Finally, an affordable CD Transport: the Shigaclone story

[Peter Daniel]

I would certainly try them, but where can I find them locally?

 

[jkeny]

Agreed, Fran, let's not go bananas on this thread, please

 

[woodturner-fran]

You can get them from minicircuits.com

link: Attenuators, Plug-In & Coaxial, Fixed

Its the HAT-XX-75 series you want. Try maybe 6, 10 and 15 dB ones. I used 2x 15dB on my shiga after removing the 300/92 pair. But just even try a single 6 or 10dB one and see what you hear.


Fran

 

[jkeny]

Somebody just emailed me that they went from a 15 to 20dB on their modified Hiface & heard " provides even more focused imaging and improvement in the layering of the soundstage than the 15dB att."

I believe it is also DAC dependent as to what is the best dB value i.e what SPDIF signal level the DAC is happiest at. Fran will concur with this - we have seen the Hiface high SPDIF output causing problems on a Buffalo (Sabre DAC) which completely disappeared with an attenuator.

By rights, these should be no different to the 300/92 pair as long as this is a true 75ohm?

 

[jkeny]

Can I ask about something that was posted way back in 2009 when this T-pad was first mooted. Audio1st asked if this T-pad was suitable:

And Kevinkr answered:

No, use the circuit detailed elsewhere on this thread (300/100) - it provides the proper loading on the DSP digital output, the proper attenuation required for the SPDIF standard, and the proper terminating impedance for the coaxial cable. What more do you want?

The dsp chip's digital driver stage on the spdif output is guaranteed for about 11 - 12 mA - your T attenuator will overload it, degrading performance and causing unnecessary die heating, possibly it will destroy the driver as well over time. Note that the T attenuator is meant to be driven by a source impedance of 75 ohms, not the < couple of ohms of source impedance provided by the Sanyo DSP IC.

Does this still hold as the RF attenuator is a T-pad? If the output from the dsp chip has a 100nF cap in series, is the load on the dsp chip now not overloaded?

 

[woodturner-fran]

Dunno? Anyone else know about this?


Fran

 

[jkeny]

Sorry, I'm wrong - it was pointed out to me, the cap is very low impedance at RF. SO my question is how come the attenuator sounds so good, particularly if it's overheating the dsp? Is it, Fran? Can you feel a hot chip when operational with attenuator?

 

[woodturner-fran]

I've had it on playing for about 2 hours now and can feel no heat from it - now I'm feeling the top side of the board, right above the LC7860,,, chip.

Fran

 

[jkeny]

Bearing in mind what KevinR said, it might be wiser to leave the 300/100 divider in place & use an attenuator in series with this, particularly as there seems to be no sonic advantage to removing this divider & using a higher dB attenuator.

 

[woodturner-fran]

IMPORTANT!!!!
IMPORTANT!!!!
IMPORTANT!!!!
IMPORTANT!!!!

jkeny's points about the current that the sanyo chip can output is a warning we need to be careful about!!

My system is working fine becuase I have Peters CEC reclocking mod implemented - and I beleive that this mod buffers the output of the sanyo chip.

The mod is at post 3786 and here is the circuit:

So basically don't remove the 300/100 pair unless you have some way of compensating for this!!


If I find out more later, I'll be sure to post it.


Fran

 

[billo44]

JVC RC-EZ57

Hi folks, I searched high and low (and this thread) but I can't find out if anyone has gutted the JVC RC-EZ57 which is available here in Japan.
Looks exactly like the JVC RC-EZ51 to my tired eyes...
Except it has a usb port on the front.
Any one know?
Might have to buy 1 to find out....

brgds

Bill

 

[woodturner-fran]

I think the rule of thumb is that if it will play a CD with MP3 files on it, it won't work....


Fran

 

[valo]

hmm it looks the same... but it can play MP3 from CD , EZ51 cant.. and i did read that the "MP3" mechanism dident have Dout

 

[billo44]

EZ-57

Thanks peeps,
That makes sense... it will play MP3 so probably different chip set like you suggest...
I won't risk it.
I can't find out the equivalent domestic models nomenclature (woody word) in Japan for the RC-EZ31 and RC-EZ51...
I wish someone had a list of machines using the same chip set and mechanism.
I better start making one I suppose!

Thanks again.
Bill

 

[vitalica]

Hi ,
Use one Shigaclone + DAC Buffalo2?
To me, unfortunately, the signal is interrupted every 10 ... 15 sec.
With another CD player everything is OK.

Regards,
Vitaly

 

[woodturner-fran]

I'm using shigaclone + buffalo no problems. If the spdif signal is too high or too low you might have that problem. Also the buffalo is fairly sensitive to other things on the mains supply. Can you try plugging the buffalo in somewhere else on a different circuit? You could use an extension lead to plug it in far away...

Fran

 

[leoparleur]

Hi ,
Use one Shigaclone + DAC Buffalo2?
To me, unfortunately, the signal is interrupted every 10 ... 15 sec.
With another CD player everything is OK.

Regards,
Vitaly

Nearby wires to the Shigaclone's SPDIF cable can cause interrupted syncing. I had problems with PS coupling caps wires passing over the SPDIF cable. Moving them a few mm away cured the problem.

 

[billo44]

Found a Donor

Hi folks,
I got lucky and found a shigaclone donor available in Japan.
Not being 100% sure I asked Mr. Peter Daniel to confirm by PM.
He replied that it seems to look exactly like the boards he's been using.
Thank you Peter.

Not too surprisingly it's a Sanyo unit, the controller board is different but I think the rest is essentially the same as the JVC.

All I have to do now is find my bench under all the junk and finish a dozen other projects before I start this one!
And read this whole thread which will take a week at least!

There are other units looking like this available in other countries, the only way to be sure I guess is to buy one. You can see three electolytics in a cluster and the plug for the door switch connection through the slot in the laser back right, if you have a small torch (flashlight).

I guess they are still out there....

Bill

 

[valo]

Nice done !

 

[Peter Daniel]

And read this whole thread which will take a week at least!

No need to read the whole thing, the most critical info has been posted here: http://www.diyaudio.com/forums/audio-sector/160373-cd-transport.html