Updated October 2026 · prices checked Oct 10, 2026.
Short answer: under $100 new, the honest picks are the original Topping DX1 (a small DAC/amp, while stock lasts) and a FiiO KA3 dongle for phones. The amps that made this price bracket famous, the Schiit Magni Heresy and JDS Labs Atom Amp+, are discontinued, and their replacements cost $119–129. So does the new Topping DX1 II. If you can stretch that far, do.
About 280 mW into 32Ω and 51 mW into 300Ω (Topping spec): roughly 3.9 V, or 4 dB of headroom on an HD 600. DAC included.
USB-C dongle with a 4.4mm balanced output rated about 240 mW into 32Ω. The under-$100 answer for phones and laptops.
Amp only, 415 mW into 300Ω (about 11 V) and 2.5 W into 32Ω. About three times the voltage of the DX1.
Replaces the Atom Amp+. JDS rates it at over 2.6 W per channel, with a low-gain setting for IEMs.
The original DX1 was sold out at Apos when I checked on October 10, 2026, and Topping announced its successor, the DX1 II, at US$119 for July 2026 (per StereoNET). StereoNET lists the DX1 II at 1 W into 32Ω and 230 mW into 300Ω, with 3.5mm and 4.4mm balanced outputs and a mic input on the 3.5mm jack. If the old DX1 is gone when you look, the DX1 II is the $119 stretch pick with a DAC included.
Do you need an amp at all?
Probably not, if your headphones need less than about 1 V for loud peaks. A phone, laptop or the $9 Apple USB-C dongle delivers about that much, which covers the ATH-M50x (~0.7 V), the HD 560S (~1.0 V) and most IEMs. The do I need a headphone amp? page has the voltage for 11 popular headphones.
You do need one for the HD 600 and HD 650 (~2.45 V), the 250Ω Beyerdynamics (~2.5 V) and planars like the HE400SE, which needs about 80 mW of current-heavy power that phone outputs can’t supply.
The picks in detail
Topping DX1: the only real desktop option under $100
The DX1 is a USB DAC and headphone amp in one small box. Topping rates it at 280 mW into 32Ω and 51 mW into 300Ω. Run the numbers: 51 mW into 300Ω is about 3.9 V, which gives the HD 600 roughly 4 dB of headroom above 110 dB peaks. That’s enough, though it isn’t generous. Into the HE400SE, 280 mW is about 3.5 times the 80 mW it needs.
Buy it if you want one box under $100 and your hardest load is an HD 600 or a budget planar. Skip it if you can spend $119: the Magni has about 9 dB more voltage headroom, and the K11 R2R (~$170) adds balanced output.
FiiO KA3: for phones and laptops
A USB-C dongle with 3.5mm and 4.4mm outputs. FiiO’s published figures are about 240 mW into 32Ω balanced and 130 mW single-ended. That’s plenty for IEMs and the DT 770 Pro 80Ω, and from the balanced jack it covers the HE400SE’s 80 mW with a few dB to spare. It is not the answer for 300Ω Sennheisers; those need a desktop amp.
Schiit Magni (Unity): the $119 stretch
Schiit retired the Magni Heresy and Heretic and replaced both with one Magni at $119, or $199 with the internal DAC card. Schiit’s specs: 3.0 W into 16Ω, 2.5 W into 32Ω, 415 mW into 300Ω, and output impedance under 0.1Ω. That’s about 11 V into 300Ω, or 13 dB of headroom on an HD 600. It’s the amp I’d buy if this page’s budget can move by $19.
JDS Labs Atom Amp 2: the $129 stretch
JDS Labs replaced the Atom Amp+ with the Atom Amp 2 (about $129). JDS rates it at over 2.6 W per channel, and it keeps the Atom’s low-gain setting for sensitive IEMs. It’s mainly sold direct from JDS Labs. Choose between it and the Magni on looks, stock and gain options; for any headphone on this site they are functionally equivalent.
Quick comparison
| Pick | Type | Price | Power into 32Ω | Into 300Ω | Volts @300Ω |
|---|---|---|---|---|---|
| Topping DX1 | DAC + amp | $99 listed | 280 mW | 51 mW | ~3.9 V |
| FiiO KA3 | USB-C dongle | check price | ~240 mW bal. | n/p | n/p |
| Topping DX1 II (stretch) | DAC + amp | $119 (launch) | 1 W | 230 mW | ~8.3 V |
| Schiit Magni (Unity) | Amp only | $119 | 2.5 W | 415 mW | ~11 V |
| JDS Labs Atom Amp 2 | Amp only | ~$129 | 2.6 W+ (JDS) | n/p | n/p |
n/p = not published by the manufacturer. Power figures are manufacturer specs (DX1 II as reported by StereoNET). HD 600 target: 2.45 V.
What to look for in a budget amp
- Voltage into 300Ω if you own Sennheisers or 250Ω Beyers: you want at least 2.5 V, and 5 V or more for comfortable headroom.
- Power into 32Ω for planars: 300 mW or more for an HE400SE, more for a Sundara at loud levels.
- A low-gain setting if you also use IEMs, so the volume knob isn’t stuck near zero.
- Output impedance under 1–2Ω, so low-impedance headphones keep their tuning.
Who should not buy an amp under $100
- IEM and ATH-M50x owners: your phone already does the job. Spend the money on headphones.
- HD 650 or Sundara owners planning to keep them for years: skip straight to the best amps under $200 . The extra headroom is worth $20–70.
- Anyone who needs a DAC too: the FiiO K11 R2R (~$170) in our DAC/amp combo guide costs less than a separate amp and DAC.
If you own a Magni Heresy or Atom Amp+
Keep it. Discontinued doesn’t mean worse: both still measure well and drive everything a Magni (Unity) does. The old reviews are still up as references: Magni Heresy , Atom Amp+ , and the head-to-head .
