Updated October 2026 · prices checked Oct 10, 2026.
Short answer: the Topping DX5 II (~$299) is the best headphone amp under $300 if you want one box with power to spare. For 300Ω Sennheisers alone, a $119 Schiit Magni (Unity) does the same job. Three former picks here, the Magni Heresy, Asgard 3 and Drop THX 789, are discontinued and have been replaced below.
DAC + amp + Bluetooth LDAC, about 6.4 W into 32Ω and 990 mW into 300Ω balanced (Topping spec). Drives anything in this price class.
Most of the DX5 II's usefulness for ~$130 less: R2R DAC, 4.4mm balanced, about 8 V into 300Ω.
Amp only, $119. 415 mW into 300Ω and under 0.1Ω output impedance: the cheapest way to drive an HD 600 or HD 650 properly.
Comparison
Yardsticks: HD 600/650 need 2.45 V for 110 dB peaks; HE400SE needs 80 mW, Sundara 40 mW.
| Amp | Price | Type | Into 32Ω | Into 300Ω | HD 600 headroom |
|---|---|---|---|---|---|
| Topping DX5 II | ~$299 | DAC + amp + BT | 6.4 W bal. / 2.2 W SE | 990 mW bal. / 250 mW SE | +17 dB / +11 dB |
| FiiO K11 R2R | ~$170 | DAC + amp | ~1.3 W bal. | ~220 mW bal. | +10 dB |
| Schiit Magni (Unity) | $119 | Amp | 2.5 W | 415 mW | +13 dB |
| Schiit Midgard | $219 | Amp | 4.8 W | 750 mW | +16 dB |
| FiiO K7 | ~$220 | DAC + amp | 2 W bal. | ~220 mW SE | +10 dB |
| FiiO K13 R2R (stretch) | ~$319 | DAC + amp | 2.4 W bal. | 600 mW bal. | +15 dB |
Manufacturer specs. Schiit prices from schiit.com on Oct 10, 2026.
The picks
Topping DX5 II: best overall under $300
Launched in mid-2025 at $299, the DX5 II is the default one-box answer in this bracket. It has 4.4mm, 4-pin XLR and 6.35mm headphone outputs, USB/optical/coax inputs, Bluetooth with LDAC, a remote, and VU-style metering. Its balanced output is rated about 6.4 W into 32Ω, which is more than any budget planar will use. Single-ended it’s still about 8.7 V into 300Ω.
Skip it if you only own 300Ω Sennheisers and a DAC: the Magni does that job for $119.
FiiO K11 R2R: best value one-box
If the DX5 II’s power is more than you’ll ever use, the K11 R2R gets you a DAC, balanced output and enough voltage for HD 600s at a bit over half the price. Its single-ended jack is weaker (around 50 mW into 300Ω), so use the 4.4mm output with high-impedance headphones.
Schiit Magni (Unity): best amp-only value
Schiit’s only Magni now, replacing the Heresy and Heretic. 2.5 W into 32Ω, 415 mW into 300Ω, preamp outputs, $119 ($199 with the DAC card).
Schiit Midgard: most power without a DAC
At $219 the Midgard is an amp-only unit with 4.8 W into 32Ω and 750 mW into 300Ω through ¼-inch or 4-pin XLR (Schiit spec). It’s the pick for planar owners who already have a DAC and don’t want to pay for one again. Sold direct at schiit.com .
Tube option: Darkvoice 336SE or Schiit Vali 3
For 300Ω Sennheisers, an OTL tube amp such as the Darkvoice 336SE is the classic warm pairing; owners of the HD 650 and HD 6XX on Head-Fi have recommended it for years. It’s a poor match for planars and anything under about 100Ω because of its high output impedance. I couldn’t confirm a current US price, so check the listing.
If you want tube character with any headphone, the Schiit Vali 3 ($149, tube hybrid, 0.5–1.8Ω output impedance) is the safer buy. More in tube vs solid state .
Stretch: FiiO K13 R2R (~$319)
FiiO’s newer R2R desktop unit, rated 2.4 W into 32Ω and 600 mW into 300Ω balanced. It’s $20 over budget and makes sense if you want R2R and more balanced power than the K11 R2R. Head-to-head with the DX5 II, the Topping has more power and Bluetooth; the FiiO has the R2R DAC.
What replaced the old picks
| Old pick | Status | Buy instead |
|---|---|---|
| Schiit Magni Heresy | Discontinued | Schiit Magni (Unity), $119 |
| Schiit Asgard 3 | Discontinued | Schiit Asgard X ($399) or Midgard ($219) |
| Drop + THX AAA 789 | Drop closed March 2026 | Topping DX5 II or Schiit Jotunheim 3 ($499) |
Who should not spend $300 on an amp
- HD 600/650, DT 990 Pro 250Ω owners with a DAC already: the $119 Magni already gives 13 dB of headroom.
- IEM, ATH-M50x and HD 560S owners: check the voltage table first. You probably don’t need an amp at all.
Related: best amp for HD 600 · best amp for Sundara · best balanced amps · DAC/amp combos under $300
