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opa 627bp in MHZS cd33

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music111 發表於 2009-3-19 23:50:20 | 顯示全部樓層
hi koifram.....

What is that DAC? Is it LITE DAC72?
Koifarm 發表於 2009-3-20 22:18:04 | 顯示全部樓層
Music111, just the enclosure is a look a like of LITE.

Inside is my hybride class D amp with SMPS supply and 64 step volume remote control. ( 2 x 400Watt).





In his own thread: http://www.hififever.com/forum/v ... mp;highlight=hybrid
alfcat 發表於 2009-3-21 11:18:04 | 顯示全部樓層
Dear Koifarm,

The Shanling T-100se is a nice CD player as well. One of my friends got one and I listened to it as well. Very pleasing sound.

My CEC is a belt drive player. It is good for music and vocals. But I think it may not be too good for classical.

I think you bypass the OPAMPS in your 100se as well, right? I tried to look back at the photos you put up last year but they are too small in size for me to recommend my friend to modify his 100se.

Can you show us some larger size photos of your modifications with the 100se please?

BTW, where did you get that DAC module?

CAT
music111 發表於 2009-3-21 16:34:42 | 顯示全部樓層
Can you guys tell what caps can be changed in the CD33F?? I have the picture attached taken yesterday...

music111 發表於 2009-3-21 16:39:24 | 顯示全部樓層
Koifarm 發表於 2009-3-22 02:28:51 | 顯示全部樓層
alfcat 發表於 2009-3-23 09:50:21 | 顯示全部樓層
Thanks Koifarm,

Unfortunately, I no longer have this CD player. I guess it is a good and rewarding CD player for DIYers.

If you know the trick to do the right thing, you get much improvement with a small investment.

BTW, I don't quite understand what you have done with the WHITE cable going from the CD to the PCB. What did you do to make the No CD error goes away?
music111 發表於 2009-3-23 12:40:16 | 顯示全部樓層
Hi Koifram,

I plan to change the diodes to UF4007 and change the caps to Panasonic FC...How much benefit do you thing will this bring?
Koifarm 發表於 2009-3-24 03:07:05 | 顯示全部樓層
music111, i can not tell you the effect of your changes because you do not specify with capacitors you want to replace.

Changing the powercapacitors is very useless if you do the passive mod next.

In the link i send before are the 3 most noticeble mods i have heard in the past 3 years.

- Passiv mod( more detail and better staging)
- Change capacitors in audiopath.( less warm with softer hights)
- change anodevoltage of the tubes from 80 to 100Volt( more dynamic )

And there is the never ending story of tuberolling.

But before that you must clear with yourself what you want to change of the sound of the MHZS player. It is useless to do every mod there is if you do not have a goal.

Below the discription:

We do the following mods:

1 – Remove the opamp and filter( it calls the passive mod)

2 – Bridge and replace capacitors in the audio path.

3 – Higher the anode voltage from 80 to 100V and replace the buffercapacitors.

It all takes a hour of work, and give you much more detail, bigger staging and it is like the curtain is falling down.



1-     passive mod.



C11 and C12 must be bypassed on the other side of the board and a few other points must be short. See below.



Connect the yellow points with solder tin.

Then remove the 3k9 resistors and the opamp. See below.

  

These are the light blue parts. And ready is the the passive mod.

It is possible that the output signal is lower then before to correct that you have to replace two resistors a channel see below.

   

Replace the green 33K for 22k/1/4 Watt and replace the 68K for 82K/1 watt and the output signal is higher. My recent experience is just replace the 33K for 27K and leave the 82K resistor as it is.

2-     Brigde and replace the capacitors in the audio path

Replace C7 and C8( see first picture ) for PIO Capacitors of 0,27 uF or 0,33 uF. Good and cheap brands are Sprague Vitamine or Russian pio k40-2. Replace C13 and C14 ( output capacitors ) for PIO Russian 2 uF (2 x parallel 1 uF) or Neutral MKP between 2,2 uF and 10 uF like Clarity Caps APW. See below.

  

C11 and C12 we already bypassed in the passive mod. So we have just two capacitors a channel.

3 – Higher the anode voltage from 80 to 100V and replace the buffer capacitors.

   

Replace zenerdiode D1 for a 100V/min. 2 Watt type, Replace C1,C2, C3 for 220uF/160V ( Panasonic or so ). We also replace D2,D3,D4,D5 for scottky diode’s like BYW100/200.

  

On the other board you have to replace C4 for 220uF/160V.

This mod is only for the MHZS 33 and 66, the MHZS88 already has a higher anode voltage.

I hope this description is useful for you.

Ronny
music111 發表於 2009-3-25 01:29:48 | 顯示全部樓層
Thanks Koifram for your help. I will definitely going to change the caps to better ones. I prefer Jensen so can you please mark which caps can be change to Jensen and with values.
Koifarm 發表於 2009-3-25 03:08:02 | 顯示全部樓層
Change C7 and C8 for jensen oil they are 0.47 uF. Change C13 an C14 for WIMA 2.2 uF/250V MKP( these are very neutral and better then the elco's). And do the passiv mod. You will like it.

C numbers reffers to my photo's.
alfcat 發表於 2009-3-25 20:33:22 | 顯示全部樓層
Koifarm,

Do you have any link to your modification of the Shanlin CD player?

CAT
Koifarm 發表於 2009-3-27 05:58:11 | 顯示全部樓層
Alfcat, the best link i have is here:

http://www.hififever.com/forum/v ... mp;highlight=t100se

But now i use the 6n6p tube. I can adjust schematic, photo's and discribtion. I shall do that after the weekend.
music111 發表於 2009-4-3 15:28:00 | 顯示全部樓層
Hi Koifram,

My MHZS CD33F is hardly one month old and it started to skip tracks even with a new CD. Can you guys suggest a high quality CD mechanism for replacing the existing pickup???


Cheers!
Koifarm 發表於 2009-4-3 19:03:04 | 顯示全部樓層
Music111 after one month you have still garantee, let you send a new drive. But first check the lens by dirt and the cables by connection. I do not know a better replacement.
music111 發表於 2009-4-25 19:07:40 | 顯示全部樓層
Hi everybody,

i received Panasonic FC caps for this CDP, they are kinda miscroscopic!! Very small compared to the present fake rubicons....another thing is that what would be suitable oscillator for this player?? I heard somewhere that 1ppm would improve the sound to a great leve...was wondering whether anyone has done this mod ?

Cheers!
AlexWong09 發表於 2009-4-27 06:53:59 | 顯示全部樓層
其實opa627好,還是opa128好呢 :?:




alfcat 發表於 2009-4-27 08:50:09 | 顯示全部樓層
Well, I have changed the clock for my CD33 some years ago.

You may follow this link to see how I did it.

http://www.hififever.com/forum/viewtopic.php?t=1553&highlight=clock

The cost is pretty acceptable at around HK$ 300 or so.

I have also tried OPA 627AM, pretty good sounding as well.

CAT
nikolas 發表於 2009-5-5 03:34:06 | 顯示全部樓層
Hi
I’m new here and speak little English
I have the problem with the dac in Mhzs cd66
I try to Removed the DAC cover and the pcm1742 and 100ohm resistors
came out with cover what can I do now?
Where can I found new pcm1742
Can someone help me?
Thanks’ a lot
music111 發表於 2009-5-7 23:36:15 | 顯示全部樓層

power filter caps

Hello guys,

What value caps are best for power filtering??

There are many cheap 0.047uF Jensen and AudioNote NOS caps available for 5 pounds... http://www.hificollective.co.uk/catalog/-c-61_68_194.html

Can these be used for 0.22uF used in power filter section??

Any thoughts??
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