¼ Inch Audiotape Workflow
General Format Review
Acetate or polyester?
- You have acetate tape if the end can be torn easily or a light can be shone through the reel.
- PVC or polyester tape will not show light through.
- The light test isn’t 100% reliable. Very thin polyester tape, or tape without much oxide on it, may appear translucent.
Reel sizes: 3”, 5”, 7”, 10.5”. Reelscan be cine spindles or metal NABhubs. Slotted cinereelscan be problematic.It’s good practice to add a generous length of leader tape to your audio tape to minimize the effects of deformation from the uneven surface created by these notches.
Speeds: 1.875, 3.75, 7.5, 15, 30 inches per second (IPS).
Track configuration: Most common configurations arefull track mono, ¼ track stereo or ½ track stereo. Many combinations exist. You can use a magnetic viewer to review the recording pattern or listen to the tape to determine.The playback head must match the track configuration.
Tape handling recommendations
Prep:
- Clean the tape pathwith 99% isopropyl alcohol and a swab. Clean rubber/plastic parts such as pinch rollers with distilled water or a cleaner specifically made for rubber.
- Review for sticky shed. Does the tape stick to itself when unwound? Certain brands have known issues—see list.
- Attach leaderto head and tail. Use enough to circle the reel 2-3times.Avoid directly touching recording surface(matte side with magnetized oxides.)
- Evaluate the tapeand stabilize the windby rewinding/fast forwardingback and forthif thetape wind is mildly uneven. You may need to wind by hand or in play mode if the tape wind is more severely compromised.
Splicing how-to:
- Use a razor to trim tape edge and leader tape cleanly at a diagonal.
- Placethetape inasplicing block channel, with the magnetic surface facing downward.
- Line up leader tape with the audiotape, joining the ends.
- Cut a small piece of splicing tape and lay down over the tape and leader joining them. Gently press down to remove any air bubbles.
- When removing the tape from the splicing block neverlift tape straight up from theblock channel, but gently at an angleto avoid tearingthe audio tape.
Never use scotch tape to splice.
Contamination or condition issues: If tape shows signs of mold, set aside for cleaning with isopropyl alcohol on a dedicated audio deck.
- Use protective safety precautions such as a mask and gloves in a well ventilated or outdoor space.
- A fume hood is preferable if available.
If tape shows heavy particulate contamination set aside for cleaning with isopropyl alcohol.
- Do not use the same deck you use for mold remediation or the mold can spread.
If tape squeals during playback, set aside for treatment with D5.
- Apply D5 to the oxide side of the tape.
- Use protective safety precautions such as a mask and gloves
- If D5 is not available, you can use isopropyl to wet the tape lightly and evenly during playback
Playback recommendation: Immediately stop playback of tapes with squealing, shedding and blocking
Storage: Tapes should be wound tightly and evenly. An uneven tape pack can allow dirt to come in contact with and abrade the tape’s surface and edges. Unevenly wound tapes can cause the tape to warp and lose its shape, which will affect playback sound quality.
Tape down ends with archival tape when storing
- Always store tapes vertically. Horizontal storage or tapes that are stored leaning at an angle will cause warping over time.
- Don’t store near electrical source.
- Store away from floor in cool dry space (ideally 65 ̊ F and 30% RH though this isn’t always possible)
