opa 627bp in MHZS cd33

Hi Viewer,

i have no idea the BYV96E can be replace to the Big one, but for your information, the original diode was the 5404, 5404 is 3amp, but the BYV96E only 1.6Amp.... so it look like a bit risky.... so i replace the 5404 with BYW96E.

n the small one original  is 4007, so it will be 1amp or less. n this  i use BYV96E.
and the E is stand for 1000V, so think it won't blow unless you have 1000V on it...
hope this will help... :roll:  
if you need some more info on this two Philips diode , i have technical data, is  PDF files from philips, i can email to u if you want, just let me know. :wink:

[quote:4b65ef911e="sound focus"]Dear all,

I am a Hifi Fever member that using Adhader08 as my nick name previously,
due to didn't log in to this forum for a long period until the password also has been forgot.
It's is a good news to see there are few new members join this forum and modifying the player lately.
Since the circuit no so reliable but modification or upgrade is a must. my personal advice is first to upgrade the tube and Op-Amp. WE, Tungsol and Bendix are the only tubes which acceptable. WE having the outstanding performance among them, WE giving me a very comfort level of listening, live like music...........

Enjoy. Wink Wink Wink Wink[/quote]

Welcome back, Brother =D>

Hi alfcat and superwhite,

Thank you for your advise.

Alfcat, don't give up to diy. this just a experience on diy.
your cd-33 can work as transport with external DAC.
Alfcat thank you for you some doides. I will report the result of changing diodes.

thank you for sharing.

Dear Viewer,

I won't give up DIY; but still I need to learn the lesson --- don't rush myself and be more careful when doing DIY. I should never take things for granted and don't be over-confident with myself ... ha..ha..

I think a safe bet for the BIG diodes is to use the PBYR 1060. KK Ho got quite some of them. He said he also got 80100 and others.

hi, superwhite,
I want to replace the diodes of cd-33, and
I would like to request you that what reading of the diodes of the cd-33 in white are?????? there have 13 diodes.
which show in the your photo is enclosed.


thanks.

Dear Viewer,

I got more of those PHBYV96E. If you need more, just tell me.

The SONY CD Heads are also ready. The person in China will mail them down to me next Tues or so. Very reasonably priced for the whole transport mechanism. He said it is not "re-cycled" ones but I haven't got the chance to open a package and check.

Will ring you up after the CD Heads arrived.

Dear Viewer,

I got a call from the seller. They won't be able to deliver the SONY heads because of the Golden Week. The courier won't be working until earliest Thurs.

Will probably arrive on Friday. Call you by then.

ALFCAT,


OK . NO PROBLEM.

THANKS.

Hi Viewer,

Sorry for my late reply. the diodes is philips BYV96E. :wink:

Dear Viewer,

I think the PBYR 1060 should be 10A (Philips brand). I am not too familiar with those DATA SHEET but it says there its Average Rectified Forward Current is 10A. The one from the shop you wrote me carries a different brand.

Hi alfcat,
i have upgraded all diodes to philips PBYR 1060 and philips BYV96E.

sound become more clear and detail very much. anyway is very great for all ranges.
if close the eye to listen, its sound like HI End cdp.

My cat also stand in front of the speaker to listen the sound, he is very enjoy.

photo will be posted later.
i am waiting your call to collect the sony 213Q CD Head with diver.


thanks for sharing

hi alfcat

photo cd-33

Hi Guys,

I'm new to this site and have been reading the various CD33 threads with interest.
Please be careful what type of op-amp you try in this cdp,  some of the fast high bandwidth types are not stable in the circuit without additional modification and may suffer oscillation causing the op-amp to overheat.
The decoupling layout is quite poor in these cdp's, theres no local decoupling capacitors close to the op-amps pins etc.

I'm going to try bypassing the op-amp same as forum member h3d.

Uk member Pinkfloyd kindly gave me his CD33, he started a few mods including replacing the 1N4007 diodes with UF4007's,  replaced the pair of 0.22uf caps after the op-amp to 2.2uf Epcos films and a few other capacitor changes.
Mods I have done so far is replace the heater supply diodes to 1N5820 and  the 4700uf 16v smoothing cap before the regulator to a Panasonic FA.
I have replaced the dacs decoupling caps and dac bias cap to Rubycon ZA,  the XO clock has been upgraded to a low noise super regged type run from a separate mini psu
kk_ho's mod of replacing the 75v zener in the psu to 100v

Dear t.

Welcome to the forum. Thanks for sharing your findings. It is always good to see people like you around to teach me more as I am a complete amatuer in electronics.

It will be nice if you can send us photos of different sections of your
CD 33. I can see that you have a new clock, something seems to be a power supply on the left ... but the photo is a bit too small for the purpose.

As Hi Fi Fever only allows photos of 1M or so .... I think you have to do several ones. Really appreciate if you could do that for us.

Cheers

CAT

Hi t,

u replace the 75V zener with 100v changing the value of other resistor & capacitor at power section right? when u increase from 75V to 100V, the current also increase, you won't find your resistor is very hot??

actually what the chatode & plate resistor in cd33?

ss

Hi Guys,

I'll try and post some more closer pictures later,  nothing much to see though really. Also I have only had this CDP for a few days so not had much time to try everything yet :wink:
yesterday I bypassed the op-amp,  the sound is much better in my opinion,  I did the same as posted here by h3d (thanks h3d)  http://www.hififever.com/forum/viewtopic.php?t=952&postdays=0&postorder=asc&start=250
it shows a diagram of the original circuit at the top and modified at the bottom,  notice the resistor changes too for the tubes

The details for the Zener mod are here, http://www.hififever.com/forum/viewtopic.php?t=1332   kk_ho  is correct regarding the roll off,  this mod improves High freguency  (thanks kk_ho)
I changed the pair of 100v capacitors to higher voltage types

Next I'm going to remove all the op-amps supply because its no longer used,  I'm also going to remove the dacs regulation circuit and replace with a better low noise ALW super regulation

hi alfcat hing,

yesterday i buy a cayin cdt-15a in 2nd hand market,
the photo is enclosed for your easy reference and sharing.

I will upgrade it later.

thanks.

hi alfcat,

this web site for cayin cdt-15a for your reference.


http://www.my-hiend.idv.tw/machine/cdt15a/cdt15a.htm


thanks.

Dear t.,

Your photos are bit too small. Hi Fi Fever allows photos up to 1M. You can trim them until they are close to 1M. As I am an amatuer, I would really like to see more details so that I can learn from you.

You mentioned the Zener. Can you HighLight them to me where they are located?

Your clock seems to be an interesting one too. You got it in UK or ...

Your help is highly appreciated.

Dear Viewer,

Finally my CD 33 is back to normal. I just replaced all the Jensens and the Nichicon back. Haven't touch the diodes yet. Also, almost forgot, add the clock back as well.

The CDT-15a seems to be a nice machine. It got 3 different sets of outputs and the materials used are far better than the CD 33. I think it must be expensive in the first place .....

So are you going to MOD it in the near future?

hi alfcat,

i am leak of money now, so I must earn money first.
the brand new cdt-15a is around HK$4,300.
its sound is better than cd88 if  no modification.
i suggect you to buy one in 2nd hand market, because no china's cdp
like it now.
thanks.

I have modded a Cayin CDT-17a,   its not my cdp but I modded it for a friend,  the sound is quite good
I fitted Burson discrete op-amps and low noise Clock circuit,  tubes was changed to Mullard ECC88

Are these any better Alfcat :wink:

Clock circuit etc

I don't have a picture of the bypassed op-amp yet but heres a picture with notes, only do these mods if you are confident

Heres the PSU showing Zener and a few other bits,  I have a lot more planned to do on this cdp,  I'll add more when I have the time

Dear t.,

Thanks for the photos. Now it is very clear for me what you are referring to. I have similar modifications with my CD 33. I think I posted the photos in another thread.

http://www.hififever.com/forum/viewtopic.php?t=1619&sid=d85768dc9df9825a1f5585aaa527bf7d

Sorry, I forgot to post the relevant photo.

You are station in UK? Your clock is an interesting one. It uses DC instead of AC?

CAT

Hi Cat,

Yes I live in the UK, this is the only forum I've found that has a modding thread for the CD33.

The clocks supply is DC, I fitted a rectifier and smoothing cap on the same bit of vero board for the small transformer.
The PFM XO low noise regulator is very good!  

I have two diy dacs I use as a reference
http://pic20.picturetrail.com/VOL1293/4634025/12749957/271121637.jpg
http://pic20.picturetrail.com/VOL1293/4634025/12749957/225303858.jpg
http://pic20.picturetrail.com/VOL1293/4634025/12749957/245458821.jpg

Dear t.,

I followed your link to the Regulator page ... but I have some difficulties understanding it.  The thing comes as a DIY project? So how can we order the parts? I was in kind of hurry today when I visited the link and as I can't get much out of it, I lost my patience.

You can take a look at the last photo I posted. I changed all the large caps in the PS part to Black Gate already. That is how I boosted the S/N ratio from 65db to 75db or so.

I haven't got any Zener at home. Viewer had promised to send me one tomorrow to try out.

All the original caps I used in the wrecked PCB are now in their original places. However, I realised that my CD33 is not performing as good as it used to be. Really strange and disappointing.

BTW, is that your cat you are using as the avatar?

HI, t.,

i buy a zener in4764a 100v 1w today.
the data sheet is enclosed for your reference.
can i use this replace the 75v zener of cd33's power supply part.

many thanks.

[quote:4e901741be="alfcat"]Dear t.,

I followed your link to the Regulator page ... but I have some difficulties understanding it.  The thing comes as a DIY project? So how can we order the parts? I was in kind of hurry today when I visited the link and as I can't get much out of it, I lost my patience.

You can take a look at the last photo I posted. I changed all the large caps in the PS part to Black Gate already. That is how I boosted the S/N ratio from 65db to 75db or so.

I haven't got any Zener at home. Viewer had promised to send me one tomorrow to try out.

All the original caps I used in the wrecked PCB are now in their original places. However, I realised that my CD33 is not performing as good as it used to be. Really strange and disappointing.

BTW, is that your cat you are using as the avatar?[/quote]

Hi Cat,

Yes, the Flea regulator is a diy type, I ordered all the parts for mine from Farnell.
Now the CD33 op-amp stage has been bypassed its psu regulator circuit is not needed so I may try removing the 15v regs and run the clock circuit from there, I'll post pictures once I've tried it.

You will notice I do not use Blackgate caps, the reason being I do not like them, they sound too Euphonic/fake  to my ears,   I've tried all the grades from standard to NX Hi-Q,  even after weeks of burn in they are not to my taste.
If you improve the regulation etc that will give far better results than BG caps  :wink:   

Give your CD33 a few days to run in, it should improve,  did you apply lots of heat using your soldering iron when you replaced the capacitors?
Capacitors internal chemicals can change when the legs are heated, it can take a while for them to settle down.
Also be careful with using lots of Sanyo Oscon capacitors, their ultra low esr can make the output of regulators go unstable causing oscillation

BTW yes, that is my cat in the Avatar

[quote:aed370592b="viewer"]HI, t.,

i buy a zener in4764a 100v 1w today.
the data sheet is enclosed for your reference.
can i use this replace the 75v zener of cd33's power supply part.

many thanks.[/quote]

Those should be ok,  measure the voltage going to the pair of 100v rubycon ZL capacitors, make sure the voltage across these caps does not exceed their rating,   mine measured 97v,  a little under the max rating,  notice the tolerance  in the Zeners datasheet states they can range from 95v to 105v .

Please be careful,  remember we are dealing with highish voltage :wink:

Dear Cat,

let your player warm up for ~30hr then only proceed for other action.....all the circuit in your new board is not run in yet. So it is like a new player now....

Dear WINDWSS,

That is why I feel strange. If I use back the Chinese Tubes + OPA2604, the S/N ratio is close to 90db!!

It is only with the Bendix Tubes or Chinese Tubes + OPA627AM the S/N ratio dropped.

OPA627 is NOT suitable to be used in the CD33 without modification, the op-amp decoupling is not good,  have you looked at the supply rails on a scope when using OPA627?  

I've now fitted a VBE modified ALW super regulator to supply the dac.
Op-amp and op-amp regulation removed

No wonder when i plug the 627 in the CD player, i actually can't heard much imporvement compare to plug into my amp.

Anyway i'm now using AD825....it suit my taste as i found 627AP's bass is fat is not so control compare AD825 and also not as detail as AD825 in my system.

Hi T,

How the epcos cap sound characteristic compare to Vishay mkp & BC mkp??

the yellow colour film cap you use is what brand?

ss

CAT SIR,

can do me a favour? since u had change zener to 100V, your anode voltage of the tube should be about 100v now, can use measure the chatode & grid voltage when CD is not playing? is it ~45v??

if not mistaken when anode voltage is ~75v, the cathode voltage ~26-28v.


Dear KK sir,

from your experience for 2c51/6n3 tube what the best voltage different between anode & cathode? 50v?

Dear WINDWSS,

I don't mind doing you a favour but you have to do me one first .... WHERE do I measure those? Ha..ha.. I am not an expert like you guys.  :

If you please, take a close up photo and mark the position where I should measure the Voltage. I can then give you the results.  

CAT

[quote:524276e859="WINDWSS"]Hi T,

How the epcos cap sound characteristic compare to Vishay mkp & BC mkp??

the yellow colour film cap you use is what brand?

ss[/quote]

Hi WINDWSS,

I also like Vishay mkp and BC mkp caps too,  the guy who owned the Cd33 before me fitted the 2.2uf Epcos,  I feel these are good caps so will keep them.
I did compare them against Audionote copper PIO, Auricap.   I liked the Epcos better,  just my opinion though :wink:   

Those yellow capacitors are 10uf Arcotronic MKP C.4G ,  these was the only type I had in my spares box in 10uf

I now have a favour to ask you guys   I still have the original 6N3 tubes fitted, has anybody tried those Russian 2C51 or 6N3P-E?  I will change the tubes after most of the mods for the electronics and was wondering what types make a worthwhile sound upgrade over the Chinese 6N3's

You guys should try bypassing the op-amp,  it saves having to worry about  what op-amps to use

Dear Cat,

Refer the attachedment, pin 2&8 is the cathode, pin 3&7 is the grid, 1&9 is the filament, pin 4&6 is the anode.

So you just put 1 probe on the ground and 1 probe on either pi which you which to test.

e.g: if you put 1 probe on the ground, another probe on the pin 6, u r measuring the one of your anode voltage, if you put the probe on pin 4 you are measure another anode voltage.

Hi T,

i did post some tetsing on the tube but not include rusia tube, anyway in mandarin.

Hi T,

Here's some brief info on the 6N3/2C51/5670 tube which i had try in my system. (Bada 6N3 CDP, audiolab 8000A (mod with BG cap & jensen big tank, AE AEGIS1 speaker (mod with vishay mkp &mkt + damping)

Tube tested:
1) Eclipse pioneer 2c51 (later known as bendix) - neutral, good detail & good bass - suit instrument lover. suit bookshelf speaker who need more bass. sound not as fast/crispy as tungsol.

2) Bendix 2c51 - characteristic similar as clipse pioneer but more dull/dark, slightly less musical & detail

3) Tungsol 2c51- very good detail & cripspy at HF & MID but bass is slightly less
4) WE 396A - more emphasis on mid (vocal), very musical, suit vocal lover but may not suit instrument lover like me

5) GE5670 - Soft, less detail, nice sweet vocal - suit vocal lover too but less detail than 396A

6) united electronic - dark, not musical...can't impress me so far...
5) GE 5670

Dear WINDWSS,

You mentioned about a "probe". Is it something that looks like a "hook"? I just have a very cheap multi-meter and it comes with two pins only. Can I use those? Will it be a bit dangerous if I just use those?

I have to make something clear first before I can go ahead and check the voltage for you. I need to turn the CD 33 on but no need to play any CD, right? But then do I have to remove the vacuum tubes from their sockets?

Please advise this amatuer. Thanks.

CAT

good questions.

[quote:6f822bafd0="WINDWSS"]Hi T,

Here's some brief info on the 6N3/2C51/5670 tube which i had try in my system. (Bada 6N3 CDP, audiolab 8000A (mod with BG cap & jensen big tank, AE AEGIS1 speaker (mod with vishay mkp &mkt + damping)

Tube tested:
1) Eclipse pioneer 2c51 (later known as bendix) - neutral, good detail & good bass - suit instrument lover. suit bookshelf speaker who need more bass. sound not as fast/crispy as tungsol.

2) Bendix 2c51 - characteristic similar as clipse pioneer but more dull/dark, slightly less musical & detail

3) Tungsol 2c51- very good detail & cripspy at HF & MID but bass is slightly less
4) WE 396A - more emphasis on mid (vocal), very musical, suit vocal lover but may not suit instrument lover like me

5) GE5670 - Soft, less detail, nice sweet vocal - suit vocal lover too but less detail than 396A

6) united electronic - dark, not musical...can't impress me so far...
5) GE 5670[/quote]

Thank you WINDWSS, thats a big help 8)   
Nice write up too

[quote:6bd60c2e58="alfcat"]Dear WINDWSS,

You mentioned about a "probe". Is it something that looks like a "hook"? I just have a very cheap multi-meter and it comes with two pins only. Can I use those? Will it be a bit dangerous if I just use those?

I have to make something clear first before I can go ahead and check the voltage for you. I need to turn the CD 33 on but no need to play any CD, right? But then do I have to remove the vacuum tubes from their sockets?

Please advise this amatuer. Thanks.

CAT[/quote]

Yes,  all you need to do is measure the voltage across those pins using your multimeter,  your cheap multimeter is fine.
Your probes/hook  should have a plastic handle which you hold, one black and one red?
use the black one going to a ground connection  and the red one to each of those pins,  simply write down what each of those pins measure.
Set your multimeter to read DC

Hi WINDWSS,

My voltages are below with 100v zener,  remember there is dropper resistors on the Anode supply before the Anode pins, I also have adjusted the resistor on cathodes because the op-amps have been bypassed

Grid 8.5v
Cathode 10.3v
Anodes 54v
filament 5.8v

Dear Cat & viewer,

T is right, just place the black pin on the ground, & red pin on the the place u need to make measurement.

No need remove vacum tube, your red pin from multimeter just touch at the 9pin socket's lead on the pcb.

Dear T,
then your CD33 circuit is a lot diferent from my BADA HD21. wehen my voltatge at zener =100v, my anode is the same =100v, grid & cothode will increase to ~45+.

ur cd33 is using 2 tube, is they use 1 tube for 1 channel?
my bada using only 1 tube (use for 2 channel)

when it zener =75v, gtid & cathode~28+v,

so the differential voltage is ~ 54-10.3 = 43.7v

my different voltage is ~47V