Cassette Deck

Cassette Deck - What you need to know

Features and Specifications - Buying Second Hand Cassette Decks

If you are thinking of buying a Cassette Deck for your Cassette to CD transfers, then this article will give you some useful information and hopefully stop you buying a faulty or suspect deck.

Firstly, here is a summary of some features and specifications you will come across.

FEATURES and SPECIFICATION

Dolby, B, C, Dolby S

Types of Noise Reduction invented and licensed by Dolby Labs to reduce tape hiss
It should be noted that if you play a Dolby encoded tape on a non-Dolby cassette deck or a cassette deck with the Dolby Noise reduction switched off, the playback will have enhanced high frequencies (treble).
Most pre-recorded cassette tapes are encoded with Dolby B noise reduction so this is a fairly essential feature to have.

HX Pro 'Headroom Extension.'

This enables higher recording levels and dynamics without distortion. Good but not essential, especially if you are only using your cassette deck for playback only.

Auto Reverse

This feature enables you to play continuous music or audio. When the tape reaches the end, the tape deck reverses the direction of 'play' and plays the 'other side' automatically. This feature can be useful but adds more mechanical complication, which can affect reliability. (Not essential)

Logic or mechanical key operation

If a cassette deck has 'logic' control, this means the user buttons are switches, which operate electrical/electronics within the cassette deck. The mechanical operations and functions of 'play', 'record', and fast wind is done by solenoids, cams and gears.
Key operation is a manual form of the above. Play, Record, and Fast wind operations are 'enabled' with a mechanical lever the user operates.

Types of Cassette Tape - Normal, High Bias, Cro2. (There are others)

Cassette tapes come in different quality and types but good quality tapes should always be used. Cheap tapes are false economy; they don't sound good, and are more prone to tangling. A Good Normal bias tape is fine for most applications. High Bias tapes usually produce better quality recordings, as they will record a wider frequency response and dynamic range without distortion. CRO2 (Chromium Dioxide) tapes are High Bias and produce good results but they can increase tape head wear.

Auto/Manual switching for Tape Type Selection

Different types of tapes require the cassette deck to set bias and equalisation differently. Some cassette decks make these adjustments automatically, by sensing the type of tape placed in the unit. This is achieved by switches that are operated (or not) by small 'cut outs' in the top of the cassette case. Some older cassette decks have selector switches to manually select the required bias and equalisation to suit the type of tape being used.

Inputs and outputs

Just about all cassette decks include 'Line' level inputs and outputs. These take the form of 'phono' sockets (very often referred to as RCA). These are a standard level output for playback and input sensitivity for record. Some older decks include a 5 Pin DIN socket.
This type of socket combines the input and output (Record and Playback) within one socket. They are also a different standard for playback and sensitivity.
The output level from a DIN socket is lower than a 'Line Out' but can still be plugged straight into a 'Line In' socket of an amplifier.
The Input of a DIN socket (Record) is usually much more sensitive than 'Line' level so Line levels will very often overload DIN inputs which will result in distorted recordings.
Of course if you are using the cassette deck for cassette to CD transfer i.e. playback only, this isn't a problem.

2 head and 3 head machines

Most cassette decks use two tape heads one for erase, and one for record and playback.
A combined record/playback head is a compromise; it hasn't been optimised for playback or record, but is a compromise between the two. In more expensive cassette decks three heads are used, so a dedicated head is used for each function, which produces superior results.

Wow & Flutter

This is an important specification. If music played on a cassette deck sounds slurred and the pitch varies slowly, this effect is known as 'Wow'. If a cassette deck produces the same symptoms but the effect is faster, this is known as flutter. Wow and Flutter is a very unpleasant side effect especially as we're not used to hearing this from CD's, which don't suffer from this defect at all. Wow and Flutter is measured in percentage and a spec of 0.2% is pretty good.

Signal To Noise Ratio

This is another important specification. This figure, which is measured in dB's is the ratio between the all the unwanted, but inevitable noise produced by the cassette deck and the wanted music and audio. This figure should be as high as possible - something like 60dB or above.

Tape Speed

Cassette decks tape speed is 1 ¾ inch per second. Some decks, but not many have vari-speed, which allows the user to change the speed by + or - 5% or so. This enables the musical pitch to be changed slightly. Useful for musicians.

Take along a copy of a tape (not the original as you never know if the cassette deck might eat your tape!) you can listen to before you part with any money.

Firstly play your demo tape right from the very beginning including the leader tape (that's the first 7 seconds which can't be recorded on). Listen to the music and make sure it sounds clear and doesn't fade in and out or sound if it's going out of phase.

If it does then the clutches and pinch rollers may need replacing. Don't buy the cassette deck.

Common faults with cassette decks are wow and flutter and speed problems so take a tape with either slow piano, or material that includes long notes that will highlight speed fluctuations, and listen very carefully.
(If you have a tape with a continuous test tone recorded then so much the better)

Leave the cassette deck running while you're chatting to see if problems arise after it's been playing for a time and the cassette deck doesn't become mechanically noisy (possible motor faults).

If you think you hear speed fluctuations at any time then don't buy the cassette deck.

Next listen to the high frequencies (treble) - are they clear? If the sound is 'muddy' then this could be due to a tape head fault.

Three main problems occur with tape heads.

1. The heads are clogged up with tape oxide.
2. They have excess wear or
3. They are out of alignment

Take a look at the tape head to see if it's clean. There shouldn't be any brown oxide on the surface. If there is, ask the owner to clean the heads for you.

You can tell if the tape head is worn by looking at the surface of the head, which should be smooth, plus if you run your fingernail very gently from front to back of the head you shouldn't feel too much of a step.
If there is a step, try a recording.

Listen to the high frequencies while you're recording, then compare the playback. If there's a marked difference, the heads may need replacing.

It's a little trickier to tell if the tape heads are out of alignment unless you have an alignment tape with you, which you probably won't. Poorly aligned tape heads will produce the same symptoms as worn heads.

Suffice to say if the recording is poor - don't buy the cassette deck !

If the cassette deck passes all the above tests and it's the right price - buy it!

Professional Cassette to CD Transfers by SoundAbout.net