SHANLING CDT-100 CD player - with
conversion to proper tube format.
is the older brother of the famous now CDT-200, but not necessarily the
power supply section is essentially the same.
build quality is the same.
mechanism is inferior but only slightly.
looks are equally awesome (or vulgar and ugly - put your opinion here).
DAC is arguably better - I must hear them side by side after
output stage is equally awful.
is no SACD - but who cares ?
laser should live much longer (T200 has a DVD-quality laser and it
lives very short I was told.)
please read CDT-200
is the analogue section. We kill the whole part which is on the right
side of the red line.
signal source is the green dot.
Burr Brown PCM1704 DAC chips - believed to be the top of the BB
range ever made - here work in parallel output stereo mode (not
differential). I think that 1794 is a better DAC from BB.
my experience this overkill set-up is only "bettered" by Kenwood 7090
with its 8 x PCM1702 - paralleled AND balanced.
section - I am sorry - must go to dustbin. This is NOT a proper tube
output stage. This is bullshit.
quick and dirty instruction
are few simple steps.
1. Remove the tube
output PCB completely
2. Find 2 noval sockets
(1 dollar each or something) and 4 pieces of 300-400- 620 or 680
resistors (1/4 Watt). Mount the resistors on sockets and the sockets in
the old tube holes.
3. You need to apply 4
wires to the tube sockets:
b) +170 V DC from power
c) signal input from
digital PCB DAC outputs I out (via sowter transformers or via R100 Ohms
d) signal output to
outgoing RCA sockets (via a MKP or PIO capacitor 1uF or bigger)
In addition you must
find the 6,3 V DC output from power supply to heat the tubes (pins 4
and 5 on the noval socket) To have enough power you must cut off the
heater line to the headphone PCB (there is no other way but to kill the
headphone feature )
This is all doable in
1-2 hours. Minimum tools are a digital meter and a soldering iron.
The sowter for T200 and
T100 are different because the T100 is not digitally balanced and the
So a better choice for
T100 would be sowter 9762 or even better
9545a which can utilize its double primaries by splitting the
parallel 1704's into two separate primaries. Seems like a good idea
anyway. Both sowters are balanced out - future compatible shall
anyone go for balanced amp. (HD Ready ;-)
The SRPP is a MAGICAL
setup which can also be OK with non-6H6P - like with 6H1P but that's
tube dependent. The best choice is obviously 6H6P . The best NOS units
come close to 6H6P but at 10 x the price. 6H6P is a no brainer. Future
proof as well. (unlimited supply forever).
The double dac in
T200 has a digitally differential outputs per each channel. T100 DAC
has two paralleled dacs per channel. Both DAC chips (monophonic) give
identical output and they are connected in parallel because .. well ..
God knows what for. This is a strange way of doubling the available
current (one is sufficient anyway) and to halve the impedance of the
source (one is OK anyway). But in "our" set-up we will split the
from two dacs and send each current into separate individual windings.
The primary mag field will be a nice sum of both fields with halved
averaged errors and doubled power.
This issue is discussed
in detail in this BBS service: http://www.diyaudio.com/forums/showthread/t-12288.html
Secondaries will be in
series for max Single Ended output gain, or just kept separate - for
balanced XLR mode if desired.
The secondaries don't
have to drive anything so they are not loaded at
all, (grids are very easy load) so the transformer is very "happy" and
top to bottom - very transparent. Overall - this situation is IDEAL for
all three partners - DAC, transformer and tube section. They play in
unison, in harmony.
My pen pal from internet found an error in PCB track layout - the
Chinese people did not notice that the digital input of the DAC in one
channel has a crossed track.
that's what he wrote:
I have now
located a fault with the layout of the original p.c.b. for
the Shanling CD-T100 (stainless steel chassis).
The R DATA output from U20
(74HC157) pin 12 goes directly to pin 1 of
U25 (PCM1704) & then through R135 (47 ohms) & R124 (47
ohms) to pin 1 of U9 (PCM1704).
This is wrong
according to both, your circuit diagram and the p.c.b. layout for Left
channel (which is correct according to your circuit diagram.
The output from
74HC157 pin 12 should go to the junction of R135 and R124 - not
directly to pin 1 of U25 (PCM1704).
Compare the original p.c.b. for
the Shanling CD-T100 with the circuit diagram and I am sure you
will find the ambiguity.
THE PDF OF