JDS Labs Atom Amp+
Our job is to help you enjoy exceptional headphones. What we explained when announcing Atom Amp still holds true: We do not release new hardware for the sake of release schedules or corporate goals. In fact, this announcement was not on our roadmap and JDS Labs is doing well without the need to grab your attention. Of tens of thousands of Atom Amp owners, virtually no one has asked for more performance. Alas, we’ve continuously improved Atom Amp and it’s no longer accurate to call Atom Amp just an Atom Amp.
Atom Amp is now Atom Amp+, our best value amplifier. Aside from subtle fit and finish improvements since release, we’re tagging “Atom Amp+” because we’ve boosted performance using the same analog IC employed in the matching Atom DAC+. More importantly, every Atom Amp+ is built with hand matched potentiometers for superior low volume imaging, up to 20dB better than the originally spec’ed Alps pots.
Atom Amp+ remains only $99 USD!
Atom Amp+ is built on the exact same circuit board as Atom Amp. The bulk of the performance boost results from upgrading the input stage ICs from NJM2068 to NJM5532, followed by small tweaks to supporting resistors.
You’d expect this material cost increase and 20% global inflation to increase the price tag. Good news: We’ve moved Atom Amp+ PCB assembly from California to Illinois USA. This is not a corner cutting change. Rather, we’re super excited to partner with a growing CM who shares our manufacturing passion for constant improvement through automation. The transition has reduced freight costs and improved delivery speed. Yield is higher than ever, with zero defects found in the first thousand Atom Amp+’s.
Power: Atom Amp+ renders the same clean output power as the original, which is more than enough for over 99.9% of listeners. JDS Labs actively opposes shipping larger transformers to realize vastly unnecessary power specs. We understand our reasonable customers would even prefer to see smaller transformers. We’re confident Atom Amp+ strikes the right balance of enough power, and not too much. We made no changes to the output stage. Retuning the input stage slightly increased maximum output voltage at higher headphone impedances.
Enclosures: Fit and finish has come a long way since release. Of all the constructive feedback we’ve received, the general consensus is that some fingers prefer a beefier knob. Extra weights are still free upon request. If aftermarket knobs are not your thing, there’s always EL Amp II+ in a CNC milled aluminum enclosure.
Potentiometers: We were not quite satisfied with the small improvements to our 2019 Alps potentiometers. We originally considered triple gain to help with lower volume listening, but recognized the potentiometer would remain an audible bottleneck. We ultimately commissioned another manufacturer to produce custom potentiometers for Atom. Gangs are hand matched for tighter L/R balance to levels ~20dB lower than Alps was able to offer. All Atom Amps built since May 2020 feature our custom pots, so we’ve already accumulated a wealth of feedback to verify consistency and reliability. This important improvement is standard in Atom Amp+.
Atom Amp+ achieves a crazy 119dB SINAD @ 20-20kHz BW. This is around 6dB better than the initial release. Totally inaudible, by the way.
It’s possible to reach 120-122dB SINAD by omitting Atom’s high pass input filter, but there’s no incentive to do so. We know customers appreciate RFI rejection from the high pass filter and prefer a distraction free listening experience.
|Frequency Response, 20Hz-20kHz
|SINAD @ 2VRMS, 1kHz
|SINAD @ 50mV, 1kHz
|Crosstalk @ 10kHz
|> 122 dB
|> 122 dB
|Dynamic Range (AES17)
|> 120 dB
|> 120 dB
|Max Continuous Power @ 600Ω
|125mW (8.68 VRMS)
|Max Continuous Power @ 150Ω
|502 mW (8.66 VRMS)
|545 mW (9.04VRMS)
|Max Continuous Power @ 32Ω
|1 Watt (5.66 VRMS)
|1 Watt (5.66 VRMS)
Atom Amp+ is In Stock today at 99 USD. For those who ordered Atom Amp after May 28th 2021, you received a free upgrade to Atom Amp+ in an enclosure labelled as Atom Amp.
While inventory allows, Atom Amp+ boards in brand new enclosures labelled ‘Atom Amp’ are available in the B-Stock listing at only 89 USD.