3 ms·

One of my favorite FPGA gadgets is the mojo 2 headphone amplifier by Chord electronics. The amplifier is nearly flawless. Coming from the old days of tube ampl

by pama 3y ago

One of my favorite FPGA gadgets is the mojo 2 headphone amplifier by Chord electronics. The amplifier is nearly flawless. Coming from the old days of tube amplifiers and amazing analogue devices it is nice to see how far the digital circuitry has gone with analog applications.

cadr 3y ago
Wow, just looked that up. That's a chunk of change for a headphone amplifier.
- pama 3y ago
  Agreed. I personally think it is the ultimate piece of equipment for sound reproduction from computers or personal recordings, unless one has a set of very specialized cans that it could even drive. But of course sound sensitivity is subjective and there are limits to what some people care about so their may exist cheaper options with some comparable quality, but at some point I gave up to quest with that little gadget.
jsheard 3y ago
https://www.audiosciencereview.com/forum/index.php?threads/chord-mojo-2-review-portable-dac-hp-amp.34160/ https://www.audiosciencereview.com/forum/index.php?threads/c... It's not bad, but it's not the best, and pretty much everything that measures better is using a more conventional architecture and in many cases is significantly cheaper. Chords use of FPGAs gets points for novelty but I don't think it has any practical merit. https://www.audiosciencereview.com/forum/index.php?threads/chord-dave-review-dac-hp-amp.35974/ https://www.audiosciencereview.com/forum/index.php?threads/c... Even their $14,000 monster desktop DAC/Amp gets beaten by units a fraction of the price in objective measurements. The audiophile market has taken a fascinating turn since ASR arrived on the scene, the snake oil salesmen are still on their bullshit but there has been an uptick in companies doing legitimately good engineering and making products with phenomenal performance for dirt cheap. There are DAC/Amp combos under $200 which are objectively perfectly transparent well beyond the theoretical limits of lossless CD audio now.
- atoav 3y ago
  As a musician I absolutely love my "so small/light forgot I had it in my backpack"-500W Bass amp, compared to a 36 kg tube one. Class D is the shit.
  - bongodongobob 3y ago
    Fellow bass player here, I concur. Get a transparent class D and pair with a tube preamp of your choice. I love my Ampeg, but it lives in the basement now and doesn't leave.
- pclmulqdq 3y ago
  I will give Chord some credit for the idea of running the DAC super fast. I play music and occasionally record myself, and I can tell you that when you look at the waveforms, there is definitely a component of the human ear that can distinguish time intervals faster than 1/(22 kHz) despite being unable to hear frequencies over about 15-20 kHz (eg very tight flams in drum parts are audible). DSD had this idea, and I am 100% on board with it. Despite being a gold standard because of how it's produced, lossless CD audio cuts off this "high-frequency" component. However, the actual analog parts of Chord's system around the fast DAC and the upscaling circuit seemed to be sort of suspect to me, from the handling of reference clocks to the nature of the output amplifiers. I'm glad ASR has confirmed those suspicions before I bought one. At some point, I started a project making a multibit DAC running at 1 Msps with the same kind of FPGA upscaling (although ADI's SHARC DSPs are amazing) but a much more conventional frontend and better handling of clocks, but I realized it was too complicated to do while also doing all the other things I was doing at the time (and way too complicated now). The idea is still on the shelf for later (although it's probably already obsolete as a concept - delta-sigma is really good).

by pama 3y ago

cadr 3y ago

Wow, just looked that up. That's a chunk of change for a headphone amplifier.

pama 3y ago
Agreed. I personally think it is the ultimate piece of equipment for sound reproduction from computers or personal recordings, unless one has a set of very specialized cans that it could even drive. But of course sound sensitivity is subjective and there are limits to what some people care about so their may exist cheaper options with some comparable quality, but at some point I gave up to quest with that little gadget.

jsheard 3y ago

https://www.audiosciencereview.com/forum/index.php?threads/chord-mojo-2-review-portable-dac-hp-amp.34160/ https://www.audiosciencereview.com/forum/index.php?threads/c... It's not bad, but it's not the best, and pretty much everything that measures better is using a more conventional architecture and in many cases is significantly cheaper. Chords use of FPGAs gets points for novelty but I don't think it has any practical merit. https://www.audiosciencereview.com/forum/index.php?threads/chord-dave-review-dac-hp-amp.35974/ https://www.audiosciencereview.com/forum/index.php?threads/c... Even their $14,000 monster desktop DAC/Amp gets beaten by units a fraction of the price in objective measurements. The audiophile market has taken a fascinating turn since ASR arrived on the scene, the snake oil salesmen are still on their bullshit but there has been an uptick in companies doing legitimately good engineering and making products with phenomenal performance for dirt cheap. There are DAC/Amp combos under $200 which are objectively perfectly transparent well beyond the theoretical limits of lossless CD audio now.

atoav 3y ago
As a musician I absolutely love my "so small/light forgot I had it in my backpack"-500W Bass amp, compared to a 36 kg tube one. Class D is the shit.
- bongodongobob 3y ago
  Fellow bass player here, I concur. Get a transparent class D and pair with a tube preamp of your choice. I love my Ampeg, but it lives in the basement now and doesn't leave.
pclmulqdq 3y ago
I will give Chord some credit for the idea of running the DAC super fast. I play music and occasionally record myself, and I can tell you that when you look at the waveforms, there is definitely a component of the human ear that can distinguish time intervals faster than 1/(22 kHz) despite being unable to hear frequencies over about 15-20 kHz (eg very tight flams in drum parts are audible). DSD had this idea, and I am 100% on board with it. Despite being a gold standard because of how it's produced, lossless CD audio cuts off this "high-frequency" component. However, the actual analog parts of Chord's system around the fast DAC and the upscaling circuit seemed to be sort of suspect to me, from the handling of reference clocks to the nature of the output amplifiers. I'm glad ASR has confirmed those suspicions before I bought one. At some point, I started a project making a multibit DAC running at 1 Msps with the same kind of FPGA upscaling (although ADI's SHARC DSPs are amazing) but a much more conventional frontend and better handling of clocks, but I realized it was too complicated to do while also doing all the other things I was doing at the time (and way too complicated now). The idea is still on the shelf for later (although it's probably already obsolete as a concept - delta-sigma is really good).