Finally, an affordable CD Transport: the Shigaclone story

[Kakselbo]

Originally Posted by Peter Daniel

Previously, I had reservations with regards to some veiling when mods were done according to pdf prepared by Okapi.

However, recently I took this board again, and did few changes: C906 is replaced by 0.1/600 V-Cap TFTF, C908 by 3n3 Wima FKP2 and two electrolytics (C929 and C939) were replaced by 10uF and 15uF Oscons. Everything else exactly as in Okapi pdf. There is of course discreet 5V regulator and now everything seems to sound fine, very close to TL0. I will do more critical listening tests in a week or two, in other system.

The attached board pic is slightly different, as it does not show Okapi pdf file mods, which I'm still using presently. It shows new caps though and 5V regulator.

Dear Peter. I tried some similar mods. And you helped me how to install caps at c906. I just tried a Duelund Alexander cap at 0,1uf instead of the Teflon cap I had installed, it was 0,.047uf. Can I please ask why you ended with Teflon. My problem is that I prefer the bass and more analogue character it has at 0,1uf but I'm not sure if it was because I changed typeof cap or because of value. I guess it is value that changes things. But please a word on Teflon? (think the polish version mentioned something about Polypropylene or was it Teflon) ps.the wima cap was small to solder on

[uncle_leon]

Kakselbo, if I may - in C906, both value and cap construction are very sensitive. Also, please keep in mind that not all teflon caps are the same... V-Caps are very expensive, and are almost unanimously regarded as being among the best the world.

[Kakselbo]

Originally Posted by uncle_leon

Kakselbo, if I may - in C906, both value and cap construction are very sensitive. Also, please keep in mind that not all teflon caps are the same... V-Caps are very expensive, and are almost unanimously regarded as being among the best the world.

Thanks. Read about v-caps and they are truly expensive. Maybe it will go in later for fun. I guess changing back to 0.1uf changed bass in my setup, just a bit interested in trying a Teflon tin cap with this value. But the Duelund Alexander sounds pretty ok very pleasant to my ear. anyway can you send me your email?

[uncle_leon]

I personally found small values around 9-10nF (ie. 0.01uF) to work best. Going above 12nF rapidly deteriorates detail, but once above 20nF, the sound doesn't change much. I haven't tried values above 100nF (0.1uF) yet. Less than 6nF again loses resolution, and going significantly below also causes read issues. Without C906, the transport is unable to read anything.

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[j baldam]

Originally Posted by uncle_leon

I personally found small values around 9-10nF (ie. 0.01uF) to work best. Going above 12nF rapidly deteriorates detail, but once above 20nF, the sound doesn't change much. I haven't tried values above 100nF (0.1uF) yet. Less than 6nF again loses resolution, and going significantly below also causes read issues. Without C906, the transport is unable to read anything.

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Hi just had a thought,
most electrolytics have large tolerances ie 20% would a more accurate cap be good at 906 given the job it's doing.
I suppose I mean, could this be the most important thing rather than make/value

[Tham]

Thanks Peter. Will certainly give it a go .

[uncle_leon]

Hi just had a thought,
most electrolytics have large tolerances ie 20% would a more accurate cap be good at 906 given the job it's doing.
I suppose I mean, could this be the most important thing rather than make/value

Tolerance only tells you the range of values you can expect when buying a given part, so by itself it cannot have any effect on the sound...

If precision was critical, I don't think Sanyo would use a cheap electrolytic cap. And also, the low values I'm using in my Shiga wouldn't work

The sweet spot I discovered is more or less 20% wide (10nF +-2nF), while most audio-grade film caps have 10% or 5% tolerance, so again absolute precision is not required here... (having said that, I was building each cap to the exact capacitance I wanted - so in my tests tolerances were effectively 0%...)

[j baldam]

hi,
I was just thinking of the design stage when a value was decided on, if the optimum was a certain value then hitting that exact value may pay dividends.

[Tham]

Originally Posted by Peter Daniel

Attached pic shows how to connect separate 5 V supply; no "latch-up" arrangements are needed.

Hi Peter,

One more question before I proceed to feed separate +5V as indicate...I have a jumper wire from +ve pin of C916 to where the +ve of 5V is to be connected to. Do I need to remove this jumper wire now?

[johnm]

Do we know what C906 actually does/is there for? I mean, there's every possibility that the value IS important. For example (and this is PURELY guess-work on my part, but since it seems to make a large difference to the sound...) what if this part (or the exact value) has something to do with the laser strength or focusing? This would obviously affect the perceived sound quality if changed (and disc reading ability too perhaps).

As I said, just guess-work. I too have played with many different caps for this position (Jensen 0.1uF copper foil, aluminium foil, Auricap, Black Gate etc etc). Whilst each one changed the sound, after a while I had to reluctantly concede that none sounded as 'right' as the original part, for all it's cheapness.

This value WAS chosen for a reason by the bods at Sanyo (as they could easily have fitted a 0.01uF or 0.2uF etc etc).

I'm all for modding (honest - not posting this to ruffle any feathers) but perhaps it's best to find out sometimes what a part does/it's importance before just 'shooting in the dark' as it were?

I changed out all the caps on the main PCB with Black Gate 'N' types at one point, then tried some os-cons. Again I strongly felt I preferred the board as it was stock, with the exception of the caps Peter mentions should be changed/removed. Again, most of us are shooting in the dark, without knowing what each replaced part actually does for the most part...

In fact my best Shigaclone sound-wise was when I had the freshly removed mechanism sitting on a rubber mouse mat, NO mods at all (no caps or chokes removed at that point), and the digital out coax connected directly to the PCB without any resistors. It grooved & boogied like no other digital device I have heard before/since. Sounded like my old Naim CDI in fact, but with more detail! All the mods bought greater levels of refinement and 'hi-fi-ness', but at the expense of a little life & soul... Go figure, as they say

I think I may well buy one more mechanism, and leave this one totally stock, but mounted in a nice chassis.

- John