Friday, 23 January 2015

Roland TR 330

Roland TR-330  (late 1972 / early 1973 ??)

This is a bit of an odd one with respect to the name. It's pretty rare too. The TR label belies its roots - it's from the Roland family of Transistor Rhythm Machines.

Did Roland base it on the TR-33 and add a zero - thus TR-330 ??
She probably lies between the TR-77 which came out in 1972 & the TR -66 which was first manufactured in 1973. (It's definitely not as advanced technically as the TR-66 which is why I think it comes before the 66 & after the 77).
And I think it sounds a lot like my TR-77 too.

Take special note of the wooden cube shape. The 330 was the first of Roland's drum machines to take this appearance which would finally evolve into the ground breaking CR-78 in 1978.

There is heaps of bass and great analog percussion - claves etc. There are 8 drum sounds.The Kick is very very good. Reminds me of my TR-808. Lots of bottom end.

The voice board has trimmers (variable resistors) for tuning the oscillator's pitch & resonance....and/or for some very nice distortion. Nice warm & round analog sounds.

The circuit boards & speaker slide out of the wooden sleeve very easily They are held in with just 4 screws on the bottom.
And it has it's own built in speaker which you won't find on any other Roland drum of this vintage.
The speaker isn't of the highest quality but if you like rather cheezy distortion you will love it.

I don't have any service manual or schematic so if anyone out there has one I'd be forever grateful.

The tempo slider is unusual. It displays the tempo both in modern BPMs (40 to 280) and in the traditional classical way ..... in Italian, as was the custom before the invention of the metronome.
The old way is def more romantic. Largo (rather slow; stately), andante (walking speed) & presto (Very fast) are words you rarely see on a drum machine.

There is one "Balancing" knob which sets the volume of the Kick  & Hi hat. It can completely mute the hi-hat or totally remove the kick which I think is very useful.

There are 10 Preset patterns. Waltz, Slow Rock, Rock Beat, Bossa Nova, Mambo, Cha-Cha, Beguine, Rumba, March, Swing.
Size: 9-1/2" wide, 7" high, 12" deep. Weight 10-1/2 lb.

On the rear panel we have a jack for an external amplifier. There is also a jack for a foot-pedal control.

The speaker is on the top. Tempo switch to the left. To the right is the transformer. Careful with this if you open your 330 up. There are high voltages here which can be lethal.

At the bottom is the clock & tempo board. I haven't modded this one yet, but I reckon here is a good place to start looking for that external sync input. Above the tempo PCB is the power regulation board.

This is the underside of the machine. On the right we have the voice board. The left is the pattern board. I haven't opened it up but I understand that its completely made from diodes..... the famous diode matrix where we have a network of intersecting horizontal and vertical buses. All discrete logic. Nice !!!

For more info on the history of Roland Drum Machines click here


  1. Hi very helpful post here!
    is there a way to get this to midi sync?

    1. try the tubbutec unipulse. i just picked up one of these and have plans to add midi trigger and clock sync to it through the unipulse. the 330's board looks close enough to the tr-77 that i think the install notes might be sufficient to install.

  2. If people only knew how good this is and what you can do with the internal pots for voice shaping.....the LAST lost Roland gem

  3. Anyone have schematics for this?

  4. I'd like to share this with all you TR330 fans. I've done this using a very simple board with a PIC processor on it. About $10.00 in parts incl connectors ( not shown) See TR330_MIDI schematic on linked page. There's also a schematic of the sound card that I drew.

    Enjoy and get creative!