MHZS - Mystery of the DAC Chip

Hi,

I have heard of marking the edge of a CD to reduce the reflection by the lens. I have marked one of mine many many years ago with a permanent marker as well.

People suggested using Green & Purple; I can't recall what is the reason behind. They said using different colors gives different results.

The Belafonte disc I mark does give a LITTLE difference. I think my set of equipment may be the constraint as this set is just a budget buy.

I have never tried marking the LENS!

Kiko, do you think you can give us a more "close up" look of the lens after marking?

Hi KiKo,

I haven't got the chance to mark the lens yet. Instead, I discoverd that there are "BLACK" CDs here in Hong Kong. Never heard or seen one before. I think they incorporate the logic you mentioned.

A photo is attached below. The set of CD comes with two discs. The Black (They call it the Purple Crystal) CD and the normally Silvery CD. The contents are the same but the sound quality is indeed different. The Black one is far superior to the silver one.

Will try to blacken the lens later.

Cheers!

Blair,

I don't think these CDs are sold in the US nor Europe. Even my Hi Fi friends are NOT aware of their existence. I discovered them just by chance and so far, there are only TWO I know in existence. One is a female vocalist (shown here yesterday) and the other is a Chinese Orchestra (Drum + other Chinese musical instruments).

Follow this link:
http://modernaudio.hkcdnet.com/main/index.php?main_page=index&cPath=2&zenid=bd7a8f2fc56551100dc08eace4416c7b

The THIRD with the lady and purple background is the first one I mentioned above.

And this link:
http://modernaudio.hkcdnet.com/main/index.php?main_page=product_music_info&cPath=8&products_id=2&zenid=bd7a8f2fc56551100dc08eace4416c7b

Gives you the Chinese Orchestrial one.

You should note that they are NOT expensive at all. Just HK$ 60 & $ 90. Total equivalent to US$ 20 or so. Very worthy of buying.

I listened to both of them. The purple one is far superior to the silver one. My set of equipment is no good for complex performance like an orchestra but still I can more or less locate where the instruments are in the setting.

Unfortunately, I can't find the English Version of the website. The reason, I guess, is because most of the discs are in Chinese. It will be really hard for them to translate the titles and the information into English.

I am not sure whether the company will mail to US or Europe. You may try to drop them an email.

CAT

Hi KiKo,

I don't think they are "Black". Perhaps I used the wrong term in my previous post. They are "URPLE". If you look at the reflection of the photo I posted last time you can see purple light bouncing back from the surface of the CD.

I lent them to a friend of mine for a close listening as his equipment are much better than mine. He also agreed that the purple one sounds much better, tho' he doesn't really like the lady singer way of singing, ha..ha..

It is said the purple CD has error level < 1/1000 mm and the way it is produced has great significance in reducing signal loss due to high spinning speed of the CD. The Purple CD is capable of "neutralizing" the defect of the red laser ... blah blah blah.

Anyway, it is a new toy for us ...  :

Dear KiKo,

In your first post in this thread I can see that you have TWO CD66 PCB sitting next to each other

Where did you get the extra PCB? I have ruined my CD 33 PCB (post in CD33 wrecked thread) and I need to consider getting a replacement PCB.

Can you provide me some information please.

CAT

Dear KiKo,

I took my CD 33 PCB back to Mainland China, to the dealer which me and my friends got our CD 33. The sales there said he will try to get me a replacement board at the minimum charge. He said a brand new PCB cost around GBP 50, which is around HALF the price of the original CD player.

The sales is trying to get me a PCB without the capacitors installed as he knows that I am going to replace all the caps anyway. He hasn't tell me how much it is going to cost me .... but should be less than GBP 50. Have my fingers crossed.

I just feel upset with myself wrecking the CD 33. It is soooo stupid of me trying to rush everything and I lost my temper on doing it. Anyway, it is a good lesson and reminder for me.

One thing for sure, I won't quit DIY .... ha..ha... Will continue after I got my new PCB back hopefully the end of this week.

Thanks for your information.  :wink:

Hi Blair,

I am still waiting for the return of my CD 33 PCB. Time comes to a standstill like .... This is indeed a very "long" week for me as I need to wait ....

I will continue to modify the CD 33 once it gets back. I still haven't got the chance to test out the large LED I got from Hi Fi Fever. Also considering adding another power supply to the OPAMP ... but this has to be done at a later stage.

Keep in touch and good luck with your Pre-Amp project as well!

My colleague is persuading me to DIY an Audio Note Pre-Amp. He said it is easy and simple and won't cost me too much even with good components.

I started playing with these toys say somewhat around May this year. Still got a long way to go, learning as I proceed. The first thing I have to learn is Basic Electronics, ha..ha... as I am an Economist, not a pure scientist.

I agree with what you've said. There is plenty of room for improvement with the OPAMP and perhaps even the DAC. I just wish I know more about these gadgets ... ha..ha..

Your suggestion on using the CD 33 as a transport is also a good one. Yet, I have to save up some money before I can go ahead with this DAC project.  I guess the LITE ones maybe my choice.

Actually I lived in N. America for almost 5 years; mainly in Canada. I can manage some of the slang and I like watching movies all the time. That helps me a bit in keeping up with the American phrase. Blair, where are you located?

CAT

Dear Blair,

Interesting work you have there. I haven't make up my mind on the Pre-Amp thing yet as it depends a lot on time available and $$$. I don't want to go into anything that needs US $ 1K or more .... hard to find that spare money.

My CD 33 PCB is back. They charged me US$ 40 for putting everything back on a new PCB. Yet, they also put the burned 2.2/ 2W dead resistor back without knowing about it.

I put the board back and turned it on. It seems okay ... I haven't connect the RCA sockets back so I have no idea how it sounds. Have my fingers crossed.

Since they put all the caps back, I have to go through the process of de-soldering them out and put back my Jensens ... painful.

CAT

Dear WINDWSS,

Yeah, thank God.

I managed to put back most of the capacitors yesterday. Spent almost 2 hours in doing so. Now, I am glad to hear the sound I am used to; though may not be everybody's cup of tea.

Will try to see if I have time to continue with the LED modification next to the laser to reduce reflection later this week or next.

Keep in touch

One think I don't understand. I put back all my previous parts back on the new PCB. However, the S/N ratio dropped to 65db ... which is 10 db less than before ... :

Dear KiKo,

I got mine from China. The sales I got my CD 33 said it cost RMB$ 900 to get a new PCB for the Analog Section with everything on.

In Hong Kong, never heard of any place doing this.

CAT

Dear KiKo,

I did the same, NOTHING related with MHZS whatsoever found. This CD comes not from a well known company nor there is a big firm behind its production.

Another active member here, Viewer, had just purchased and modified a second hand CAYIN CDT-15A or so. That one has some support, I think. You can check out what Viewer did in my other thread "Interesting S/N Ratio for the CD 33".

The shop I got the CD 33 has NO web page or so. It is not a big store at all. Kind of like the Variety Store next to our neighbourhood (I mean the scale & way of operation). Some said the Bada CDs are very similar to the MHZS but there is no proof that they came from the same source.

I only have the Chinese Address of the company. Unlike firms in Western Countries, this address may also be a FAKE. If you need anything, you may drop me a note and see if I can ask the sales I know to arrange for you. Last time he told me that he did this as a favour for me (to get a new PCB). Yet, each time we go there, we bring him a lot of business ... ha.ha.. and I think he doesn't mind to continue giving us favour.

CAT

Dear KiKo,

Long time no see. Glad to see you back.

The photos are missing. Hi Fi Fever allows upload to 1M only. I think your Hi Res photos have to be in different sections of the PCB.

Awaiting for your report.

CAT

Dear KiKo,

These photos are very useful. Although I am just an amateur, these photos give me / us a better understanding of the layout of the whole thing.

As I scan through the photos, your CD 66 uses 12AX7 instead of the 6N3?

Vash, t, WINDWSS and I are looking at the readings we got from the tubes. Please also check out our other thread"

http://www.hififever.com/forum/viewtopic.php?t=952&postdays=0&postorder=asc&start=700

Got to pick up my wife now ... ttyl

CAT

Dear Friends,

It is so nice to see people coming from all parts of Europe and our friend Blair from USA. I guess it is really hard to find a chance for people of different parts of the world to come together like this.

Although I am not the operator, I sincerely welcome you all to share your interesting experience.

I am a bit busy right now as this is the quarterly examination period at my college. I have to set a number of papers (not to mention marking them). For this week or two, I may not be able to contribute much but will continue the DIY thing by mid Nov.

For the time being, I will continue to read your posts and give some comments if possible.

Keep in touch guys and happy DIYing.

CAT

Dear friends,

I have a plan to build an AudioNote 7 pre-amp before Christmas. My friend told me that the material cost will be around HK$ 2K (approx. US$ 230).

Just hope I can spare the time after the half yearly examination.

CAT

Dear Koifarm,

The DAC board you are using -- LITE AC-AH, I think it is no longer available at DIY Gene ... sigh

Dear Koifarm,

Strange, that board was NOT available yesterday at DIY Gene. Today, it is!

If I use that board, I will by-pass all the analog part, is that correct? In that case, it will be the same as having an External DAC connected through the coaxial out.

Please correct me if I am wrong as I don't know Electronics at all.  :

Dear Koifarm,

I understand your logic but I need further help from you as I am a dummy in this field.

The LITE DAC-AH board got several connectors which I highlighted in YELLOW circle in the photo that comes with this message. What and Where should I connect these to? I think one should be the INPUT source, one the OUTPUT and the next should be POWER. But there is still one left?

I used KiKo's CD 66 PCB as a reference as it has high resemblance with the CD 33 PCB. Can you point, by means of arrors or so, where should I connect those items mentioned above.

It would be better if I use a separate Power Supply for this board, is that right?

CAT

Dear t.,

So I need a separate PSU to supply power to this unit and connect the power output to the connectors on the top.

For the lower LEFT connectors, where should I connect the L.R and the Gnd to? Any idea which point on the CD 33 PCB?

I can get hold of the board but I need to know where should I connect the wires to the PCB. Please advise. Many thanks.

CAT

Dear Koifarm,

Thanks for your information. I am just about the get the LITE DAC-AH board. Now, I have to give it a second thought.

KK Ho once said to further modify the CD 33, it is best to have separate power supply for different sections.

Can you share some information on HOW this can be done.

CAT

Dear t.,

I just got my LITE DAC-AH today. It is really late now here in Hong Kong, close to 11:15pm and I don't have the time to unscrew everything to reveal the DAC yet.

Just connect it through the Coaxial out from the CD 33 and then into the Matisse. Wow ... what a BIG difference! Vocals are far better than before with good spacing effect and openess. More details are provided ... very nice.

There are a couple of things that I need to clear out.

1. What is I/V Resistors?
2. What is the I2S line?
3. Do you leave the 0.47u/400v Capacitors on when you connect the DAC signal out?

I am really sorry but I am just not familiar with these terms.

CAT

Dear Koifarm,

I have the idea on where to connect the SIGNAL OUT now and the ground. However, still no idea where I input the SOURCE to the DAC.

When Standalone, the DAC accepts COAXIAL and OPTICAL. But now I have to feed the signal from the CD 33 onto the DAC-AH board. How should I do that.

I still have no idea what is the I/V Resistor.

Enclosed are the photos of the DAC-AH.

CAT

Dear Viewer,

I will take a look at the DAC-AH PCB after Wednesday earliest. These few days are really working like a DOG.

Thanks for the inform. After I finished rushing everything this week, I will post the photos of mine DAC-AH for you to take a look.

CAT

Dear KiKo,

Haven't seen you for a week and you were hiding in your garage to fix this whole thing.

Looks very interesting to me but honestly I lost track as you proceed.

As an amateur, I realised that you added some huge capacitors. You did this to ensure a steady flow of power to the DAC / Analog part? Instead of using an extra Power Supply, you can capacitors instead?

If you can afford the time, can you explain a bit on the logic of going through each and every step? I know that you added in a lot of stuffs but I don't know what is the purpose of adding them ...  :cry:

CAT

To Viewer,

I dis-assembled the DAC-AH today after work. It looks like they haven't fix the "out of phase" problem afterall. My PCB looks exactly like yours to me.

I post the photo of my PCB with this message for your reference.

I can follow some parts of your photo but the second one is a bit too small and looks like it is out of focus. It seems to me that you scratched the PCB in order to solder something in.

On the Top View, you replaced TWO items with a diamond formation of the PHBY diodes. What is the purpose of doing that?

Wow, you use Mundorf 0.1uf caps on top of the Philips ones? How much did you pay for them?

CAT

Dear t.,

Say is it possible to swap to another DAC chip? I haven't been following too closely these days 'cos busier than the bee .... :cry:

CAT

Dear Viewer,

Wow, how much did you invest in that thing? I can see you have a separate clock like the CD 33; at least 4 heavy weight Caps lying on both sides and film caps on top of the Philips ....

After rushing for 3 weeks, I feel really sick. Many of my F.5 boys got this "Hand, Mouth and Feet" disease and they are urged not to go back to school. Currently I am suffering from a flu (at least I think it is) as well. Just hope I can recover soon.

Thinking of DIYing a Marantz 7. Any good suggestion or where to get the board and the components?

CAT

Dear KiKo,

I haven't bought much items from diykits. VIEWER got more experience with this shop.  All I know about this shop is where it is located and the owner is a pretty nice middle age man.

Thanks for posting the schematics. I hope my colleague can read it as I can't yet. Will try to learn more about electronics next year when I have more time.

CAT

Dear t.,

From you photo, I can see that you removed two of those caps, replaced the OPAM by putting in some caps, resistors ... and you have at least THREE? boards instead. One for the clock, what are the others for?

Do you think you can draw us a schematic too for your modification?

CAT

Dear Koifarm,

So finally how do you fit your DAC-AH into your CD33. Your first trial was that you don't like the fitting very much.

I got mine at present as an external. When we move into the month of December, I should have more time for DIY. First, I think I will fix the DAC-AH "out of phase" problem. Second, I hope to seek help from people like you, Blair, KiKo and others in helping me fix my good friend's KT88 Amp. Lots of interesting work coming up.... :wink:

CAT

Dear friends,

Three weeks from now I should be free from the busiest months of the whole year. Really long for that time that I can try out what you guys had suggested to me in the last few weeks.

CAT

Dear Viewer,

I tried to look around for Cayin CDT-15 but there isn't anymore. What a pity .... Two weeks ago someone put one up but it was sold almost the other day.

Just got my Marantz 7 .. ha..ha.. will spend the next few weeks working on it. And t, Koifarm, etc. posted some interesting stuffs above.

CAT

Dear KiKo,

Will come back on your issue later after I finished everything by the weekend.

CAT

Dear KiKo,

Yes, there are LOTS of questions and I am a bit confused. Sorry.

Can we just start off with a few so that I can make sure I got the answers for you.

What do you want to know in the FIRST place?

I don't think I can call the person up. He lives in China and he speaks Putohghua. I speak Cantonese ... completely different dialog.

CAT

Dear KiKo,

In Hong Kong, we use Traditional Chinese (written text) and people in China use Simplified Chinese. We can manage to read both. The worst case is I send Kingwa an email.

Second, I don't know Putonghua but there are others, including my wife, that knows the dialog. Therefore, it won't be a great problem.

CAT

Dear KiKo,

1. In next time I want to buy your RC1. How to install - in chinese?
How uninstall RC1? The steps with your picture from yesterday.
----------------------------------------------
安装RC1: 将RC1模块上连接好的电线连接到图中 STEP 1 所示位置.
将图中所示 STEP 2位置的两个用焊锡相连的焊盘分离,
将图中所示的 STEP 3 的开关"1" 打到OFF 状态,即这个开关 "1"与"2"是OFF, "3-5"是ON.
在图中RE-CLOCK 位置的插座上插上RC1.

[In English]
To install RC1: Connect the wires from Module RC1 to the position labeled in STEP 1.
Separate the two soldered connection points in Step 2.
Turn Dip Switch 1 in STEP 3 to the OFF position, i.e. dip switch 1, 2 is OFF and 3, 5 are ON
Place RC1 in the photograph's RE-ClOCK position.

KiKo, I don't see a "RE-CLOCK" position label in the diagram!

拆去RC1:将RC1的电线从STEP 1 处焊走,
将图中所示的STEP 2 两个焊盘用焊锡连上
将图中所示的STEP 3的开关"1" 打到"ON"位置.

[In English]
Dis-assemble RC1: De-solder RC1 wires from the position stated in Step 1
Re-solder the separated points in STEP 2
Turn the dip swtich 1 in STEP 3 back to ON.


End of Part 1

Here comes Part 2

2.replace SM5840-how to set a new DF - maybe DF1704 in place where has be SM5840. How to change sharp/soft after replace in cd player?
使用DIP28的转换板,这将不能将DF1704直接焊接到原CD机中SM5840的位置,只能尽量短地将DATA,BCK,WCK等输入输出端口用引线连接,再接上+5V与GND,架空在原SM5840上方.
你需要告诉我你的CD机使用的DSP 与DAC的芯片型号,或将CD机的线路图发给我,这样才可以预先设置好DF1704的状态.
从DF1704的PIN27连接一个开关,通过这个开关就可以控制声音的SOFT/CLEAR

Use DIP28 adaptor. You cannot directly solder DF1704 onto the position of SM5840 inside your CD. All you can do is to TRY connecting DATA, BCK, WCK these inputs & outputs termiinals by means of hook up wires in the shortest distance. Then, you connect back +5V and GND and make the whole thing float on top of the SM5840.

You need to tell me which model of DSP and DAC chip sets your CD is using, OR you can send me the schematics of your CD player. Then I can pre-set the DF1704 status for you.

Connect from PIN 27 of DF1704 an ON/OFF switch. Through this switch you can control SOFT/CLEAR of the output volume.

End of Part II

Part 3 .... ha...ha... This is getting interesting

3. In your DAC - sharp/soft DF1704.

That will help very much if you can write it again in your language, please.
--------------------------
图中所示的开关"2",拨到ON位置是SOFT,拨到OFF是CLEAR,
如果方便操作,你可以将开关拨到OFF,然后在机箱后面安装一个拨动开关,开关如图所示连接到DF1704的PIN27及GND,这样就可以在不打开机器的状态下控制

Turn the switch 2 in the photo to the ON position will be SOFT setting. Turn it to OFF will give you CLEAR.

If you want to make it convenient, you can switch it to OFF and then install an external switch outside the case connecting to PIN27 & GND of DF 1704 as shown in the photo.

End of Part III

And FINALLY this one:

Hi!Kiko:
Sparrow 是专门为 Sennheiser 或音色偏温暖或中性的耳机设计制作,
它的声音表现较中性,平衡,而稍带有一点甜美,
作为一个前级使用或缓冲器(BUFFER)使用,声音也会表现得很清晰而甜美.
它有一组RCA输入,一组RCA输出,一组耳机输出,应用了我们最新的电流增益技术.
Kingwa
[/quote]

Sparrow designs especially for Sennheiser and other headsets that come with a warm or neutral sound. Sound Sparrow produces tends to be Neutral, Balanced and a bit sweet.

As a Buffer or a Pre-Amp, it will sound clear and sweet.

It has one set of RCA input, one set of RCA output, one headphone output, making use of our new technology in "current amplification".

<Kiko, I am not too sure about the last term "current amplification" as I don't know that technical term in Chinese, sorry. I put it down just by guessing.>

CAT

Dear KiKo,

I think I MISSED something in Part 1. Perhaps that is why it caused the confusion.

安装RC1: 将RC1模块上连接好的电线连接到图中 STEP 1 所示位置.

Let me do this again and see if this is better.
INSTALL RC1: Connect the ALREADY CONNECTED wire(s) in the RC1 module to the position(s) marked in STEP 1.

I am not sure whether there are ONE or TWO wires as in the Chinese version Kingwa didn't tell exactly how many wires should there be.

is it enough to attach the reclocking module in the place "clock module" on PCB or is it necessary to connect two pins of the module to the place on step1?

This one confuses me as well. In the INSTALL RC1: instruction, it says connect the ALREADY CONNECTED wire(s) in the RC1 module ... There are wires already connected? As I have no idea what this RC1 is and what it does, I can only directly translate what Kingwa said onto you.

It looks like there are lots of interesting TOYS with the site you sent me. Some look like "monsters" to me, ha..ha... I have no idea what this module is and how it should be placed. Sorry about that.

CAT

Dear KiKo,

I am pretty busy these days. Let me do this translation for you guys bit by bit. You have to be patient, ha...ha...

What is the difference between C-2C and Sparrow? The price difference is great - 165 for one, 310 for the other. Whats the reason?

Sparrow 是专门针对Sennheiser 的HD580-650进行调整的,声音表现出较中性但有一点甜美,但有些用户也将它去驱动其他一些低阻抗的耳机,并认为表现不错,
C2C具有强大的驱动力,声音表现极为传真,相当于将CD机或DAC的声音通过一条有增益但没有音染的线材连接到耳机,这就要求你的CD机或DAC具有较高的档次,否则,CD机或DAC的失真,不和谐声将被传递到耳机中.

[English] Sparrow is specially designed and tuned for Sennheiser HD-580-650. Sparrow sounds neutral with a bit of sweetness. Still, some users use the Sparrow to drive other low resistence (= high impedience??) Headphones. These users are also satisfied with the Sparrow's performance.

C2C got tremendous driving power. It gives off realistic sound equivalent to connecting an "boosting" but with no "overwhelming effect" cable from your CD or DAC directly to your headset. (This last sentence is hard to translate.... Hope you guys understand). This has high demand on your CD player (i.e. you need a good CD player) or else any distortion will be magnified and transmitted to the headset.

So much for the first part.

CAT

Dear KiKo,

Long time no see. I am also planning on other projects as well like CD PRO 2, 1955Pro. Hope to share more here after Dec.

Been VERY busy in the past 3 months and I seldom logon any forums. Missed a lot of issues around.

CAT