[rocketron]

Can I ask about the suitability of the Mojo 2 as a DAC only, feeding a separate headphone amp?
I've bought the Mojo 2 and I'm considering getting a small tube headphone amp (Schiit Vali 2++) and I was wondering about the fact that the output of the Mojo 2 is designed to drive headphones, not act as a line-level signal to feed a pre-amp.
I thought that the voltage and output impedance needed to be particular values, as found in a standard line-out such as RCA connectors, rather than the headphone amp output from the Mojo 2.
Is this not a case of amping an amp (which I've always heard is something that should be avoided)? Maybe @Rob Watts could give me some guidance if you have time?

I found this post which suggests that the output is actually not a headphone amp in the traditional sense but rather a high-level DAC analogue output so I should be fine.
Can anyone confirm?

Absolutely no problem at all running a Mojo 2 into a Vali 2++.
I set the Vali 2++ on high gain adjust the volume dial to about 12oclock then increase the Mojo 2 volume.
It’s usually around the blue colour.
Then fine tune from there with the Vali 2++ volume dial.

The Vali 2++ is a fantastic cheap little amp.
Have fun tube rolling and check out the Vali tube rolling thread.

 

[Daniel Johnston]

Can I ask about the suitability of the Mojo 2 as a DAC only, feeding a separate headphone amp?
I've bought the Mojo 2 and I'm considering getting a small tube headphone amp (Schiit Vali 2++) and I was wondering about the fact that the output of the Mojo 2 is designed to drive headphones, not act as a line-level signal to feed a pre-amp.
I thought that the voltage and output impedance needed to be particular values, as found in a standard line-out such as RCA connectors, rather than the headphone amp output from the Mojo 2.
Is this not a case of amping an amp (which I've always heard is something that should be avoided)? Maybe @Rob Watts could give me some guidance if you have time?

I found this post which suggests that the output is actually not a headphone amp in the traditional sense but rather a high-level DAC analogue output so I should be fine.
Can anyone confirm?

As was stated above. There is zero issue using the Mojo 2 as a DAC only. I use it to feed the Folkvangr. Just adjust the output to be about 2V (IIRC the lighter blue setting).

It s not double amping connecting the Mojo 2 to a separate amp.

 

[jsk ksj]

As was stated above. There is zero issue using the Mojo 2 as a DAC only. I use it to feed the Folkvangr. Just adjust the output to be about 2V (IIRC the lighter blue setting).

It s not double amping connecting the Mojo 2 to a separate amp.

Why is it not double amping ? The mojo2 doesn't stop amplyfing when connected to another amp.

Ps I have no issue with doing it if it sounds great

 

[Daniel Johnston]

Why is it not double amping ? The mojo2 doesn't stop amplyfing when connected to another amp.

Ps I have no issue with doing it if it sounds great

That's a technical question above my head. From what I understand, the headphone out of Mojo 2 is direct from the FGPA. It is the same pathway that is used for the line level out to any amplifier. So yes, it does provide enough power and amplification for headphones/IEMs. Where as an amplifier has a gain stage and amplification stage. From what I understand, it's the gain stage that is the issue with "double amping". Having two gain stages connected I think is the issue. Since the Mojo 2 has no gain stage, it's not double amping.

Anyone can feel free to chime in if I'm not explaining things correctly.

 

[jsk ksj]

That's a technical question above my head. From what I understand, the headphone out of Mojo 2 is direct from the FGPA. It is the same pathway that is used for the line level out to any amplifier. So yes, it does provide enough power and amplification for headphones/IEMs. Where as an amplifier has a gain stage and amplification stage. From what I understand, it's the gain stage that is the issue with "double amping". Having two gain stages connected I think is the issue. Since the Mojo 2 has no gain stage, it's not double amping.

Anyone can feel free to chime in if I'm not explaining things correctly.

You've convinced me, but I know nothing

 

[Zap67]

so just connect a cable terminated on the opposite side in rca to the headphone output of the Mojo 2? did I get it right?

 

[Daniel Johnston]

so just connect a cable terminated on the opposite side in rca to the headphone output of the Mojo 2? did I get it right?

Yep.

3.5mm to stereo RCA is all you need.

 

[Birch]

Zap67 said:
so just connect a cable terminated on the opposite side in rca to the headphone output of the Mojo 2? did I get it right?

Yep.

3.5mm to stereo RCA is all you need.

Just pick the price-point you're comfortable with, DIY, Amazon, Nordost, ... many choices

 

[rocketron]

You can do as above or just use a Audioquest 3.5mm to RCA adapter.

The way I understand it is the Mojo doesn’t have an amp.
It just outputs voltage.
You’re increasing or decreasing the out put voltage with the volume control.
I could be wrong and some one clever please correct me if I am.

 

[vlach]

You can do as above or just use a Audioquest 3.5mm to RCA adapter.

The way I understand it is the Mojo doesn’t have an amp.
It just outputs voltage.
You’re increasing or decreasing the out put voltage with the volume control.
I could be wrong and some one clever please correct me if I am.

Make sure to verify the L and R channels are not reversed on that Audioquest adapter, it is the case with mine.
Rob Watts explained a while back that the Mojo has one (1) amplification stage following the FPGA DAC output.

 

[RiccardoPL]

I had had it for a whole day before I realised that the charging led kept flashing when in desktop use, that is, connected to power.

The charging led keeps flashing, as if it was charging while using it despite battery being full.

I have the same issue, the blue LED is flashing, and Mojo 2 doesn't enter desktop mode, even after an hour. I have tried different chargers and cables. Since you mentioned that it enters desktop mode for you within 2-3 minutes, I'm concerned.

 

[ducnsh]

I have the same issue, the blue LED is flashing, and Mojo 2 doesn't enter desktop mode, even after an hour. I have tried different chargers and cables. Since you mentioned that it enters desktop mode for you within 2-3 minutes, I'm concerned.

I think you got a faulty device, I am using the Mojo2 almost time in the desktop mode at the office and at home, by keeping the full battery, it takes maximum 3 minutes to enter the desktop mode.

 

[jarnopp]

Why is it not double amping ? The mojo2 doesn't stop amplyfing when connected to another amp.

Ps I have no issue with doing it if it sounds great

There are some relevant posts Rob has made about his approach. Start with this one:
https://www.head-fi.org/threads/objectivists-board-room.769647/page-103#post-12178402

More search results to explore:
https://www.head-fi.org/search/13433921/?q=Mojo+amp+stage&c[users]=Rob+Watts&o=relevance

Bottom line: the most transparent sound will be direct from a Chord DAC, and only use an amp if you need more power or like the added distortion, which can be euphoric of course.

 

[RiccardoPL]

I think you got a faulty device, I am using the Mojo2 almost time in the desktop mode at the office and at home, by keeping the full battery, it takes maximum 3 minutes to enter the desktop mode.

I did as follows - I left the Mojo 2 charging overnight (as I set it up, the blue LED was pulsing, indicating sufficient charging with a white ball), and in the morning, it was in desktop mode. I disconnected it from the power supply and after some time, I connected it again - the attached photo shows the result in less than 7 minutes. I hope this was just a temporary issue, and I will keep an eye on it.

 

[Soundizer]

for driving full sized headphones how does Mojo 2 compare to FiiO K9 DAC/Amp?