The Pettyjohn IRON V3 is an analog overdrive pedal from Pettyjohn Electronics, part of the company's Foundry Series. Pettyjohn describes it as being all about "that cranked thick american amp sound," with what the maker calls depth, warmth, character and dimensional feel from real magnetic saturation1. It sits in the overdrive camp rather than distortion or fuzz, and it is built around the same JRC4558 chip family that shaped the classic Tube Screamer style of circuit, which you can read more about in our Boss SD-1 vs Ibanez TS9 comparison1.
"that cranked thick american amp sound"
Controls and clipping
The IRON V3 keeps its control layout focused:
| Control | What it does |
|---|---|
| DRIVE | Sets the overdrive gain amount1 |
| CLIP toggle | Three-way switch selecting among Pettyjohn's top three soft clippers, arranged in the feedback loop of the JRC45581 |
One of the CLIP positions is TS style symmetrical clipping, voiced with special NOS diodes included as stock, chosen by the maker for smoothness, great low end and musical harmonic content1. On the current version, Pettyjohn has also made the knobs and labels easier to read on stage1.
The high internal voltage is the other half of the design. The pedal takes a standard 9V adapter input and generates 36 volts internally, running the JRC4558 at plus and minus 18 volts for what Pettyjohn calls 36 volts of headroom1. More headroom generally means the circuit has more room before it clips the signal harshly, which is the design intent behind a cranked-amp style drive.
The IRON V3 needs a current-hungry supply: 200mA for the Standard version or 300mA for the Deluxe, from a standard 9V adapter1. That is far more than a typical overdrive, so check your pedalboard power supply's per-output current before adding it to a daisy chain.
Where it came from
The IRON Version 3 is Pettyjohn's take on what the maker calls "that cranked thick american amp sound," built around analog magnetics and real magnetic saturation rather than digital modeling1. The pedal carries a three-way CLIP toggle that puts Pettyjohn's top three soft clippers in the feedback loop of a JRC4558 running at plus and minus 18 volts for 36 volts of headroom1.
An earlier iteration of the IRON, documented in 2018, went further still:
- It included an extra JRC4558 chip inside the unit2
- That chip could be swapped out for even more tone possibilities2
Availability
At the time of the maker's product page, dated 26 October 2026, the IRON V3 was listed at $369.00 with limited stock showing only 1 left1. The pedal comes in the Foundry Series custom enclosure with in-set screws1.
Questions
Does the Pettyjohn IRON use a transformer?
Pettyjohn describes the IRON V3's sound as coming from real magnetic saturation, and the Foundry Version 3 line introduced in 2023 added inductor based EQ or transformer options drawn from the company's 2022 limited runs. The maker's product page for the IRON V3 centers on its JRC4558 circuit and NOS diode clipping rather than naming a transformer as a fitted part.
Is the Pettyjohn IRON V3 true bypass?
The IRON V3 uses a relay quiet bypass switching system with a soft touch switch, which Pettyjohn says gives totally quiet switching, and it auto-bypasses when power is switched off. That means the pedal passes signal on its own if it loses power, which matters on a board where a dead supply should not kill your sound.
How much current does the IRON V3 draw?
Pettyjohn specifies 200mA for the Standard version and 300mA for the Deluxe version, from a standard 9V adapter. The pedal converts that to 36 volts of internal power, so it needs a supply with more current on tap than a typical low-draw overdrive.
What op amp does the Pettyjohn IRON use?
The IRON V3 runs an authentic JRC4558 op amp, the chip long associated with Tube Screamer style overdrives. Pettyjohn runs it at plus and minus 18 volts for 36 volts of headroom, well above what a standard 9V pedal circuit provides.
Where is the Pettyjohn IRON made?
Pettyjohn Electronics states that all Foundry Series pedals, the IRON V3 included, are handmade in the Pacific Northwest of the United States.
Sources (2)
- IRON V3 | Pettyjohn Elec, Pettyjohn Electronics
- A Drive For All Occasions, Pettyjohn Electronics, 2018-12-13
