Poogeing The SACD (Part Deux): Shanling SCD-T200C

[KBK]

I've got two of these units, both a few hours old. They will both be modded, and I will add my custom clock as well. One is only about 3 hours old, and already--- it is on it's back with it's innards removed/exposed. The soldering gun is up and running..and here we go........

One thing noted, is the SACD chip is the PCM1738('P' designation, I believe). I've gota bunch of 1793's lying about, can they be swapped out and is it worth bothering? I can look up the pins, signals, etc myself, but if one of you know offhand...

There are 4 OPA 627AP's on the I/V section, running into a pair of OPA2604's. This can be used direct out, or sent to the Tube section buffer, for 'tube' output. The tube is one per channel (I/O, again = buf and out) Is the OPA2134 a good improvment over the 2604? It's socketed DIPS here, so the swap is a bit of joke.

Already I'm getting itchy..I can see the room for improvment! For example, the DC power rails buffs for the tube section, on their local boards.... 10uf at 350v? NOPE! Needs more juice!

Cheap electrolytics around the DSD chip.. loose those puppies, add some oscons etc. Tons of room for improvment in this puppy! Lots to work on, with lots of promise.

The entire unit is modular, which is nice for working on one board at at time.

Anyone else have one of these units?

[Peter Daniel]

A friend of mine has Shanling SCD-T200C, modified by Partsconnexion. Last Friday I plugged in NOS, TDA1543 based DAC into SPDIF output of that player.

It was clearly better than Shanling built in DAC. It is a very nice player though, and has certain midrange properties, that NOS DAC didn't present that well (yet).

Here what modified version includes:
http://show.audiogon.com/cgi-bin/shm...AAshanling</a>

He actually has the latest model, with aluminum chassis, instead of stainless steel.

[KBK]

It has quite a few jumpers that are going to have to be removed,and hardwired with some decent wire, buffering of the tube power supplies, extensive damping (aluminum goooooddd...steel..baaad!), dac power supply buffering, etc,etc, etc...

I've seen the list of mods. Removal of the volume control supposed to be one of the big changes, which I am not sure the parts connexion mod includes.

I've already done about five mods,and the improvement is quite noticable.

It's a good starting point,as a decent quality base to start from, as a SACD player goes. It only took about an hour..then.. 3 hours of fixing the first failure of the boards gave me the fits to find the issue. The board traces are quite light..and can cause grief. That was my issue this time around.

It can cause quite the panic at 1:30am in the morning when it doesn't work after a round of mods...then you have to fix it. And the bloody thing is only one hour old. Dang! UG! Nuthin' like blowing up expensive kit that's brand new.....

These two units are the latest with the alumium chassis as well.

[ThorstenL]

Konnichiwa,

First note that I do commercially modify these units, please do not ask for details beyond those I am providing here....

Originally posted by KBK
One thing noted, is the SACD chip is the PCM1738('P' designation, I believe).

The PCM1738 operates both as Filter for DSD (SACD) and DAC for RBCD.

Originally posted by KBK
I've gota bunch of 1793's lying about, can they be swapped out

No, pin assignement are very different.

Originally posted by KBK
There are 4 OPA 627AP's on the I/V section, running into a pair of OPA2604's. This can be used direct out, or sent to the Tube section buffer, for 'tube' output. The tube is one per channel (I/O, again = buf and out) Is the OPA2134 a good improvment over the 2604? It's socketed DIPS here, so the swap is a bit of joke.

Leave the OPA627 alons, upgrade the OPA2604 to an OPA627 Module. Get browndog adapters, single Op-Amp to Dual. Shanling only use one halve of the Op-Amp for each channel, so you can buy only 2pcs SMD OPA627, one needs to go on the top of one brown dog adapter, the other on the bottom of the other one.

Also, the PGA2311 Volume control chip can be removed and input/output per channel shorted, unless you are desperate to have a volume control. Major improvement.

Originally posted by KBK
For example, the DC power rails buffs for the tube section, on their local boards.... 10uf at 350v?

Note, these are bypass only, the real PSU Capacitors are on the PSU PCB....

Originally posted by KBK
Cheap electrolytics around the DSD chip.. loose those puppies, add some oscons etc.

The export units I have seen tend to have loads of Elna Cerafine/Starget, but there are some positions around the DAC where Os-Con's are a better choice. Check the datasheet, it should be obvious which pins are in effect analog (Elna Silmic, Cerafine, Starget preferred) and which are digital (Os-Con).

Originally posted by KBK
Anyone else have one of these units?

In my "big" mod package I actually rebuild the Valve Buffer sto be come thge sole analog stages, passive I/V Conversion and loads of work on the powersupplies everywhere, upgraded clock system and so on.

The basic "3D Acoustics" package is actually merely re-specifying some components, Wima Film ouput coupling Capacitors instead of electrolytic ones, replace the OPA2604's with my own "secret fav", upgraded rectifiers and analog stage regulators, some Os-Cons and such stuff, simple and inexpensive to apply.

Sayonara

[KBK]

Originally posted by Kuei Yang Wang
Konnichiwa,

Note, these are bypass only, the real PSU Capacitors are on the PSU PCB....

Sayonara

The thing I have noticed over the years, is if one gets the rest of the system working properly, bypass caps are found to be harsh and degrading to the music signal, creating a distortion of the trnsient peak detail information (as ther transient current draw off the PS goes through the LCR characteristics of the capacitor{s}), and thus creating a false sense of detail. Broken transients. smeared transients. etc.

Imagine the PS as a hollow air filled conduit, and the capacitors as a bunch of Helmholtz Resonators attached to it, of various sizes and positions on that conduit. Then, run through all the air mass loads that could run through that conduit at different frequencies. See what I mean?

Therfore, I will increase the size and quality of the local buffer caps, upgrade the power rail wiring and that should decrease the false detail to a large degree. If I could do it with -zero- bypass caps, I would.

I have also come to the understanding that OS-CON works well , if not spectacularly with analog PS systems. IF, I repeat IF you take care of all resonant issues in a given system. Right down to the exectution of the tweeter's design. Correct everything and then OS-CON make much more sense in analog power supplies. Just my personal findings.

Thanks for your help!

[KBK]

All I know, is I find it awfully hard to enjoy digital, no matter what I do with it. No matter what flaw I 'clear up'. It still lacks. Or, conversely, annoys.

[ThorstenL]

Konnichiwa,

Originally posted by KBK
The thing I have noticed over the years, is if one gets the rest of the system working properly, bypass caps are found to be harsh and degrading to the music signal, creating a distortion of the trnsient peak detail information

!!!??? Sorry, but that does not match my experience. OF course, bypassing must be done right, if you do it wrong you create nasty tank circuits that smear transients, but if done correctly the reverse holds. Don't blame "bypassing" if you did not implemented it correctly.

Originally posted by KBK
Imagine the PS as a hollow air filled conduit, and the capacitors as a bunch of Helmholtz Resonators attached to it, of various sizes and positions on that conduit. Then, run through all the air mass loads that could run through that conduit at different frequencies. See what I mean?

I can imagine it, but that particular imagening has nothing to do with reality, sorry.

Originally posted by KBK
Therfore, I will increase the size and quality of the local buffer caps, upgrade the power rail wiring and that should decrease the false detail to a large degree. If I could do it with -zero- bypass caps, I would.

If you use only very few (or even one) bypass capacitor and you do not very carefully manage the current loops then you are indeed making a dreadfull contraption. I use a minimu of 3 bypass capacitors per Electrolytic and place them where the current loop is shortest through the smallest bypass capacitor, in other words so that it makes it electrical sense. This does not lead to false detail or such, but rather to a "blacker black" kind of effect..

In fact it is virtually impossible to get a reasonable PSU behaviour without bypassing, too much inductance in the whole thing.

Originally posted by KBK
I have also come to the understanding that OS-CON works well , if not spectacularly with analog PS systems.

The Elna Silmic/Starget tend to have lower noise under these conditions. If the HF behaviour is critical os-con, if the audio behaviour is critical Elna Silmic or Cerafine is my personal preference. Os-Con's only have one thing going for them, good HF behaviour in a small, high capacitance package.

Originally posted by KBK
Right down to the exectution of the tweeter's design.

Tweeter? Whasthat? Okay, i du use a Supertweeter, but no conventinal tweeters, if at all possible, they invariably cause discontinuity in the sound.

Sayonara

[KBK]

Wait-a-minute! Dammit!..... oh yeah.

This is the AUDIO forum. We are almost bound...... by contract to the audio gods that be.....to disagree on things. And sometimes...vehemently so.

I will refrain from going further down that path..and hopefully we will have a successful discourse. Or at least a civil one.

Except (isn't there always another.. ) to say that in a wideband complex system that involves a huge number of various frequencies and levels... not hitting a point where two components of such a nature won't react adversely with respect to one another.... is highly unlikely.