Abstrakt Instruments Intros Avalon Bassline 303 Clone With A Twist


At the 2015 NAMM Show, Brian Castro of Abstrakt Instruments introduced the Avalon Bassline, a new Roland TB-303 clone with a twist.

The back of the Avalon Bassline has a cartridge slot, designed to let you swap out different filters, giving the synth different sonic personalities.

At the Show, Castro was demoing the Avalon Bassline in a booth shared with Social Entropy, who introduced the Engine x0x-style sequencer:

Here’s a much longer, in studio demo, of the Avalon Bassline. The demo features Avalon Bassline & TR-909, straight to Steinberg MR-816x, no signal processing:


  • The Avalon Bassline synth is an analog monosynth based on the TB-303. It combines a 100% mirror of TB-303 RevD mainboard together with a panel board containing additional analog and digital circuitry.
  • Uses all original spec parts of the original TB-303 (transistors, caps, IC’s, diodes, transformer, etc..) together with a BA6110 VCA with current gain calibrated to match the original BA662.
  • Fully backwards compatible with the original TB-303 (actually works with an original TB-303 CPU).
  • Sub oscillator has saw, sqr, and tri both -1 and -2 oct.
  • The cartridge slot is for filter carts which can be hot-swapped and used in place of the internal TB-303 filter.
  • Additional analog controls include sub/ext level control, filter tracking, accent decay, vca decay (goes full off), AD utility envelope with bi-polar modulation of the VCA and VCF.
  • I/O on back includes CV & Gate In/Out, accent sweep cv out (amplified and normalized to 0-5V), filter cv input. Audio out consists of saw and sqr out (+/-5V), external input, and vca & filter outputs.
  • Sequencer control has TB-303 pitch/time modes as well as a new realtime mode making use of the the step led switches (yes those are switches). Too many features to list – browse the panel to get an idea. patterns can be 64 steps in length with numerous time signature options. There are 448 internal patterns and 56 tracks. These can also be saved and loaded via sysex.
  • Sync modes are internal, MIDI and DIN, and it outputs both MIDI and DIN Sync. Also has USB-MIDI, and synth can be played externally.
  • Extremely high build quality including custom pots, german key switches, and 4-piece steel enclosure.

Official availability and pricing is to be announced.

via Kylee KennedyAbstrakt Instruments

18 thoughts on “Abstrakt Instruments Intros Avalon Bassline 303 Clone With A Twist

  1. I couple of years ago I built a x0xi0 with custom enclosure from Brian’s kit. He was sooo very helpful when I had questions along the way, top-notch customer service. He is definitely an authority on the TB-303 and I know he’s spent a lot of time getting everything right to meet his high standards for this new synth.

    This is the 303 clone (and so much more!) that you’ve been waiting for.

    1. I’ve been trying to get a x0xi0 for a while now. Brian’s site has said ‘more coming Nov 2014’ and he hadn’t responded to a couple emails I sent asking about ordering , I was starting to get worried. It all makes sense now though, he’s been busy working on this it appears. Looking forward to more demos.

  2. abstraktinstruments.com lists the filter cartridges:
    • 12dB svf
    • 24dB ladder
    • 24dB japan
    • 24dB 4075

    And on gearslutz Brian mentions a:
    • 12dB multimode Wasp filter

  3. This sounds really really good & promising!
    Unfortunately there’s a phase problem with the audio at the “First Look” Video but they already stated they would swap the soundfile asap.
    Give us the real sound! Can’t wait…! 🙂

  4. Am I the only one whose sick of seeing 303 clones? Go ahead and thumb this down but id like to see some unique and interesting new bass synths. Whatever happened to originality and pushing the sound forward? That’s the very basis of techno. Not going back to the old sounds constantly. This generation is taking the future out of futurism. Sigh.

    1. Some of us love acid /techno. I have since 88 . The 303 can be used in lots of ways and often its hidden in tracks that aren’t ‘acid tracks’ as such.There are quite a few bass synths but the 303 has a certain tone and the unique accent. I would love to see all new synths with accent built in , triggered by velocity. You can get bass synth sounds off any synthesizer.

      1. I agree the TB303 is a true classic ‘magic’ sound.

        Its a bit like saying the Electric Guitar is overused and old fashion in rock music.

        Any improvement over bulky plastic cases from xoxox’s and an perhaps elektron style sequencer is not a bad thing.

  5. Looks like Brian has done an amazing job as usual! Very professional looking piece of kit! Bass is bass and a saw wave is a saw wave, but the 303 made a cheap little box sound amazingly funky, a combination of a wierd sequencer and some basic filter/envelope controls! (Un?) Fortunately no one has been able to better it in the 30+ years since it was released . . .

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