SPOTIFY: How does it calculate loudness?

” We currently use ReplayGain, which was the most recognized standard for calculating loudness when Spotify first started. In the future, we plan to use a new standard for calculating loudness, called ITU 1770 (from the International Telecommunication Union). This defines the integrated LUFS (Loudness Units Full Scale) measure, and it’s what we recommend you […]

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UNDERSTANDING: Balancing EQ and ketchup

PS AUDIO / Paul McGowan In just about every commercial recording studio in the world, (and most every recording you hear) the practice of EQ’ing is commonplace: correcting problems like unwanted background noise, microphone imbalances, and other anomalies that affect the clarity and quality of sound. Unfortunately, like ketchup, salt, pepper, and other condiments, it […]

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USB Digital Microscope: How to use it to set 92 Degree Stylus Rake Angle (SRA)

Analogue Planet write …. The stylus rake angle is the angle the stylus’s “contact patch” makes to the record surface. If you have a relatively inexpensive cartridge with a spherical stylus you don’t have to worry about SRA because the contact area remains the same regardless of arm height. On the other hand, elliptical styli […]

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ANDREW SCHEPS: Lost in Translation – Audio Quality in Streaming Media

Lost In Translation with Andrew Scheps provides an engaging, revelatory and humorous presentation of current audio format comparisons. The demonstration showcases the auditory differences of master recordings played back in different formats such as vinyl, CD, MP3, AAC and online streaming models. Scheps (http://www.uaudio.com/blog/artist-int…) has engineered and mixed for some of the biggest acts in […]

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Quill

VALVE Magazine Online! Tech tips and other unsolicited advice. The 75 Minute Restoration

From VALVE Volume 2 Number 7 July 1995 Bill called a couple Saturdays ago to tell me that he had traded a Mac 1700 (a hybrid receiver, with tube tuner and solid-state amp) for a Scott 340 receiver. The person he traded with acknowledged a greater value for the Mac than the Scott and offered […]

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PS AUDIO: Balanced is better

Paul McGowan writes … In my mind, there’s no question that between components the best connection is balanced. Balanced cables offer lower noise and better sound. I understand there are single-ended holdouts (wait, we disagree on something in audio?). Perhaps their equipment doesn’t support balanced. Perhaps their cable collection doesn’t include balanced. Or maybe they […]

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BENCHMARK AUDIO: Application notes – Rules of Thumb for Music and Audio

John Siau writes: As an engineer I like to use “rules of thumb” to make quick estimates that help explain what can be expected from the physical world around me. These rules of thumb are easy-to-remember approximations that eliminate the need for complicated and needlessly precise calculations. If you learn a few key rules of […]

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BENCHMARK: Audio application notes – Intersample Overs in CD Recordings

John Siau writes: We have frequently used Steely Dan’s Gaslighting Abbie from Two Against Nature in our listening tests. This is a spectacular CD recording with lots of dynamics and a low noise floor. Nevertheless, in a little over 5 minutes, this track has 559 intersample overs on the left track and 570 on the right track for a total […]

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TECHNICAL: Popping noise on turn off

Q: Hello Colin. The unit in question is a Lafayette 4 channel decoder. When turning off my system, there is a popping noise from the rear speakers unless I turn the volume down on the decoder first (I’m only using the rear outputs). I’d like to eliminate the problem. I’ve searched bypass capacitor and coupling […]

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BENCHMARK: Audio application notes – Interpreting THD Measurements – Think dB not Percent!

John Siau writes: Distortion measurements (THD, THD+N and IMD) are traditionally expressed in terms of percent. But what do 1%, 0.1%, 0.01% or 0.001% mean in terms of loudness or audibility? If you are like most people you just know that 0.001% is the best of the three numbers listed above. If you are a well-trained […]

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MAINS TRANSFORMERS: Step-down transformers with unchanged mains frequency?

Hi Colin, Pls can you help me? Can I safely run a USA spec amp designed for 110v 60Hz in the UK on 240v 50Hz, with a step down transformer (but it will still be 50Hz). So many conflicting views across the web. I think a lot of people believe it can work ok the […]

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UNDERSTANDING: Streaming

PS AUDIO / Paul McGowan There are tons of misconceptions and even a few audio myths growing around the subject, so I think he’s right. Today we will start with a simple overview, then dig in a bit deeper in the days to follow. Creating a seamless streaming music experience requires a well-designed system comprising […]

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OUTPUT TRANSISTORS: What is it that causes them to blow?

Dear Colin, Generally speaking, what is it that causes output transistors to blow? Do they tend to die a natural death? Bad drivers? Emitters? Problems with the rectifier circuit? Assuming there wasn’t shorted speaker wires or excessive moisture. The amp bias and the +/-77 voltage was fine before they blew. It happened on power up. […]

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AUDIO INSIDER

SPECIFICALLY: McIntosh transformers

PAUL McGOWAN: A recent post covered output transformers on tube power amplifiers and why they were needed.  It also covered the fact that IMHO transformers are the last thing I would add to the output stage of a solid state power amplifier because output transformers like this contribute so much to the sound quality of […]

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STAR EARTHING: What is it and what’s the point?

Hello Howard. Can you ask Colin please what is star earthing and does he / will he using it in his new designs? Ta muchly J.N Peterson {Colin} Dear J.N.Peterson star earthing should be used in all analog designs, that is a single zero or earth for every component on the circuit board and normally […]

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AUDIO INSIDER

SOME MAKERS WILL HATE THIS: How does one measure the differences between amplifiers when they clearly sound different?

How does one measure the differences between amplifiers when they clearly sound different? The first and simplest measurements are frequency response and noise levels: frequency response shows us that everything we put in makes it through to the output and noise levels are an obvious thing to measure so we don’t have hiss. Fancier measurements […]

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POWER LINES: The dedicated ones

Paul McGowan: If you’re serious about building a high-performance audio system you have to pay attention to the AC power. It’s a constant theme with me because power is the foundation of our systems. There aren’t many great structures standing on weak foundations. Power Plants solve many problems but they need a head start. One […]

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MARANTZ / ROWLAND: Classic 9 + Rowland Coherence, hot pins on XLR connectors.

Can I use other tubes than the EL34s on the Marantz 9s? The amps themselves and the manuals are marked with those specific tubes. So I don’t know if tube rolling would create problems. If you feel it’s technically possible and advantageous, what would you recommend in connection with the Quads?  Also, a phase issue […]

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PS AUDIO: Why haven’t these (switch mode power) supplies been used to better advantage?

Paul McGowan … Perhaps the single biggest reason to use a switch mode power supply (SMPS) on a power amplifier is that the output of a properly designed one is more like perfect DC than that of a conventional supply; and not just by a little bit. Conventional supplies switch back and fourth between plus […]

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