If you have have followed the Chord Hugo2 thread on Head-Fi, you might have occasionally seen members ask if they needed to add an amp to their Hugo2. Most often than not, the typical reply from happy Hugo2 owners has been, ‘Why add an amp and lose the transparency?’. While I typically discourage people from adding unnecessary equipment to their chain, I am also a proponent of headphone amplifiers, when your headphone could benefit from it. And that applies if your DAC is a Hugo2 as well. So when I see people discouraging others from trying an amplifier with their Hugo2, I feel they are not giving the right advise. But I can’t blame them, as Chord themselves market their product to be capable of driving some demanding headphones. You can see a picture of an Audeze LCD-4 paired with the Hugo2 on the product page. Plus, this isn’t a simple issue where one answer fits all, as it would depend on your headphone. So what I did was, try various headphones and IEMs with and without a headphone amplifier in the chain, fed by Hugo2 and analysed if adding an amp was beneficial or detrimental. After testing through a few amplifiers and many headphones/IEMs I would like to share my observations. Please note that these are purely subjective opinions based on my personal experience.
Chord Hugo2 – A DAC-Amp That Isn’t:
Before I dive into the actual subject of this article, let’s take a second here to understand a certain detail about the Hugo2. If you are reading this article, I presume you are fairly familiar with, what a Hugo2 is, and what it can/cannot do. But what some of you might not know is, unlike most DAC-Amps, Hugo2 doesn’t have an analog Amp stage. Hugo2’s gain/volume is adjusted in the digital stage. All it rather has, is a simple analog stage, to which, the Headphone Outs and Line Out are connected. What this means is, when you are connecting an external headphone amplifier to the Hugo2 via Line Out, you are not really bypassing Hugo2’s internal amp, as there isn’t one to begin with. So adding an amp to the chain fed by Hugo2 is simply an addition and not a substitution. This is handy because, you know how the Hugo2 sounds, and any changes to the sound when an amp is added to the chain can be chalked up as the sound characteristics of the amp.
Audio Chain and Gears Used:
Audio Chain: MacBook Pro (JRMC)-> Chord Hugo2 -> Headphone Amplifier -> Headphones/IEMs
Headphones/IEMs: Sennheiser HD800, HD650, MrSpeakers AFO, Audeze LCD 2C, Audeze LCD-i4, Empire Ears Phantom, Sennheiser IE800, IE80S, FLC 8N
Headphone Amplifiers: Schiit Lyr 3, Eddie Current Black Widow 2, Massdrop EC ZDT Jr.
Amp in the Chain:
Regardless of the amplifier used, there were some consistent changes that were observed when an amplifier was introduced into the chain. Most of the observed changes were positive in nature, a few changes were amp dependent and one negative change.
Improved Bass Slam, Larger Soundstage, Improved Macro Dynamics, Effortless Presentation
All headphones and IEMs exhibited an improved bass slam and a larger stage. I am not referring to big-bass or an increase in bass quantity here. What I am referring to is deeper and harder hitting bass. High-Impedance Dynamic HPs also displayed an improvement in macro dynamics and had a more effortless presentation with an amp.
Slight Loss of Background Blackness
If there was one aspect that I missed about Hugo2’s headphone out, it was the super black background. With an amp in the chain, it’s not like the background is not black. If Hugo2’s background is OLED level of black, amps’ background were more of black level on a good LED screen.
Transparency, Micro-Details, Depth & Layering, Tonal Shift
These aspects were highly dependent on the quality of the amp. A good amp will get you positive results without any compromise in the above mentioned aspects. Using a cheapo, low performing amplifier is going to result in a compromise in those aspects and probably not offer the benefits we discussed earlier. While price is not an indicator of performance, good amps don’t come cheap. While there are some very good amps that can be had for less than $200, you shouldn’t expect these amps to retain the goodness of a $2500 DAC. But that doesn’t mean that all expensive amps are good. I know a couple of mega buck amps that actually perform poorly. I can’t stress this enough because, people try a crappy amp with the Hugo2 and jump to the conclusion that amps destroy transparency. Do a lot of due diligence in picking an amp. If possible try to attend meets or visit stores to get a first hand experience.
Tonal Shift is going to be purely subjective. Some like to add a tube-amp to add some sweetness and warmth to the sound. While some might prefer to add very neutral sounding amps such as GSX-MK2, to simply bring in some improvements in bass slam and soundstage, while keeping the tone as-is.
Summary and Conclusion:
– Difficult-to-Drive Planar HPs and High-Impedance Dynamic HPs seemed to benefit the most with an amp in the chain. Not only the positives outweighed the negative, but it felt like they sounded restricted directly out of the Hugo2. It’s not something you would notice unless and until you have had a chance to run the headphone with an amp. But once you have heard it with a good amp in the chain, it’s hard to go back. In fact, unless I had no other option, I wouldn’t listen to these HPs directly out of the Hugo2.
– Easy-to-Drive Dynamic & Planar HPs, Medium to Low Sensitivity IEMs also seemed to exhibit similar benefits with an amp in the chain. But then these didn’t sound restricted without an amp. While these HPs do sound good directly out of the Hugo2, I would still prefer to use an amp for the added benefits such as stage and bass slam. But sometimes I won’t mind keeping things simple and running them directly out of the Hugo2.
– Super Sensitive IEMs are a totally different story here. Unlike the heavy-weight headphones that require an amp to be driven well, Hugo2 may be way too powerful for IEMs like Zeus and Andromeda. They not only hiss out of the Hugo2 but also suffer from not having sufficient headroom for finer volume adjustment. For such super-sensitive IEMs, perhaps a low-noise-floor portable amplifier might help.
– Choose an amp wisely. Don’t use cheapo, low performing amps and expect the sound quality to be improved or retained. Buying amps also come with other complications such as interconnects, and issues related to power and power supply.