gizm0x x0x-heart MODs Eurorack Module 2026

These are the last few units available in this batch.
The next sale is scheduled for the end of MAY.

This is a gizm0x x0x-heart MODs Eurorack module
Handcrafted in small batches in Japan – every single unit is individually calibrated by hand for precise tuning and reliability. Due to limited production capacity, pricing reflects true value and sustainability.
a faithful analog recreation of the iconic Roland TB-303 bassline synthesizer voice, packed into a compact Eurorack format.
It includes the classic analog oscillator, ladder filter, VCA, envelope generator, and accent circuitry that made the TB-303 legendary for acid basslines and squelchy leads.
No built-in sequencer (pair it with your favorite Eurorack sequencer for full control). Black front panel.

Key Features & Improvements by gizm0x:

• Extensively tuned and refined based on years of repair experience with original TB-303 units for authentic sound and stability.
• Four additional modification switches over the standard x0x-heart:
  Bass Boost switch – Adds extra low-end punch.
  Resonance Boost switch – Pushes the filter resonance further for more aggressive squeals.
  Envelope Modulation Increase switch – Deepens the envelope's impact on the filter for more dramatic sweeps.
  VCF High-Range Shift switch – Extends the cutoff frequency range for brighter tones.
• Redesigned PCB for better reliability and maintenance:
  Dual-row connectors to eliminate past contact issues.
  All calibration trimpots moved to the rear for easy adjustments.
  Key capacitors upgraded from MLCC to film types for improved audio quality.
  Internal routing of previously exposed wiring cables.

This module delivers that classic 303 acid sound with modern enhancements and build quality – perfect for techno, acid house, or any modular setup craving authentic analog bass.

Warranty: 1-year coverage for natural faults (repair labor free).
Excludes damage from drops, water exposure, etc. Buyer may cover return shipping in some cases.

Great opportunity to add a premium 303 voice to your rack!

modular grid：modulargrid.net/e/other-unknown-x0x-heart-mods-eurorack

※Regarding import duties for U.S.:

Based on current U.S. import regulations, electronic musical instruments may be subject to import tariffs, even for relatively small items.

For reference, with a declared value of approximately USD 430, the estimated tariff rate is around 2.7%, which would be roughly USD 11–12.

I will ship this product via EMS.
That said, when shipping via EMS, it is not uncommon for packages to clear customs without duties being charged, especially compared to courier services such as FedEx or DHL.

However, this cannot be guaranteed, as customs decisions are ultimately made by U.S. authorities.
For this reason, it is safest to assume that a tariff of up to 2.7% may be applied.