Time stretching/pitch shifting without DSP, possible or not? Options

[bennetng]

I mean time stretching without changing pitch and pitch shifting without changing speed.

I ask this because my friend recently purchased a turntable (Stanton ST150) and it has time stretch function.

http://www.stantondj.com/pdf/products/turn...t150_manual.pdf

The manual says

Note: This turntable has separate analog and digital circuits. If you are
looking for a purely analog signal, use the Phono output. For access to
the Key correction feature use the Line output or S/P DIF output.

Note: Key lock and Digital output
processing is only available when the LINE
output is used.

So from my common sense and English level (not my native language), the line out is in fact converted from digital. But my friend insisted on thinking that the processing is done in analog domain and said if EQ can be done in analog domain, why time stretching/ pitch shifting can't?

What is your opinion?

[John_Siau]

I seem to recall that there were analog frequency-shift devices that were built with "Bucket Brigade Devices" (BBDs). A BBD device passes a charge down a long string of switched capacitors, and can be used as an analog audio delay line. These BBD frequency-shift devices were sampled analog systems, and not digital.

The BBD would be loaded with a short segment of audio, and then played back at at different shift rate. The segments of audio were simply spliced together by repeating or omitting chopped segments. These systems could frequency shift, but could not time stretch.

In many cases, time stretching was accomplished by using a tape recorder, and the frequency-shift device was used to restore a normal pitch.