ATS Mini versions compared: V3 vs V3S vs V4 vs V4b
The ATS Mini has been through several board revisions — V1, V2, V3, V3S, then V4 (with V4a and V4b board variants, the latter sold openly as "V4B"). The version numbers suggest bigger differences than exist: the receiver, the processor and the display are the same on every revision, and they all run the same open firmware. What changed is the antenna input stage, a battery bug, the case and the wiring for on-device decoding. Here is the honest comparison.
The comparison table
| V3 | V3S | V4 | V4b | |
|---|---|---|---|---|
| Receiver chip | SI4732 | SI4732 | SI4732 | SI4732 |
| Processor | ESP32-S3 | ESP32-S3 | ESP32-S3 | ESP32-S3 |
| Display | 1.9″ colour (identical) | Same | Same | Same |
| Coverage | 150 kHz–30 MHz + FM 64–108 MHz | Same | Same | Same |
| High-impedance (JFET) whip input | Yes — introduced here | Yes | Yes | Yes |
| Battery drain when switched off | Affected — JFET stage wired to the unregulated battery rail | Fixed (moved to the regulated rail) | Not affected | Not affected |
| CW/RTTY decoding without soldering | No — needs a one-wire mod | No — needs a one-wire mod | Only with a V4a/V4b board inside | Yes — audio tap to the ESP32 fitted at the factory |
| Case | Plastic, AMNVOLT-branded | Plastic, AMNVOLT-branded | Sturdier plastic case | Sturdier plastic case |
| Antenna jack | SMA female | SMA female | SMA female | SMA female |
| Battery | Built-in rechargeable, USB-C | Same | Same | Same |
| Runs current firmware (2.34+) | Yes | Yes | Yes | Yes |
| Works with this app | Yes | Yes | Yes | Yes |
| Still sold | Superseded — buy a V3S instead | Yes (budget pick) | Yes | Yes (current top revision) |
What each revision actually changed
V3 added the high-impedance JFET input stage that makes the short whip work as well as it does — and shipped with a real flaw: the stage was wired to the unregulated battery, so early V3 boards drain a few milliamps even with the radio switched off. V3S is the corrected board, and the reason "buy V3S, not plain V3" is standing advice. V4 brought a sturdier case and audio improvements. The V4a/V4b boards add one thing more: the SI4732 audio output is wired to the ESP32 at the factory, so the radio decodes CW and RTTY on its own — a firmware feature that older boards can also run after a one-wire solder mod. None of these steps changed how well the radio hears; the front end’s character and the display are the same throughout.
Which one should you buy?
- Starting fresh: the V4 (V4b board) — current revision, no soldering for decode features, and the version most listings sell. See the receiver page for the checked listings.
- On a budget: a V3S — the same reception and the same firmware for less money. You give up the factory decode wiring and the newer case, nothing else that matters.
- Avoid: a plain V3 (the battery drain), anything sold as "V5" (the makers say V4 is final, so V5 listings are fakes), and unbranded metal-case units — counterfeiters reportedly drop V1-class boards into metal shells.
Firmware: the great equaliser
Every revision here runs the same open firmware, and that matters more than the board differences. Bluetooth control, fast direct tuning and this site’s USB remote all arrived in firmware 2.34, and a V3S flashed to the current release has every one of them. The features that genuinely need newer hardware are few — essentially the solder-free CW/RTTY decode path. Details in firmware versions, and buying-checklist notes in the receiver guide. Once you have any of them on your desk, connect it to this app — the experience is identical.
Recommended gear
- ATS Mini Amnvolt V4BReceiverThe revision this comparison recommends when starting fresh: sturdier case and the factory decode wiring.
- ATS Mini v3ReceiverThe budget route — same reception and the same firmware for less. Check the listing sells a V3S, not an early plain V3.