Finally, an affordable CD Transport: the Shigaclone story

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BigE

BigE

Member
Joined 2008
Thank you Peter,

I think I am beginning to understand why there is a large cap on the output of the 8V regulator.

EDIT: a) Motor speed control could be affected by the performance of the 8V supply. b) Noise could pass through the secondary regulator without some sort of filtering of the 8V rail -- but 1000 uF is too big for that -- still thinking about that one...
 
BigE

BigE

Member
Joined 2008
There is no snubber capacitor across the transformer primaries?
Has a snubber been attempted?

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jitter

jitter

Member
Joined 2004
okapi said:
a large cap at the output of a voltage regulator serves to lower the output impedance of the regulator. One byproduct of reduced output impedance is an improved transient response. It will also help with ripple rejection, but there is not much ripple left after the input cap and the regulator.
Click to expand...

You might get away with a smaller capacity if you use a lower ESR cap.

To explain this: the company I work for is an OEM of industrial electronics. The power amp of a measuring device we produce for a client has shunt regulated PSU's. Sometimes we have to use an electrolytic cap in a key position where a certain Wima cap is preferred but not available on short notice. The Wima cap (I think an MKS) has a much smaller capacitance than the substitute elco. I presume this has something to do with ESR.
 
S

surfstu

Member
Joined 2008
i recieved my dac today, i opted for the toroidal transformer that came with it. Its has a +8v and a 0 which i presume is the only connection i need to make to the dac board if I am bypassing the opamps.

It also has a +13v, 0, -13V winding. I am making the psu from the pdf file on page 2 of this thread. Do you think it is possible to use the +13 0 -13V windings to power the cd player? is there any benefit of making the cd player in the same unit as the dac?

I bought a +12 0 -12 toroidal from RS spares for £15, but i am thinking i could take this back if i can use the spare windings from the dac transformer.

cheers stuart
 
kevinkr

kevinkr

Administrator
Joined 2004
kta-hifi.net
Paid Member
surfstu said:
i recieved my dac today, i opted for the toroidal transformer that came with it. Its has a +8v and a 0 which i presume is the only connection i need to make to the dac board if I am bypassing the opamps.

It also has a +13v, 0, -13V winding. I am making the psu from the pdf file on page 2 of this thread. Do you think it is possible to use the +13 0 -13V windings to power the cd player? is there any benefit of making the cd player in the same unit as the dac?

I bought a +12 0 -12 toroidal from RS spares for £15, but i am thinking i could take this back if i can use the spare windings from the dac transformer.

cheers stuart
Click to expand...

Toroids provide relatively little HF noise isolation between their primaries and secondaries, and even less between secondaries in a lot of cases. I think you would want to keep the supplies entirely separate right down to the transformers in order to reduce the likelihood of noise injected from one supply to the other. The motors in the transport are noisy and also draw relatively large currents during seek, etc.

Also transformers have AC outputs, not the dc ones you seem to imply via the use of +/- symbols. AC transformers are generally specified without polarity. Examples based on yours would be 8V or 0-8V and 26VCT or 13-0-13 volts, etc. Other conventions also apply, but polarity does not.
 
kevinkr

kevinkr

Administrator
Joined 2004
kta-hifi.net
Paid Member
surfstu said:
cheers kevin,

now i will be forever wandering how you know to double check everything before applying power,
i thought this was quite a simple mod, care to share you headaches?

cheers stuart
Click to expand...

Hi Stuart,
Talking in general, dint of hard experience,etc.. Mine is based on the RC-EZ32 which uses the same chipsets from the same family, but uses an external micro-controller like the actual Shigaraki. I blew one up.. :hot: Fortunately I was able to get another and it has worked fine with all of the extensive mods I made, and now for over a year.

Kevin
 
N

nrg2009

Member
Joined 2009
Nice player Peter! Looks sharp. I like your wood cutting board as a base too. Nothing wrong with that in my opinion. I'm going to start using that since my wife likes the plastic cutting boards better anyway.

You said all in one player, meaning it plays SACD as well, or did you mean DAC and transport on one cutting board?
 
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