The de Havilland Mosquito Rolls-Royce Merlin Engine.
Thursday, 17 June 2021
Thursday, 10 June 2021
Israeli Iron Dome Anti-Missile Defence in action
I found this video posted on Facebook.
Cleaned it up a bit.
Monday, 7 June 2021
"I don't want to hurt the small birds..."
If ever, you experience a less comfortable take-off from a commercial airport than usual, please consider that the Airline Captain might be busy avoiding small birds.
Thursday, 27 May 2021
Fender Passport Powered Mixer, Power Supply From Hell
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| Fender Passport PD-500 |
This 500W per channel portable Mixer/Amp is now back up and running.
After the service agents declared the equipment US (un-serviceable), I decided to give it a go, since I have the time and don't have to make a living fixing blown-up switch-mode power supplies.
It's a tough one, for a technician. The failure is often very destructive which makes it hard, if not impossible to do a repair/reconstruct financially viable.
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| Exploded capacitor remnants |
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| Incorrect value capacitors ill-fitted |
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| Where the failure started, creating a domino effect of cascading failures |
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| Circuit diagram indicating points of failure |
The Fender Passport PD-500 in particular is a rather complex design. Repairs are usually done by board replacement, which is prohibitively expensive, which relegates too many PD-500's obsolete.
They can be fixed however.
Sometimes:)
Monday, 17 May 2021
Cambridge Audio azur 540R AV - Service and Repair
A great 6 x 100W channel Audio Video Amplifier
with DSP (digital signal processing) that supports Dolby Surround 6.1
Optical / Analogue / Composite Video and 6 x Speaker connections
Despite the fact that the amplifier was working fine, it was manufactured in 2005 and a full checkout was a good idea.
As it turned out, there were a number of issues with the Amp.
Faulty or degrading electrolytic capacitors are one of the main reasons old electronic audio equipment fails.
Disassembly in progress...
After replacing the capacitors below, the amplifier was reassembled but went into overload protection mode.
One side of a resistor was not soldered into place for some reason.
Having repaired and checked the headphone board did not resolve the problem completely though.
The Amplifier now worked using headphones but went straight into overload protection mode when the phones were unplugged.
I did what I usually do: studied the circuit diagram and then gave myself time to think.
Since the protection circuit monitors output data prior to the output relay isolation and muting circuits - the issue lies somewhere between the amplifiers output jumpers from the main board and the speaker binding posts.
After a second strip-down and inspection of the speaker printed circuit board (PCB), a previously botched repair job was evident.
The PCB was repaired, re-soldered and cleaned up.
After a provisional assembly the amplifier tested OK.
Final assembly and complete workout:
A complete assembly was done, and all systems (except composite video) were fully tested.
Analogue, optical, Stereo, Dolby Digital-EX/DTS ES, Pro LogicII/Neo 6 and all DSP modes were tested and passed.
The 6.1-pre-amp sub-woofer also tested OK - including sub-sonic.
The Cambridge Audio azur 540R AV is back in service with 600W of Dolby 6.1 Surround Audio excellence.
Wednesday, 17 February 2021
Vox AD30VT guitar amp motorboat? You are not alone!
It can be fixed, apparently.
Read the comments section. But not for long I'm afraid to say.
My suggestion, sorry my question actually: what made you buy one of these?
Monday, 15 February 2021
Friday, 5 February 2021
Friday, 22 January 2021
Gypsy guitarists Tommy Emmanuel & Joscho Stephan
And just for a speed comparison: Michael Angelo Batio. He shouldn't be in the same post though, me thinks.
A friend pointed my in the direction of Joscho Stephan a Gypsy Jazz Guitarist...
Reminds me of Django Reinhardt & Stéphane Grappelli
Here is Django Reinhardt circa 1945
Phil (Wings of Pegasus) is a British Guitarist, Teacher and Reviewer with 42,435,345 views on YouTube (Jan 2021)
Phil is highly recommended.
Despite his obvious success on YouTube, Phil is modest, kind and fair.
One of the best music-performance reviewers I've come across.
I get the idea that his motto is, "First do no harm."
Antoine Boyer, "Scarlatti Sonata K386 on my homemade guitar"
Antoine Boyer, "It took me 7 years to build this classical guitar following the great advice of the luthier Yohan Cholet. Starting in 2012 I was expecting to finish it the following year... Life isn't always what we expect and that's for the best ! These 7 years were such an amazing adventure having time with Yohan and his family. And that's surely the most beautiful part of the guitar!
Cedar top - Indian rosewood body - Walnut neck"
Brian May's Fantastic Guitar Solo
"More than 50 years playing guitar with a more than 50 years old home made guitar it’s fantastic" - YouTube comment.
It's Brian May's technical knowledge of the whole sound processing chain, from finger to ear, that evolved into this wonderful timbre, so distinct that it takes only a second or two to recognize the "Queen" sound.
Brian May's Nine Vox AC30 Amplifiers On Stage
Vox AC30 (circa 1963)
My favorite Tube guitar Amp.
I enjoy restoring them more than any other Amps that I work on. Probably on account of the relationship the musicians develop with these gems over the years.
Liliac - Holy Diver - (Official Cover Music Video)
5-piece Los Angeles-based, family Rock/Metal band, “Liliac” has sparked the world by storm. This female-fronted band consisting of all siblings’ ages 12-21 has brought a unique and fresh sound they call “Vamp Metal”. Liliac first came into the scene by covering famous/popular rock and metal songs, which went viral on all social media platforms. They began writing hook-heavy original material with their father producing and recording in his home studio. They released their first EP “Chain of Thorns” in 2019, which hit #1 on Amazon’s Best Seller for Rock Music Charts. In the summer of 2019, their first North American tour consisting of 40 dates brought in thousands of fans and sold-out shows, which was a huge success for the band. With their youth, passion and hard work, you will hear more about them because they are here to impact the world!!!
Marcin Patrzalek - What Happens Now? - Q&A (Nov 2019)
Marcin Patrzalek - An Internet sensation at a young age, his videos amassed over 150+ million views before he turned 19.
In January 2020 Marcin got signed by Sony Music making him one of the first percussive guitarists to sign with a major label.
Marcin Patrzalek - Toxicity (System of a Down) on One Acoustic Guitar - His First Official Video Published On Youtube
"Marcin is a young guitarist, arranger, writer and producer. He is known for combining percussive guitar techniques with modern electronic production. An Internet sensation at a young age, his videos amassed over 150+ million views before he turned 19. He won two major talent shows in Europe (Poland, Italy) and reached mainstream audiences through his performances in America's Got Talent. His creations borderline the impossible - arranging full symphony orchestral pieces onto one guitar, combining hip-hop production with instrumental guitar music, and jumping between classical, flamenco and hyper modern influences. Among Marcin's most popular creations are his arrangements of Beethoven's 5th Symphony, Moonlight Sonata, Still D.R.E. and many originals." - YouTube.
Thursday, 21 January 2021
Wednesday, 20 January 2021
Stand-up comedians - I cannot stand them. Except for Woody Allen and Dylan Moran.
A selection of Woody Allen’s work is published here to remind us that it is not necessary to be obscure, obscene, or gross to attract attention. Just be human.
Stand-up comedians - I cannot stand them. Except for Woody Allen and Dylan Moran.
A selection of Woody Allen’s work is published here to remind us that it is not necessary to be obscure, obscene, or gross to attract attention. Just be human.
Stand-up comedians - I cannot stand them. Except for Woody Allen and Dylan Moran.
A selection of Woody Allen’s work is published here to remind us that it is not necessary to be obscure, obscene, or gross to attract attention. Just be human.
Stand-up comedians - I cannot stand them. Except for Woody Allen and Dylan Moran.
A selection of Woody Allen’s work is published here to remind us that it is not necessary to be obscure, obscene, or gross to attract attention. Just be human.
Stand-up comedians - I cannot stand them. Except for Woody Allen and Dylan Moran.
A selection of Woody Allen’s work is published here to remind us that it is not necessary to be obscure, obscene, or gross to attract attention. Just be human.
Stand-up comedians - I cannot stand them. Except for Woody Allen and Dylan Moran.
A selection of Woody Allen’s work is published here to remind us that it is not necessary to be obscure, obscene, or gross to attract attention. Just be human.
Stand-up comedians - I cannot stand them. Except for Woody Allen and Dylan Moran.
A selection of Woody Allen’s work is published here to remind us that it is not necessary to be obscure, obscene, or gross to attract attention. Just be human.
Stand-up comedians - I cannot stand them. Except for Woody Allen and Dylan Moran.
A selection of Woody Allen’s work is published here to remind us that it is not necessary to be obscure, obscene, or gross to attract attention. Just be human.
Stand-up comedians - I cannot stand them. Except for Woody Allen and Dylan Moran.
A selection of Woody Allen’s work is published here to remind us that it is not necessary to be obscure, obscene, or gross to attract attention. Just be human.
Stand-up comedians - I cannot stand them. Except for Woody Allen and Dylan Moran.
A selection of Woody Allen’s work is published here to remind us that it is not necessary to be obscure, obscene, or gross to attract attention. Just be human.
Stand-up comedians - I cannot stand them. Except for Woody Allen and Dylan Moran.
A selection of Woody Allen’s work is published here to remind us that it is not necessary to be obscure, obscene, or gross to attract attention. Just be human.
Stand-up comedians - I cannot stand them. Except for Woody Allen and Dylan Moran.
Except for Woody Allen, who's work I publish here to remind us that you don't need to be obscure or obscene or gross to attract attention. Just be human.
Stand-up comedians - I cannot stand them. Except for Woody Allen and Dylan Moran.
A selection of Woody Allen’s work is published here to remind us that it is not necessary to be obscure, obscene, or gross to attract attention. Just be human.
Stand-up comedians - I cannot stand them. Except for Woody Allen and Dylan Moran.
A selection of Woody Allen’s work is published here to remind us that it is not necessary to be obscure, obscene, or gross to attract attention. Just be human.
Stand-up comedians - I cannot stand them. Except for Woody Allen and Dylan Moran.
A selection of Woody Allen’s work is published here to remind us that it is not necessary to be obscure, obscene, or gross to attract attention. Just be human.
Stand-up comedians - I cannot stand them. Except for Woody Allen and Dylan Moran.
A selection of Woody Allen’s work is published here to remind us that it is not necessary to be obscure, obscene, or gross to attract attention. Just be human.
Stand-up comedians - I cannot stand them. Except for Woody Allen and Dylan Moran.
A selection of Woody Allen’s work is published here to remind us that it is not necessary to be obscure, obscene, or gross to attract attention. Just be human.
Stand-up comedians - I cannot stand them. Except for Woody Allen and Dylan Moran.
A selection of Woody Allen’s work is published here to remind us that it is not necessary to be obscure, obscene, or gross to attract attention. Just be human.
Stand-up comedians - I cannot stand them. Except for Woody Allen and Dylan Moran.
A selection of Woody Allen’s work is published here to remind us that it is not necessary to be obscure, obscene, or gross to attract attention. Just be human.
PayPal
What can I say? Paypal is a nightmare...
However, someone at PayPal support cared enough to persist and sort out the technical difficulties associated with a PayPal account linked to a FNB bank account.
Friday, 8 January 2021
Testing out an Ibanez TSA-30 after repair
An Ibanez Tube Screamer guitar amplifier, on account of its unreliability and propensity to hum, came into the workshop for investigation and repair.
It became apparent that the engineers decided to compromise on the way the amplifier provides power to the valve pre-amplifier stages and the solid-state signal processor.
Proposed changes to the circuitry were modeled, prototyped and implemented.
I invited Greg Gunther, an astute musician and teacher, to answer the client's question, "Is the amplifier bullet proof?"
The recording was not rehearsed and done in a single take with the amplifier set to run between 70% to 90% of its rated output power of 30W.
No equalization, filters or soft clipping were used, in the post processing.
Wednesday, 6 January 2021
Friday, 18 December 2020
Welcome to Point Systems Audio
Welcome!
Over time I will publish any interest that I wish to share and Audio Technology projects from the recent past to the present.
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