HELM Bolt DAC & DB12 Amp, Killer Combo For Your "Good" Headphones

Wayde Robson

Wayde Robson

Audioholics Anchorman
I recently got a chance to test out not one but two different portable audio accessories for headphones that turn out to make each other better. The first is the tiny portable DAC/Amp unit called HELM Bolt, this one has been making waves over the last year among headphone enthusiasts as a popular way to circumvent your phone's DAC with respectable power levels, adequate power but not the overkill potential you really want to drive your headphones. I was ready to give it a moderate rating as a portable DAC/Amp inside about 1K words and call it day. I honestly didn't think much of the DB12 amp, but it was a THX AAA amp so I thought I'd give it a try.

It turns out the addition of the DB12 in-line amplifier really updated the experience in tangible ways outside of its 12dB volume boost. Operating in tandem, they give you a nice offboard DAC upgrade (Bolt), then grants basic off-phone music app controls and more clean portable power than you'd expect without an AC outlet. Overkill potential achieved!

Now that warmer weather is finally here (outside this week of MORE snow), I've been indulging my hobby of long headphone walks with the dog. The combo has granted these little details added to a user-experience I wouldn't have thought were a big deal until I actually started taking them granted. I'm using the combo with a pair of closed-back Focal Radiance headphones for which I'd recently ordered a balanced XLR cable for use with my home headphone components, an XLR connected DAC-to-Amp stack and a Cambridge Audio media player. I realize XLR is unnecessary, but I wanted to try full XLR. It turns out, my Radiance headphones almost never see the new XLR cable because the Bolt/DB12 are now (practically) permanently attached. They do such a great job of bringing out that warm midrange in the Radiance without making the sound over-boomy, which I've come to expect from popular budget consumer headphone accessories. The DB12 amp strapped to a belt loop keeps basic app controls in reach, like pause/plan, skip forward/back. It seems like a small thing, but I never realized how much I'd appreciate not having to dig my phone out of my pocket to execute those simple commands. Together I give them a "Gotta Have It!"

Helm Bolt + DB12: Wins the Portable DAC-Amp Combo



I've got a kind of unrelated question about that DAC.
Does Android see the HELM as a headphone jack, or a line output?
If you turn up the volume past nominal, do you get pestered by the "Listening at high volume for a long time may damage your hearing" warning?

My reason for asking is because I strictly use my phone's 1/8" jack to plug into the Aux input in my car.
Bluetooth isn't available, and I despise how BT sounds anyway.

My phone randomly drops to nominal level while I'm driving.
More randomly than that, when I try to turn the volume back up to full blast (to get the best signal:noise ratio), I get the warning, which demands I look at my phone screen while I'm trying to drive.

If you still get the warning, perhaps I might need the HELM and the dB12 like you suggest, then leave the phone's volume at nominal? I don't want to buy two pieces of kit when one will do. Any input you have would be appreciated. Thanks for your review.

  • RBHsound.com
  • BlueJeansCable.com
  • SVS Sound Subwoofers
  • Experience the Martin Logan Montis