Review and Measurements of New JDS Labs Atom Headphone Amp

[Silou]

Dude, shipping and taxes are so high where I live that I end up paying double for anything I buy from either US or EU...

The problem here is that they just demand the same amount of money for shipping to every other country other than the US. Even if I wanted to ship it to Mexico I would have to pay the 37.13$.

 

[xineis]

The problem here is that they just demand the same amount of money for shipping to every other country other than the US. Even if I wanted to ship it to Mexico I would have to pay the 37.13$.

That is probably the USPS rate. I would pay US$ 35.64, for instance.

 

[Silou]

That is probably the USPS rate. I would pay US$ 35.64, for instance.

Yes that is exactly what i would have to pay aswell. I just added the insurance cost of 1.49$.

 

[trl]

How does the Atom pair with sensitive IEMs?

I know it wasn't designed for that, but I have both an IEM and a power hungry can.

EDIT ---------------------------------------
Also, that 60 Hz spike is due to the power circuit, right? It probably isn't audible, but I didn't see the usual highlight about this behavior.

It's based on Objective2 but with different buffers I guess, so with the gain at 1X or 1.5X it's a very good amp for IEMs for sure.

One of the most sensitive IEM I've seen it's around 110dB/mW @20Ohms. Not hearing the background noise and hum means that you need a headamp able to deliver a SNR better than 90dB for your IEM when you're already listening to about 110dB peaks (which is quite high level actually).

In this particular case, with 110dB SPL IEMs @ 20Ohms:
1mW @20Ohms - means 0.14V RMS, which means -17dbV; lowering this amount by-90dB that would be -107dB SNR for the amplifier.
So, Objective2 and Atom fits very well with IEMs.

 

[wadec22]

Very excited for JDS. If I didn't already have the THX, I would buy this today.

Can't wait to see a matching DAC!

 

[maty]

A good/very good headphone amp must be the 50/60 Hz at least at 95 dB.

The JDS 60 Hz spike is 30 dB more, about 125 dB. You do not need to clean the power.

 

[xineis]

It's based on Objective2 but with different buffers I guess, so with the gain at 1X or 1.5X it's a very good amp for IEMs for sure.

One of the most sensitive IEM I've seen it's around 110dB/mW @20Ohms. Not hearing the background noise and hum means that you need a headamp able to deliver a SNR better than 90dB for your IEM when you're already listening to about 110dB peaks (which is quite high level actually).

In this particular case, with 110dB SPL IEMs @ 20Ohms:
1mW @20Ohms - means 0.14V RMS, which means -17dbV; lowering this amount by-90dB that would be -107dB SNR for the amplifier.
So, Objective2 and Atom fits very well with IEMs.

Thanks for the nice explanation! Another problem that I have run into since I bought my IEM was that I usually cannot get the volume knob past 11~12 o'clock at low gain. Of course, I could remedy that with something like the IEMatch.

 

[JJB70]

Wouldn't you have to pay the VAT even if you bought one locally?

In the UK we are allowed to bring about £400 in VAT free on our person. However if goods are delivered by post the allowance is trivial. And we even have to pay the cost of levying the VAT, which is also charged on the shipping cost! Royal Mail charges about £13 as a customs handling fee. So it is well worth waiting if I have a visit states side planned or asking a friend if they could carry stuff.

 

[derp1n]

Not sure why people are claiming this is based on the O2. Looks quite different to me.

 

[JJB70]

Be interesting to see if there is any push back on the plastic case. Given the terrific performance and low price I think a plastic case is a very acceptable trade off to keep such a great performing amplifier so cheap but people can be funny about these things. I have seen companies try to offer great performance at affordable cost partly by losing expensive feeling packaging and metal and coming unstuck.

 

[trl]

Thanks for the nice explanation! Another problem that I have run into since I bought my IEM was that I usually cannot get the volume knob past 11~12 o'clock at low gain. Of course, I could remedy that with something like the IEMatch.

O2 has the possibility of having a gain of 1X, that means 2V RMS at INPUT means 2V RMS at OUTPUTS when volume to the max. with 0dB music levels. With most logarithmic potentiometers that would be around 0.2V RMS when knob's position is to the 12 o'clock. So, indeed, with a gain of 1X you will probably listen around 1-12 o'clock with very sensitive cans, but I find this quite normal. Abnormal would if you'd need to listen with a volume around 8 o'clock, where channel imbalance is quite big (usually >0.5dB between the channels).

You might need a DAC with digital volume control inside to connect it to your headphone amplifier. IEMatch is an option here, but it's a last resort after all.

Also, Mac, Linux and even Win10 has a 32-bit volume control inside, so you could also adjust the volume from your OS.

L.E.: In case you want to calculate SPL and volume levels to do a best match for your cans and headamps, you could use the below tools:
- http://www.digizoid.com/headphones-power.html
- https://reference-audio-analyzer.pro/en/dbv-dbmw.php
- http://www.sengpielaudio.com/calculator-db.htm
- http://www.sengpielaudio.com/calculator-db-volt.htm
- http://www.sengpielaudio.com/calculator-thd.htm
- http://www.sengpielaudio.com/calculator-amplification.htm
- http://nwavguy.blogspot.com/2011/09/noise-dynamic-range.html

 

[PierreV]

FWIW, for export/imports you have specific codes, for example, detailed in the Harmonized System Codes (HS Code 2017) - that's what is negotiated in trade agreements. For example, I guess this could be exported under (rough guess, several options imho)

851840 Amplifiers; audio-frequency electric

Now, each pair of countries/regions (say US - EU) can have different rates on the same items depending on the direction. So, typically a package sent from US to EU will be subject to a customs duty dependent on its code number. There is some ambiguity in the code and some things can fall under several different codes. Optimizing codes as to lower fees is an actual job.

The big no-no are exporting stuff with a wrong code, no code at all (although the shipper will usually catch missing codes) or under value - this is typically what happens when you hear stories of people buying a $10 trinket and ending up paying $200 in fees/fines/taxes. If there is something wrong, your customs/post office may end up charging you a "stopping" or a "processing" fee.

Assuming the code is correct, one would end up paying base (price + shipping price + duty fees + insurance fees)*(1+applicable VAT rate)

Assuming incorrect code, it would be (price + shipping price + duty fees + insurance fees + processing/stopping fee)*(1+applicable VAT rate) + eventual fine.

Assuming no code, the same as above or bounce or total loss depending on the mood of the guys who process things and legality/duty fraud attempt. Customs Clearance Fees are usually not applied when everything is perfect (I guess you could sue/complain if they were) but whenever a wrongly labeled package is sent, customs can intervene and charge you for their "specialist" time.

When the deal is direct to customer, there is usually some tolerance, but relying on it is a bit like playing the lottery, especially on high value items.

And, of course, as far as shipping is concerned, volumetric weight matters more than actual weight.

A reference for EU

https://ec.europa.eu/taxation_custo...s-online-coming-from-a-noneu-union-country_en

As an aside, this is mostly why a no-deal brexit would be so disruptive. EU to EU has become child's play compared to what it was before. And, of course, a very complex system favors large entities, think amazon, and put a severe load on the small guys...

 

[bakker_be]

FWIW, for export/imports you have specific codes, for example, detailed in the Harmonized System Codes (HS Code 2017) - that's what is negotiated in trade agreements. For example, I guess this could be exported under (rough guess, several options imho)

851840 Amplifiers; audio-frequency electric

Now, each pair of countries/regions (say US - EU) can have different rates on the same items depending on the direction. So, typically a package sent from US to EU will be subject to a customs duty dependent on its code number. There is some ambiguity in the code and some things can fall under several different codes. Optimizing codes as to lower fees is an actual job.

The big no-no are exporting stuff with a wrong code, no code at all (although the shipper will usually catch missing codes) or under value - this is typically what happens when you hear stories of people buying a $10 trinket and ending up paying $200 in fees/fines/taxes. If there is something wrong, your customs/post office may end up charging you a "stopping" or a "processing" fee.

Assuming the code is correct, one would end up paying base (price + shipping price + duty fees + insurance fees)*(1+applicable VAT rate)

Assuming incorrect code, it would be (price + shipping price + duty fees + insurance fees + processing/stopping fee)*(1+applicable VAT rate) + eventual fine.

Assuming no code, the same as above or bounce or total loss depending on the mood of the guys who process things and legality/duty fraud attempt. Customs Clearance Fees are usually not applied when everything is perfect (I guess you could sue/complain if they were) but whenever a wrongly labeled package is sent, customs can intervene and charge you for their "specialist" time.

When the deal is direct to customer, there is usually some tolerance, but relying on it is a bit like playing the lottery, especially on high value items.

And, of course, as far as shipping is concerned, volumetric weight matters more than actual weight.

A reference for EU

https://ec.europa.eu/taxation_custo...s-online-coming-from-a-noneu-union-country_en

As an aside, this is mostly why a no-deal brexit would be so disruptive. EU to EU has become child's play compared to what it was before. And, of course, a very complex system favors large entities, think amazon, and put a severe load on the small guys...

This must be the clearest way I've ever seen the import duty system explained. Well done!

 

[L5730]

Another UK resident here: Anything over £135 is subject to filthy customs duty on top of other charges. Under that value and it's just VAT (currently @20%) plus the 'handling' fee of £8 to Royal Mail.
So for us in the UK, that $99 item turns out to be ~£80 + £16 + £8 = £104 + shipping (~£30). TOTAL £135, which still seems reasonable.

I got my Topping D10s via Amazon.co.uk 'fulfilled by', which works rather nicely for me. The price you see is the price you pay. From what I understand of the US, that concept isn't always applied, even in shops where you get taxes added at the point of sale - that would cause one massive argument over here!

Looks an interesting headphone amp. I have yet to get a decent pair of cans and am currently using an HP USB headset with some brutal EQ adjustments via EQ APO program.

edit: typo

 

[trl]

Not sure why people are claiming this is based on the O2. Looks quite different to me.

I'm sure it's not the same schematic, but PCB design looks pretty similar: I can see same input and gain adjust switches, the voltage-gain opamp is in the same position/location on the board as on the O2.
However, power regulators are in the same position too, but now are LM317/337 instead of LM7812/7912, a new relay introduced to remove the "thumb" on power ON/OFF, the two MOSFETs where replaced by a relay + comparator opamp (LM358 perhaps), new powerful output buffers. It's clearly an improved design over the original O2, so it would be lovely to actually see ATOM's schematic and a high res. close-up with the internals.

 

[Jimster480]

Yeah. For today. Keep in mind how much has changed in 24 hours with this news. What will tomorrow bring??

Still would be transparent in basically every way.

 

[Jimster480]

+1 for testing randomly sampled released stuff shipped to customers. While I don't suspect any kind of foul play, this approach would be cleaner in principle. But, yes, of course I will get one

secondary question: when the perfect cheap amp, perfect cheap dac have been found, what's the point of testing others?
And what will I read on my breaks? Transparent, airy, agile, punchy, discerning cable reviews for a good laugh?

Topping D10/D30.

 

[folzag]

Ya know... if one really didn't like the plastic case, and one really did like the Khadas Tone Board DAC, then one would have the perfect DIY project mating-up the two in a single enclosure.

I wonder if the JDS transformer has adequate capacity to power both.

 

[amirm]

I wonder if the JDS transformer has adequate capacity to power both.

Khadas tone board is USB powered so you don't need to go that way.

 

[Bliman]

I thought I buy a Topping dx3pro. And then this comes along. Is there a dac around the 100$ that can keep up with this amp? Or is it still better to buy the combinaton of dx3pro? I would use it with a beyerdynamic dt250 250ohm. And I would use it for the computer.