I heard about this little USB-C dongle DAC/amp called the Helm Bolt from Michael Lavorgna's website Twittering Machines. He used to write for stereophile and audiostream, I always liked his writing style and alternative taste in music even though I was not always a big fan of the types of products he was pushing. anyway, Twittering Machines is a breath of fresh air compared to most mainstream audio review sites, and in recent a dongle shootout Michael picked the Helm Bolt as his favorite: https://twitteringmachines.com/the-dongle-dac-survey-part-2-the-reviews/ I was in the market for a dongle but out of the loop on what was good, and didn't really want a generic chi-fi product. the description of the Helm from the shootout seemed up my alley so I ordered one in March and it arrived in April. the price is $99 USD although there is a significant 50% discount for military and healthcare personnel so check that out if you qualify. In the box is the dongle, a little carry pouch and a USB-C to USB-A adapter for use with computers and laptops. I also got a free hat for pre-ordering in between production batches. the hat is of middling OEM quality. I would not recommend ordering just the hat as a fashion accessory. it will go on top of my leaning tower of hats. although advertised as a dac/amp it's only capable of driving efficient and low impedance headphones directly. it did not have quite enough volume for my HD600s, resting at about 70 - 75 dB SPL (I am guesstimating this figure) at maxed volume with a recording of average loudness. it does appear to adjust the output voltage based on the impedance of the connected load. I assume this was done to control the gain for earphones versus line sources. as a DAC/amp I hooked up the Bolt to my 2008 Mac Pro using the included USB-A adapter, to my iPhone XR using a USB-C to Lightning adapter, and to my modern Windows desktop PC. sound quality was rather crummy from the motherboard of my desktop PC, excellent on my Mac, and in between the two with the iPhone although leaning much closer towards the quality of the Mac. I mention this as YMMV depending on what you USB source you plug the Bolt into. I used the Bolt to listen to my trusty Koss KPH30 (like a portapro but clearer and more balanced tonally) and new-to-me ESX900 headphones (review here). It really is a sublime sounding dongle, I was kind of dumbfounded by what $99 can get you these days. I have to agree with what Mr. Lavorgna wrote in his dongle shootout about the Bolt - and the words that come to mind to describe its sound are full, rich and sweet. in comparison, the Apple lightning dongle sounds anemic and congested, flatter with less nuance. the Bolt + Koss or ESX900 could be a desert island solution for listening to music while waiting for rescue efforts. as a DAC enthused by the results of the Bolt driving headphones directly, I purchased an Audioquest 3.5mm to stereo RCA adapter to use the Bolt as a DAC into my main headphone amplifier. compared to ~$3000 of R2R DAC, the Bolt fought valiantly. it lost in the areas D/S DACs always lose: the transfer of subtle emotions, the transfer of musical flow (timing), and the most honest transfer of musical timbres. the Bolt does have a sort of sweet, sugary timbre, but it's rather subtle and honestly very preferable to AKM for me. I guess this thing uses an ESS chip, but not sure. however in most other areas, it was very difficult to fault the Bolt as a DAC. maybe I am just out of the loop and all dongles these days including the $20 ones from China sound this good, but I sort of doubt it. I could also list any number of full-sized DACs I have tried from $100 - $3000 that sound worse than the Bolt, but you guys probably wouldn't believe me, so I won't. in conclusion, buy two of these, one for you and one for a loved one. if you don't have any loved ones, buy one for a stranger and they will love you for it. I think it's very much worth the $99 asking price. I will personally take it any day of the week over the current Modi, unless for some reason you really needed the connectivity options of the Modi. it's also great that the Bolt is MQA certified, meaning that I can preserve the artist's true intention by fully unfolding master quality authenticated source files. unfortunately I don't have a TIDAL premium account, so I wasn't able to test this feature. still, having the MQA logo on my DAC helps me sleep at night.