JDS Labs Element II — Official Release & Benchmarks

JDS Labs Element II

The Element is a timeless mechanical design which has remained in demand for over four years with only minor electronics improvements. While we could keep building the same, we’re excited to share more of our best work.

Element II has been re-engineered as the flagship JDS Labs amp+DAC and amplifier. If you’ve been looking for a metal version of Atom Amp, Element II adopts the core amplifier technology in a CNC milled, aluminum chassis. Preamp RCA outputs are button controlled, so you can use the large knob to adjust your speakers without disconnecting cables.

Of matching caliber, Element II destroys digital-to-analog performance of the previous generation. An XMOS USB controller and MEMS oscillator improve jitter by two orders of magnitude, and the AK4493EQ DAC pushes dynamic range and THD+N to impressive levels.

Hardware Overview

Amplification and Power Stages

Element II is DC coupled throughout, relying on +/-15VDC rails derived from internal AC rectification with 50% more input capacitance and lower ripple compared to the first generation. The amplifier and USB DAC are both powered by an external 16VAC 1000mA transformer. Element II runs safely warmer than Element, as expected from powering its own DAC (no more USB power).

Amplification circuitry and PCB layout are inspired by Atom Amp, with greater PCB surface area dedicated to amplifier thermal relief. Higher noise tolerance NJR opamps are utilized in the voltage gain stage, along with thin film resistors for tighter channel matching. In short, this means less variation from one assembly to another.

The amplifier accepts up to 2.2VRMS at high gain of 4.73x, with headroom for Element II’s 2.0VRMS DAC. Low gain is set to unity (1.0x) for sensitive headphones. Volume is controlled by an Alps 9mm potentiometer with optimal 15A taper.

Relays

Instead of mechanical switches, a microprocessor controls hardware muting, gain, and preamp output events.

Integrated Preamp

The Mode button allows you to easily toggle between headphones and RCA preamp output. Firmware forces Low Gain when entering preamp RCA output mode, and remembers your gain setting when returning to headphone mode.

DAC

Element II relies on an AK4493EQ for digital-to-analog conversion. We debated sticking with the popular AK4490EQ, but favored the small increase in dynamic range.

USB Input

Element II is the first JDS Labs DAC to utilize an XMOS XU208 based USB Audio Class 2 implementation, supporting up to 32/384kHz PCM.

The XU208 is clocked by an SiTime MEMS oscillator with phenomenally low jitter, outperforming the original Element by two-orders of magnitude. Jaw dropping. Can I hear it? Afraid not. But it remains technically impressive and we did not have to re-invent the wheel. I only regret not moving to XMOS sooner.

Element II ships with a custom 1m (3.2ft) USB cable equipped with a ferrite core for best EMC and noise performance. We have been using TDK ferrites to conduct in-house measurements for years, and find that jitter measurements are more repeatable from one system to another when doing so.

Firmware and Drivers

Element II uses all new firmware for both its microcontroller and USB stage. We enabled and verified DFU operation in the XMOS codebase, meaning Element II supports future USB controller updates.

No drivers are required by Windows 10 or modern version of Mac OS or Linux. You may optionally install Element II’s XMOS driver for ASIO support. For now, Element II will rely on royalty-free XMOS drivers. If there is sufficient demand, additional features will be considered in the future.

Current versions of Android and iOS have also been tested successfully. Please note that UAC2 support varies with mobile devices (see FAQ).

Benchmarks

All tests are conducted with Elements II’s supplied 16VAC 1A transformer and ferrite equipped USB cable, using XMOS release driver v4.13.0 under Windows 10, using a dScope Series III analyzer.

Power measurements are observed with a 32.4 ohm load at 100Hz and 1000 Hz for at least three minutes continuously, while maintaining < 0.0025% THD+N.

Amplifier Performance

Element Element II
Frequency Response 10Hz-20kHz (192k) +/- 0.1dB +/- 0.02dB
THD+N 1Khz, 150 ohm 0.0009% 0.0008%
THD+N 20Hz-20kHz < 0.003% < 0.001%
IMD CCIF 19/20 kHz -6.03 dBFS 0.0004% 0.0001%
IMD SMPTE -6.03 dBFS 0.0005% 0.0005%
Noise (A-Weighted) -108 dBu -115 dBu
Crosstalk -10 dBFS 100K RCA -67 dB -88 dB
Output Impedance 0.1 ohm 0.1 ohm
Channel Balance +/- 0.56 dB +/- 0.56 dB
Max Continuous Output, 600 ohm 140 mW (9.4VRMS) 165 mW (9.9VRMS)
Max Continuous Output, 150 ohm 505 mW 656 mW
Max Continuous Output, 32 ohm 1.1 W 1.3 W
Element II Analog Input – Noise (A-Weighted)

DAC Performance

Element Element II
Frequency Response 10Hz-20kHz (192k) +/- 0.15dB +/- 0.13dB
THD+N 20Hz-20kHz < 0.003% < 0.001%
IMD CCIF 19/20 kHz -6.03 dBFS 0.00110% 0.00041%
IMD SMPTE -6.03 dBFS 0.00120% 0.00029%
Noise (A-Weighted) -102 dBu -109 dBu
Dynamic Range (A-Weighted) 112 dB 118 dB
Linearity Error -90 dBFS -0.02 dB 0.00 dB
Crosstalk -10 dBFS 100K RCA -100 dB -107 dB
USB Jitter Components 12kHz -106 dB -127 dB
Features
Maximum DAC Line-Output, 100K 2.1 VRMS 2.0 VRMS
RCA Output Line-Out (fixed) Preamp-Out (adjustable)
Relay Muting Yes Yes
USB Controller SA9023A XMOS XU208
D/A Converter PCM5102A AK4493EQ
Element II USB DAC – Jitter @ 12kHz, -1dBFS

Prototyping Banter

Element II has been in the works for years and we’ve accumulated a box full of canned prototypes.

In fact, Atom Amp was derived from Element experiments. We’d tentatively planned Element II for a 2018 release, but I was frustrated by unimpressive performance gains, or worse, diminished performance, of early prototypes. At one point, analog input was accomplished through a costly ADC. I took a step back and checked our goals: (1) Enable preamp output, (2) Modernize the amp+DAC , and (3) Don’t fix what’s not broken. Focusing only on the top goal was the trick, and this led to a tangent we dubbed Atom Amp. The lessons learned from building Atom Amp were merged back into Element II.

Alas, Element II missed its first release in early 2019 due to EMC compliance failure. We had embarked on an idea that required a USB daughter-card, in order to simplify inventory and production batches. I knew it would be a risk for I2S to jump a ground plane. This choice was the first time we failed FCC and CE emissions checks. We returned to a single board and invested in a 1.5GHz spectrum analyzer to rapidly reach compliance. Thus, Element II debuts at version 2.11. šŸ™‚

Reviews

  • More coming soon!

Availability

Element II is in stock and ships today!

12 thoughts to “JDS Labs Element II — Official Release & Benchmarks”

  1. > Element II missed its first release in early 2019 due to EMC compliance failure. We had embarked on an idea that required a USB daughter-card, in order to simplify inventory and production batches. I knew it would be a risk for I2S to jump a ground plane. This choice was the first time we failed FCC and CE emissions checks. We returned to a single board and invested in a 1.5GHz spectrum analyzer to rapidly reach compliance. Thus, Element II debuts at version 2.11. šŸ™‚

    That’s really impressive. Congratulations on the launch, guys!
    In fact, you hinted at end of year release. YOU ACTUALLY DID IT~~~~

  2. Are there any performance-related pros and/or cons to the Element II versus the EL stack or is it literally just the same hardware in a single box?

    1. Element II is an EL Amp with the USB stage and DAC from EL DAC II. There are no performance differences that I have observed.

      Element II is your best choice, unless you need the additional inputs of EL DAC II.

      1. Well, I ordered mine. I have been looking for a transparent DAC with an amp as good as the Atom for a while. This sounds like it fits the bill perfectly.

  3. Darn you! Your amplifiers and DACs are so unbelievably good and now that I just had settled in and was getting comfortable with my Atom and Khadas Tone Board stack, this aural delight comes along…

  4. I own the Element which is already very good. Do I need to upgrade to Element II to gain any audible improvement (especially now Element II is DC coupled, can I expect any audible improvement)?

    I guess the coupling caps are used to block bias current going into the pot like in the O2? Will removing the caps result in some noises when turning the pot in the long run? May I know the reason for removing the coupling caps?

    1. @Jimmy – Yes, the original Element is already a competent amplifier. Element II measures even better, but should not yield dramatic changes to sound quality.

      DC coupling was chosen for Atom Amp last year for its higher performance, and we made the same decision for Element II and EL Amp II. Of the thousands of Atom Amps in the wild, we have no concerns. Keep in mind that wiper noise can also occur with AC coupling. Switching to DC coupling does not stop this effect. It only eliminates source DC offset, which is increasingly rare. By using DC coupling, a few customers have quickly realized when their sources fail with high offset–the result is much different when using a DC coupled amp.

      1. John, thank you for your explanation. May I ask a few follow up questions to have your expert answers?
        – What is the reason for the wiper noise, if it is not due to bias current going into the pot?
        – What kind of sources could have high DC offset which as a user should avoid?
        – Can I safely use some jumper wires to short the coupling caps in my Element and my O2 to have some performance gain?

        1. Wiper noise occurs by nature of rubbing against a surface, much like brake pads on a car. It’s usually a quiet process, but there is no guarantee. Again, adding DC bias pronounces the effect whether the amplifier is AC- or DC-coupled.

          To my knowledge, the only actively produced audio sources on the market with DC offset are those which have failed. Consumer audio devices should not present DC offset.

          Yes, you are welcome to jump the AC capacitors on your Element and O2.

  5. The video review at the bottom of the page makes me think that this amp has too much power for IEMs, like the Shure range etc., even with the low output setting. I feel like Iā€™d want to pipe the audio through ~30dB pads so that the potentiometer could be somewhere above nearly off. Seems safer too. Am I overly concerned for no reason, or misinterpreting?

    1. @Patrick With thousands of Elements produced over the years, we have no such feedback from those using IEMs. There should be no difficulty using low gain of 1.0x with the gradual 15A taper. Element II has greater dynamic range and lower noise floor than the first generation, so IEMs should pair better than ever.

      If you still need more volume range with an ultra efficient IEM, you can reduce the DAC volume level as needed. I have no concerns with IEMs.

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