If the cassette tape heads are not cleaned enough, it may degrade your recording and playing audio quality. If you haven’t clean the tape heads for years, the cassette tape heads could be covered with dirt, which can cause more serious problems such as eaten tapes and mechanical damage. How to Clean Cassette Tape Heads in 3 Steps What Do You Need: You will need Q-tips or other quality cotton swabs. The cheap ones can be frustrating as they dont have enough cotton on the end or it comes off easily. The next item you will need is denatured alcohol. This is what's reccomended by tape techs as the correct liquid. Denatured alcohol can be found at most any hardware store but the issue is I have never seen it in less than quart sized containers. The rubber pinch roller is another area of much debate on what to use. Some techs say use only rubber roller cleaner as anything else will dry the rubber out. Some say they have used denatured alcohol on them since dinosaurs roamed the earth and never had an issue. Me? I've been using the same rubbing alcohol since I made my first mixtape in the 1980's and never had an issue. On very old machines like the 1960's Norelco that's in pic 3, it's not uncommon for the heads to have a little weirdness on the edges. If its not in the tape path, it's not an issue. This is just leftover "flash" from the plastic machining. Plastic encased heads like those seen on early Philips / Norelco machines became uncommon as tape tech advanced.

All tapes shed oxide, some just shed much more than others. This oxide presents itself as a brown residue on certain parts of the tape machine. If ignored, it just keeps caking on reducing the highs in the audio at first and progressively making the sound muddier. It will not only affect the audio but can also adversely affect how the machine handles the tape. Worst case scenario the tape is skewed, pulled at an angle, which permanently damages it by leaving creases. A machine that skews tape will eat tape. One of the joys of cassette tape is having to look for a bic pen to try to manually rewind a tape a machine has eaten! Dip a swab into isopropyl alcohol and use the tip to rub the tape heads from different angles until the tapes heads are clean enough. And you may need to use a few swabs, when a swab comes off and is still white, you know the tape heads are clean.In the pics you will see a Q-tip pointing to each part you need to clean. Does it matter which way you scrub? Not really. I have found it easier to clean a pinch roller by scrubbing across the face of it in the same direction the capstan engages it.

In pic 3 I pointed out the center of the heads and guides. The tape crosses the heads at the center, the guides are mainly there to prevent very poorly made cassettes from jamming things up. The guides will collect tape oxide in the corners and that should be cleaned.

Removable doors are generally only found on middle to high end home units and on very old shoebox style portables. Few boomboxes had them and only pro type portables of later years had them. In the pic there are two cassettes. The top one is a BASF from the 1980's. Note the shiny dark color. The lower one is a Scotch from the early 1970's. Note the dull brown color. Those older dull brown tapes are capable of soiling up the heads in just one pass. Alcohol (usually isopropyl alcohol or rubbing alcohol), effective for cleaning heads and guide rollers. Some machines have removable doors as seen in the second to last pic. On home units, if the door does come off it's usually by giving the face of the door a light pull up and away from the rest of the door. Not all have removable doors. Close examination of the door when it's open will usually tell you if it's removable. You'll see they are two distinct pieces.