[Rob Watts]

  Rob, I'm curious how the digital amplifier project is going. Have you decided the name? Is it possible for you to give us some information how it is going?

Its second priority, Davina is what I am working on at the moment. 
 
Project code word is Hugo amp, but it's unlikely to be actually called that.
 
Rob

 

[Mython]

   
Project code word is Hugo amp, but it's unlikely to be actually called that.
 
Rob

 
 
How about Huge-amp?

 

[Hutnicks]

Damp
 
It works on sooo many levels.

 

[Mython]

On a serious note, I am intrigued as to how your eventual digital amp may sound, Rob - my only experience of a digital amp stage is in Sony's NW-ZX1 DAP, which I feel sounds horrendously artificial/synthetic (but superb, when bypassed & plugged into a Hugo

). It amazes me that anyone takes it seriously as an audiophile product.
 
However, that is a tiny Class-D amp stage, and although I don't claim to understand the technical differences, I do appreciate that you have stated that your digital amp will not be a class-D design; added to which, I know you would never release an amp that sounded artificial.
 
I'm honestly intrigued..

 

[Kakki]

  Its second priority, Davina is what I am working on at the moment. 
 
Project code word is Hugo amp, but it's unlikely to be actually called that.
 
Rob

 
Rob, thank you for your reply.
 
I have the same feeling as Mython and am very interested in how your digital amp will sound as I'm planning to replace my current system with your Dave and the digital amp.
 
Did you have any chance to test the 1st sample of the amp?

 

[Peter Hyatt]

Rob,
 
I too echo the gratitude that others express regarding the time you take to answer questions and explain the science behind Mojo.
 
I enjoy reading some of your non-scientific opinions, as well, such as what you thought of piano recordings prior to Hugo as well as the 9 months of 'improvement' you experienced with Hugo.  (I'd love to know:  how many hours per day, per week that you averaged in the 9 month timeframe!) 
 
When you have some time, could you mention a few of your favorite songs/parts that highlighted Mojo/Hugo's talent?
 
Thank you.  

 

[Mython]

  Rob,
 
....  
When you have some time, could you mention a few of your favorite songs/parts that highlighted Mojo/Hugo's talent?
 
Thank you.  

 
Funny you should ask that:
 

   
On another issue - you mention some high res recordings - now my experience of hi res is mixed. Sometimes it can sound much worse, usually a bit better than redbook, sometimes it can sound extraordinary. What are your best recordings that work sonically and musically?
 
Thanks Rob

 
 
I reckon someone should start a thread, dedicated to your question, Peter

 
It's be nice if more Chord DAC users (including Rob) would contribute a few suggestions to your excellent thread...
 
 
 
 
@ Rob: I echo Peter's question, and, in particular, I'd love to know what choral & orchestral tracks you use as references for depth-preception
 
 
.

 

[scotsstax]

hi rob beautifully put....i am also a soundstage depth freak!!! used to own celestion sl600s and god they could image!!!! also spica tc50 quad 57s i now have stax sr507s, rob whats your opinion on the tda1541? i take its the filter that is the weak part so nos or not??!!! cheers all the best ps the sl600s were my favourites, they dont make them like this anymore sadly.... love to hear a dac 64 with tube output...

 

[Rob Watts]

  Damp
 
It works on sooo many levels.

Yes I had already suggested that, Chord were non too keen!
 
I want to get away from digital power amp word, as this is synonymous with Class D which is often awful....
 
Rob

 

[Rob Watts]

  Rob,
 
I too echo the gratitude that others express regarding the time you take to answer questions and explain the science behind Mojo.
 
I enjoy reading some of your non-scientific opinions, as well, such as what you thought of piano recordings prior to Hugo as well as the 9 months of 'improvement' you experienced with Hugo.  (I'd love to know:  how many hours per day, per week that you averaged in the 9 month timeframe!) 
 
When you have some time, could you mention a few of your favorite songs/parts that highlighted Mojo/Hugo's talent?
 
Thank you.  

 
At home I listen to Radio 3 - a classical station -  using 320k AAC - mostly thru the night on iPlayer - and work at the same time. I like the serendipity of radio, and getting to hear composers that I have not come across. But for away (as the BBC is awful 48k abroad) I use my 4 TB hard disk, which is now full, so I am waiting for portable hard disks to be larger than 4 TB - that or do some pruning. I have been recently been buying a lot of CD's and high res (HR) downloads, so I will put together a list of tracks that work for me.
 
When listening to the hard disk, I set to random play, and when a track comes along that sounds really good, I look at it. Normally its modern HR, but many times it is redbook, and sometimes quite old recordings.
 
My depth track actually came from an audio company - a selection of music - so I do not know where the track comes from. Hopefully I will stumble upon it one day and find out!
 
In terms of tracks that work with Mojo/Hugo/Dave - my surprise is how good compressed music can sound, or archive recordings. Often when you make and improvement to SQ, bad recordings sound worse. What was really strange about Hugo was for the first time, bad recordings were acceptable musically - it did not hide the problems in the recordings, but allowed you to hear what was musically good about it - being in touch with the music. For me, Hugo was a major crossing the Rubicon in my career, as now I could enjoy good music even with poorer quality recordings, which was something I had never experienced before.
 
Rob

 

[Peter Hyatt]

Thank you Rob, and Mython.  It is always interesting to see what Mojo highlights for others and then off to Tidal to give a listen.  I have not experienced this much sheer volume in new music since I was a teenager; all due to Mojo.  From an obscure (to me) 18 year old Norwegian singer, Aurora  up to JF's recommendation of Stravinsky, to Mython's reminder of how beautiful the cello is (Yo Yo Ma) on to searching for some piano music after reading Rob's experience with piano music and Hugo.  It is a very exciting time for me and for my wife, who is also hooked. 
 
Scott mentioned soundstage depth:  80% of what I listen to is through the Beyerdynamic T1 (2nd gen).  I like the relatively neutral sound, but in terms of IEM, I landed Shure 535 and they are nice, but I, too, yearn for 'more' during the IEM time listening.  I am open to selling them and spending a bit more and like Scott, want to hear that wide and deep soundstage.   
 
I find it interesting that Mojo/Hugo fans seem to seek out each other's opinion on such things, looking for both music and equipment that work best with the Chord products.  
 
Thanks again, to all, for the suggestions.  

 

[The Life]

Thank you Rob, and Mython.  It is always interesting to see what Mojo highlights for others and then off to Tidal to give a listen.  I have not experienced this much sheer volume in new music since I was a teenager; all due to Mojo.  From an obscure (to me) 18 year old Norwegian singer, Aurora  up to JF's recommendation of Stravinsky, to Mython's reminder of how beautiful the cello is (Yo Yo Ma) on to searching for some piano music after reading Rob's experience with piano music and Hugo.  It is a very exciting time for me and for my wife, who is also hooked. 

Scott mentioned soundstage depth:  80% of what I listen to is through the Beyerdynamic T1 (2nd gen).  I like the relatively neutral sound, but in terms of IEM, I landed Shure 535 and they are nice, but I, too, yearn for 'more' during the IEM time listening.  I am open to selling them and spending a bit more and like Scott, want to hear that wide and deep soundstage.   

I find it interesting that Mojo/Hugo fans seem to seek out each other's opinion on such things, looking for both music and equipment that work best with the Chord products.  

Thanks again, to all, for the suggestions.  

From personal experience with my Mojo, I'll recommend the Noble K10 as an iem with great depth.

 

[GabbaHey]

Hi Rob.. In your devopment of Davina.. Have you compared the current crop of commercial ADC units (Delta Sigma chip based) and if so what do you think are their shortfalls? Is it transient peaks are being lost? Is it still too soon to hazard a price point on your ADC?

http://www.analogplanet.com/content/analog-digital-converter-files-identified-converters-profiled#70gvp0D4FPWjBRQz.97

 

[tkteo]

  Stwr
  It's be nice if more Chord DAC users (including Rob) would contribute a few suggestions to your excellent thread...
 
@ Rob: I echo Peter's question, and, in particular, I'd love to know what choral & orchestral tracks you use as references for depth-preception
 

 
I own various samplers from Chesky Records, Stockfish Records etc. Among these, I notice one track from the Chesky Ultimate Demonstration Disc and one from the Mordaunt-Short Stereosound and Image Perfection disc that are recommended for testing depth. I listened to these via a DAP connected to Mojo via coax. Sounds good but unfortunately I don't have a reference point to real life conditions so I cannot really evaluate this idea of depth under such stylised conditions with much certainty.
 
I also mentioned to Mr Watts today during his presentation, the website hifistatement.net, where there are jazz tracks in 16/44.1, 24/192, and DSD formats for listening pleasure and comparison if desired.

 

[Rob Watts]

Hi Rob.. In your devopment of Davina.. Have you compared the current crop of commercial ADC units (Delta Sigma chip based) and if so what do you think are their shortfalls? Is it transient peaks are being lost? Is it still too soon to hazard a price point on your ADC?

http://www.analogplanet.com/content/analog-digital-converter-files-identified-converters-profiled#70gvp0D4FPWjBRQz.9

 
I have looked at the chips used for ADC's and the best ones offer -122 dB SNR, and THD and noise of -110dB. I am actually targeting 135 dB SNR, and THD and noise to be the same as Dave.
 
But by far the biggest problems are:
 
1. Depth perception - the work on Dave indicates that you need 350 dB capable noise shaping to accurately preserve depth - and current devices are only about -140 dB
 
2. Noise floor modulation - a chip based ADC has a lot of noise floor modulation, and I have solved this problem by using Pulse Array and discrete integrators.
 
3. Aliasing. The conventional view is that aliasing products in the 20-22.05 kHz range is inaudible. But it is not, as this aliasing errors degrade the timing of transients - which are audible.
 
I hope Davina will be less than Dave in terms of price. But since it is a technology prove of concept, its not about cost.
 
Rob