The Enduring Appeal of Magnetic Audio Tape Series – V

To make a good tape recording it is necessary to:

Maintain the tape deck in good condition.

  • Worn or scratched erase, record or playback heads will impair sound quality. Examine the heads for wear (usually a groove in the head caused by the repeated passing of tape). Worn heads should either be restored (relapped) or replaced. Whether heads are restored or replaced, the deck will require expert readjustment and recalibration.
  • Examine the pinch roller(s) for cracks, brittleness and for being out of shape. The pinch roller holds the tape against the spinning capstan shaft. Together, the capstan shaft and pinch roller control the precise speed at which the tape passes over the heads. The pinch roller should have a little resilience; it should not be too hard and should not be sticky or too soft. If the pinch roller has become sticky, out of shape, excessively soft, hard or damaged, repair or replace it.  Even “new old stock” (NOS) rollers may not be ideal, as the rubber may have deteriorated over the years.  It is generally better to have the pinch roller restored using new rubber. Terry Witt provides an excellent service in this regard.
Terry's Rubber Rollers - Click photo to visit site.
Terry’s Rubber Rollers – Click photo to visit site.
  • Have the electronics/calibration checked every year or two. Have the deck checked sooner if sound noticeably deteriorates. It’s a good idea to locate a properly trained tape deck technician to service and/or restore your deck. An internet search for “tape deck service specialists” should return plenty of choices. Alternatively, ask in a comment at the end of this article and we’ll do our best to provide the information you need. In the USA we used JM Technical Arts for our Revox A77 restoration and Sam at Skywave Tape Deck Repair for our TEAC C-1.

Use a good quality tape

  • For new open reel tape I use RMGI LPR35. It works great on my TEAC A3300S.  If, like me, you use a combination of old and new tapes, have the deck calibrated to the new tape, since this is most likely to be the tape you add to your library as your collection grows.  I also use Maxell UD (35-180) and XLI (35-180B) and, most recently, I bought a set of 10 TDK Audua L-3600M tapes off EBay. These TDKs had only been recorded once and cost a mere £39.95 for the lot—proving that bargains can still be found! Metal reels are favoured for appearance and tend to be quite expensive, but plastic reels work perfectly well.
  • For cassettes I use two main types, both of which are Type II (Chrome Dioxide) formulations—TDK SA/TDK SA-X and Maxell XLII/Maxell XL-IIS. The TEAC C-1 does not calibrate for Type IV (metal), so although it will record well to Type IV and plays it back very well, it doesn’t justify the high price charged these days for Type IV tapes. I find that both the TDK and the Maxell allow me to record “hot”, with the needle well into the red range of the VU meters, without distorting. The result is extremely low noise, highly dynamic recordings that astonish people who have never heard a top quality deck playing a well-made recording. Although new tapes are still available, these are a standard, Ferric formulation (Type I), which is not ideal for making high quality recordings. The best options are new old stock (sealed) Type II or Type IV tapes found on auction sites, as well as on local ads if you are lucky. Also a good buy are tapes that have been recorded on very few times and still have spare blank labels and contents cards in the case (known as a jewel case).
  • For 8-tracks, the options are few and far between, relying on the second-hand and new old stock market. Because of their construction, 8-tracks often require restoration, even if they have never been used. The 8-Track Shack is a source of blank cartridges and they also sell parts to restore the tapes. 8-Track Heaven is an excellent site for 8-track enthusiasts which includes guidance on tape restoration and a lot of valuable information on this niche recording medium.

Maintain the tape heads, pinch rollers and tape path in good condition

  • For heads and metal parts on the tape path clean off tape deposits (reddish brown in colour) using cotton buds/Q-tips soaked in 90% or 99% isopropyl alcohol. Be careful when cleaning the heads–don’t press too hard and work from side to side along the same line as the tape will pass, never across the head (at right-angle to the tape path).
  • Don’t clean the pinch roller with alcohol, as it will harden the rubber and shorten the life of the roller. Clean it with warm soap and water (remove the roller, wash it using a clean cloth soaked in soapy water until all traces of tape deposit have been removed).  Then rinse and dry it thoroughly afterwards and relubricate the roller spindle before remounting the roller, using a drop of clean motor oil.  Alternatively, use a rubber cleaner made specially for pinch rollers, such as SR Audio PRC-2 Pinch Roller Cleaner available in the USA via Amazon.com and in the UK via Avalon Audio. US mainland readers can also buy a pinch roller cleaner/restorer from US Recording.
  • If the pinch roller is not in perfect condition, we suggest having it restored using new rubber at Terry’s Rubber Rollers, who we have used several times for both open reel and cassette pinch roller renewals, at reasonable cost and with excellent results (possibly even better than the originals).
  • Demagnetise the tape heads and metal contact parts on the tape path, using a suitable head demagnetiser and strictly following the unit’s instructions. Making a mistake with a demagnetiser can ruin the tape heads, so be careful when using one!

Record the signal at as high a level as the tape formulation will allow without becoming distorted

  • This is easier to do with a 3-head machine than with a 2 head machine. Although the VU meters do allow the operator of a 2-head machine to roughly set the level of input signal, it is not possible to monitor the recorded track without stopping, rewinding and playing it back. That is because both playback and record are performed by just one head. This head cannot simultaneously record and play back. With a 3-head machine, the playback head is mounted immediately after the record head. This allows the recordist to listen either to the source signal or to the recorded signal, making an instant subjective comparison, tweaking the recording controls as necessary until the recorded signal sounds identical to the source signal. Most of the popular open reel decks are 3-head designs. 3-Head cassette decks were (and are) more expensive and desirable than their 2-head variants. I don’t think there are any 3-head 8-track decks—correct me if I am wrong.

Things to watch out for when recording:

Record function lag

  • Starting the record function too late may result in missing the very beginning of a signal, due to the time taken for the pinch roller to engage (a split second, normally) and for the tape reels to stabilise (overcome inertia) as the tape is pulled through by the capstan and pinch roller. To eliminate this, I use the Record+Pause function to take up any tape slack and always start the recording a split second or a second before the signal begins. When recording from vinyl, I let the stylus contact the silent part of the lead-in or if recording a track in isolation, I allow the previous track to finish. I then release the record+pause function (in the case of the Teac A3300S this just means pressing the “play” button). If a track fades into or out of another track on the record, I fade the recording out or in using the line-in control, preceded or followed by hitting the record+pause or record+play buttons. I like to leave a second or two of silence after a recorded track to allow me to set up the next recording without leaving any burst of un-erased previous recording. Practice makes perfect, so if you are new to recording, I suggest practicing making a few recordings onto an old reel of tape before doing any archiving onto high quality reels. You’ll soon become expert!
  • Vibration of sources are a potential issue. We have concrete floors downstairs now, but our previous home had wooden floors. Any vibration you can hear through your turntable stylus you will also hear in the resulting recording. Even people walking up and down stairs, or banging doors can be picked up, depending on whether the noise (vibration) transmits to your turntable. I often mention to my wife when I’m about to do some recording so that she can move around the house without banging doors. It also encourages me not to get into arguments with her!  🙂

Watch for our final post in the series which will cover:

 ‘Sound Quality and Nostalgia

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Technique: Skill Through Practice

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