September 2nd 2009
Akai CD37 with Stelmach DAC
I love AKAI for their tape recorders - reel to reel old machines and
also cassette tape three head machines. That company used to be very
very close to high end. But at some point they lost it. CD players were
not nearly as good as three head tape decks. Below is an example of a
good player that was just okay, but not high end by all means.
CD-37 is a medium player, not the top league even from AKAI.
Just look what they were proud of: Digital output and random
program. Hardly something to get us excited. And they used three fonts
to communicate that iffy success.
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Advanced interpolative dulal converter - it is anothey way of saying :
this player has a converter.
The owner of this player installed a Polish made Stelmach DAC instead
of the original Burr Brown PCM-1701. Stelmach DAC is very popular
and famous in Poland. Lets see whats inside.
The mechanism is based on a Sony KSS210 A basic simple and cheap
laser. Akai mechanism is made of plastic, it is not very
impressive. Just an OK plastic mechanism. Nothing comparable to the
best Sony mechanisms like BU1 / kss190A.
Stelmach DAC
This is the Stelmach DAC board - with cristall CS4398 DAC chip and all
power supply regulators and input section.
The DAC chip seems to be fantastic one, we know it can play well. It is
similar to the Lampucera DAC CS4397 and to the Zhalou DAC2,5 (identical
chip).
Above is the DAC and it's surrounding circuitry. Note that this
chip is configured as monoponic hence we have TWO OF THEM. The four
resistors on the left side of DAC - standing in upright position - are
the four signals from DAC . Mormally in stereo that would be - L+, L-,
R+ and R-.. In mono - they are on one chip L+, L-, L+, L- and the same
for the other channel.
We can tap our lampizator input from there.
These chips numbered from 01 to 13 are PROBABLY the logical chips from
74CXX series that enable this DAC to be connected to any digital
circuit - translating any digital format like Philips i2S or Sony - to
the format acceptable by the DAC. In this mode Stelmach DAC can
work in ANY circiut there exists. The good thing is taht the DAC
uses the direct digital signal, not SPDIF. So we are two big
steps closer to the "true" information.
Effectively the CD player with Stelmach becomes an INTEGRATED
PLAYER and not like a transport and DAC. This is definitely
the way to go.
The player will loose its own character and the Stelmach / Cirrusa
signature will dominate. Theroretically it wil not matter anymore what
spins the disc - Sony, Rotel, Akai, or Revox.
I like that product. I wish it had tubes added from the beginning.
Above - you can see two dac chips in symmetrical fashion.
Stelmach dac is really beautifully made, with very nice PCB, many many
goodies like all caps with a small bypass, premium parts, neat layout,
and everything looking like top league high-end.
However, having said that - I was expecting a better sound.
Listening test
Stelmach dac in AKAI produced an uninvolving sound, somehow small, laid
back, not too detailed. Apparently all was there, nothing to complain,
but - I expected more. I had a preconception about the Cirrus / Cristal
DAC that it should be more musical, more immediate, with a kind
of "spark". I listened to it for
an hour and I gave up. As much as I liked the DAC board itself, there
was not enough quality for me. Maybe something was wrong. I cant
honestly tell.
I lampized it for a moment with my boxed external lampizator but still
no big success. DAC was still rather uninvolving. It was like driving
an Opel Vectra 1,6
- OKAY to get from A to B but nothing to write home about. I really
dont know where Mr. Stelmach went wrong. Or is it me? It is not
the opamps
because lampizator was not better. Is it the digital part before DAC ?
Is it supply ? I dunno. MAybe the dac is so pure and natural that
it is not impressive, it is just honest, and it takes more than a while
to accomodate to that style, to appreciate it, to discover new quality.
Like with top wines - they are addictive not after the first sip. The
cheap wines are designed and engineered to impress after first sip.
I cant recommend it seriously, but I very much encourage you toio try
it and draw your own conclusion. For a long time I havent seen a
product made so well and I hope that eventually this DAC will succeed,
even if this applies only to Polish
market.
An interesting case maybe to be solved later by someone. Maybe I
will contact Mr. Stelmach and ask for guidance how to use this product
optimally, how to connect it to LAmpizator etc.
Back to Akai - I think that lampized AKAI with its ow great PCM1701 DAC
would be better , judging by the great result with the same dac
chip
inside the Luxman CD103 player.