Yamaha
CDX-480 CD player
Megalampized
in Dec 2007
Yamaha is a company with excellent marketing. One of the best.
While being just a simple Japanese manufacturer of mediocre grey boxes,
they have a reputation which most competitor's can only be jealous
about. While I find NOTHING AT ALL that sets yamaha to a higher
category than the average "others" like Sanyo, JVC or Samsung; but
YAMAHA! - OOooo , this just HAS TO BE GOOD. It is sortof like Heineken
beer, Alfa-Romeo cars Smirnoff vodka, Levis jeans or French Wines - the
consumers at large seem to be massively hypnotized and they genuinely
believe these products are great if not the greatest. I think it has to
do with CONSISTENCY of marketing message.
Enough politics, I will make too many enemies here. Anyway, back to
Yamaha, someone challenged me that his Yamaha is a NATURAL SOUND
product and that It will probably impress the living daylights out of
me. I gladly accepted the challenge and took the CDX-480 for a spin.
On the workbench upon inspection I wanted to throw the towel and stop
this experiment. The guts of Yamaha are so ridiculous that I can't be
bothered... well.. ooops .... lets remove the
prejudice and look again.
What is funny, there is NOTHING "Yamahish" about this player inside.
The mechanism and control part is a cheapest Sony KSS210 with
ancillaries. Nothing sophisticated, but an OKAY workhorse. Or work
mule.
The PCB is typical Japanese - cheap looking, not impressive, and pure
Technics. Yes. This is a MASH based player just like the hundred others
out there, like my own babe CAL.
Remember the cal? It was a great sounding but fake high end player.
What a coincident: Technics versus Miss Natural Sound - just two
different marketing messages, but inside - THE SAME THING.
If I didn't know any better I would probably ridicule the player and
close the case, but actually I LOVE TECHNICS DAC CHIPS. I like the
Matsushita National MN series of MASH. They sound very clean, open and
naturally warm.
http://www.alldatasheet.com/datasheet-pdf/pdf/14287/PANASONIC/MN66271.html
The thing that got my attention is that this player has a very simple
analogue stage. I still havent recovered from the op-amp bonanza inside
the Shanling 300 and Yamaha has .... only ONE OP-AMP in total (double
one - that is for stereo). Yes, after MASH comes one opamp, a muting
transistor
and the output RCA jacks.
This is VERY ELEGANT approach and I understood what they mean: natural
sound is a simple way of saying ONLY ONE OPAMP INSIDE.
So far so good: lets lampize it and see if it makes any sense.
I opted for a megalampizator because MASH signal is strong enough
(remember, megalampizator is a simple single ended class A triode in
anode follower mode and its voltage amplification is circa 2x. Not 20x
like other tubes. That's why megalampizator is NOT suitable for current
output DACs like TDA1541A.
This is the double triode being the entire output stage of this player.
I took signal from MASH legs and fed it via a cap to the tube grid.
Since this is a double triode, I just needed one tube, one heater and
double anode supply. One socket and one drilling. Very convenient.
The looks and ergonomics are okay, very distinctively Yamaha, but the
amber display uses font 12 or so hence I can't see it from 2 meters.
The new transformer (230 : 110 + 6,3 VAC 20 VA) fits near the original
one.. Between the trafo and the drawer are the anode caps.
Unfortunately, since the current to the anode in this tube is circa 10
x bigger than in 6H1P, I also needed 10 x the capacitance in the CRC
bridge. I glued together half my drawer of the leftover odd size caps
to arrive at 3 x 220uF.
This is a good look at the output stage. Like in almost all Japanese
players, the DAC is underside. So it is not visible. Lets agree it is
under the place on the middle of the left edge of the photo. From that
point you can see a nice symmetrical STEREO row of components, from
extreme left all the way to the RCA's on the extreme right.
Worth noticing are especially large hi-frequency killer caps - the C105
and C106 near the RCA's. These make your music dead (and without the
noises too). Generally if I see these caps, and I see them in 95 % of
players, I call the engineer an asshole and a bastard too.
This mechanism is simple, fast, reliable and easy (cheap) to replace.
Nothing to write home about.
The hole for octal socket takes a 27 mm crown bit.
This tube is a very macho thing. Mr. Freud would have something to say
about it.
Output caps of new stage
The end result is very pleasing to my eye: the platinum/titanium grey
colour of Yamaha is almost identical to the tube silverish grey.
Could there be something more simple than this ???
Actually, the funny thing about the MASH setup is that we do not need
to disconnect the old circuit. We can leave it for comparison.
The heaters are AC and there is no hum. DC would become too demanding
on my transformer (we need 3 A of heater current !!!) The trick that
Ewgennyi taught me is to put a pair of matched 100 Ohm resistors
between the heater pins and the earth. Sort of the poor man's humming
pot.
You can notice a very low anode voltage of just 40 V DC but apparently
this is just okay.
THE SOUND:
As you probably already guessed from my too long intro, I loved this
player. It plays a biiig, effortless and spacious sound. YES, it
sounds natural, it does not attract attention to ANYTHING NASTY. I
could not criticize this sound even had someone twisted my arm. The
marriage of the big 6N13C tube and this player is excellent synergy. I
could just listen and listen. Could not find a fault compared to my
other super duper gear. The bass is especially good. So deep and
powerful, it shakes the house proper.
After a month I tried to install the 6SN7GT tube (6h8, 6N8) and just
changed the resistors - anode to 20K, and cathode to 500 Ohms. It plays
to my ears even better - there is more micro detail, more air, and more
kick. This set-up remained permanent.
THE DAC INFO
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