Audio Band-Aid

Sometimes in the field, one has to improvise. Lately the Peanut Whistle blogger has found himself seeing this in practice. Our latest venture at the new radio station involves a funny contraption that reminds this blog of a Rube Goldberg Machine.

We were called to fix the audio from the control room computer. It runs a version of Adobe Audition that is used to record satellite shows for later broadcast. The audio into and out of the machine was distorted—badly. Prior to the Memorial Day holiday, it was imperative that we get the audio fixed. Toolkit in hand, the hunt began for the gremlin that invaded the board, once again.

The console is an ancient, but serviceable,  mono 10-channel rotary pot LPB Signature III that has extra inputs on select channels. For whatever reason, previous engineers had placed conflicting sources on the same pot. For example, the Enco DAD presenter feed was on the same switch as the satellite feed. That was corrected.

First thing, the Adobe Audition computer, an E-machines brand, was rerouted so we could eliminate possible crosstalk. That was not the problem. The wire pulled away from the source and it was discovered that the computer tower had been placed on the floor! A great location for board ops to kick it. The audio was coming from the soundcard port on the back of the tower (arguably, not an ideal pro connection.) The speaker port had been damaged inside, as well as the odd jack and assorted adapters. A 1/8” to 1/4” stereo phone plug adapter into a 1/4” phone to stereo RCA phono plug, then into a stereo to mono y-adapter and finally an RCA cord to the board. No wonder the jack had been damaged; all the length and weight not only had bent the 1/8” plug, the jack on the sound card had been virtually hollowed out. (See the photos below)

In the example above, we recreated the adapter “pigtail” with a mono phone adapter, otherwise, it is the same as the studio’s.

The repair session took place afterhours and Radio Shack was closed. Bummer, so we frantically rummaged through the parts attic and found a new mini-plug in a plastic bin full of random electrical stuff. This was lucky, to say the least.

After recreating the improvised circuit, the connection had to be replaced to the front of the computer where an extra speaker terminal was placed (more good luck.)

Levels had to be tweaked in Windows. The line in jack, although noisy due to electrical and RF interference, was okay, required electronic adjustments as well. Oddly enough, the connection from the board was a straight wire, terminating in a mini-plug (1/8”). A return trip is guaranteed. The repair is only a Band-Aid. Next we will relocate the E-machine higher and provide a USB interface with pro XLR and RCA connections for a noise free balanced circuit.

Stay tuned.

High Fidelity

Let’s face it, I screwed up. How?  The domain name of my Aircheck blog expired, so many of the links to specific posts and pages became invalid. Today Peanut Whistle is re-posting (in all its parts) one of my favorites: The Hi-Fi

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Back in the late 1950’s or early 60’s my paternal grandparents bought a new General Electric stereo. It contained an automatic record changer, AM/FM stereo tuner, amplifier (not solid-state, but genuine tube electronics), and loudspeakers. All of these components were housed in a massive, handsome wood veneer cabinet.

Flash forward to Independence Day 2009 my dad’s younger sister asked me if I wanted the Hi-fi that their parents owned. I had been eying the unit for many years: in its various homes, near and far. Honestly, I was afraid the console had been lost over the years but was surprised that it had found its way into my Aunt Bonnie’s storage shed.

Long story short, that fourth of July, I became heir to the stereo. I was not expecting the nearly 50 year old relic to even turn on. To my surprise, after replacing the frayed power cord, the old GE energized and was soon filling the air with high-fidelity music. The FM and AM worked well. The Turntable was a different story. Records played off-speed and faint. Ever the tinkerer, over the next weeks, I disassembled the electronics. The “head” unit (pre-amp / tuner) was problematic. Most of the contacts needed cleaning. The wiring was suspect. I discovered that the record player was rim-drive. The “tire” (illustrated above right) that turns the platter was way out of round; a part probably not currently available. The left speaker sounded cracked. Sure enough, it had some irreparable moisture damage. I decided the the cabinet was the only part worth saving, so I gutted the ancient electronics. Most purist collectors might cringe, but I replaced the tube amp and speakers with (relatively) newer solid-state electronics: a 100 watt Sony receiver, belt-drive turntable, and dropped in a pair of Yamaha bookshelf speakers inside. The one remaining original speaker, which I kept as a souvenir,  is in fairly good shape. Besides the cracked woofer, I did not throw away anything. I just threw the old parts inside. I intend to make future improvements to the Hi-fi. I consider this project a restomod, similar to the way car builders take a rust bucket, add modern performance speed parts and produce a classic with new guts.

The cabinet is currently being used as a TV stand. The console stands at 30 inches, is 16 inches deep, and about 54 inches long; more than adequate as a make-do entertainment center. And, the main problem with it is the low quality materials it is made of: ply-wood and mystery wood skinned with a rosewood veneer. Frankly, the cabinet is not worth saving. However, it serves as a superb prototype for woodworkers interested in mimicking early 60's style. I have drafted plans for a new credenza/entertainment center based on the hi-fi. It would be a great project. I have yet to work out the internals; but, inspiration is found on certain furniture store websites. Most of the credenzas I have seen are superior to our model in question in terms of materials.

A skilled craftsman could render a cabinet better than mass produced retail offerings, I'm sure.

This stage in the game is my planning phase: taking photos and making measurements. Some of the crazy things that I have considered for the 50 year old cabinet are; a complete restoration of the original tube electronics, dropping in new “guts”, replacing the old works with a professional grade turntable of the period, or just modifying the case for a more universal purpose.

Considering budget and the fact that the console was water damaged during long storage, the latter option was the preferred route. I intend to reinterpret the design and use the hi-fi as a home for my present am/fm receiver, speakers, HDTV, and Blu-Ray player.

Appraisal

I’m underway first with the rat’s nest of wiring. The half century old harness is in surprisingly good shape; all solder joints still intact. Very little rust is present. Dust and grime are abundant. Using this unit daily would be problematic, so I choose to trash this fire hazard wiring.

When I energize the unit in 2009, the radio performs well on both AM and FM although the switching between sources is quite scratchy and inconsistent (volume, tone and selector switches need contact cleaner). The ancient tube amplifier powers the built in speakers just fine with more than acceptable fidelity. Audio out of the left side of the cabinet is distorted on bass sounds (I suspect a cracked woofer.) The left loudspeaker is water damaged beyond repair. I keep the right one for a souvenir. The automatic record changer is useless. Even when new it was not exactly state-of-the-art. By 2011, I need a new game plan as far as the electronics are concerned. I decide to purge the contents and start with an empty carcass. What is left concerns me.

Conclusion

On close inspection the hi-fi actually looks better than it is. The unit is made with birch plywood with a rosewood veneer, mostly ½” with a few ⅛” panels. The only solid wood appears to be a long board that reinforces the back and the 4 tapered legs turned in late ‘50 modern style. The top is distressed from years of storage and abuse. The finish has long lost its sheen. A peek underneath the lid reveals what the cabinet must have been in its former glory.

The deeper I dive into the console, the more I am convinced to scrap it altogether before drowning in an unrewarding money pit. Realizing that the old GE console is more of a family relic than a truly vintage representation of hi-fi art, my mission now is to find a better example then restore it. Better yet, I will design and build my own.

Stay Tuned.

Audio Alchemy

During my first 4 years in radio I worked in a studio wired for monaural sound only. Stereo aircheck recording was not feasible with the available equipment. However, in 1985, I used a small “disco” mixer to make stereo mix tapes for personal use. Previously, I experimented with re-routing the left and right outputs of a single turntable to the two mono pre-amps then into program and audition respectively; successfully recording in stereo. This method was cumbersome because the left and right inputs were controlled by two separate knobs on the board (one routed to audition, the other to program.)

The studio’s Technics SP-15 turntables audio cords were re-routed from the usual phono pre-amplifiers to the small (cheap) stereo mixer. The diagram on the right is a speculative idea of what if I had used this set up to record an actual aircheck. Using this type mixer would have been real world challenging due, in part, to its inability to switch on and off monitors and microphone.

By 2009 I had the ability of digitally isolating the live vocal portions of my original aircheck recordings and carefully synchronizing in stereo music from CD’s and other digital files (mp3, wav, etc.) It was impossible to remove all unwanted mono audio. Some “phasing” between the new stereo and old mono occurred.

With this in mind an alternate wiring path would have been preferable for future “stereo rebuilds”. The simple diagram to the left illustrates an easy method of electrically isolating the DJ microphone from the (mono) music and other prerecorded elements of my shows. The isolated vocal tracks could have been later used to assemble a true stereo mix, either analog or digital.

Stay tuned

©2011 Neal Rhoden. The Peanut Whistle Weblogs. All rights reserved.

Rock On

Welcome to October or as I like to call it, ROCKtober.

Yesterday I rambled on about my first encounter with the Compact Disc. Although every effort has been made to proofread each post, sometimes an error will slip through. Previously I wrote:

“Christmas 1982 the audiophile community was all abuzz over the shiny 12 millimeter disk that would revolutionize sound forever.”

The date is correct, but it should have read “12 centimeter disk.” Recalling the original press reports of 1982, designers of the CD made the disks 12 centimeters as an homage to the 12 inch Long Play vinyl record album. Further, they made the 74 minute capacity of the CD standard length because it is roughly the length of Beethoven's fifth symphony, which was very popular among the Japanese, who through Sony partnered with Phillips to invent Compact Discs.

Stay tuned

©2010 Neal Rhoden. The Peanut Whistle blog. All rights reserved.

Ones and Zeros

Christmas 1982 the audiophile community was all abuzz over the shiny 12 millimeter disk that would revolutionize sound forever. The CD or, as originally known  the Digital Audio Compact Disc, was billed by Sony and others as “perfect sound forever” and I had to have one. By 1983 I was in the showroom of my local high end audio shop Audio Outlet. I was 17 and newly employed so all I could afford then was only a listen. CD players cost as much as my first car and CD’s themselves were about 18 bucks so buying one was not feasible. The technology was so new that most people would have to wait at least a decade before CD’s would be common in homes and 15 years, the late 90’s, before most cars were equipped with players.

Looking back on 1983 at my first audition, I didn’t believe my ears. The sound of instruments was clear and distinct with life like separation as though the musicians were actually performing live. I forgot that I was listening to a recording and transcended to a different setting altogether. As good as that first session was, none of the music I liked was yet available on the new format so I had to continue buying vinyl for a while. As much as I wanted one I told the eager salesman that “My ears loved it but my pocketbook couldn’t take it.” It would be four more years before I got my first CD player. That was 1987 and CD’s were still about $18 a piece, worth every penny however scarce. As time progressed the hardware and software became much cheaper. For me, though, recording digitally on CD was only a pipe dream. My hobby, and by then profession, was recording. I did everything in an analog world.

The best thing about digital sound is not what it adds it is in what is missing. Freedom from noise, tape hiss, immeasurable wow and flutter, extended frequency response and wide dynamic range are all earmarks of the CD. Many sound enthusiasts claim that digital sound is harsh and bemoan the loss of what analog added to the signal. Most call this “warmth.” Modern recording engineers agree that analog is better and attempt to replicate the sound in software. I would have seen this trend as a step backward in my youth, although now I appreciate both approaches to recording sound.

Analog reminds me of how 35mm film makes an image warm and inviting while digital is akin to the look of live video, realistic and stark. Both technologies continue to coexist. Since no technology really is “perfect forever” blending both is the way to go. The best attribute of digital is its ability to archive without any loss of quality on the shelf. Analog tape, on the other hard, degrades over time. Cassette tapes, especially, lose high frequency content over time. That is why I have been transferring my analog originals to digital with a few recordings made into CD’s. Most of the transfers exist on my hard drive. I began my digital migration in 1995 with the now defunct Sony Mini Disc then to CD and finally Mp3 files. A Peanut Whistle subscriber has suggested that I transfer my dad’s old recordings to CD. Thanks, I’m way ahead of you. I’ve been doing just that for the past 15 years.

Stay tuned

©2010 Neal Rhoden. The Peanut Whistle. All rights reserved.

File Under: Audio

The dictionary defines an audiophile simply as “an audio enthusiast.” A short, all too simple definition for my lifelong obsession with sound. Thanks go to my dad for getting the ball rolling on my aural hobby. As early as age three I remember his portable reel-to-reel and microphone recording me in one of his interviews with me his toddler son barely old enough to talk. Flash forward a few years later I had taken up the hobby recording sound effects—doors slamming, thunder clapping—with a stereo cassette boom box and an electret condenser microphone. Just like Daddy I had been bitten by the audio bug.

Age 17, I began and continued a career in radio only as an excuse to play with all the knobs and switches that shaped sound. It was never for the purpose of money or fame. I was also a very young and capable soundman in church often wearing my emotions on my sleeve because older folks often lacked the deep understanding of audio I possessed. In time I learned to put my hobby in perspective: got a real job, learned how to deal with ignorance, developed diplomacy and generally became less of a nerd. As the short dictionary definition proves, society as a whole cares much less than I do for audio. That’s alright we all have our interests. If only I could combine my experience and attitude now into my teen ears.

Stay tuned

©2010 Neal Rhoden. The Peanut Whistle blog. All rights reserved.

Mr. Microphone

“I’ll be back to pick you up later,” the young man announced from his convertible to the blonde stranger standing on the curb. His voice had been mysteriously amplified over his car stereo. One of the wonders of the late 1970’s, Mister Microphone was one of those $19.95 as-seen-on-TV wonders that everybody had to have. A toy, really, it was a cheap wireless mic that sent a signal via FM that was tuned in on a nearby radio affording many hours of fun—such as picking up chicks. I assure you no young woman has ever been wooed by one of these novelties. Sorry Romeo.

Stay tuned

©2010 Neal Rhoden. The Peanut Whistle. All rights reserved.