The SMD Tantulum caps on the digital boards have been replaced by 100uF Sanyo Oscon SP.
I'm sorry for the blurry picture. It was taken with my mobile phone...
16 47uF Blackgates Fk awaiting to replace the SMD caps
The bottom of the DAC board
The Blackgates in place and ready to roll
When removing the 74HC04, the TCXP should be connected like this: two 47r resistor between each of the receivers and the TCXO
The 74HC04 Mod. After providing the Chameleon and schematic to a friend of mine he mentioned that the 74HC04 buffer found on the digital board is not needed at all. The 74HC04 only adds jitter (which we all try to prevent) and the TCXO can easily drive both receivers at the same time. STEP 1: Remove the 74HC04 Just cut every leg of the chip with a sharp knive, one at a time. Once you've cutted them all the chip will come loose. STEP 2 & 3: Next picture
STEP 2: Remove the two 100K & 100R resistors (#1 in the picture). I used some 0,5mm solid Mundorf silver/gold wire to reconnect the solderpads again. STEP 3: Solder two 47R resistors between legs 3&4 and 10&11 (#2 in the picture). I used 0805 size SMD resistors which just fit in between the legs.
Finished Mod! Gone in 600 seconds :-)
Just received the best sounding resistors I've ever heard. :-)
2x 175R Texas components resistors for the passive I/V of the Chameleon
I had a few hours of free time yesterday and counted 17 MKP1837's in my drawer.. Time to do Wood's mod: Replacing the stock SMD caps by the blue Vishays. Luckily I have a tweezer soldering iron so removing the SMD caps was literly a 30 second job. I had to remove 3 rows of black gates in order to be able to do the job. Then put in al caps one by one. I personally think it wasn't a difficult job to do. The sound changed exactly as Wood described: Fast, Faster, fastest! Speed, An exploding Transient bomb! That what the Chameleon (and Valab) was a bit lacking suddenly is there. It sounded a bit harsch at first but those 1837's break in quite fast (+/- 40 to 50 hours) and when I listened again 8 hours later the sound was already much more neutralized. If you like a smooth, warm, chocolate sound keep your Chameleon as is. If you like speed and detail (like me) hop in those 0,01uF Vishay's! Total costs: € 8,-
Another close up of the DAC board with 47uF Blackgate FK and 0,01uF Vishay MKP1837 caps.
Overview of the temporary setup of my Chameleon.
Above two huge 4,7uF Mundorf Silver/Gold/Oil caps. To big to fit into the chassis.
Chameleon vs Tentlabs XO I've been curious for quite a while if the Chameleon would benefit from a better clock, The Chameleon has 2 XO's on board: 1) a 12 Mhz XO for the S/PDIF and USB input and 2) a 24.576 Mhz XO for the upsampling board. I decided to go for the upsampling board first and this XO has now been replaced by the Tentlabs XO 2.2 Above the temporary test setup for the Chameleon: On the left the Tentlabs XO Supply, on the right the Tentlabs XO 2.2
Connecting the clock is easy: 1) Remove the 47uH choke 2) Remove the 100R resistor located in the middle at the top of the upsampling board.
next: solder the XO output of the tentlabs to the upsampling board as shown above and you're done :-)
The temporary Chameleon setup up and running. Next thing to try is to replace the other XO by a Tentlabs XO 2.2 too... :o)
This the clock of the onboard 1ppm 25.576 Mhz TXCO of the upsampling board.
A picture of the new clock from the Tentlabs XO 2.2 Now this is what we would like to see. The differences in the sound quality are as obvious as the differences in the pictures...
Testing with a second Tentlabs XO 2.2 and Tentlabs Power Supply. It replaces the 12Mhz XO
Overview of the new temporary setup. *sponsored by Tentlabs* ;-)
I received a very nice parcel through the post today: My Paul Hynes SR1-MR power supplies & Z17 3.3 regulators for the Chameleon. Tonight I'll start with part 1: replacing the on board regulators for these low noise versions. The power supplies wil be added later.
The LM1117-3.3 removed from the upsampling board. Please note that you have to connect the big soldering plane on the left with the middle one of the three smaller planes on the right.
Regulator number one installed.
the digital input board contains 2 LM1117-3.3 regulators. The one on this side is for the WM8805 SP/DIF receiver. The one on the other side of the board for the USB receiver.
Again you have to join the big soldering plane with the smaller plane in the middle.
The Paul Hynes Z17 3.3 connected. It's "slightly" bigger than the standard LM1117 ;-)
The new regulators working in full glory!
Another close up of the Paul Hynes Z17-3.3 regulator.
Drawing of all parts that need to be installed in the enclosure. The two SR1-MR supplies will be used to feed the +5V and +8V for the DAC. The +12V/+5V regulator is only used for switching relays and leds.
Designing the frontpanel with Schaeffer AG's Front Panel Designer.
Drilling holes...
06-2011: Being busy with more important things in life, one year later I still haven't finished the DAC. Time for some action: Finished the design of the chassis and send to Schaeffer AG. Meanwhile I fitting the components on the board as planned. It turned out that my design was a bit to tight so I decided to skip the third toroidal transformer. It was an overkill anyway because it was meant to be used for powering some leds and relays only.
Drilling holes... *me hates this job*
All boards & transformers assembled to the chassis.
Top view
Left side of the DAC: Power supplies only.
Right side of the DAC: The Modded Chameleon and two Tentlabs XO clock modules.
Milled & Engraved frontpanels arrived on June the10th! :-)
Overview of the Finished DAC. Sorry, a bit shaken & stired.
Top Middle: The modded Chameleon with the huge Mundorf Silver/Gold/Oil output caps. Right: 2 Tentlabs XO 2.2 clockgenerators Bottom middle: relaykit for selecting the digital inputs & led control on the frontpanel
Left: Schaffner AC Inlet (With netfilter) and 2 trannies: One for the digital part of the DAC (small) and one for the D/A board (the big brother) Top middle: 2 Paul Hynes SR1-MR power supplies. The small green board on the left is just to feed +5V to the relays and leds. Middle bottom: 2 Tentlabs XO Supplies for the Tentlabs XO 2.2 clocks.
Overview II
view on the back side of the frontpanel.
Overview III
Bottom of the DAC. First try to get the heat dissipated with heatsinks. It turned out not to be enough...
Some extra (chipset) heatsinks where needed in order to dissipate the heat better from sudden places.
Backpanel of the DAC (made by Schaeffer AG)
2 S/PDIF inputs on BNC, USB input and the WBT RCA outputs
Frontpanel of the DAC: 2 red leds indicate the selected S/PDIF input, the green led indicates that the DAC is locked to an incoming S/PDIF signal. The yellow led turns on once it is connected to a computer. The black push button in the middle is used to select the inputs.
The DAC On Top. Nearly crashing my input selector/volume control with its 5 kilo... Better pictures of the finished product will follow later
