Cassette Transfers
Given The Audio Archive philosophy of standardizing on the best possible equipment for each sound recording format, we have selected the Nakamichi CR-7 series (CR-7, CR-7A, CR-7E) for all of our compact cassette transfers.
Why not the Nakamichi Dragon? "Isn't it the defacto gold standard for transfers?", you might ask.
The Nakamichi Dragon was a technological statement - a tour de force for 1982. One could argue that it is the ultimate stake in the ground representing all that could be achieved with the cassette format with few limitations. However, this does not mean that it is the ideal playback machine for all archival and preservation work.
The Nakamichi Dragon was designed to record and reproduce the highest quality recordings with an amazingly flat frequency response from 20 Hz to 20,000 Hz. This is indeed the perfect tool if you must preserve such high quality recordings.
But what happens when you must play back oral histories created 30 years ago on a $40 portable cassette recorder?
It is well known that one of the most critical factors in magnetic tape playback is playback azimuth alignment. For this, the Nakamichi Dragon features automatic playback azimuth alignment by locking onto frequencies above 3000 Hz. This is without question a great feature.
Let's now come back to our field recordings made on a $40 portable cassette recorder. You will find that there may not be enough high frequency information for the Dragon to automatically align the azimuth. Now that great feature has become a problem.
Enter the Nakamichi CR-7 series, introduced in 1986 - four years after the Nakamichi Dragon. With four more years experience, Nakamichi makes a new statement. The CR-7 series is simpler, yet comparable performance specifications to the Dragon. More attention is paid to the analog electronics in the CR-7. The audiophile community applauds the sound of the CR-7.
And the CR-7 series has a manual playback azimuth adjustment.
Which is why we have standardized on the Nakamichi CR-7 series with
- Comparable performance specifications to the Dragon
- Audio quality as good as or better than the Dragon
- Simpler design for easier long-term maintenance and service
- Manual azimuth adjustment
Just to complicate matters, not all Nakamichi CR-7 series machines are equal. Earlier machines have two weaknesses: an equalization error (up to S/N 8677), and a short-lived rubber idler (up to roughly S/N 10500). Some audiophiles actually prefer the rubber idler for listening because it is quieter than the gear drive that replaces the rubber idler, however it also requires regular replacement every two years or so. For transfer work, the gear drive does not affect the sound. Of the four CR-7 series machines that we have in production, the lowest serial number machine is 13566. Both the CR-7 series and the Dragon were produced up to 1993.
Dolby Noise Reduction
We prefer to use outboard noise reduction frames, rather than the built-in Dolby noise reduction that comes with the Nakamichi.
Our preferred outboard noise reduction frame for the cassette format is the Dolby Model 422 (introduced in 1990), which supports Dolby types B, C and S. The Dolby Model 422 was used for professional and commercial audio cassette mastering. The advantage of using an outboard Dolby decoder is better Dolby signal tracking. Because Dolby noise reduction is encoded in the high frequencies, any loss in high frequencies during playback will affect the Dolby performance, resulting in a more veiled sound and other analog audio artifacts. The Dolby 422 can be tuned to a specific tape for optimal decoding and best frequency response, whereas the built-in Nakamichi Dolby decoder cannot.
Damaged Cassettes
There is a wide gamut of problems that can potentially plague a cassette. These problems include:
- Poor head contact
- Leaders that have detached from the hub(s)
- Leaders that have detached from the tape
- Hubs that will not turn
- Tapes that squeal
- Mold and fungus
We can remedy all of the above problems, with the exception of mold and fungus. We are not currently equipped to handle and dispose of biohazardous materials.