Whether or not you are a gigging or hobbyist musician, you’ve always been on the lookout or had an interest in a portable amplifier/interface, small enough to fit in a gig bag. There have been quite a few inexpensive, “good-enough” quality, portable amplifiers in the past, but none of them performed to your expectations. I recall the early days when the old-school, paperback-book-sized, Rockman and a pair of sub-$20 headphones were the hot ticket! In late 2014, Phil Jones Bass introduced the solution to high-quality portability with the HA-1 Big Head Portable Headphone Amplifier/Audio Interface. Nothing came close to this advancement in portable audio electronics for musicians. Phil Jones has done it again with the announcement of the HA-2, which was introduced in late 2018 and debuted at Winter NAMM 2019. The HA-2 is a little different externally – very slightly bigger, with a different control layout from the HA-1 – but internally, the updates are significant. The HA-2 is now a high-resolution USB audio interface that supports PCM playback with up to 384kHz sample rate/24-bit resolution. On DSD playback, sample rates of 2.822MHz and 5.644MHz are supported. It is truly an ideal choice for musicians and engineers that desire high performance and the purest sound quality. Piqued your interest? Read on…

Phil Jones BigHead Pro

The Company Line

Look carefully on the About page of www.pjbworld.com and you will come to realize that Phil Jones has been designing compact bass amps and loudspeakers that achieve highest in fidelity and volume audio equipment since 1968. Phil Jones owns several patents for loudspeaker technology and has been at the forefront of big sound in small footprint audio technology for 52 years! It was not until year 2002 that Phil Jones Bass was established exclusively for the bass guitar player. Check out Phil’s impressive accomplishments on his website. I highly recommend it.

First Impression

The HA-2 is similar in appearance to its predecessor, also housed in an aluminum casing, but that’s where the similarity stops. The case length grew by about an inch. The predecessor’s angled exterior shape was re-designed for a more modern look with a smoother, rounded casing. The three power indicator lights that were on the front of the HA-1 unit are now gone, and only a single smaller green power indicator light is present on the HA-2. The headphone-out port remains the standard 1/8”. The volume/tone adjustment controls have setting indicators on the housing exterior, and the controls were relocated to either side of the headphone-out. On the back of the HA-2, a 1/4” Line-out was added. These exterior changes are indeed subtle improvements. The rubber feet are now pre-installed on the bottom of the unit, rather than supplied with the unit in the accessory package. The top of the new HA-2 now states “BIGHEAD PRO” versus “BIGHEAD” on the HA-1. The HA-2’s accessory kit includes a soft carry pouch (not as stout as the previous pouch, IMHO), USB cable, and a 1/8” to 1/8” stereo audio cable. Inside the HA-2 is a rechargeable lithium ion battery, capable of up to 8 hours of use. PJB states it also functions as a preamp to drive powered amplifiers, and it has both passive and active instrument inputs with a 2-band EQ that is ideal for guitar and bass, and versatile enough for other instruments. The obvious and probably most-used function will be its intended use as a portable headphone amplifier.

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Closer Look

A big improvement for some of you with bigger fingers is the new design placement of the adjustment knobs and the headphone-out port, which sits in between the adjustment knobs. This new layout should help prevent the user from unintentionally changing desired settings. As a secondary improvement, there are indicator markings next to the knobs, which help the user dial in the volume/gain and treble/bass more precisely. Now, there aren’t detents when rotating the knobs, but the exterior marks may help you dial in and maintain your settings, visually. As I stated above, the headphone-out port is a 1/8”, and depending upon your preferred headphones, you may or may not need a 1/8” to ¼” inch adapter, which is not included in the accessory kit. 

MP3 audio playback while using as a headphone amplifier

I plugged in my iPod through the Aux In and noticed improved sound quality through the headphones. MP3 audio was an obvious improvement over the HA-1, with more range, detail and clarity, and we all know MP3 is compressed and not the best audio. The HA-2 does improve the output of MP3 audio due to the much higher-power (200mw in the HA-1 vs 300mw in the HA-2) of the built-in headphone amp. Most users are going to be very happy with the audio improvement. MP3 audio never sounded better!


Phil Jones BigHead Pro

Hi-res audio playback while using as a headphone amplifier

Now, for the hi-resolution audiophile crowd, you are going to be ecstatic with the audio improvement in the HA-2. I plugged in an Astell & Kern AK320 into the HA-2, and the audio improvement with hi-res music is very significant! Not only does every little nuance of a 192/24 music track come to life, but the audio is very detailed, the bass is improved and tighter than with the previous HA-1 model. The highs are clear and the overall sound signature blends evenly, without stressing the ears. After listening to various hi-res music, I noticed the HA-2 was quite warm and the battery life indicator had changed to Red, indicating that charging would be necessary very soon. This is something that did not occur when testing MP3 audio.

Bass output while using as a headphone amplifier

I plugged in three different basses, with all controls at their neutral settings. The BigHead Pro produced a detailed, tight, seemingly accurate tone with amplification that was non-tiring/stressful to the ears. The adjustment knobs precisely dialed in tones anywhere from precise tight bass to an aggressive tone. A warmer setting is still possible with HA-2 by adjusting not only your bass, but with minor adjustments to the HA-2 Bass/Treble and Gain controls. I did notice an increase in loudness/amplification out of the HA-2 versus the HA-1. It is not too significant, but it is noticeable, and does not seem over-done.

Phil Jones BigHead Pro

Phil Jones BigHead Pro

Audio Interface and Recording

I plugged the HA-2 direct into my Presonus Studio One Pro software and found that the HA-2 was recognized instantaneously. All I had to do was change the audio in/out in my Macbook Pro, the Presonus software, and I was up and recording in a minute or less. The volume control on the HA-2 while using as an audio interface only affected the headphone/monitor playback. The gain control boosted the volume without creating any distortion until 75% to maximum. I could not hear the bass/treble controls making a huge difference in the tone, other than a subtle change. I was quite pleased with the ease of use and connectivity as an audio interface. Seriously, this little HA-2 is quite a performer for its size and limited capabilities, as compared to dedicated audio interfaces. I compared the HA-2 to my Focusrite Scarlett 4i4 3rd gen and found the tones similar, with the exception of the Focusrite having a less-nasally or muted tone. The new 3rd generation of Focusrite audio interfaces also have an “Air” setting, which gives an added boost with an open-air, concert hall sounding effect. I compared with the “Air” on and off, and still feel the 4i4 provided a preferable recording in either setting. But I have to give credit where it’s due, and the HA-2, in a pinch, can do the job, and it does it very, very well, if you are out on the road and need an audio interface at that moment. 

Desktop PC w/iRiver audio software

Just for grins – and I know this is not fair – but I had to compare my McIntosh MHA150 Headphone Amplifier to the HA-2 with Focal CLEAR headphones. After comparing the two systems with the same songs and 192/24 sample rates, it was obvious (and expected) that the McIntosh system has a wider, neutral soundstage, giving you the feeling of being enveloped in your favorite audio music. The HA-2 had a narrower, flatter, and fatter bass audio output with the same songs/sample rate. The HA-2 gave you the feeling of being in front of the music audio, rather than being enveloped/surrounded by it. I said it wasn’t fair, but I had to compare. Overall, the sound output quality of the HA-2 is seriously quite impressive and much closer in audio quality than I ever expected to the McIntosh system. The difference was mainly in the overall soundstage.

The Bottom Line

Phil Jones Bass has redesigned the HA-1 (an impressive unit to begin with) and has taken audio processing to a new level and significantly improved the sound output and functionality with the new HA-2. The exterior controls are re-located to improve the functionality for the user experience. The overall package is still similar in size and weight, maintaining that portability we all want and need. Your ears will be pleased with the headphone output quality and will not tire from long listening periods, and the improved bass tones are tighter, with full range of tone, ensuring the audio is delivered with the perfect amount of clarity and detail with any audio input whether, it be MP3 or hi-res. As an audio interface, the HA-2 is quite the impressive performer for practice or recording and the ultimate in portability. It does have the somewhat nasally or muted tone, versus a clearer /neutral tone from a dedicated audio interface, but unless you compare the two systems side-by-side, you won’t know or hear the difference. Note: the quality/capabilities of your headphones will also play a big factor in the audio output while using the HA-2. If you do not have some dough invested in great cans, then you’re not going to get the full wow-factor of the HA-2.

The functionality and performance of the HA-2 is a highly recommended portable tool to have in your gig bag for musicians of any level. This review is not based on a loaner or freebie from Phil Jones Bass. After owning the HA-1 for a couple of years, I purchased the HA-2 as soon as it was available.

Associated test gear for this review:

Macbook Pro running High Sierra OS version 10.13.4

Apple iPod with MP3 compressed audio

Astell & Kern AK320 DAC loaded with 24-bit high-resolution lossless audio

Sadowsky Jazz bass, 4-string

Marleaux Consat Custom bass, 4-string

Don Grosh P/J bass, 4-string

DAW software: Presonus Studio One Pro

Focal CLEAR open-back headphones

McIntosh MHA150 Headphone Amplifier

Pros: Audio quality, multi-functionality, usefulness, size, ruggedness, adjustment knob placement

Cons: Pricey, soft/less protective pouch, no 1/8” to ¼” inch plug adapter


Manufacture:Phil Jones Bass
Model:Bighead Pro (HA-2)
Frequency Response:10Hz – 40kHz
Power Output:300mW/ channel
Headphone Impedance:16-64 Ohms
Controls:Volume, Gain, Treble/Bass (for instrument input signal), On/Off switch
Inputs:¼” instrument input, 1/8”AUX Input, USB DC input
Outputs: 1/8” Headphone out, ¼” Line Out, micro USB digital interface
Power: Internal lithium-ion rechargeable battery or USB power
Accessories: Soft carry bag, 1/8” to 1/8” stereo signal cable, micro-USB cable
Dimensions:3” W x 5.9” D x 0.9” H
Weight:0.6lbs / 290 g
Price: $359

Response to Bighead pro.

Congratulations on a very well written and concise review on the Big Head Pro. This is the most elaborate review that I have ever seen in our unit. Kudos to your reviewers and your magazine.

There is just one additional application I would like to point out on the Bighead Pro: It can also serve as a great signal booster/preamp for live situations using the ¼ inline out jack into your existing rig. The HA-2 is especially useful for upright bass players who are using passive piezo pickups. It can also give life to passive bass guitars and even guitars (acoustic or solid body electric) , with its uniquely shaped 2-band EQ.

New digital processing  technology in audio has made the Bighead Pro possible, and as a bassist myself, I am enthusiastic on how the future is shaping up for bass players with  innovative new products coming on the market,

PJB will continue with our intensive R&D to strive to create ever higher performance products for the bass community.

Phil Jones