My custom CD 63KI case with granite base

[SimontY]

Hi Mesh,

Well, I might not remember them all at once, I'll need to find my list. But from the top of my head, I:

1 Changed feet to 3 oak cones (more musical, less upfront)
2 Added copious amounts of bitumen to chassis (better all round)
3 Added blue tac to transport and bracing bar
4 Removed output muting transistors (small improvement maybe)
5 Replaced DC blocking caps with silver jumper wire (very large improvement - so much more dynamic and even detailed from what I remember)
6 'Reclocked' with Audiocom DVC-1 add-on clock (good improvement)
7 Fed DVC-1 with offboard home made 5v PSU (same again or more)
8 Shielded and grounded all ICs (maybe some improvement)
9 Added braided CAT5 mains cable (smoother, less harsh, possibly better imaging)
10 Added 0.33uf 'x' cap to mains input (again, smoother)
11 Added chokes to live and neutral mains
12 Replaced some diodes with Schottky (did with mains cap, got much better/sweeter treble)
13 Changed op-amps to OPA2164(?) (big improvement - bass solidity+depth, detail, imaging etc.)
14 Swapped about 20 resistors around opamps for metal film 1% tol. L+R channels matched to 0.1% tol. with my multimeter (totally different sound character, and I mean it, wasn't sure I liked it at first, but certainly much smoother and probably more natural)
15 Changed some small psu line resistors for inductors + ferrite beads
16 Put dollop of blu-tac on clock crystal
17 Cleaned all connectors and internal fuses with Deoxit
18 Accidentally disabled/broke display (when changing resistors)
19 (Botch-job!) grounded chassis to stop case from slightly electricuting me (maybe minor sonic change too)
20 Changed 2 output caps to roll-off more treble
21 Re-used Elna Silmic (from output) in decoupling in output area
22 Couple of BG standard in one PSU line
23 One psu cap. (digital prolly) changed to large ultra low z type

Well, I might have missed a few, but that should give you some ideas!!

I now have a player with stunning bass, very good treble, and good midrange. The midrange may be limited by my speakers and music, I just don't know anymore. Detail retrieval is incredible compared to the original. Backgrounds are pretty black and dynamics are good. Timing is pretty good too. All my own opinion of course, and please don't read too much into it all.


-Simon

[SimontY]

Ooh, forgot a couple of things:

I added bypass caps to the Elnas that feed the HDAM buffer - 220nf and 22nf - I had a nightmarish time soldering three together!! The Black Gate's were also bypassed, and there is a BG on the input from my 5v psu, where it enters the player (1,000uf, 25v). The opamps were also given extra 220nf film caps, at their + and - v pins to ground. This may have been part of the large improvement here.

I should at this point state that most of these mods are not my ideas, but have come from the excellent tnt-audio pages. Thanks to those guys!

Anyone any ideas on removing the last hint of digital 'bite'?

I intend to somehow try the (conterversial) LED light bathing mod, but I don't know how to fit it all in with this transport


-Simon

[Mesh]

Thanks SimonY for some excellent mods to do. How many hours did all these mods take ?

[analog_sa]

Did you experiment with various other materials? Granite is my least favourite material in audio but our tastes may simply differ.

[Mesh]

I have built lots of hifi stuff with Al, I wanted to try Granite for the base for it stiffness. The original case was of course steel. What dont you like about Granite?

[SimontY]

Hi mesh,

I surprised myself at how many things I've done when I put them all down in one list!! I did the mods over months, one or two at a time, the total number of hours is huge, but I enjoyed [almost] every minute Actually I am still going with them, though I've decided I'm nearly there with the player now

It may help to list the most significant (subjectively of course!) mods for you:
- removal of output caps/dc blocking
- change of opamps to good ones, and decoupled with film caps
- reclocking, and use of a good psu for new clock
- damping of chassis and use of 'coupling' type feet, rather than soft feet
- changing diodes to Schottky types

You may aswell beef up some of the psu caps with decent quality ones too, this seems to help in several areas, sounding more 'correct', dare I say it!

I wouldn't worry about what analog_sa thinks about granite. As you have all that weight at the bottom of the chassis and feet to tightly couple to your rack you should have a sensible system for 'draining away' stored vibrational energy. I think this makes more sense than 'decoupling' with rubber or whatever some people use. And it all looks cool


-Simon

[Mesh]

Hi SimontY,

Ill start my upgrades by doing the ones you have just suggested. Thanks for your help.

[analog_sa]

a sensible system for 'draining away' stored vibrational energy.

Nonsense. Heavy mass acts like a mechanical equivalent of a large capacitor and actually stores vibrational energy very effectively. Eventually some of this energy gets back to whatever sits on top of it, delayed and with a different spectrum to create some very unpleasant colourations (or pleasant, if you've developed a taste for the 'loudness switch' type of sound granite imposes)

[SimontY]

Mesh,

It's a pleasure to help

You must be careful when you remove those DC blocking capacitors though. I don't know if you understand what their function is, though I guess it's self-explanatory! They stop any rogue DC from reaching your amp, and ultimaltely speakers, which apparently, don't care to receive DC.

I don't personally have a problem, and you may not. Apparently by closely matching some resistors further up in the path, DC is minimised. Which reminds me, changing these resistors is also recommended, particularly if you find the sound harsh at all, I think.

Hope this info helps, and I don't mean to sound patronising, but I don;t know what you do and don't know about electronincs. Personally I know very little, hence why my ideas include disclaiming type phrasing such as "...apparently" and things like that.

Enjoy!

-Simon

[SimontY]

Nonsense. Heavy mass acts like a mechanical equivalent of a large capacitor

Yes, I expected some sort of rebuttal from this forum member.

Again, don't worry too much. As long as it's on something that is bigger than itself and nicely connected to the floor ie. via spikes, it should be reasonable, if not ideal.

The reason analog just gave for not using heavy things I actually agree with, one can't really deny it. But the worst thing you can do is to have something heavy AND try to decouple it from everything else, AFAIK. This way the energy will have nowhere to go really, and the cd player will resonate for a longer period of time (possibly), making the sound 'thuddy' IME.

This effect was demonstrated clearly in my case by going from stock feet (ie. foam pads) to oak cone feet. The sound became much freer and more natural. The bass was less thuddy and one-note. The sound was easier to listen to and less in-your-face.

I used to have mass on my MDF/steel bolt rack in the way of several large paving slabs. I removed them one day to see if I preferred the sound. Again, similar effect - the sound is more natural, and the bass is more light-footed.

If you havent already, spike your rack to the floor. This seems to add another level of naturalness, speed and detail to a system.

Most people think a rack won't make much difference, and this may be because they've only heard metal/glass ones, and use soft supports, which just seems the opposite from ideal!

Anyway, back to work, before I get in trouble!!


-Simon