what is it about 4-Channel Pickups?

Hi
seen on ePay a old CEC 4-Channel Turntable. It has a standard MC-20 MM Pickup, what is definately NO 4-channel pickup.

could anyone Xplain to me, what pickup would be necessary to play 4-channel recordings and tell a bit about this technique?

Thanks, Helge

Cd-4

The short answer:

There were two methods to quadraphonic playback on vinyl. One method used a matrix (SQ and QS) to encode the signal to two channels and a complimentary matrix to decode the two channels into four. Any ordinary stereo cartridge can be used to play back these types of quadraphonic records.

The second method (CD-4) used a high frequency, frequency modulated (30kHz. +/- 15kHz.) signal (similar to the FM multiplex system). Playback of CD-4 discs needed a phono cartridge that could track the up to 45kHz.signal pressed into the vinyl. For successful playback a specially shaped stylus was required for good results. The Shibata (introduced by Audio Technica) cut was the first of these. Later other manufactures introduced styli with special cuts that would correctly track the high frequency grooves. Pickering made the “Quadrahedral”, Shure the “Microridge” etc.. Playing a CD-4 disc with an ordinary cut stylus will tend to damage the disc because the stylus can not track the high frequency content.

Thank a lot for the Info!!

so, whats the Sense when a Turntable is especially "4 Channel Stereo Player"



if it depends on the source vinyl or the Pickup. whats special on the Player itself?

Helge

Dynacophil said:

if it depends on the source vinyl or the Pickup. whats special on the Player itself?

Helge

Click to expand...

In order to keep the high frequencies from being attenuated, the arm and lead capacitance must be lower than what was typical back then. Most cartridge manufactures recommended a total load capacitance of 100pF for optimum flat frequency response. Turntable manufactures responded by making their turntables with lower arm capacitance and including a low capacitance interconnect wire for use between the turntable and preamplifier.

TCdriver!

thank you again!

so it really is a difference to a normal player... if it stays cheap i will try to get it.

Helge