An Interview with Charles Altmann
Have you heard about the €840 portable audio player that started going viral around the web late last year? It’s a really expensive player (the introductory price was €550) and everybody was questioning if the player is really worth its price. I’ve read through Charles’ blog entry on the development of the Tera-Player, and I got the impression that this guy is a true genius with deep understanding of both the hardware and software aspect of what it takes to make a good audio player. I also discovered that Charles also has many equally impressive projects that include the €950 Attraction DAC and the €950 BYOB Amplifier.
But just because someone has a deep understanding of the programming or the technology behind digital to analog conversion, doesn’t mean that he can make a good sounding player, so I have reserved any comments until I can actually listen to the player.
At this point, I have had the Tera Player in my possession for two months now (Disclaimer: it was a loaner sample, I don’t have the money to buy a €840 DAP), and I have been very impressed with the performance of the Tera-Player, even in comparison to the other high quality sources like the Hifiman HM-801, the Cypher Labs AlgoRhythm Solo, and the Fostex HP-P1. Now, I’m working on a formal review o the Tera-Player, but there were some questions that I had about the design of the Tera-Player that prompts me to ask some questions to Charles, and he was kind enough to take the time to reply to every one of my questions. Here is the full length of the interview, straight from my email program.
The black text is me, the blue is Charles’.
After using the Tera-Player for two months now it’s officially my favorite
portable player and the one that I use the most. The sound is superb, and I
enjoy the simple screen-less UI, the fast response time, the tough build
quality, making it a very ideal high quality player to use day in and day
I am very happy that you like it
I’m getting ready to write the review for the Tera-Player, but I have a few
questions and I hope you can answer it for me:
1. I understand the first blog entry you posted on the Tera-Player is dated
as early as 2008. So development time is roughly three years now? What’s the
hardest part of this development period?
It took me almost 4 years to finish the Tera-Player. I was not at all content
with the sound quality of any DAP I had tried, in fact some of them gave me a
I was also tired of mp3. I wanted high-resolution audio with superior sound
quality in a portable player, so I decided at a very early stage to use the
wav format, as it is the oldest and most simple file format for audio. There
is neither reduction nor compression taking place in the wave format, it just
the orginal samples of the recording written down.
The hard parts of creating the Tera-Player are obviously the software and the
higher level of sound quality. I also had problems with the first generation
of ARM7 processors (which were used in the early prototypes), but when the
ARM Cortex came out, I realized that I could achieve 24/192 playback speed in
such a tiny device, which seemingly nobody else has managed at this time of
But sheer playback speed is nothing if you cannot transport the sound
quality. That was the biggest effort and to really get it right took a very
long time. While the first prototypes from 2008 already sounded superior to
anything else on the market, and friends who took a listen were blown away, I
was still not entirely satisfied and decided instead of going to maket
earliest – and then adding mkII, mkIII … mkwhatever version later on – to
take the long way home instead.
I just kept continuing the perfection of the sound quality more and more
until I was really really satisfied and came to something like a
technological end, considering given means and target.
2. Why the decision to use a NOS Philips D/A chip? I understand that you
used the Burr Brown 8552 DAC on the development stage, so I assume the NOS
Philips is better? Would you tell us which Philips chip is used here?
I started building DACs back in 1997, and have built many experimental
prototypes and a couple professional DACs since then. I have learned that
there are basically two different kinds of DACs made: R2R and sigma-delta,
and I like the sound of R2R DACs better, because they sound more real and
less artificial to me.
So the decision to use an R2R DAC for the Tera-Player was made right from the
start. The problem is, that R2R audio DACs suitable for a portable device
(i.e. small, low power consumption) are not made anymore (which is a shame).
So I looked at industrial R2R DACs and found the DAC8552 worth to give it a
try. It sounded very good, so I played with it for a while, but finally it
was not good enough.
(note: you can read more of Charles’ writing on R2R and Sigma Delta DACs HERE)
I use the PCM1704 since 1998 in the Altmann Superlative DAC and the TDA1543
since 2004 in the Altmann Attraction DAC, but both are not suited for a small
portable player with long playtime.
So I found another Philips DAC, with improved SNR and THD over the TDA1543,
smaller package and lower power consumption. This sounded very good from the
start, but I still have spent another year on the final implementation for
perfecting the sound quality to its full potential.
Continue to the next page…