Keyboard Magazine "In The Studio"
Article # 16
Tape Recorder Mainainence Tips
This month I've put together some tips for tuning up your tape recorder and making sure it stays in shape. For those of you readers that read the June 86 special issue on recording, these little tips can make your recordings sound better.
Keeping things Clean ...
The starting point for all tape recorder maintenance begins with routine cleaning. This means at the start of each recording session and at the end it is important to clean the tape path properly.
First you will need the following supplies : 1. A box of Q-Tips ( the Plastic Molded type ) 2. Isopropyl Alcohol ( Lily 91 % or better ) 3. Rubber Cleaner ( Friends or Teac ) The first two items can be purchased from any drugstore the latter can be purchased from Teac audio dealer or from Friends .
I recommend the plastic molded type of Q-tips because the cotton fibers stay attached to the Plastic better than with the wooden ones. The is specially made head cleaner by Ampex but in the hands of the inexperienced can cause great damage to your deck. Also certain manufactures coat their heads with a plastic that can be removed by the stronger head cleaners. Stay with the alcohol, it works fine. Never, never use alcohol to cleaner your Rubber parts ( such as the Puck - the rubber wheel that pushes the tape against the capstan ). Once again, check with your manufacturer. The are certain parts on professional decks that look like rubber, but really can only be cleaned with alcohol.
What and how to clean .....
First dip a Q-tip into the alcohol. Next start with the tape guides and the captain ( the shaft of the motor that spins ). Even if your deck is of the cassette variety, it probably has tape guides, usually near the heads. Be sure to observe this next rule. Always clean in the direction of the tape. This means if the tape moves left to right, clean with left and right motions, not up and down ones. It may not matter as much with the guides, but Q-tips are abrasive. Rubbing too hard and in the wrong direction can scratch your heads. They may be made out of metal, but they're delicate, so be careful. Use your Q-Tip till it gets dirty. It will usually turn brownish ( from the loosen oxides ) and when it does use the other end and then a fresh one. Clean only the metal parts with alcohol !!! .. Do not get any alcohol on the rubber Pinch roller ( the puck ). Alcohol with clean rubber nicely but in a short while your puck will get hard and slick and eventually crack. Be sure that you have left no traces of the cotton fibers from the Q-tip when you have finished cleaning! The littlest of fibers ( especially if it dries and sticks to the heads ) can hinder the record and playback frequency of your deck.
Next inspect the rubber puck and if the manufacturer recommends using a rubber cleaner then grab a fresh Q-tip and proceed. Be sure you have adequate ventilation! Rubber cleaner stinks ! So unless you enjoy the high, up some windows. Inspect the puck. If it has a slick or discolored band around its middle, you are in for some rubbing dude! That band can cause irregular tape speed and thus a recording that plays back in and out of tune. If your deck isn't new and persistent rubbing doesn't remove that band, you're going to have to get a new puck. Don't ever use sandpaper to try and restore the rubber! This usually happens when you've been breathing too much rubber cleaner for too long a time! Anyhow, if you can't clean it, you'll have to replace it.
In closing, your recorder should be cleaned before and after each session. It may seem like a royal pain but once you make it part of your procedure, it's painless.
A simple test ......
For those of you more adventurous types, here's a little test that will inform you of your deck's frequency response. A 1 Khz tone is usually the standard alignment frequency for level adjust. If you don't have a waveform generator use one of your synths instead. Play a C an octave higher than middle C. This is actually ??? Hz and will do fine. Make sure the wave form you use is a Sine wave. Use only one Oscillator. Be sure there is no modulation so there is no beating or change in level. You can be sure by patching your synth into your recorder and observing the VU meter on the deck. If the needle on the VU meter stays steady and solid, you have the right waveform set up on your synth. Set the output level of your synth so that the recorders VU meter is at 0 db. If you can patch your synth into both channels of your recorder, you can check both simultaneously. Record about 30 seconds to a minute of that tone onto the type of tape you use normally. After you've finished rewind the tape and play it back. If you have a three head deck, first observe the level on the VU meters of both channels in Sync and then Repro. If you deck has been properly aligned, the tone should play back at the same level (0 db.) as which it was recorded. If not, it would be wise to get your deck serviced. You can also substitute a higher frequency ( around 10 Khz. ) and a lower frequency ( around 100 hz. ) to check on the whole frequency spectrum. The 100hz represents the bass, the 1Khz represents the midrange and the 10Khz represents the treble. A properly aligned recorder/reproducer should and will reproduce exactly what has been recorded into into it.
The reasons why ...
If you've tried the test and your recorder did not pass ... Here are some reasons why! 1. You are using the wrong type of tape - This occurs when you haven't read the bit in the manual where the manufacturer recommends using a particular brand of tape. 2. The heads are dirty - Well I've already explained how to clean your Deck, so clean it! 3. You've dropped your recorder - Or it was banged or jarred in shipping and has to be aligned again. Meaning either the Playback or the Record or the Bias (the current for the type of tape used) alignments are wrong or all of them. 4. The guy at the factory - Who originally aligned your deck sniffed too much or not enough rubber cleaner! 5. The VU meters are out of calibration - or the monitor cal is out. This would cause the levels to actually be the same but appear to be wrong on the VU meters. To depend on your meters..they have to be calibrated too. 6. The last and most painful - Your heads are now old and worn and need to be re-lapped ( a process where the heads are re polished to perform like new again ) and thus the deck has to be re-calibrated again too!
The proper procedure for aligning a deck includes first setting the VU meters. Then aligning the playback amplifiers to a Reference level tape. On the tape are many frequencies including the 1k, 10k and 100hz tones. Then the Bias is set by recording the proper frequency onto the type of tape you'll be using. And last the record amplifiers are aligned to the three frequencies ( 1k, 10k and 100hz) so that your recorder will not change the sound of what's being recorded.
Bringing your Deck in for service ....
First be sure who ever is going to repair and/or align your deck is qualified. Meaning, he is an authorized service representative of the manufacturer who made your recorder. Being authorized he will be skilled in repairing your deck properly. He will also be aware of any updates that also can be made while your deck is in for repair. He should also have and use the original replacement parts. Bogus parts will make your deck work but for how long?
Always make sure the work is guaranteed and check the alignment with the above test I've given you. Don't take someone else's word for it! Use your eye's and above all your ears. And if you are driving make sure you have a car! If you've found this article interesting and would like to learn more about Tape recorder alignment, send a postcard c/o of Keyboard Magazine.
Being prepared for anything is The Real Thing !
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