Revolutions Per Minute

    Martin Theophilus of The Museum of Magnetic Sound Recording, Part Two

    Martin Theophilus is the Executive Director of the Museum of…

    Around the World in 80 Lathes, Part Five

    In our previous episodes, we had a good look at…

    Around the World in 80 Lathes, Part Four

    In previous installments (Issue 151, Issue 152 and Issue 153), J.I.…

    Around the World in 80 Lathes, Part Three

    In previous installments (Issue 151 and Issue 152), J.I. Agnew…

    Around the World in 80 Lathes, Part Two

    Writing about the history of disk recording lathes poses a…

    Around the World in 80 Lathes, Part One

    Audiophiles and record collectors often obsess about what kind of…

    The DMM Dubplate, Vol. 1 and the Art of Pushing the Boundaries, Part Four

    Parts One, Two and Three of this series appeared in…

    The DMM Dubplate, Vol. 1 and the Art of Pushing the Boundaries, Part Three

    Part One and Part Two of this series were published…

    The DMM Dubplate, Vol. 1 and the Art of Pushing the Boundaries, Part Two

    In the previous episode (Issue 147) we dived into my…

    The DMM Dubplate and the Art of Pushing the Boundaries, Part One

    Before I begin writing about the DMM Dubplate Vol. 1…

    Martin Theophilus of The Museum of Magnetic Sound Recording, Part Three

    Martin Theophilus is the Executive Director of the Museum of Magnetic…

    Around the World in 80 Lathes, Part Six

    In previous installments, this series examined Neumann disk mastering systems,…

    Martin Theophilus of The Museum of Magnetic Sound Recording, Part One

    Martin Theophilus is the Executive Director of the Museum of…

    The Giants of Tape, Part 10: The Telefunken M15A, Part Four

    Part One, Part Two and Part Three of J.I. Agnew’s look at…

    The Giants of Tape, Part Nine: The Telefunken M15A, Part Three

    Part One and Part Two of J.I. Agnew’s look at…

    The Giants of Tape, Part Eight: The Telefunken M15A, Part Two

    In the previous episode (Issue 140), the Telefunken M15 and…

    The Giants of Tape, Part Seven: The Telefunken M15A, Part One

    To follow a few installments dedicated to Ampex (Issues 136…

    The Giants of Tape, Part Six: the MCI JH-110, Part Two

    In the previous episode, we talked about the merits of…

    The Giants of Tape: The MCI JH-110, Part One

    In the last few installments in this series, California was…

    The Giants of Tape, Part Four

    This time we’re going to have a look at another…

    The Giants of Tape, Part Three

    In Part One (Issue 134), J.I. Agnew profiled the legendary…

    The Giants of Tape, Part Two

        Ampex doesn’t really need much of an introduction.…

    Around the World In 80 Lathes, Part 17

    In the previous episode (Issue 166), we looked at the…

    Around the World In 80 Lathes, Part 26

    Our next destination on our lathe journey remains along the…

    Around the World In 80 Lathes, Part 25

    After visiting Denmark over the last couple of episodes (Issue…

    Around the World In 80 Lathes, Part 24

    J.I. began his overview of Danish-made Lyrec record cutting lathes…

    Around the World In 80 Lathes, Part 23

    Having visited Japan and their disk recording lathes in previous…

    Around the World In 80 Lathes, Part 22

    Over the last several episodes, we have traveled to different…

    Around the World In 80 Lathes, Part 21

    In the previous episode (Issue 170), we looked at the…

    Breaking News: HD Vinyl Enters Bankruptcy (and Some Thoughts On Vinyl Manufacturing)

    Over the past 130 years or so, very little has…

    Around the World In 80 Lathes, Part 20

    By the 1970s, disk recording had pretty much disappeared from…

    Around the World In 80 Lathes, Part 19

    Those among our readers with an interest in photography will…

    Around the World In 80 Lathes, Part 18

    When it comes to the preservation of vintage technology, the…

    The Giants of Tape, Part One

    Tape machines have been made in various shapes, sizes, forms…

    Around the World In 80 Lathes, Part 16

    It has been quite a while since 1989, when professional…

    Around the World In 80 Lathes, Part 15

    At this point in our lathe appreciation journey, I feel…

    Around the World In 80 Lathes, Part 14

    Previous installments discussed various design approaches to record lathe cutter…

    Around the World In 80 Lathes, Part 13

    Previous installments discussed various design approaches to record lathe cutter…

    Around the World In 80 Lathes, Part 12

    In our previous episode (Issue 161), we discussed the “lightweight”…

    Around the World In 80 Lathes, Part 11

    Cutter heads for record-cutting lathes have come in various shapes…

    Around the World In 80 Lathes, Part Ten

    Previous installments covered the earlier history of Neumann and Scully…

    Around the World In 80 Lathes, Part Nine

    Previous installments covered the earlier history of Neumann lathes. Neumann…

    Around the World In 80 Lathes, Part Eight

    Introduced in 1970, the Neumann VMS-70 was the result of…

    Around the World in 80 Lathes, Part Seven

    The last episode in this series (in Issue 156) discussed…

    An Ode to Cassette Tape: Part Two

    When thinking of the ultimate cassette deck, many people think…

    Vinyl and Absolute Polarity: Q&A

    Bob Lehman, a classically-educated retired electrical engineer and long-term audiophile,…

    For the Record: Restoring a Vintage Disc Cutting Lathe

    A customer recently imported a vintage Presto 75A disk recording…

    Vinyl and Absolute Polarity: A Technical Exposition

    One might think that the whole issue of absolute polarity…

    How to Lie with Measurements

    In view of my recent series on linearity and other…

    Linearity in Audio, Part Three

    Up to now we have only talked about the most…

    Linearity in Audio, Part Two

    Another common usage of the term “linearity” in electronics refers…

    Linearity in Audio, Part One

    In my previous article on vacuum tubes in Issue 103,…

    Secrets of the Phono Cartridge, Part Two

    At the heart of all phono cartridges we will find…

    Secrets of the Phono Cartridge, Part One

    Phonograph disc reproduction cartridges (phono cartridges as they’re known to…

    Vacuum Tubes: A Brief History

    Vacuum tubes, also known as thermionic valves, or just valves…

    Vinyl and Absolute Polarity: Q&A, Part Two

    In Part One of this dialog between J.I. Agnew and…

    An Ode to Cassette Tape – Part One

    I still remember how, as a very young boy, I…

    Variations on a Theme of 1/4-Inch Tape

    In our previous episode, we had a look at the…

    The Multiple Facets of Magnetic Recording: A Brief History

    Grooved media – phonograph cylinders, gramophone records and so on…

    How Do We Get It Out Of There?

    As we have examined throughout several previous issues of Copper,…

    From The Cylinder To The Disk Record…And Back?

    When the first demonstrations of sound recording and subsequent reproduction…

    Screws, Machine Tools, and the Invention of Sound Recording

    How are the ancient Egyptians, Archimedes, Leonardo Da Vinci, and…

    How Records are Made, Part 3: Quality Control

    The telephone rings. “We have a few pallets for you,…

    How Records are Made, Part 2: Plating and Pressing

    The disk mastering stage, discussed in detail in the previous…

    How Records Are Made, Part 1: Disk Mastering

    As mentioned in our previous column in Copper #91, the…

    The Sound of Recorded Music

    Different time periods in history are associated with particular architectural…

    Eight Decades of Wrong Assumptions: The Loudness Wars

    Let’s cut straight to the chase: Who won the loudness…

    The Big Move, Part Three

    In Part One and Part Two, J.I. Agnew wrote about the…

    The Big Move, Part Two

    In Part One (Issue 131), J.I. Agnew wrote about the…

    The Big Move, Part One

    Ten years ago, I moved to a new building carrying…

    The Story of a Vintage Piano, Part the Second

    In Part One, J.I. Agnew began his search for the…

    The Story of a Vintage Piano, Part the First

    In previous issues I have gone into some detail about…

    Vintage Tube Amplification During a Lockdown, Part Two

    In Part One, (Issue 127), J.I. told us about being…

    Vintage Tube Amplification During a Lockdown, Part One

    There are some things that you just have to do…

    Vertical Tracking Angle Meets Stylus Rake Angle, Part Two

    In Issue 125, J.I. covered the mechanical aspects of record…

    Vertical Tracking Angle Meets Stylus Rake Angle, Part One

    The geometric considerations with regard to vinyl disk recording and…

    The Coil and Its Significance for Recorded Sound

    A few days ago I was in the lab (which…

    The Rise, Fall, and Resurgence of the Vinyl Record

    Two of the world’s leading chip manufacturers have recently announced…

    How Loud Is a Record?

    In this article, I shall attempt to shed light on…

    How Hi Would You Like Your Fi?

    “High Fidelity” is an ambiguous term. How much Fidelity is…

    Acoustic Design Consultant Philip Newell, Part Two

    In Part One (Issue 119), acoustical design consultant Philip Newell…

    Sound Pilot: Interview with Acoustic Design Consultant Philip Newell

    Philip Newell has been professionally involved in audio since 1966.…

    The Long-Lost Record Label Concept, Part 2: Self-Released Album Psychodrama

    In Issue 117 J.I. talked about the origin of the…

    The Long-Lost Record Label Concept – Part 1

    The record label, that round paper label in the middle…

    Colored Vinyl: Eye Candy, But is It Ear Candy?

    Records, from the age of shellac to the vinyl era,…

    Are 180-Gram Vinyl Records Really Better?

    Disk records have been around for a while, long before…

    How Not To Fix Things (Especially Things That Turn)

    There are few things more frustrating than having trusted an…
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    Stop by for a tour:
    4865 Sterling Dr.
    Boulder, CO 80301

    Join the hi-fi family

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