[Rob Watts]

@Rob Watts, Is there an EQ for setting for the Mojo 2 that technically/closely aligns with the first generation Mojo? I'm finding the original Mojo is more dynamic and "rose tinted" in tone. The Mojo 2 is more resolving in terms of absolutes but it is hard to compare the two with such a difference in sound.

There isn't a setting that will precisely replicate a Mojo sound, as it's nothing to do with frequency response - both are perfectly flat. Sure you can boost 125Hz by a couple of dB's to give you a warmer balance - but it won't sound like a Mojo as the bass will be more extended and warmer but the precision and accuracy of Mojo 2 will still be there.

When I went from Mojo to Hugo 2 initially I found it bright. But after a month going back to Mojo was a big shock; it just sounded coloured and out of focus in the bass. It is remarkable that it's only down to a single capacitor in the signal path modifying the tonal balance and degrading the bass. But small things matter hugely in audio.

 

[Kentajalli]

Capacitors, their type (plastic, paper-in-oil, electrolytic etc.) in signal path and their effects on sound has long been known, specially in Tube amps, where one needs to block high DC voltages.
Many do not believe in that, since Capacitors (and cables) effect on sound is difficult to measure in a lab (can't measure it = doesn't exist).
Certainly in my amp (Tube) a plastic capacitor sounds harsh, replace that with a vintage Russian (i.e. cheap) paper-in-oil capacitor and the harshness goes away, treble cleans up and deep bass gets extended. Imagine what no capacitor sounds like.
This is why, some manufacturers proudly declare that their amps are DC coupled.

 

[iDesign]

There isn't a setting that will precisely replicate a Mojo sound, as it's nothing to do with frequency response - both are perfectly flat. Sure you can boost 125Hz by a couple of dB's to give you a warmer balance - but it won't sound like a Mojo as the bass will be more extended and warmer but the precision and accuracy of Mojo 2 will still be there.

When I went from Mojo to Hugo 2 initially I found it bright. But after a month going back to Mojo was a big shock; it just sounded coloured and out of focus in the bass. It is remarkable that it's only down to a single capacitor in the signal path modifying the tonal balance and degrading the bass. But small things matter hugely in audio.

Thank you, Rob. +2dB at 125Hz is similar to the more dynamic, warmer, and "rose tinted" musical tone of the original Mojo. Now in comparing the two, the most perceptible difference is in the resolution-- the Mojo 2 is an evolution of an already outstanding device and I appreciate the original Mojo as much I did when it arrived in 2015.

 

[flyte3333]

Hi @Rob Watts

Here is JA's measurements of Dave:

https://www.stereophile.com/content/chord-electronics-dave-da-processor-measurements

Can you please explain how this is not noise floor modulation?

I know your measurement is done differently and with newer AP - but still, how is this not considered noise floor modulation?

The 2 signals are not both 'bottoming out' JA's old AP here - otherwise I'd say it's not up to the task for noise floor modulation measurements.

We can see the noise floor is changing with input signal, no?

I'm not trying to say this is audible btw - this is very low stuff.

 

[flyte3333]

And this plot below. Even though it's 2 completely different types of test signals overlaid, we see 2 different noise floors at different input levels.

I'm obviously not understanding something here but if this is not evidence of noise floor modulating with input signal level, can you help to explain.

Thanks !

 

[iDesign]

Atkinson‘s measurements were taken on an obsolete SYS2722 and the APx555 is needed to more accurately measure the DAVE.
https://www.ap.com/analyzers-accessories/2700-series/

 

[flyte3333]

Atkinson‘s measurements were taken on an obsolete SYS2722 and the APx555 is needed to more accurately measure the DAVE.
https://www.ap.com/analyzers-accessories/2700-series/

As I wrote above, I would put it down to that, if Dave's measurement 'bottomed out' his old SYS2722

i.e. if noise floor reached the limit of SYS2722 then we would see that in JA's measurements.

But JA shows different noise floor levels, meaning his system did not 'bottom out', for those measurements I showed above?

I would say yes, JA's system is too old, if those measurements all showed a noise floor of only -150dB.

But we see changes in noise floor to higher levels right with different input levels?

Isn't that noise floor modulation?

 

[Jawed]

Do you happen to have a link to Rob’s guide?

https://www.head-fi.org/threads/chord-hugo.702787/page-568#post-10955256

and, briefly:

https://www.head-fi.org/threads/watts-up.800264/page-188#post-16666547

Jawed

 

[feddar]

Single driver speakers do have amazing depth - due to the simplicity of the connection. But they do sound a little strange in response terms, and that's not something I have so far been able to live with.

May I ask what you mean by ‘strange in response terms’? And would adding the subwoofer help that out for you?

 

[kennyb123]

May I ask what you mean by ‘strange in response terms’? And would adding the subwoofer help that out for you?

Great questions for Rob. My two cents on it is that it can take one’s ears and brain to adjust to them. I’ve been listening to traditional three range speakers for all my adult life. There’s a way that these present music that is easy to acclimate to when hearing similar speakers. A friend has Magneplanar speakers and I usually struggle to adjust to them. One thing that really impresses me about them though is their continuousness if they are properly set up. Indivisible drivers don’t call attention to themselves. This continuousness is even better executed on the Voxativ speakers. But having a single speaker handle everything does come with tradeoffs. Read Art Dudley’s reviews of the Voxativ speakers as he articulates well the tradeoffs - though I think he goes a bit too far with it. Ultimately it will come down to a personal decision as to which attributes one favors. I do think that owning a TT2 or DAVE opens the door to really making Voxativ speakers shine. @ray-dude might have some thoughts on this.

 

[Kentajalli]

Great questions for Rob. My two cents on it is that it can take one’s ears and brain to adjust to them. I’ve been listening to traditional three range speakers for all my adult life. There’s a way that these present music that is easy to acclimate to when hearing similar speakers. A friend has Magneplanar speakers and I usually struggle to adjust to them. One thing that really impresses me about them though is their continuousness if they are properly set up. Indivisible drivers don’t call attention to themselves. This continuousness is even better executed on the Voxativ speakers. But having a single speaker handle everything does come with tradeoffs. Read Art Dudley’s reviews of the Voxativ speakers as he articulates well the tradeoffs - though I think he goes a bit too far with it. Ultimately it will come down to a personal decision as to which attributes one favors. I do think that owning a TT2 or DAVE opens the door to really making Voxativ speakers shine. @ray-dude might have some thoughts on this.

You do know Maggies have multiple drivers too?
I love them, and yes you are right, once setup right, the fluidity and depth of stage is lovely.
I couldn't get into single drivers either.
bandwidth is not wide enough (not enough bass or treble), but since there is no crossover circuit, and a point source for sound, then some issues with multidriver setups won't occur.
seating position angle, timing mismatch between drivers play hell with depth perception.
Also direct amp to transducer connection means best electrical damping of the diaphragm .
Good for classical music, live recordings.

 

[kennyb123]

You do know Maggies have multiple drivers too?
I love them, and yes you are right, once setup right, the fluidity and depth of stage is lovely.

Yes I know that all too well, which is why I added the caveat about them being properly set up. The tweeter section can really be distracting if care isn’t taken to find the right placement.

Continuousness is the only positive quality I have appreciated in Maggies. How they move air detracts from the experience - particularly from the midbass on down. I can really only appreciate them with classical music.

I couldn't get into single drivers either.
bandwidth is not wide enough (not enough bass or treble), but since there is no crossover circuit, and a point source for sound, then some issues with multidriver setups won't occur.

Have you heard Voxativ?

 

[Rob Watts]

Hi @Rob Watts

Here is JA's measurements of Dave:

https://www.stereophile.com/content/chord-electronics-dave-da-processor-measurements

Can you please explain how this is not noise floor modulation?

I know your measurement is done differently and with newer AP - but still, how is this not considered noise floor modulation?

The 2 signals are not both 'bottoming out' JA's old AP here - otherwise I'd say it's not up to the task for noise floor modulation measurements.

We can see the noise floor is changing with input signal, no?

I'm not trying to say this is audible btw - this is very low stuff.

All ADCs have very large levels of noise floor modulation. To measure the (lack of) noise modulation on my DACs you must use an effective distortion free analogue notch filter to eliminate the fundamental, then ADC the residual. That way, the innate noise floor modulation of the ADC is eliminated. The APx 555 does this by employing 2 ADCs per channel - one for the residual notched system, one for the fundamental. So ignore all measurements unless this is done.

Atkinson‘s measurements were taken on an obsolete SYS2722 and the APx555 is needed to more accurately measure the DAVE.
https://www.ap.com/analyzers-accessories/2700-series/

Correct. You could use the analogue notch on the SYS2722, and ADC the residual, but I don't know how effective this would be. Clearly this is not being done with Stereophile's published measurements, as you can see the fundamental.

May I ask what you mean by ‘strange in response terms’? And would adding the subwoofer help that out for you?

One aspect is certainly the bass, and a sub would help. But I think they would still sound coloured.

 

[flyte3333]

All ADCs have very large levels of noise floor modulation. To measure the (lack of) noise modulation on my DACs you must use an effective distortion free analogue notch filter to eliminate the fundamental, then ADC the residual. That way, the innate noise floor modulation of the ADC is eliminated. The APx 555 does this by employing 2 ADCs per channel - one for the residual notched system, one for the fundamental. So ignore all measurements unless this is done.



Correct. You could use the analogue notch on the SYS2722, and ADC the residual, but I don't know how effective this would be. Clearly this is not being done with Stereophile's published measurements, as you can see the fundamental.



One aspect is certainly the bass, and a sub would help. But I think they would still sound coloured.

Thanks for the explanation ! This explains a bit more than when I asked previously about similar thing (different Stereophile DAC measurements),

I know all your thoughts about the popular audiophile linear PSU's.

What about a linear PSU that uses an EI core AC-to-AC transformer (say 230Vac to 12Vac) before the usual low noise circuitry?

Can such transformers do a good job with AC RF filtering? Compared with SMPS?

 

[Kentajalli]

Have you heard Voxativ?

I am a poor working man , can not afford speakers at tens of thousands!
Perhaps at the next hifi show, if they turn up.