[morinu]

First 2 hours with the Mojo and it is blowing my mind with the HD600... I can't believe how good they are together... 

 

[Rob Watts]

@robwatts @mojo ideas

How about an impedance module that allowed us to adjust output impedance until we perfectly matched mojo to our ciems/headphones?

The technically perfect impedance is zero, and that's why I worked so hard to get it as low as 0.075 ohms with Mojo.
 
The reasons going for as close as zero are:
 
1. Frequency response. The impedance of the headphone varies with frequency, and so by having a high output impedance will cause frequency response variations. Zero impedance eliminates this problem.
 
2. Distortion. The impedance of a headphone varies with level, and having a higher output impedance will increase the total distortion - given that Mojo distortion is so low, this is actually quite a significant an effect. Again, zero impedance eliminates this problem.
 
3. Damping factor - probably the most important reason. A drive unit is a resonant system - that is a mass on a spring - that is damped mechanically and electrically. Electrical damping is due to the headphone creating a current due to the motion of the driver in the magnetic field - and how well this is controlled depends on the electrical impedance the driver sees - in our case, the cable impedance and Mojo's impedance. Again, zero impedance gives the best damping, with an infinite damping factor.
 
I did some listening tests many years ago with loudspeakers and damping factor and found that it made a massive difference to the sound. Damping of 10 gave a very soft, big fat bass - but everything sounding one note in the bass - simply because the loudspeaker was doing its own thing at the resonant frequency. Going from 10 to 100 gave a tighter bass, with much better pitch reproduction - you could follow the bass line much more easily. Above 100 to 1000 it sounded tighter - no big change in pitch (being able to follow the bass tune) but the perceived tempo of the music became faster as transients are much better controlled. Going above 1000 gave a small improvement in how tight it sounded.
 
Rob

 

[masterpfa]

  After listening the Mojo with the Grado GR10, i didn't feel in improved the staging or the instrument separation, instead giving it a little more grunt and richness in the bass and low mids.I was worried that switching to the Beyerdynamic dx160, it would give the same additions to a headphone that already has a very rich presentation of the low end. To my surprise, the Mojo actually smoothened the low end, making it more clear and fluent, and brought the mids a little more up-front. I then switched to the Dunu DN2000J, and here it gave me a better soundstage, improved the instrument separation and smoothed the high end, reducing sensibly any sibilance.
It feels like the Mojo is working a little magic on the phones i'm using, organising better what the headphone is doing good, and improving on what the headphone is lacking.
I'll keep switching to my other 15 headphones to see if the magic continues.

 
Great job guys!!!

We await your verdict
 

  First 2 hours with the Mojo and it is blowing my mind with the HD600... I can't believe how good they are together... 

Welcome to the club.

 

[masterpfa]

On the top, that way I use the feet on the Mojo and the volume and power button aren't pressed accidentally. Lots of examples in this thread's gallery of how people stack their Mojo, like this one of mine.

Just re-united my AK100 and Mojo after a period of using the Onkyo DP-X1.
I had to do a double take as I thought to myself, I don't remember posting this picture 
Same model, colour, case and interconnect only the headphone connected is different. I even have the same worktop surface (OK that laast one not strictly true) 

 
I had been waiting for my replacement Sys-concept cable.
Now I have returned to the compact size stack I need for my commute.

 

 

[Ra97oR]

 
This is how I currently have my Mojo as when I am carrying it around in my pocket.
 
I feed it with my phone in a different pocket to reduce bulk.

 

[Currawong]

 

I understand, and that's why I didn't quite believe what I was hearing, I went into the blind test expecting to find out that transport mattering was just ********. Imagine how stunned I was to hear the difference.

Even between the two versions of the m1, the sound is different as a transport. I know it's hard to believe especially when rob himself has said that it shouldn't matter, but you got to try it out to understand what I'm hearing.

If you check out the Esther thread, @Currawong has tried it too and he said that the difference between the ak100 and the Esther m1 as a transport is significant.

Make of that what you will, but I urge you to give it a shot, if you have access to the AK players Try the ak380 vs the ak100 or something and see if you can hear a difference. The 380 is a pretty good transport to my ears, not as good as th Esther but definitely among the better ones. Do give it a shot and let me know how it goes

Actually, I'm not saying there is no difference between sources. I'm saying it isn't the Femto clocks.

I didn't want to report it but I hear a clear difference using the AK100 mk2 and the AK240 as a source.

 
I don't have a Femto clock version of the M1 and was expecting zero difference between using it and the AK100 as the transport. However, much like I had with the Hugo, the best results I got sonically were with the coax input. In the Hugo's case, it was with Soundaware's D100PRO. I have no idea why, unless one of the devices has an output that isn't bit perfect. If not that, the only thing I could speculate is that the Hugo and Mojo's electronics have to perform less timing recovery and the internal electronics end up generating less noise themselves. 

 

[Joe Bloggs]

@robwatts @mojo ideas

How about an impedance module that allowed us to adjust output impedance until we perfectly matched mojo to our ciems/headphones?

Actually, starting from an effective zero ohm impedance from the Mojo, there's a very cheap and simple "impedance module" for any CIEM or headphones: it's called a headphone cable / extension cable with in-line volume control. They put a variable resistor between the amp output and each headphone channel.

Unfortunately I don't see such an "impedance adapter" ever becoming a HiFi item. Or do I...?

 

[x RELIC x]

I don't have a Femto clock version of the M1 and was expecting zero difference between using it and the AK100 as the transport. However, much like I had with the Hugo, the best results I got sonically were with the coax input. In the Hugo's case, it was with Soundaware's D100PRO. I have no idea why, unless one of the devices has an output that isn't bit perfect. If not that, the only thing I could speculate is that the Hugo and Mojo's electronics have to perform less timing recovery and the internal electronics end up generating less noise themselves. 

What I found absolutely shocking was the clear and unexpected difference between the AK240 and the AK100 mk2 with the exact same optical connector.

 

[x RELIC x]

Actually, starting from an effective zero ohm impedance from the Mojo, there's a very cheap and simple "impedance module" for any CIEM or headphones: it's called a headphone cable / extension cable with in-line volume control. They put a variable resistor between the amp output and each headphone channel.

Unfortunately I don't see such an "impedance adapter" ever becoming a HiFi item. Or do I...?

That would explain the difference I heard with the different cables included with the Sennheiser Momentum (v1.0) that I briefly owned.

 

[Multimediers]

   
I haven't seen any MK2-appropriate TRRS-to-mono-TRS cables on Taobao, using the suggested search term
 
.

https://item.taobao.com/item.htm?spm=5706.1529727.a31f1.4.SmNVtI&scm=1007.11502.21311.100200300000003&id=528390962477&pvid=5e6a9193-0115-4887-a3ba-6f1ee2d8530f
 
not trying to help them ad. here but just an example from Taobao for available options of 3.5mm coaxial cable for Fiio Mk2s with Mojo

 

[WCDchee]

What I found absolutely shocking was the clear and unexpected difference between the AK240 and the AK100 mk2 with the exact same optical connector.

I know, same with the x5 and the m1pro, and they're both coaxial!

 

[x RELIC x]

https://item.taobao.com/item.htm?spm=5706.1529727.a31f1.4.SmNVtI&scm=1007.11502.21311.100200300000003&id=528390962477&pvid=5e6a9193-0115-4887-a3ba-6f1ee2d8530f

not trying to help them ad. here but just an example from Taobao for available options of 3.5mm coaxial cable for Fiio Mk2s with Mojo

That's very helpful for a lot of owners. Curious why they use a TRS plug at Mojo end when a TS plug is all that's required.

 

[Multimediers]

That's very helpful for a lot of owners. Curious why they use a TRS plug at Mojo end when a TS plug is all that's required.

I am curious on this point, too. Anyway, it will not make any difference in performance.

 

[audi0nick128]

Interesting to hear about the Esther m1 (pro) and the reported experiences.
I am not certain how these differences in SQ can be explained. But when Mr. Rob Watts says his DACs are immune to jitter I do believe him.
That being said I can imagine other effects beeing responsible for difference in SQ. Rob mentioned disruptive currents have to be taken in account.
This might explain a recovery reclocker to be effective when used with mojo. It might just be the cleaner power supply.
So now it seems like the system to check out might be Esther-Mojo-Ether C
Speaking of those stray currents again, did anyone test Mojo with a grounding device, like a entry level Minimus Entreq Grounding Box?

Cheers

 

[x RELIC x]

Interesting to hear about the Esther m1 (pro) and the reported experiences.
I am not certain how these differences in SQ can be explained. But when Mr. Rob Watts says his DACs are immune to jitter I do believe him.
That being said I can imagine other effects beeing responsible for difference in SQ. Rob mentioned disruptive currents have to be taken in account.
This might explain a recovery reclocker to be effective when used with mojo. It might just be the cleaner power supply.
So now it seems like the system to check out might be Esther-Mojo-Ether C
Speaking of those stray currents again, did anyone test Mojo with a grounding device, like a entry level Minimus Entreq Grounding Box?

Cheers

The differences I heard was with an optical connection, which is immune to 'stray currents'. I really think that it's down to the way the player is decoding the file and perhaps (just a hunch) there may be DSP going on in some players that aren't being advertised. Of course, strictly speaking of what I've heard on my devices. RF noise and other 'stray currents' may affect other players, but I'm still doubtful it's jitter that would cause a difference.