FAQ, tips and tricks - General Questions

CLV and CAV Technology.
Is Digital Audio Extraction with the Plextor CD-ROM drives possible?
What is a Buffer Underrun?
How do I prevent Buffer Underrun from happening?
Fingerprints and dust on the CD-R media, can it cause problems?
How many bytes does it take extra per session when writing a multisession CD?
Can the PX-708A/UF or PX-712A/SA/UF write on the DVD+R DL media or can it do this in the future by updating the firmware?
Can we obtain a different colour of front bezel for a Plextor drive?

- CLV and CAV Technology.

The 4x, 6x, 8x and 12x drives use the CLV-method (Constant Linear Velocity), which means that the Data Transfer Rate (DTR) is constant. To hold a constant DTR the rotation speed must change from high (at the inner side of the CD-ROM) to low (at the outter side of the CD-ROM). The PX-20TS CD-ROM drive is a P-CAV (Partial Constant Angular Velocity) drive. This means that it starts reading the data at the inner side of the CD at 12-speed using the CAV-method. As the drive reads further to the outside of the CD the data transfer rate will increase. At a certain point, when 20-speed is reached, the CD-ROM drive changes to the CLV-method. This means the data will read out at a constant speed of 3000 Kb/s (20-speed). Most other CD-ROM manufacturers use the CAV-method but only mention the highest speed !
The PX-32CS and PX-32TS drives use the Full CAV method.
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- Is Digital Audio Extraction with the Plextor CD-ROM drives possible?

Yes indeed, it is possible. With the 8x and 12x drives you even can extract the audio tracks at 8-speed (1200 Kb/s). With the PX-20TS drives it is possible at 12 to 20 speed, and with the PX-32CS/TS at 14-24 speed. So Audio extraction at higher speeds is possible with your Plextor CD-ROM drive. Therefore these drives are mostly chosen for professional purposes.
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- What is a Buffer Underrun?

When writing a CD each track has to be written without any interruption. The PlexWriter therefore has a built in buffer of 2Mb to compensate the reduction in the transfer rate from the computer.If this transfer rate is to slow, the buffer runs out of data. This is called a Buffer Underrun. Buffer Underrun will cause the disc that is being written to be unusable.
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- How do I prevent Buffer Underrun from happening?

Make sure you have checked the following things :

Close all other programs (Especially those that can activate on their own).
Disable the screensaver.
Disable schedulers, animated icons, anti virus software, system sounds, ...
Disconnect from the network. Others may access your computer or send you a mail.
Defragment your disk, check the space in your temporary directory.
Disable Power Managers.

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- Fingerprints and dust on the CD-R media, can it cause problems?

Normally it shouldn't be a problem because the laser will focus beyond the dust, fingerprints or minor scratches. However a dusty disc should be blown off to prevent dust from entering the drive and winding up on the reader mirror or lens. When you have to clean a disc make sure you do it with a lens tissue and you only wipe in a radial direction. Top

- How many bytes does it take extra per session when writing a multisession CD?

After the first session, closing another session takes up 13.8Mb of disc space because of the writing of the Lead In and Lead Out again. This means if you write a disc in ten sessions, you can only write about 512Mb of data on this disc.
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- Can the PX-708A/UF or PX-712A/SA/UF write on the DVD+R DL media or can it do this in the future by updating the firmware?

The PX-708A/UF and the PX-712A / SA are single layer recorders with a maximum storage capacity of 4.7 GB. They cannot write DVD+R DL media.(9.4 GB) This will not be changeable by means of a firmware update. A dual layer recorder manufactured by Plextor is the PX-716A/SA/UF model. With the latest firmware installed, one should be able to read DVD+R DL media in the PX-708 and PX-712A. A complete list of recommended and compatible media is available on our media page.

However by means of installation of the latest firmware, DVD+R DL discs created on a dual layer recorder can be read.
Firmware updates are made available to implement minor adjustments and increase support and quality of the drive, the latest firmware revisions are made available on our firmware download page.
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- Can we obtain a different colour of front bezel for a Plextor drive?

Both black and white front bezels can be ordered from Plextor Europe for the latest models only. Price for these is set to 15 € including taxes and transport costs. Payment must be done using either VISA or MASTERCARD. For more details: Contact form.
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