was the only one until I looked across the sales floor.

I envy those that fix automatic gearboxes and landscape gardens.

“Progress isn’t made by early risers. It’s made by lazy men trying to find easier ways to do something.” sci-fi author Robert Heinlein


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