[Jalo]

@Mathieulh, I copied my discussion with Nanaholic over the DMP-Z1 thread below:

“@Nanaholic, I appreciate your raising the issue of application of the formula, I guess our differences lie with the concept of constant. Generally speaking, If one just look at a formula with three variables, it is true that if two of the three variables are known then the value of the third variable can be known. It is also true that by varying any two variables you can change the value of the third variable. And that is what you did with the application of the formula above by plunging in two of the three variables thereby changing the value of the Vrms and what you did is accurate in general terms except the following:

Let me prefaced it by saying I am not a fan boy of AK and I do not have any inside connections with AK to know what those published value means other than what is being published on their website. I actually own two WM1Z, one WM1A and the Z1R to give you some perspective and I do not feel any urge to defend AK at all. My only interest is to understand and get good sound.

Having said that, when I read “12 Vrms, Condition No Load” to me it simply means that is the value of the device, Khan, AK 380 or whatever the device happens to be by circuitry design without any load. So to me of the three variables:

A. Vrms of the device by circuitry design
B. Resistance in Ohm
C. Output power in Wattage

One can vary variable B by changing headphones with different impedance value, one can also change Valuable C for any amount a person wants or desires by varying valuable A and B. What we cannot change is the circuitry by design inside the Khan, AK380, SP1000 etc. that produce the Vrms under no load condition hence I hold variable A (Vrms) constant. Without assuming variable A is constant you are correct by varying B and C variable A (Vrms) has to be different. I will be happy to agree with you if my assumption that the stated Vrms is not derived by hardware design. But if the Vrms value is produced by hardware design then one must hold it constant and my application of the formula is accurate. I can only assume that the volt root mean square (Vrms) is a value produced by the amplifier circuitry otherwise what else could have generate the power in a dap if not for the hardware and that is why you cannot reverse the formula to come up with different Vrms because we cannot alter the hardware inside the circuitry.

Those websites that you cited for power calculations is accurate but they do not know or take the assumption that one of the Variable cannot be varied.”

 

[rutter]

About power output being predictable, here are a few examples I saw of desktop amps that led me to believe you need to see the specs.

http://www.auralic.com/download/TAURUSMKII_USERSGUIDE_R1.pdf

Page 14.
Single-ended vs Balanced
32ohm 4500mW 1200mW
120ohm 1200mW 4500mW
300ohm 500mW 2000mW
600ohm 250mW 1000mW

Balanced has a mid-centric hump, which I had never seen before.

https://www.schiit.com/products/magni-1

Maximum Power, 16 ohms: 3W RMS per channel
Maximum Power, 32 ohms: 2W RMS per channel
Maximum Power, 50 ohms: 1.3W RMS per channel
Maximum Power, 300 ohms: 430mW RMS per channel
Maximum Power, 600 ohms: 230mW RMS per channel

Single-ended the Taurus MKII has a ratio of 1/9 from 300 ohm to 32 ohm whereas the Magni is between 1/5 and 1/4.

https://www.schiit.com/products/mjolnir-2

Maximum Power, 32 ohms: 8.0W RMS per channel
Maximum Power, 50 ohms: 5.0W RMS per channel
Maximum Power, 300 ohms: 850mW RMS per channel
Maximum Power, 600 ohms: 425mW RMS per channel

300 to 50 ohms here is about 1/6 whereas with the Magni it's about 1/3, 300 to 32 is much different too. And of course balanced vs balanced with the MKII is just entirely different.

PS

A couple of things from last night. One, what was happening in relation to USB dac with the DX220 appears to be a bug and would be corrected. Two, crinacle was necessarily wrong in his recommendation given it was applied to me; spending extra money on a dap or source for the IER-Z1R can fix major problems or address them well enough. Maybe he should look to expand into daps for instance, make his reviews more reflective of reality. It is a deplorable one I didn't like myself, but it is what it is. Buying expensive headphones and iems is unfortunately about half the cost, even half the cost of the dac and amp.

CONCLUSION - CAMPFIRE AUDIO SOLARIS REVIEW - SOMETHING VERY SPECIAL
A lot of companies that have entered the world of the portable audiophile over the past decade have felt like a cash grab. Some milk the willing buyers for every penny via placebo, marketing or hype. Campfire Audio make expensive earphones but every single one feels like a product of passion. A product of true craftsmanship and with an uncompromising approach to the aesthetic, construction and fidelity. The Solaris is more than just an earphone, it’s an experience and one that I think any hobbyist would be lucky to have at least once.

...

Big brands have marketing budgets to gain traction in the market yet brands like Campfire are succeeding because of their stellar reputation. The Solaris is a masterpiece and will only further it.

These are a special, special earphones in so many ways that it is easy for me to recommend them.

Just skipped to the conclusion of a new review about the Solaris. I love it when I see this, it is either a cynical lie or just reviewer cluelessness. How many times do you see reviewers who praise every single expensive iem make a statement like this to the effect of in a market where everything is overpriced this isn't, it's awesome. These people are a joke and do a disservice to market prices. Disgusting.

 

[BruceyWayne]

Can’t wait to power my z1r with nuclear plant

 

[rutter]

I like your style. You're fortunate that nuclear power plants come in pocket-size so you actually have options, surprisingly.

 

[candlejack]

Can’t wait to power my z1r with nuclear plant

Just make sure to get the Plutonium version. The Uranium versions don't get the best peak power performance needed by the z1r.

 

[rutter]

Or just get an iPhone and get an entire phone on top of the dac and amp (plus the player part!) for the same price. Then replace the IER-Z1R with Apple earbuds and you might be about as well off.

 

[BruceyWayne]

I’m actually just going to use z1r with my iPhone XS Max and dongle.

 

[rutter]

Out of curiosity, what is the dongle supposed to do?

 

[BruceyWayne]

New iphones don’t have headphone jack

 

[rutter]

That's it? So the dongle is like something Donald Trump would call himself. Best value in the history of the portable audio market.

 

[jeffreyw311]

That's it? So the dongle is like something Donald Trump would call himself. Best value in the history of the portable audio market.

It actually is, the Apple dongle is a very well engineered audio product. Noise floor is astonishingly low and it puts out enough power/voltage for sensitive IEMs.

 

[rutter]

Cool. How does it do that?

 

[jeffreyw311]

Cool. How does it do that?

Custom ICs. Whatever you might think about Apple, they still have the best mobile processor designs in the world. Google’s dongle is awful in comparison.

 

[rutter]

I don't use dongles so I wouldn't know. Explain it to me like I'm five ears old and am capable of asking a series of questions. How do the iPhone dac, amp, and dongle effectively replace a dap? How have you arrived at the idea that with more capable and much more expensive iems, which don't have the extremely high sensitivity, extremely low impedance, and probably don't have the same drivers as for instance a Campfire Solaris, you shouldn't be using a dap? I hear a major difference going between two daps, let alone a phone with a hanging dongle. You can even hear significant differences changing iBasso amp modules. Why do even the Campfire Solaris folks recommend daps over smartphones with dongles? What daps have you heard to compare?

 

[jeffreyw311]

I don't use dongles so I wouldn't know. Explain it to me like I'm five ears old and am capable of asking a series of questions. How do the iPhone dac, amp, and dongle effectively replace a dap?

A DAP is just a mobile phone with maybe some extra audio chips or discrete audio parts. It still uses the same mobile SoCs as a mobile phone, many are even Android based.

The dongle contains a DAC and amp. Some more expensive DAC and amps might discrete parts but that doesn’t automatically mean it performs well.

The main reason the Campfire Andromeda was once married to the Sony ZX2 and ZX300 was because their 3 ohm output impedance produced the best frequency response from the Andromeda. It wasn’t because they had anything special to them.

How have you arrived at the idea that with more capable and much more expensive iems, which don't have the extremely high sensitivity, extremely low impedance, and probably don't have the same drivers as for instance a Campfire Solaris, you shouldn't be using a dap?

What you just said is completely false. 99% of IEMs have very high sensitivity and low impedance. All IEMs are well above 100db sensitivity.

Majority of 64Audio are well above 100db sensitivity and are below 10 ohms impedance.

Anole VX is 110db sensitivity and 15 ohms.

I can go on and on.

Where do you get the idea that expensive IEMs aren’t high sensitivity or have high impedances?

I hear a major difference going between two daps, let alone a phone with a hanging dongle. You can even hear significant differences changing iBasso amp modules.

Have you thought for a second that different DAPs might just have different sound signatures and react differently to different IEMs? It’s not a one size fit all solution.

Why do even the Campfire Solaris folks recommend daps over smartphones with dongles? What daps have you heard to compare?

Entire Sony and AK lineup, most of Fiio’s lineup, Shangling M0 and M5s, iBasso DX200 and DX220, Questyle QP1R.

Campfire IEMs are extremely responsive to output impedance. Audiophile DAPs vary in output impedance, a lot of Sony DAPs are around 3 ohms. The dongle has an output impedance of ~0 ohms, some people with the Solaris would prefer a DAP with higher impedance as it would boost the presence region.

iPhone dongle works fine, end of story. If you want a different tone, go get a DAP. But the idea it’s not a capable audio device is incorrect.