Jomo Audio Trinity BS (Brass)

Heart & Soul.

PROS: Very large stage, great detail and texture, phenomenal reproduction of guitars, provide great energy to the music, excellent build quality.

CONS: Expensive, can at times be a little picky about poor quality recordings.


I would like to thank Joseph Mou of Jomo Audio for loaning me the Trinity BS (Brass) in exchange for my honest opinion. No incentive was given for a favorable review.

Trinity BS

  • Drivers: 2 x Electrostatic with internal transformer, 4 x Balanced Armature, single 8mm Dynamic Driver¬† (4-way crossover)
  • Frequency response: 20Hz – 80KHz (Theoretical)
  • Impedance: 30 Ohms at 1KHz. RDC: 40 Ohms
  • Wiring: High purity silver-plated copper internal litz wiring
  • Shell: Proprietary 3D semi-custom ergonomic universal shell design with solid brass nozzle design
  • Price: S$3,799 (~US$2,800)



Jomo Audio is a custom and universal IEM company based in Singapore, a place I once referred to as the audiophile’s equivalent of Willy Wonka’s chocolate factory. Considering all the technology crammed into the Trinity under review here, I readily get this image of Joseph Mou standing in a white room telling his Oompa Loompas… “If Willy Wonka can do that with a chocolate bar, how about we shrink those electrostat headphones down to earphone size?!” That is probably not quite how it happened, but the result is there and I think that image is just too funny not to pretend that is how it went.

Of course in reality Jomo teamed up with one of the world’s leading electrostatic driver manufacturers to miniaturize their electrostatic driver and its transformer to fit inside a tiny Jomo IEM shell. Then of course Joseph went on to say: “How about we add all the other technology in there as well to create a triple hybrid? You know, since we have Wonka Vision Jomo Vision up and running anyway?”

Okay, I am being a bit silly here, but Jomo have done some pretty unique things in the past, like the gorgeous carbon fibre shells, both in custom and universal, for the Flamenco. Those I have drooled over many times, although I believe the Flamenco now come with a new shell design that looks pretty gorgeous too. I guess that is the spirit of “Takumi” mentioned on Jomo’s “About Us” page, the Japanese term for Craftsmanship Spirit. Always the drive to continue to hone their craft and create technologically innovative and artistically beautiful new IEMs. Certainly exemplified in this case by the triple hybrid Trinity in its beautiful brass and purple version.

As these were demo units, there was nothing really to unbox and I can’t say anything about the packaging (although the aluminum case for the demo units is incredibly nice and I would love to have a few of those lying around for my own IEMs) or accessories, so I will skip straight on.

Build quality and fit.

At this price point I would expect great build quality and that is certainly what I the Trinity offer. The beautiful shells feel very solid while they still stay nice and light. The brass nozzle is fixed nearly seamlessly in place and looks great with the sparkling purple of the shell. These are IEMs that I feel confident using without concerns, although I would be hesitant about subjecting them to too much abuse. I would say these are very solidly built without overdoing it to keep the weight comfortably light. A really good balance: more solid feeling than my Empire Ears Phantom and not as heavy as the Rhapsodio Zombie.


The fit is described as “semi-custom” and I do indeed get a really nice fit with these. While the shells are on the larger size (not unexpected considering the tech inside) they fit surprisingly flush and are extremely comfortable. I often have issues getting a comfortable fit and can change tips many times before I find the ones that work for me, but not with the Trinity. I used the supplied Tornado tips and those worked perfectly without any need for tip rolling. The choice of tips is very important to get right, as it can have a considerable impact on the seal, sound and comfort, so I was very happy it all worked out so easily. Great fit, great comfort and I could wear the Trinity all day without any issues. Also helpful was that the stock cable supplied was a nice thin and supple one, although I must admit I was a little surprised not to find the Effect Audio Ares II as a stock cable. At this price point the included stock cable feels quite out of place, especially considering that (if I remember correctly) other Jomo IEMs do come stock with Ares II. Not a huge problem for me because I have several cables lying around, including Ares II, but it does make me wonder if the stock cable could be holding the performance of the Trinity back a little. Well, perfect time to get in some listening and find out!


All listening was done with my AK70 and FiiO K3/Macbook Pro from the SE out (stock cable) and balanced out (aftermarket cables).


Page 2 – Sound Analysis.

Page 3 – Aftermarket cables, Comparison, and Conclusions.

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