Holmes Engineering


Since 1966

Ron Holmes, IEEE


Oval Callout:


For a limited time only download for free:

DOWNLOAD CHAPTER ONE  Carbon Microphones

DOWNLOAD CHAPTER TWO  Crystal, Electret, Condenser + repair/mod

DOWNLOAD CHAPTER TWO  Ribbon and Dynamic Microphones

           Hello! I’m Ron. Welcome to Holmes Engineering. Our website offers free books for musicians and those who love old audio equipment. You will also find a page to identify the most commonly used audio plugs and adapters. NEW: you will also find the first three chapters of my new book on the history of microphones.


           I started out fixing my friends’ musical equipment when I was a junior in high school. Dad offered me a tiny shop at the back of the family shoe store on Main Street in Longmont, Colorado. (Photo below shows the front window of the shoe store circa 1950.) As I became better at my craft, I later modified equipment and created some of my own original equipment.


           Over the years, I modified and repaired hundreds of vintage tube amplifiers, high fidelity amplifiers, antique radios, early recording equipment, early special effects devices, vintage studio recording equipment, EMT plate reverbs, vintage studio microphones (condenser, ribbon, dynamic), studio and theater monitor systems, recording sound boards, studio electrical systems, studio grounding systems, film chain

Systems, including camera and film projectors.



           I worked as an audio designer for manufacturers. My projects included a reproduction tube microphone, drum beat counter and a special effects reverb. I have done hundred of custom audio designs and modifications on types of recording equipment.


           Ron Montrose and I were friends and worked for more than a year developing a small portable amplifier. Garth Powell and I developed a high-end vacuum tube headphone amplifier that was awarded a Golden Ear Award from Absolute Sound.


           From 2002 to 2014, I designed and built the Harp Commanders as a tribute to my father who played harmonica in a band in the 1940’s.


           I am currently working on a high-end four-channel, vacuum tube preamp mixer for recording and I will soon finish my new book on microphones.






           Ron is a full member of IEEE (Institute of Electrical and Electronics Engineers, Inc.) He previously worked for the University of Iowa Department of Physics and Astronomy where he was on the team that created the Dynamics Explorer I satellite. He assisted with the design and manufacture of high-reliability circuitry, soldering and assembly. He went with the design team to NASA’s Goddard Space Flight Center in Maryland to test the Dynamics Explorer I instrumentation under launch conditions.


           He holds a lifetime First Class Radiotelephone FCC License and was a broadcast engineer in the United States Air Force and later in the San Francisco Bay Area.


           He and Linda have been married since 1976. They have triplet granddaughters and a grandson that they have helped raise.


           Ron also trained in Swedish and Shiatsu massage. He is a graduate of the Holistic Health Institute in Berkeley, California. He is also a graduation of the Berkeley Owner-Builder Remodeling School and a graduate of Zoom Graphics AutoCad program. He has extensive experience with plant propagation and the use of herbal products. He is a student of Classic Hollywood Cinema. Ron is active in cat rescue. His cat, Walker, was featured on the cover of the Ronnie Montrose album Music from Here.


           Ron agrees with Jerry Garcia, “What a long, strange trip it’s been.”


Holmes Family Shoes

449 Main Street

Longmont, Colorado


Circa 1955

This site was updated on

March 30, 2018.  This site is owned and operated by

Ron Holmes & Linda T. French. Copyright  2002-2018

All Rights Reserved



Our website will take time to download because it is filled with large, detailed graphics.