[King of thorns]

How do these USB dongle DACs compare to cheaper desktop ones...? They did advance a lot in recent years to the point their measurements and sound almost matches desktop counterparts but is having more inputs/outputs the only thing desktop DACs have going for them now?

More specifically, I'm looking for a cheap DAC to pair with my iFi Zen Can and Sennheiser 560s for desktop use and first I was eyeing the SMSL SU-1, but then I stumbled upon reviews on some dongle DACs and I gotta say I started considering getting one instead, partly because I can use it on a phone too. Something neutral and transparent like Tanchjim Space, iBasso DC03 Pro, Fiio KA3 or Moondrop Dawn...would SMSL SU-1 still be a better buy than one of those?

 

[backdrifter]

I was disappointed with the KA5. Maybe I didn't give it enough of a chance. But the DC04PRO was so much better to my ears, I decided not to hang onto it.

 

[Brain Damage]

How do these USB dongle DACs compare to cheaper desktop ones...? They did advance a lot in recent years to the point their measurements and sound almost matches desktop counterparts but is having more inputs/outputs the only thing desktop DACs have going for them now?

More specifically, I'm looking for a cheap DAC to pair with my iFi Zen Can and Sennheiser 560s for desktop use and first I was eyeing the SMSL SU-1, but then I stumbled upon reviews on some dongle DACs and I gotta say I started considering getting one instead, partly because I can use it on a phone too. Something neutral and transparent like Tanchjim Space, iBasso DC03 Pro, Fiio KA3 or Moondrop Dawn...would SMSL SU-1 still be a better buy than one of those?

The RU7 comes with a LO function and pairs really well with the ZenCAN. If you're looking for a dongle DAC that can serve purely as a DAC for desktop situations as well as it's primary use as a DAC amp OTG, the RU7 is a no brainer IMHO.

 

[marekm]

For desktop-only use, buy desktop DAC. SMSL: SU-1 is a steal, but there are plenty more models to choose from, including iFi ZEN DAC.

 

[Tamizhan]

Currently I've two IEMs, final E3000 and KZ PR2 and a tempotec sonata HD V. I thought 2vrms is enough for them. As I continue to sink my teeth into good audio, it seems power is a relative term. People go into all sort of setups for these simple budget IEMs. If 4vrms is the minimum for good sound, why do 2vrms and 1vrms dongles exist? And if we go up the ladder where do I stop 1W? But I'm seeing people reporting desktop level amplifiers for these to shine.
On the other hand, for headphones like Hifiman, people go above 4W even.
Sorry for the rant. Just confused about how trying to get the best out of these budget performers, inevitably leads to high priced amplifiers.

 

[baskingshark]

Currently I've two IEMs, final E3000 and KZ PR2 and a tempotec sonata HD V. I thought 2vrms is enough for them. As I continue to sink my teeth into good audio, it seems power is a relative term. People go into all sort of setups for these simple budget IEMs. If 4vrms is the minimum for good sound, why do 2vrms and 1vrms dongles exist? And if we go up the ladder where do I stop 1W? But I'm seeing people reporting desktop level amplifiers for these to shine.
On the other hand, for headphones like Hifiman, people go above 4W even.
Sorry for the rant. Just confused about how trying to get the best out of these budget performers, inevitably leads to high priced amplifiers.

Most IEMs in general do not require robust amounts of power. There are exceptions like the PR2 and E3000 which have low sensitivity (or others with high impedance), but majority of IEMs can be easily powered off weaker sources.

 

[XTF1]

Currently I've two IEMs, final E3000 and KZ PR2 and a tempotec sonata HD V. I thought 2vrms is enough for them. As I continue to sink my teeth into good audio, it seems power is a relative term. People go into all sort of setups for these simple budget IEMs. If 4vrms is the minimum for good sound, why do 2vrms and 1vrms dongles exist? And if we go up the ladder where do I stop 1W? But I'm seeing people reporting desktop level amplifiers for these to shine.
On the other hand, for headphones like Hifiman, people go above 4W even.
Sorry for the rant. Just confused about how trying to get the best out of these budget performers, inevitably leads to high priced amplifiers.

Some basic science... There are 3 characteristics that matter when talking about IEM (or headphones) "power": 1/ the impedance (expressed in Ohms), 2/ the sensitivity (expressed in dB SPL/V) and 3/, the efficiency (also called sensitivity to confuse everybody!!! ...but expressed in dB SPL/mW). These characteristics are generally reported at 1 kHz per convention, but they may vary with the frequency. SPL stands for Sound Pressure Level--how "loud" your IEM sounds.
Let start with 3/: for the same sound level (the dB SPL numerator), a low-efficiency IEM will require more power (in mW, the denominator) from the dongle than a high efficiency one.
Now 2/: for the same sound level (dB SPL), a low-sensitivity IEM will require a higher voltage (in V, the denominator) from the dongle than a high sensitivity one.
The impedance 1/ ties 2/ and 3/ to the dongle: a dongle can be characterized by its max. voltage (e.g. 1, 2, 4 V RMS) and its max. current (in mA), or much more common, its max power (in mW, the product of voltage by current). The impedance of the IEM determines how loud (in dB SPL) the dongle can drive the IEM before hitting one of its internal limits--its max voltage, or its max. current / max. power. A 1V RMS dongle may not be able to drive adequately a high-impedance IEM due to not enough available voltage, even if it has enough available power. A low power dongle may not be able to drive a low-sensitivity/efficiency IEM due to not enough available power, even if has enough available voltage.

But as @baskingshark said, you can forget about this for most IEM and dongle pairs: they'll do just fine! In a lot of (most...) cases, "power" is irrelevant--to use your example: a 4V RMS dongle used at 1/8 of its volume is not going to sound inherently "better" than a 2V RMS dongle used at 1/4 of its volume, or a 1V RMS dongle used at 1/2 volume... Sure, the 4V dongle has more "headroom", but it's really irrelevant when your IEM only needs say 500 mV RMS to reach insane sound levels or destroy it. Think about a car: if it needs 20 hp to maintain a normal cruising speed, it does not matter whether the engine can deliver 50, 100, or 200 hp, 20 hp is all you need at that speed.

None of the above tells you anything about "better sound". A 1V dongle can sound better than a 4V one, but a 1V dongle will never sound good it is pushed to its volatge or power limit. Unfortunately (IMHO), there tends to be a correlation between better characteristics, higher limits, "better sound" and price of a dongle--higher price dongles may be better "engineered". BUT not always !!! Hence the importance of forum threads like this one...

 

[marekm]

Hence the importance of forum threads like this one...

Posts like this one, to be precise. Thank you

 

[TheUnknow]

Test Eversolo H2 : un DAC USB-C/ampli casque au format mini, qui concilie qualité et petit budget

First review of Eversolo H2 and it's from a french website.

The sound has almost nothing to envy to that delivered by good desktop devices, whether in terms of level of detail, naturalness or tonal balance.
Everything is perfectly balanced, open, nuanced, whether from headphones or Hifi headphones.
Of course, the musicality is absolutely not sacrificed, and the balance of the sound signature is such that it does not cause any sibilance, unless it comes from the headphones.
On this point, the Eversolo H2 absolutely does not smooth the signal; it remains as uncompromising as we could wish.

 

[Tamizhan]

Another issue in chasing the tail is I've stopped enjoying the music as one coherent song and started looking at individual parts like bass, mids and treble. I'm missing even the beautiful lyrics and trying to analyse what level of instrument separation or soundstage is this headphone putting out.

 

[baskingshark]

Another issue in chasing the tail is I've stopped enjoying the music as one coherent song and started looking at individual parts like bass, mids and treble. I'm missing even the beautiful lyrics and trying to analyse what level of instrument separation or soundstage is this headphone putting out.

Haha you have fallen into the audiophile trap of using music to listen to audio gear, instead of using gear to listen to music.

 

[ftllens]

Good way to avoid that is to just use Harman How to Listen program to test headphones and train your ears. It's right that cans should be used to listen to music not the other way round

 

[iFi audio]

Some basic science... There are 3 characteristics that matter when talking about IEM (or headphones) "power": 1/ the impedance (expressed in Ohms), 2/ the sensitivity (expressed in dB SPL/V) and 3/, the efficiency (also called sensitivity to confuse everybody!!! ...but expressed in dB SPL/mW). These characteristics are generally reported at 1 kHz per convention, but they may vary with the frequency. SPL stands for Sound Pressure Level--how "loud" your IEM sounds.
Let start with 3/: for the same sound level (the dB SPL numerator), a low-efficiency IEM will require more power (in mW, the denominator) from the dongle than a high efficiency one.
Now 2/: for the same sound level (dB SPL), a low-sensitivity IEM will require a higher voltage (in V, the denominator) from the dongle than a high sensitivity one.
The impedance 1/ ties 2/ and 3/ to the dongle: a dongle can be characterized by its max. voltage (e.g. 1, 2, 4 V RMS) and its max. current (in mA), or much more common, its max power (in mW, the product of voltage by current). The impedance of the IEM determines how loud (in dB SPL) the dongle can drive the IEM before hitting one of its internal limits--its max voltage, or its max. current / max. power. A 1V RMS dongle may not be able to drive adequately a high-impedance IEM due to not enough available voltage, even if it has enough available power. A low power dongle may not be able to drive a low-sensitivity/efficiency IEM due to not enough available power, even if has enough available voltage.

But as @baskingshark said, you can forget about this for most IEM and dongle pairs: they'll do just fine! In a lot of (most...) cases, "power" is irrelevant--to use your example: a 4V RMS dongle used at 1/8 of its volume is not going to sound inherently "better" than a 2V RMS dongle used at 1/4 of its volume, or a 1V RMS dongle used at 1/2 volume... Sure, the 4V dongle has more "headroom", but it's really irrelevant when your IEM only needs say 500 mV RMS to reach insane sound levels or destroy it. Think about a car: if it needs 20 hp to maintain a normal cruising speed, it does not matter whether the engine can deliver 50, 100, or 200 hp, 20 hp is all you need at that speed.

None of the above tells you anything about "better sound". A 1V dongle can sound better than a 4V one, but a 1V dongle will never sound good it is pushed to its volatge or power limit. Unfortunately (IMHO), there tends to be a correlation between better characteristics, higher limits, "better sound" and price of a dongle--higher price dongles may be better "engineered". BUT not always !!! Hence the importance of forum threads like this one...

This is very useful and should be framed onto HF's main page somewhere.

As for IEMs and dongles, indeed in most cases power won't be any issue. Most IEMs are easy loads after all

 

[PhonoPhi]

This is very useful and should be framed onto HF's main page somewhere.

As for IEMs and dongles, indeed in most cases power won't be any issue. Most IEMs are easy loads after all

Easy loads are well-designed IEMs with impedance of 30-40 Ohm, good sensitivity, so that a simple Apple dongle (designed for ca. 40 Ohm earpods) can drive them well.

The electrical power is the product of voltage and current, so that the limitations can be on both sides.
The limitations in voltage are most straightforward and easy to understand: not enough voltage - not enough power to drive IEMs sufficiently loud. These voltage limitations (or the lack of thereof) are commonly discussed, as above.

Current limitations are more subtle and harder to measure/document properly.

Here, the IEM design comes into play: low-impedance IEMs, e.g. at 6-9 Ohm (nominal value at 1 kHz, and can be even lower at other frequencies), need to use much lower voltage and much higher currents. That causes some problems.
Firsr, lower voltages of the powerful sources comes close to their noise floor causing noticeable hiss (here Ifi offers some good solutions, but with multi-drivers, especially multi-BAs, changes in tonality are common with supplementing the source either with impedance adapters or resistive brdges).

Second, modulating relatively high currents fast at lower voltages is demanding for a portable power source. In fact, how many dongles are certified to drive the loads below 8 Ohm? (Very few I know are certified to work below 16 Ohm). With limitations in current modulations, most power-demanding drivers get underpowered, and also overall dynamic range can suffer.

Despite these limitations, IEM designers seem to compete - who would make lower and lower impedance. Lower-impedance IEMs sound louder out of the box, hence more vivd, etc. - a form of the "loudness war" of the IEM world.
Then, sources start to matter, even cables can matter, and even the level of the battery...

With all this complexity and uncertainly, a simple solution is to get properly designed IEMs and fully enjoy them with a simple source, but we know it is not always a preferred "audiophile" way

 

[ApaucalyptiK]

Good stuff about the Tanchjim Space :
https://www.audiosciencereview.com/...pace-portable-headphone-adapter-review.46231/

Conclusions
First a confession: when the company reached out to me a few months ago, I had not heard of them and thought this would be a very low performing device. So I responded that I don't think it would do well. They assured me that it would and showed me measurements that were just hard to believe. They sent me a sample which unfortunately got lost. What you see here is the second sample. As you see, performance is just stunning. Use of dual DACs and excellent engineering has translated into a top of the line desktop class DAC but in a container that is the size of an America quarter! Functionality is excellent with nice tactile volume controls. And the thing manages to look attractive to boot! Other than finding out why it won't produce 4 volts, it is the most perfect headphone adapter I have tested!

It is my pleasure to recommend the TANCHJIM Space dac and headphone amplifier. I will be using it as my everyday adapter for my phone from here on!