94 mk II before / after - Page 2 - diyAudio
Go Back   Home > Forums > Source & Line > Digital Source

Digital Source Digital Players and Recorders: CD , SACD , Tape, Memory Card, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 23rd June 2007, 10:25 PM   #11
diyAudio Member
 
Join Date: Dec 2003
Location: Sydney
..
Attached Images
File Type: jpg dac board.jpg (98.6 KB, 1305 views)
  Reply With Quote
Old 23rd June 2007, 10:28 PM   #12
diyAudio Member
 
Join Date: Dec 2003
Location: Sydney
...
Attached Images
File Type: jpg coupling caps.jpg (91.3 KB, 1209 views)
  Reply With Quote
Old 23rd June 2007, 10:36 PM   #13
diyAudio Member
 
Join Date: Dec 2003
Location: Sydney
Clock oscillator transformer, IEC mains connector and silver ribbons (see red "X").
Attached Images
File Type: jpg iec and transformer.jpg (94.1 KB, 1183 views)
  Reply With Quote
Old 23rd June 2007, 10:44 PM   #14
diyAudio Member
 
Join Date: Dec 2003
Location: Sydney
.
Attached Images
File Type: jpg powersupply.jpg (94.8 KB, 1142 views)
  Reply With Quote
Old 23rd June 2007, 10:46 PM   #15
diyAudio Member
 
Join Date: Dec 2003
Location: Sydney
..
Attached Images
File Type: jpg blackgates.jpg (87.5 KB, 1114 views)
  Reply With Quote
Old 26th June 2007, 03:48 AM   #16
KP11520 is offline KP11520  United States
diyAudio Member
 
KP11520's Avatar
 
Join Date: Apr 2007
Hey Boky,

You have been busy.... Rather than ask you what you did, maybe the better question would be what didn't you do (if anything, I'm sure this list is short)?

I see a lot of putty, why do you use that? The flat connector wire, is that silver? No insulation? What circuit upgrade went on the breadboard?

I asked you this on a Rotel you did also, How does it sound now? Was this kind of upgrade big money? Did you take it as far as you felt was a good value (I know that is subjective)?

Of all the CD Players that you have done, how does this one rate?

This is encouraging for us beginners to see, it takes away some of the mystery and fear! Thanks!

Regards//Keith
__________________
If Wile E. Coyote had enough money to buy all that ACME ****, why didn't he just buy dinner?
  Reply With Quote
Old 27th June 2007, 03:06 AM   #17
diyAudio Member
 
Join Date: Dec 2003
Location: Sydney
Quote:
Originally posted by KP11520
Hey Boky,

You have been busy.... Rather than ask you what you did, maybe the better question would be what didn't you do (if anything, I'm sure this list is short)?

I see a lot of putty, why do you use that? The flat connector wire, is that silver? No insulation? What circuit upgrade went on the breadboard?

I asked you this on a Rotel you did also, How does it sound now? Was this kind of upgrade big money? Did you take it as far as you felt was a good value (I know that is subjective)?

Of all the CD Players that you have done, how does this one rate?

This is encouraging for us beginners to see, it takes away some of the mystery and fear! Thanks!

Regards//Keith

Hi Keith,

This is the 3rd CD94mkII I modified. From the experience I gained with the first 2 players, I suggest you modify the digital power supply section and leave analog one as is – it’s already pretty good. This player suffers from closed-in sound with limited high frequency extension. However, it is one of the most natural sounding CD players I ever heard. So, start with the best clock oscillator and its power supply & transformer you can get your hands on. Save some money by making your own power supply. I used fast switching soft recovery diodes, Black Gates FK and N types, JRC 12V regulator, silver ribbons. You could feed properly distributed / buffered clock signals to each DAC chip for best results. Replace sound coupling caps (my favourite best performance / cost cap is AURICap) and try to use solid core conductors – silver ribbons if possible; avoid litz cables. Check the photos above which will explain what caps I used. There are some 0.1uF high quality caps I used for DAC board power supply rails decoupling with great results. I also used them to replace disk ceramic caps on the main board – same function. The IC’s are AD826 X 4 + OPA672 X 2 (all socketed – I to V can be AD8066 if properly decoupled and if the rest of the system can cope with this amazing IC). Mains wiring was replaced as well with silver ribbons – this application requires double run of much wider ribbons. If you want to play with silver conductors – make sure they are annealed. The “figure 8” mains connector was replaced with IEC connector that allows use of different power cables. This requires a fair bit of cutting and drilling… Depending on the rest of the system and personal preferences, solid core copper, silver plated copper, silver-and-then-gold plated copper, or pure silver mains IEC cables can be used with different results. Servo board has also received 0.1uF decoupling caps in place of ceramics.

There’s no point in randomly replacing all the caps hoping for good results. This will usually provide worse than the original sound results and it can be very costly experience. The above mods provide very good value for money and will open the sound providing upper range sparkle, very good definition, very wide and high sound stage while preserving the natural sound presentation that’s so easy to listen to for extended periods of time.

Start with clock oscillator and power supply, install IEC connector and replace the IC’s as suggested. This mod will give you risk-free results you’ll be amazed. Follow with Black Gates and 0.1uF caps, section by section, and check the sound after each.

And don’t forget two sets of belts – one for clamping and the other set for sliding mechanism sections. All 3 CD94’s I modified arrived to my place with clamping / sliding problems.

Good luck
Boky
  Reply With Quote
Old 27th June 2007, 12:48 PM   #18
KP11520 is offline KP11520  United States
diyAudio Member
 
KP11520's Avatar
 
Join Date: Apr 2007
Hi Boky,

You are a gentleman and a good sport! That is a great and very informative summary and will be a one stop thread for future DIYers with a 94 mkII!

It seems like the AD8066, in the right situations can be one of the best!

Thanks again for the info! Keep them coming, they are going to be a selling feature for this site as they fill up the reference library! It's too bad we don't have a way, like on "Star Trek" to file the before and after results and differences that can be downloaded and experienced right from our own PC. I think they call it a "Holodeck" on the newer Star Trek movies and series spin offs. That would be nice to have in the DIYaudio "Reference Library"!

Regards//Keith
__________________
If Wile E. Coyote had enough money to buy all that ACME ****, why didn't he just buy dinner?
  Reply With Quote
Old 12th July 2007, 07:24 PM   #19
diyAudio Member
 
Eric Juaneda's Avatar
 
Join Date: Dec 2006
Location: Avignon, France
Hi Boky,

Thanks for this impressive upgrade.

On my CD 94 (first version), I ground IC's radiations by putting coper plate or piece of board on each of them. (TDA1541 of course and all over). Don't forget to link coper plate short to ground.

I link ground plane to the box (blue square on the picture). Original PCB has only one connexion between ground and box.

You probably already do it, grounding box to earth greatly enhance sounding too.

Regards

Eric
Attached Images
File Type: jpg tda1541-ground.jpg (85.0 KB, 1019 views)
  Reply With Quote
Old 14th July 2007, 08:06 AM   #20
diyAudio Member
 
Join Date: Dec 2003
Location: Sydney
Hi Eric,

The photos I've taken are of the unit I modified for the customer. I agree with you about copper shielding and improvements this mod brings to the sound. I use very wide pure silver ribbons if the customer is willing to pay (and is a believer).

I am not sure if the original CD 94 uses "green-caps" 0.1uF around TDA1541 chip. Try replacing them with 0.1uF Nx Black Gates. Great improvement.

Cheers,
Boky
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



New To Site? Need Help?

All times are GMT. The time now is 04:46 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2