So last year Focusrite decided to change their range of 1st gen Scarlett series to 2nd generation and I found myself looking at my older 18i20 unit which had just lost a couple of bucks in value.
Scary stuff, but not as scary as vehicle depreciation. So the question that arises is does one sell now, get new or hang on? This is a dilemma which we all face at some time or another. The solution is usually to use common sense and logic. Team marketing hope that you have neither. Continue reading “Upgrading to the new Mixer or Mic-preamplifier”
Building electronic circuits is a fascinating pastime and if not your profession many new adventurers find the world of SPICE (Simulation Program with Integrated Circuit Emphasis), building PCBs (Printed Circuit Boards) and getting a professional finish rather scary. And expensive!
Firstly, your best friend is your computer. Many years back Joe Inventor was the amateur radio Ham. Our biggest and best supplier of electronic components in the Western Cape was then of course Hamrads. Continue reading “Building circuits and PCBs”
The group Live will be performing at the Grand West Arena on the 7th November. Rumour has it that Ed Kowalczyk will be appearing with them as lead vocalist – remember him, he that went solo for a while. Although Chris Shinn replaced him after 2012, Ed is back.
Audiophile Class D – Part Two – Practical Examples
Just before we get started, Kenneth, a reader wants to know why if we claim to be “Analogians” why we keep on harping on Class D? I think an explanation by way of clarification is necessary.
Kenneth, although the name of the website is a play on words, my name is Ian, we do understand the importance of digital electronics. Actually just as important and in many cases more so than analogue. I do not think that a switching amplifier is indeed a digital device even if the PWM and switcher itself are controlled by DSP. The raw class D amplifier has a triangle waveform generator, a comparator and PWM. If digital is all around bit-rate and 0s and 1s at a predefined 5V level then this is surely not digital. Just as if a rail shifting amplifier can be made to switch to various voltage levels through a digitally controlled switch it does not necessarily make the amplifier a digital one. What does seem to be the tendency is that switching amplifiers are being termed more “digital” now than ever and this is going to stick. Possibly we do need to have a more inventive description however.
In today’s throwaway world it becomes enticing to purchase something cheaply because either you are cheap 🙂 or more importantly, if it doesn’t work you can just trash. There is of course a cut off point to what is cheap. A student may baulk at paying R200.00 for a gadget which Joe, the JSE executive would not dream of buying, opting for the Apple equivalent instead.
We will refer here to electronic goods and of course, the South African market.
The purist may rate the ultimate audio amplifier as being a straight piece of wire with gain. Possibly driving his or her Sennheiser HD800s. In South Africa this may well put you back R40 000.00. Maybe it’s time to put aside the Woo Audio, Schiit or Linear Tube and take a listen to Class D. On real speakers.
And now for the world’s most famous IC – the 555 Timer
This Signetics – Hans Camenzend IC was not just a best seller but for electronics specialists possibly the most versatile chips of it’s time. Possibly still is. What was most intriguing was that for any youngster just starting out in electronics, this was an experimenter’s dream. It was low cost and with just a handful of components one could learn one helluva lot about oscillators (astable or free-running), bistables and monostables. Of course it could be used for a lot more than just a police siren.
If you read the previous article on how quickly we can become deaf through negligence or just plain stupidity (like this scribe) I have managed to get some gems together for the DIY types.
Firstly, for those wanting to repair car amplifiers, Perry Babin has done an incredible job in keeping to the facts and make his tutorials available for free or chargeable as a download. There has been a lot of time and effort going into this so full marks to the author for doing such an amazing job. I guess the best way to get started is from this link: Basic Car Audio Electronics. Continue reading “Car Audio – More on amplifiers and SMPSU”
Some scientific types believe that the walls of Jericho fell because of resonance. In a few years from now we are going to be seeing a lot of hearing loss amongst generation-Y and Millenials. Generation Baby Boomer may well be exempt except for the musician variety. Many musicians today suffer from tinnitus. The frightening aspect to all of this is that it can happen to anyone, especially those subject to loud music on a day to day basis. When wearing headphones on a day to day basis one would think that a feedback system would warn the user when dangerous SPLs are being generated but no.
Above: If this is what the Yellow Pages looks like after a few seconds imagine the guy’s cochlea.
The problem with headphones is that we do have a tendency to use them at a level which may not seem uncomfortable at first but will cause damage over a prolonged period. And one doesn’t know until one day you find yourself asking someone to repeat what they have said. Over and over again.
I touched on the subject of Jericho specifically because of the ease at which large structures can be made to resonate and cause untold damage. The human body can be broken down to various sub-parts each with it’s own resonance and the chest and surrounds are believed to be at that very frequency where our modern car audio culture is aiming – deep high powered bass. Okay, this is opinion only, I am not a scientist neither the most knowledgeable about the human anatomy. There has been research done in this field and it seems credible that high powered audio will not only damage your hearing but other parts of the body as well. In fact disintegration is highly likely.
Audio Outputs for auto sound
In the 70s car audio would in all likelihood be working around powers of about 4.5W RMS into a 4 Ohm load using our wonderful formula (Vcc * Vcc) / 8RL. Supply rails at 12V. At 13.8V we are looking at about 6W, 12W into a 2 Ohm load and 48W bridge tied into 2 Ohms. The thing is I don’t really recall many car audio systems being bridge tied until the 80s. 20W into 4 Ohms was more or less the norm and this was loud enough. Why then ramping the supply rails up to +40/-40V and into a 2 Ohm load? Marketing is a fairly reasonable assumption. Youngsters of today compare sound systems and the likelihood that they are making comparisons based on quality rather than raw power is negligible. Power is king.
Upholstery sound killer
Upholstery kills the high notes. We do not have a pre-emphasis feedback system which will crank these registers whilst applying attentuation to the bass. Listening to rap music at the traffic intersection is a case in point. Loud belching, farting, burping like sounds emanating from the car next to you is not uncommon. The thing is, and I mean this in all sincerity, what is it doing to you listening to that hellfire and brimstone spitting sound system? Having good acoustics is the first point of action.
Insane power levels
To Mom and Pop 10W per channel was more than sufficient and when they hit their 70s and if they were in good health their hearing mechanisms were usually intact.
New York band Manowar hit the SPL charts a few years back when they reportedly spewed out enough power to push dB meters to nearly 130dB. This is insane. Car audio enthusiasts see this as small puppy. Pushing levels to nearly 140dB at a few hundred Hz is common. And they drive playing at this level?
Our conversation level is usually at around 60dB, jackhammer at around 105dB and explosive power tools at around 120dB (nail guns). Ford Bronco with a 48kW sound system generating an SPL of 175dB? Utter madness.
Marketing the stuff
Ironically the best audio is found in luxury vehicles. Money spent on quality and not quantity.