Belt Driven "Direct Drive" Units

[TRC]

To me, "Direct Drive" implies exactly that; a non-belt drive system. My Fairchild 412 Turntable operates with a belt, and is therefore belt-driven. My Sony PS-X5 and Sansui SR-636 tables have no belts and are therefore direct-drive.

However, my Pioneer 10.5" RT-909 Open Reel machine is a three motor deck employing separate motors for the reel table, but the third for the dual capstan drive is shared by use of a belt. My 7" RT-707 employs the same, as does my Nakamichi BX-300 Cassette deck.

Now to me, these are not true direct-drive machines. Would you agree or am I missing something.

And if these are not truly direct-drive units, why then are they identified as such?

TRC

 

[mhardy6647]

It's just marketing.

 

[goldear]

To me, "Direct Drive" implies exactly that; a non-belt drive system. My Fairchild 412 Turntable operates with a belt, and is therefore belt-driven. My Sony PS-X5 and Sansui SR-636 tables have no belts and are therefore direct-drive.

However, my Pioneer 10.5" RT-909 Open Reel machine is a three motor deck employing separate motors for the reel table, but the third for the dual capstan drive is shared by use of a belt. My 7" RT-707 employs the same, as does my Nakamichi BX-300 Cassette deck.

Now to me, these are not true direct-drive machines. Would you agree or am I missing something.

And if these are not truly direct-drive units, why then are they identified as such?

TRC

Normally when one speaks about direct or belt drive in the context of tape decks, you are talking about the drive mechanism for the capstan(s).

Your 909 is a belt drive unit, but it does feature direct drive _reel_ motors.
Your 707 is a 100% direct drive unit. The only belt is used for the counter
Your BX-300 is partially direct drive. The Front capstan _is_ direct drive, but the rear capstan is a slave device which is driven by a belt connecting to the front capstan. But the hubs are not direct drive on any Nak: they are driven by an idler, and one motor is shared between by the hubs. The third motor on a Nak drives the transport.

The only 100% direct drive cassette deck that I am aware of was the Revox B215.

 

[SaSi]

The only 100% direct drive cassette deck that I am aware of was the Revox B215.

And the B710 / B710MkII. All three decks used an almost identical transport mechanism, employing 4 motors. 2 DC for the reels and another 2 FG controlled for the capstans. A really smooth transport for the tape employing sophisticated tricks such as identifying when the cassette was almost wound in FF/REW to slow down FF/REW at the end of the tape.

But lots of problems can arise from this otherwise uncomplicated mechanism.

From all the belt drive mechanisms in R2R, the one I've seen and personaly hate is the X1000R, X2000R, X10R Teacs. The belt drives both flywheels and depending on direction, the belt must engage a different part of the flywheel giving the speed differential between capstans. It works, with a clean new belt and clean flywheels and minute adjustments all over - from the pinch roller pressure to back tension. Even if one of those things get's out of spec, the whole thing messes up.