Iron Stack Released — A Breathing Wall-Gain Machine

[kbudrin]

Iron Stack — a responsive wall-gain amplifier built around overload, pressure and recovery dynamics.

Originally developed as an experimental branch of the amplab engine, Iron Stack slowly evolved into its own standalone project focused on massive nonlinear gain behavior and reactive cabinet dynamics.

Instead of aggressively removing low-end to keep high gain “clean”, Iron Stack lets the system overload, choke, recover and reorganize itself in real time. Sustained chords can literally fall apart and pull themselves back together while the cabinet struggles under master pressure.

The result feels less like a static amp snapshot and more like a huge nonlinear machine under load.

Sound-wise it ended up somewhere between:

* giant transistor stacks
* overdriven tube amps
* doom/sludge walls of gain
* industrial machinery barely holding together

Features:

* evolving nonlinear gain behavior
* dynamic overload recovery
* responsive cabinet breakup/stress
* highly reactive master section
* standalone app + plugin

No neural captures.
No IR obsession.
Just pressure, overload and controlled collapse.

Iron Stack available in two versions: Full Edition with dynamic cabinet modelling and Free Community Edition with a static cabinet model.

Latest Demo:


Project site:
BudrinLabs Iron Stack


Changes:

Major Update — Iron Suite / IronStack 2.1.0
This is a major release, in the same class as Amplab 2.1.0 — not a patch on the old IronStack build.
What changed
This thread started with IronStack alone. From 2.1.0 Iron is a three-amp suite on one DSP foundation and one shared FX route:

• IronStack — wide-spectrum high gain
• IronHybrid — tighter lows, more open upper path
• IronClean — high-headroom clean / pedal platform

Switching products changes the amp architecture, not a skin or a preset pack.
New Iron FX chain
The effects route was rebuilt:

• editable blocks in playing order
• full suite path: Pre-EQ / Drive / Preamp / Mod / Power / Cab / Post-EQ / Delay / Reverb
• model selectors where they belong
• FX opens inside the main editor and fills the face area
• dynamic cabinets remain load-aware (not IR loaders)

Community vs full
IronStack Community 2.1.0 — free for Windows / macOS / Linux

• full IronStack amp + dynamic cab
• FX cut to Preamp / Power / Cab / Room
• no gate / drive / mod / delay, no model pickers
• SPACE / ROOM stay live on the faceplate

Iron Suite 2.1.0 — paid

• IronStack + IronHybrid + IronClean
• Standalone + VST3
• complete FX route across the family

Platforms
All desktop packages aligned to 2.1.0 for Windows, macOS and Linux.
Links

• Audio overview: https://budrinlabs.com/audio
• Iron / Community downloads: https://budrinlabs.com/ironstack
• Iron Suite (full): https://ko-fi.com/s/6082d75aa0

v1.0.0

* Release version!
* Reworked the gain stack for a more open, natural high-gain response.
* Improved the high-frequency behavior: the top end is no longer choked too early, while still avoiding harsh fizzy overload.
* Expanded the Response control in the full version, letting the power section move from a tighter, faster feel to a looser, more reactive stack.
* Updated Android engineering demo to the current 1.0.0 DSP engine.

v0.2.0:
* reworked cabinet response under heavy master pressure
* smoother and more believable high-frequency overload behavior
* reduced harsh “digital itch” during saturation
* improved low-end collapse/recovery dynamics
* more elastic and reactive sustain behavior
* better integration between cabinet stress and gain topology

v0.2.1

* Added mirrored Windows audio output for the standalone version, allowing realtime demo/video recording while monitoring through ASIO devices.
* Reworked cabinet response under heavier overload conditions.
* Improved cabinet collapse/recovery behavior during sustained low-frequency pressure.
* Adjusted upper breakup response for smoother overload transition under extreme saturation.

v0.3.0

* New industrial-style front panel with drawn controls, toggle switches and status lamps
* Added standalone utility section with Noise Gate, Reverb and Cab Sim switching
* Added lightweight Freeverb-style room reverb, implemented inside the DSP engine
* Noise gate added for noisy single-coil setups and direct standalone recording
* Dynamic bypass retuned for smoother low-gain behavior and tighter high-gain lows
* Cabinet overload now has more usable headroom before speaker breakup
* Edge control now shapes both the high-end voice and the dynamic bypass response
* Improved low-gain feel and reduced “cold fizz” artifacts
* Updated cabinet behavior for a wider playable range before the speaker starts falling apart

v0.4.0

* Reduced input level for humbuckers and high-output pickups
* Less unwanted low-gain breakup and crackling
* Removed clicks and sudden sound drops while turning controls
* Smoother, more natural real-time control response
* Improved low-end control to prevent bass from overwhelming the distortion
* Wider and more useful midrange adjustment
* Reduced harsh high-frequency fizz
* Better cabinet headroom at clean and low-gain settings
* Added a free experimental Android version for use with USB audio interfaces (available on Project Site
)

v0.5.0

* Removed the inter-stage filtering approach from the gain stack
* The high end now feels more open and natural, without the previous “choked” top-end response
* Reduced harsh, sandy high-frequency distortion while keeping the amp aggressive
* Improved low-end stability, so heavy settings stay big without falling apart too early
* Updated the free Iron Stack Community edition for Windows, macOS and Linux


Iron Stack was originally developed as an experimental branch of the amplab engine.
Main amplab thread:
viewtopic.php?t=630286

[kbudrin]

Iron Stack 0.2.0 released

This update focuses heavily on cabinet behavior and high-frequency response under extreme overload conditions.

Changes in 0.2.0:
- reworked cabinet response under heavy master pressure
- smoother and more believable high-frequency overload behavior
- reduced harsh “digital itch” during saturation
- improved low-end collapse/recovery dynamics
- more elastic and reactive sustain behavior
- better integration between cabinet stress and gain topology

One of the main goals of this update was making the system behave less like a static distortion chain and more like an overloaded physical structure struggling under pressure.

Under extreme load the cabinet can now choke, compress, partially collapse and recover in a far more natural way while preserving the massive low-end character Iron Stack is built around.

Project page and demos:

https://www.budrinlabs.com/ironstack

[kbudrin]

Finally managed to record a proper realtime Iron Stack demo video without OBS and ASIO trying to kill each other

The demo uses the latest 0.2.0 build with the updated cabinet behavior and smoother high-frequency response under heavy saturation.

The video demonstrates different gain ranges and realtime knob interaction, including how the amp reacts under heavier master pressure.

Demo video:


Project page:
https://www.budrinlabs.com/ironstack

[kbudrin]

Iron Stack 0.2.1

* Added mirrored Windows audio output for the standalone version, allowing realtime demo/video recording while monitoring through ASIO devices.
* Reworked cabinet response under heavier overload conditions.
* Improved cabinet collapse/recovery behavior during sustained low-frequency pressure.
* Adjusted upper breakup response for smoother overload transition under extreme saturation.

[zerocrossing]

Finally managed to record a proper realtime Iron Stack demo video without OBS and ASIO trying to kill each other

The demo uses the latest 0.2.0 build with the updated cabinet behavior and smoother high-frequency response under heavy saturation.

The video demonstrates different gain ranges and realtime knob interaction, including how the amp reacts under heavier master pressure.

Demo video:


Project page:
https://www.budrinlabs.com/ironstack

Very interesting. I could see this getting some use in my studio. I like that it's not yet another Marshall/Vox/Fender/Mesa clone. Is this meant to be free, or will it be a commercial release?

[kbudrin]

Very interesting. I could see this getting some use in my studio. I like that it's not yet another Marshall/Vox/Fender/Mesa clone. Is this meant to be free, or will it be a commercial release?

Thanks! That was actually one of the main goals behind Iron Stack — not trying to recreate an existing amp family, but exploring overload/recovery behavior as its own thing.

At the moment it's released as a small commercial project on Ko-fi (€20), but it's a one-time purchase with all future updates included, not a subscription.

I'm still actively evolving the DSP side of it, especially the cabinet dynamics and nonlinear recovery behavior.

[zerocrossing]

Very interesting. I could see this getting some use in my studio. I like that it's not yet another Marshall/Vox/Fender/Mesa clone. Is this meant to be free, or will it be a commercial release?

Thanks! That was actually one of the main goals behind Iron Stack — not trying to recreate an existing amp family, but exploring overload/recovery behavior as its own thing.

At the moment it's released as a small commercial project on Ko-fi (€20), but it's a one-time purchase with all future updates included, not a subscription.

I'm still actively evolving the DSP side of it, especially the cabinet dynamics and nonlinear recovery behavior.

Nice. I’m definitely watching this.

[kbudrin]

Iron Stack v0.3.0 public beta is out.

This is the first build where Iron Stack really starts to feel like its own instrument rather than an amplab side branch.

Video demo:


Website:
https://www.budrinlabs.com/ironstack

v0.3.0

* New industrial-style front panel with drawn controls, toggle switches and status lamps
* Added standalone utility section with Noise Gate, Reverb and Cab Sim switching
* Added lightweight Freeverb-style room reverb, implemented inside the DSP engine
* Noise gate added for noisy single-coil setups and direct standalone recording
* Dynamic bypass retuned for smoother low-gain behavior and tighter high-gain lows
* Cabinet overload now has more usable headroom before speaker breakup
* Edge control now shapes both the high-end voice and the dynamic bypass response
* Improved low-gain feel and reduced “cold fizz” artifacts
* Updated cabinet behavior for a wider playable range before the speaker starts falling apart

Iron Stack is still a public beta / preview build, but the core sound direction, UI and standalone workflow are now much closer to the intended product.

[kbudrin]

Patch v0.3.1 released. Changes:

* Expanded the Mid / Attack control range significantly
* Mid control now goes from a deep mid cut to an extreme mid push, with neutral behavior around the center position
* Improved midrange shaping for more flexible voicing, from scooped and tighter to aggressive and forward
* Reduced low-end boom that could overpower the whole signal path
* Rebalanced the first gain stage so bass does not overload the chain too early
* Improved high-gain clarity by keeping the low end more controlled before later stages
* Preserved the aggressive Iron Stack feel while making the response easier to shape

[agharta]

This might as well be written in Klingon for all I can grasp!
Good luck with it and watch out for the photon torpedoes.

[kbudrin]

Iron Stack v0.4.0 — Release changes

- Reduced input level for humbuckers and high-output pickups
- Less unwanted low-gain breakup and crackling
- Removed clicks and sudden sound drops while turning controls
- Smoother, more natural real-time control response
- Improved low-end control to prevent bass from overwhelming the distortion
- Wider and more useful midrange adjustment
- Reduced harsh high-frequency fizz
- Better cabinet headroom at clean and low-gain settings
- Added a free experimental Android version for use with USB audio interfaces

An experimental Android build available on a project page:
https://www.budrinlabs.com/ironstack

[pekbro]

Interesting, any chance for a proper demo version?

[kbudrin]

Sure, I'll release it within next few days

[pekbro]

Sure, I'll release it within next few days

Great thanks! looking forward to checking it out.

[kbudrin]

You asked for it, so I made it: a free, cut-down Iron Stack Community Edition is now available.

It includes the preamp, power amp and a simple static cabinet filter, so you can try the core sound and feel. The noise gate, reverb and full dynamic cabinet are not included.

Windows, macOS and Linux downloads:

https://www.budrinlabs.com/ironstack