Helm Audio Bolt Review (Portable DAC & Amp)

[tomaszffffff]

Apparently, as some reddit users noticed here it's a sister of Zorloo Ztella, maybe even the exact copy of it, interesting to see them measure differently. Makes me wonder whether it's been improved or maybe just a matter of different pair and quality control.

 

[IVX]

tomaszffffff, as I remember, Ztella also was measured ASR, and the same result i.e. 4x times worse than ESS promised

 

[Nango]

I stopped using Hidizs S8 on my android phone for the same reason. Provided USB-C to micro USB cable is pure crap. I had to order an aftermarket USB-C cable for my E1DA 9038D and 9038GS3 (provided ones had no connection issues but were very stiff and and the metal part got lose in the plastic with time).
I got this one : https://fr.aliexpress.com/item/32961312907.html?spm=a2g0s.9042311.0.0.38156c37o8Q6Xk , and was so perfectly happy with that I ordered his USB-C to micro USB brother for the S8 : https://fr.aliexpress.com/item/1005002053361868.html?spm=a2g0s.9042311.0.0.38156c37o8Q6Xk .
No connection issues since, I can use my S8 mobile again, wich is nice, it's a great dongle (maybe a bit power shy for running power hungry headphones with strong EQ). The only real issue left in mobile use is maybe the physical volume controls. Buttons are easily triggered in your pocket or against clothes or external surfaces if you let the dongle lay on his cable. Increments are huge, so they're basically useless anyway, and it can be a very bad surprise for your ears if you're listening at a strong volume and increase it more by accident.

I now own Hidizs S8 and S9, E1DA 9038D, 9038GS3 and Powerdac V2, I'll maybe try to write a subjective comparative review about them, all are great devices, all with their own strengths and weaknesses (in comparison to the others, I think most people will be happy with any of them, I enjoy all of them in different ways). I have eyes on Luxury & Precision recently bread dongles, I usually like well implemented Cirrus Logic dacs, the ones I have and had always provided a nice balance between details, bass body, imaging and separation. From the previously mentioned dongle, the S8 is maybe the most balanced regarding these points.

Also available those WHS9415 based dongles with little 23mA consumption won't drain phones battery that fast.

 

[ZolaIII]

Also available those WHS9415 based dongles with little 23mA consumption won't drain phones battery that fast.

Best effort QC DAC underperformes even against now againg Sabre32 entry line ES9028KM2 (LG G7 rewiev) and has 2x less power than ES9601K. So very little use of high integration there and in the meantime QC actually downgraded future performance of their codec/parts. And that should be bottom end acceptable this day's (ESS 32 entry line). CS43131 run around in circle's around those and are very efficient. Unfortunately dongle/portable market is not very creative regarding design, less and less those with their own battery and only two ever (part of the same series) that could actually and charge phone slowly (Android only).

 

[Nango]

Yes, indeed dual CS43131 inside the Tempotec BHD and 120mW/32 Ohm is the new game changer for ~50-60$.

 

[DanTheMan]

I bought a Hidizs 8 and it was very good, but the physical quality was poor. There was some kind of problem with the connection between the telephone and the dongle, sometimes it worked and sometimes it did not, and the supplied cables and connectors were lousy. I sent it back and ordered a Hidizs 9 instead. It has even better specifications, and it is better built, but too late I realized that it also drains the battery in a smartphone very quickly. Now I use Hidizs 9 only for my desktop computer, but am thinking of giving Hidizs 8 a second chance.

The cables are total crap with the 8 And buying other cables with a ‘lightening end’ for it seems to be impossible (if you find one, please let me know). For the most part I just use the iPhone dongle and a discontinued Fiio A5 amp that I think is likely the best portable amp ever made. At home, I use the 8 all the time. I’d love to see how the 9 measures. I just discovered its existence last night.

 

[Mulder]

The cables are total crap with the 8 And buying other cables with a ‘lightening end’ for it seems to be impossible (if you find one, please let me know).

I’d love to see how the 9 measures. I just discovered its existence last night.

The cables sent with the Hidiz 9 is much better, but they do not provide a lightening cable anymore. I use a converter like this now. https://www.ddhifi.com/productinfo/94995.html

The Hidizs 9 do sound as good as the previous version. If it measures better I can´t say I hear, but the build quality is much better.

 

[ZolaIII]

Cables are always problematic... The most elegant solution whose regular sized USB port with costume USB driver found on now old Tempotec Sonata iDSD & iDSD Plus flask alike portable DAC/AMPs. It enebled you to use regular cables (iOS/Android) and even slowly change phone (Android only) and listen without audio interruptions (exclusive use, audio player only) but whose limited to software which support it with costume driver integrated (HiBy Music). While it whosent ideal nor great implemented it whose a step into the right direction and so far only one I am aware of.

 

[DanTheMan]

The cables sent with the Hidiz 9 is much better, but they do not provide a lightening cable anymore. I use a converter like this now. https://www.ddhifi.com/productinfo/94995.html

The Hidizs 9 do sound as good as the previous version. If it measures better I can´t say I hear, but the build quality is much better.

Thank you! Looks like the ticket.

 

[Andysu]

Helm does in fact sell a $199 amplifier featuring THX AAA circuitry. However, it is curiously designed to be an “in-line“ amplifier fed through a cellphone‘s (or DAP’s) headphone output. So, however good/bad the performance is of the cellphone’s analog output circuitry will be a limiting factor.

https://www.thx.com/blog/helm-launches-headphone-amplifier-with-thx-aaa/

https://helmaudio.com/products/db12

A very odd product.

View attachment 112825

Looks like consumer THX snake oil. I don't touch any of that razer thx rubbish.

 

[michman66]

For 100.00 bucks to use with Android phone, I'll like a few opinions please. I already own DF Black. Before I order the Bolt any others I might consider. I'd also be feeding output into a Raspberry Pi4. Thx

 

[Jet Black]

This is a review and detailed measurements of the Helm Audio Bolt portable headphone Amp and DAC "dongle" with MQA decoding. It is on kind loan from a member and costs US $99 on Amazon with Prime shipping.

The bold design seems a bit more substantial than some others:

View attachment 112659

Not much else to it than a 3.5 mm headphone socket:
View attachment 112660

Interestingly, there is THX certification for this device. Didn't know there was such a program. This is the description:

View attachment 112661

Will be interesting to see how it measures!

There are no controls on the unit which is a miss. I like to see volume controls as a minimum.

Testing with Windows indicate there is an ADC in there so I imagine it could have microphone support but I am not sure.

Helm Bolt Measurements
Let's start with our usual dashboard:
View attachment 112662

Not bad! SINAD is dominated by second harmonic distortion. Definitely a competent design:
View attachment 112663

While there is some source of jitter, overall response is by far cleaner than many other dongles:
View attachment 112664

So maybe THX certification means something.

Due to some interface issues regarding how I measure, I can't run other DAC tests so let's get into power starting with 300 ohm load:
View attachment 112665

Response is a bit nervous (noisy) but power is good for a dongle:
View attachment 112666

Same for 32 ohm load:

View attachment 112667
View attachment 112668

Sweep the load impedance we get:

View attachment 112669

With both 300 and 600 ohm loads, we are voltage limited as is usually the case. As a result, there is no distortion even at full volume. Once we get down to 50 ohm, current limiting sets in causing clipping. To compute the available power for any of the output devices, find the corner before clipping occurs (graph shoots up) and use the formula on the graph. For example, for 12 ohm you have 0.83 * 0.83/12 = 0.057 or 57 milliwatts.

Helm Bolt Listening Tests
I was pleasantly surprised that it could drive my 25 ohm Ether CX headphone to reasonable level without distortion. Switching to Sennheiser HD650 produce good power and again, no sign of distortion. Quite adequate for on the go job.

Conclusions
Nice to see another high performance dongle DAC and amp. While performance is not the best we have seen, it is quite good indicating proper engineering.

I am going to put the Helm Bolt MQA on my recommended list.

EDIT: video review just posted:

------------
As always, questions, comments, recommendations, etc. are welcome.

Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

Sir reviewer, pls also make a detailed review of ibasso dc03. No one have ever reviewed that thoroughly yet.

 

[0RF30]

Sir reviewer, pls also make a detailed review of ibasso dc03. No one have ever reviewed that thoroughly yet.

https://www.audiosciencereview.com/...s9-review-headphone-adapter.21152/post-713180

 

[Jet Black]

Yes, indeed dual CS43131 inside the Tempotec BHD and 120mW/32 Ohm is the new game changer for ~50-60$.

Also ibasso dc03 in that regard

 

[tsoltan]

Has anyone tried raspberry -> helm bolt -> 3.5 jack to RCA -> amp? Cuz it looks like the cheapest mqa solution?
Would that work?

 

[Bernd]

Has anyone tried raspberry -> helm bolt -> 3.5 jack to RCA -> amp? Cuz it looks like the cheapest mqa solution?
Would that work?

Hip, yup that works: my OS on the RPI 4 is RoopieeXL. However another member of the forum reported that Volumio did not recognize the BOLT

 

[911jason]

Hip, yup that works: my OS on the RPI 4 is RoopieeXL. However another member of the forum reported that Volumio did not recognize the BOLT

I'm planning to give this a try in the next few days. Really hope I can make it work with Volumio so I can use Tidal Connect.

 

[AdamG]

I'm planning to give this a try in the next few days. Really hope I can make it work with Volumio so I can use Tidal Connect.

Welcome Aboard @911jason.

 

[Darwin]

Amir,

‘Excellent review. Thank you kindly for taking the time to do this for us! FYI.

NOTE: If you are a Veteran, Police, Fire or First Responder HELM offers a most amazing 50% Discount. I paid $50 USD for this Dongle. So if you can take advantage of this discount it’s a pretty great deal.

Good to know. I need something to try out with Apple Music now that they are going high res.

 

[Urib]

This is a review and detailed measurements of the Helm Audio Bolt portable headphone Amp and DAC "dongle" with MQA decoding. It is on kind loan from a member and costs US $99 on Amazon with Prime shipping.

The bold design seems a bit more substantial than some others:

View attachment 112659

Not much else to it than a 3.5 mm headphone socket:
View attachment 112660

Interestingly, there is THX certification for this device. Didn't know there was such a program. This is the description:

View attachment 112661

Will be interesting to see how it measures!

There are no controls on the unit which is a miss. I like to see volume controls as a minimum.

Testing with Windows indicate there is an ADC in there so I imagine it could have microphone support but I am not sure.

Helm Bolt Measurements
Let's start with our usual dashboard:
View attachment 112662

Not bad! SINAD is dominated by second harmonic distortion. Definitely a competent design:
View attachment 112663

While there is some source of jitter, overall response is by far cleaner than many other dongles:
View attachment 112664

So maybe THX certification means something.

Due to some interface issues regarding how I measure, I can't run other DAC tests so let's get into power starting with 300 ohm load:
View attachment 112665

Response is a bit nervous (noisy) but power is good for a dongle:
View attachment 112666

Same for 32 ohm load:

View attachment 112667
View attachment 112668

Sweep the load impedance we get:

View attachment 112669

With both 300 and 600 ohm loads, we are voltage limited as is usually the case. As a result, there is no distortion even at full volume. Once we get down to 50 ohm, current limiting sets in causing clipping. To compute the available power for any of the output devices, find the corner before clipping occurs (graph shoots up) and use the formula on the graph. For example, for 12 ohm you have 0.83 * 0.83/12 = 0.057 or 57 milliwatts.

Helm Bolt Listening Tests
I was pleasantly surprised that it could drive my 25 ohm Ether CX headphone to reasonable level without distortion. Switching to Sennheiser HD650 produce good power and again, no sign of distortion. Quite adequate for on the go job.

Conclusions
Nice to see another high performance dongle DAC and amp. While performance is not the best we have seen, it is quite good indicating proper engineering.

I am going to put the Helm Bolt MQA on my recommended list.

EDIT: video review just posted:

------------
As always, questions, comments, recommendations, etc. are welcome.

Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

This is a review and detailed measurements of the Helm Audio Bolt portable headphone Amp and DAC "dongle" with MQA decoding. It is on kind loan from a member and costs US $99 on Amazon with Prime shipping.

The bold design seems a bit more substantial than some others:

View attachment 112659

Not much else to it than a 3.5 mm headphone socket:
View attachment 112660

Interestingly, there is THX certification for this device. Didn't know there was such a program. This is the description:

View attachment 112661

Will be interesting to see how it measures!

There are no controls on the unit which is a miss. I like to see volume controls as a minimum.

Testing with Windows indicate there is an ADC in there so I imagine it could have microphone support but I am not sure.

Helm Bolt Measurements
Let's start with our usual dashboard:
View attachment 112662

Not bad! SINAD is dominated by second harmonic distortion. Definitely a competent design:
View attachment 112663

While there is some source of jitter, overall response is by far cleaner than many other dongles:
View attachment 112664

So maybe THX certification means something.

Due to some interface issues regarding how I measure, I can't run other DAC tests so let's get into power starting with 300 ohm load:
View attachment 112665

Response is a bit nervous (noisy) but power is good for a dongle:
View attachment 112666

Same for 32 ohm load:

View attachment 112667
View attachment 112668

Sweep the load impedance we get:

View attachment 112669

With both 300 and 600 ohm loads, we are voltage limited as is usually the case. As a result, there is no distortion even at full volume. Once we get down to 50 ohm, current limiting sets in causing clipping. To compute the available power for any of the output devices, find the corner before clipping occurs (graph shoots up) and use the formula on the graph. For example, for 12 ohm you have 0.83 * 0.83/12 = 0.057 or 57 milliwatts.

Helm Bolt Listening Tests
I was pleasantly surprised that it could drive my 25 ohm Ether CX headphone to reasonable level without distortion. Switching to Sennheiser HD650 produce good power and again, no sign of distortion. Quite adequate for on the go job.

Conclusions
Nice to see another high performance dongle DAC and amp. While performance is not the best we have seen, it is quite good indicating proper engineering.

I am going to put the Helm Bolt MQA on my recommended list.

EDIT: video review just posted:

------------
As always, questions, comments, recommendations, etc. are welcome.

Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

Mine is faulty from the outset it has been 4 months that they are supposed to replace it, but nothing.