Audio Restoration – Working with warped records

I recently did a project to digitize a couple of Voice-O-Graph records dating back to the 1950’s. Voice-O-Graph made recording booths where you could make your own recordings on 78 or 45 RPM disks. These disks were 78 RPM and showed a bit of cracking and warping.

When confronted with poor condition like this, it is best to do as little as possible to the record. While you want to get the recording off the record, you need to prevent inflicting further damage. I don’t want to use any glues or coatings. I’d like to get the record into a flat plane so the stylus can ride in the groove, and that’s all. The cracks will certainly cause some pops, but that can be cleaned up later, in the digital editing.

Both disks were recorded on one side only. The first disk had multiple cracks, and warped up on two sides. This would cause the needle to jump out of the track, like a skier over a mogul.


In order to get it to lie flat, I used a 33 RPM record and masking tape. In order to avoid damage to the record, I used a low-tack painters tape. This makes for easy removal without any residue.


The second recording likewise had multiple cracks. But this one rose in the middle as well as curling up on one edge.


I used a spring clip on the spindle to push the center down, and a little tape on the one edge.


In the end, both recordings had minimal popping from the cracks. My customer had requested minimal cleanup, so I trimmed the EQ to cut down the rumble and hiss and to accentuate the recorded voices.


Direct Out Modifiocation for Allen & Heath ZED Mixer

I recently acquired an Allen & Heath ZED 12-FX mixer to use for home recording and live mixing. This is replacing a Mackie 1202-VLZ Pro that I have used for several years. I was looking to add a more channels and to improve on the EQ capabilities.ZED 12-FX Front Panel

For recording, I use a PC/Windows system running Cakewalk SONAR 8.5 with an M-Audio Delta 1010LT sound card. This gives me 8 input channels. I typically have recorded using the direct out capability on the channel Inserts of the Mackie mixer. By inserting a 1/4″ mono plug only half way (to the first click) the Mackie provides a direct out, without interruption of the signal through the channel. Unfortunately, the ZED mixer does not provide this capability.

I have performed this modification only on a ZED 12-FX mixer. However, it should be applicable to all mixers in the ZED series. There will be differences in the removal of the channel cards on some of the other ZED series mixers.

This article describes a modification to the mono channel of the ZED mixer to add a direct output function. This modification is not approved by Allen and Heath. As an unapproved modification, this may void your warranty. Continue reading

Festival Sound – Planning is important, but flexability is critical

I am providing sound for the Old Time Fiddler’s Gathering, June 19-20 in Watkins Glen State Park, Watkins Glen, New York. The main stage will be the setting for 4 bands each day, with each band playing 60 minutes. I will have 30 minutes between bands to reset the stage and perform a rough sound check.

Over the past few weeks, I have drawn up my own equipment lists. I have a spreadsheet of the needs for each band; how many microphones, which microphone, where to put the direct lines, monitor configurations. I have stage drawings for each band. And I have my master equipment list to keep track of everything that needs to get loaded.
Continue reading

Exploring Assistive Hearing Technology

I recently surveyed an in-house sound system for a local place of worship. I was able to make some adjustments to the levels and equalization to improve the overall sound and clarity. I also advised they replace the speakers, which are not providing clear sound.
One of the congregants asked that I also explore possibilities for installing an Audio Induction Loop system, which can assist people with hearing aids. I had never heard of this technology before, so I have some learning to do.
Many hearing aids include a Telecoil (or T-coil), which is used primarily for picking up audio signals from telephones. Using an inductively transmitted signal from the telephone handset to the hearing aid provides a clearer sound, and allows the wearer to hear the phone without amplifying other ambient sound.
The Audio Induction Loop is a wire that is run around a room, or a portion of a room, to provide sound pickup for people with T-Coil equipped hearing aids. The induction loop creates a magnetic field that is picked up by a T-Coil. This is preferred to simply turning up the hearing aid, as it provides the PA system sound directly, without amplifying the ambient room noise.
Audio Induction Loops are required in the United Kingdom, and the technology to implement them right now appears to be primarily manufactured in the UK.