[Gimbal]

Hi, this is impressive, read the hole thread and are about to do no one upgrade, Q: what about voltage? can i go higher with a bigger transformer ?, the TDA7294 accept 40V+-
KR Anders

 

[ramachandra]

You need to keep an eye on the heat what the TDA Amps will produce, and there are few other tings to worry too. Like the increase of the heat on the +18 -18V regulators. According the the datasheet of the TS79M18 the maximum input voltage is 35V so it is not vise to exceed. I do not know how much more current the SMD resistors can take on the panel, probably the ceramic caps are rated to 63V. Because the original speakers sometimes fail with the unmodified system I have a bad feeling what will happen when you try to pump more Watts out of them.

 

[DaddioJ]

  I do not know for sure. My first guess is the positions of the cables. There are people with the same or similar similar experience and happen after a period of time so I have the reason to think it is  related to the aging electrolytic capacitors. Probably you are about to recap the system anyway, and for our benefit please let us know if it worked.

 
all done with the 2nd unit. All Nichicon KW series Every Cap. and all OP amps Changed. sounds Amazing!   but Popping is still very Present. only when its connected from something. say a TV. via optical and so it the HuM, when off and switch on.  even without the Sub Connected. and turned on. still Hums
 
P.S.
 
it seems i have a "Singing" transformer . i should have kept the extra one i had. Damnit

 

[XenonMB]

Hi,
 
i came upon your thread after searching online for a cure for the "humming" problem many people have after prolonged use of their z5500s.
First off all, awesome guide and thanks so much for it. I orderes the 10000uF and 4700uF for my z5500 and today i opened it up and removed the old ones but i saw what had previously been out of my sight due to the old 10ks being in the way.
 
http://imgur.com/DBcuqJP
 
i soldered the new caps in just to try and see, but as expected the same humming is still present so i guess this burnt c27 is the problem. can i replace it? what exactly should i get as replacement if possible? i can't tell the rating/uF, does anybody know?
 
Thanks in advance for the help and thanks again for the great guide

 

[ramachandra]

My guess list:
 
First you need to get rid of the burnt cap to make sure no short circuit present, ceramics tend to fail in short. Maybe that is all you need.
 
Recheck the new solder joints, or even scrape off the green film from the copper tracks around the pins and extend the area of soldering. Oxidation cause bad solder joint sometimes.
 
Get 0.1uF X7R or MP0/C0G ceramic or film capacitor minimum 63V for replacement. (Somehow I think this is not the solution if the humm is present, because this small caps are there to filter out high frequency noises)
 
Check the bridge rectifier.
 
Another but low possibility is the capacitors around the two 18V regulators, if they are getting close to retirement the noise of the regulators filtered out poorly, and have an effect on all the OpAmps in the system. 
 
The source of the humming is important, because if it coming from all the speakers your system have a problem with power supply probably, or if it coming from the Sub or other speaker(s) alone that will narrow down the choices.
 
(look like the question I have answered have been deleted meanwhile)

 

[DaddioJ]

  My guess list:
 
First you need to get rid of the burnt cap to make sure no short circuit present, ceramics tend to fail in short. Maybe that is all you need.
 
Recheck the new solder joints, or even scrape off the green film from the copper tracks around the pins and extend the area of soldering. Oxidation cause bad solder joint sometimes.
 
Get 0.1uF X7R or MP0/C0G ceramic or film capacitor minimum 63V for replacement. (Somehow I think this is not the solution if the humm is present, because this small caps are there to filter out high frequency noises)
 
Check the bridge rectifier.
 
Another but low possibility is the capacitors around the two 18V regulators, if they are getting close to retirement the noise of the regulators filtered out poorly, and have an effect on all the OpAmps in the system. 
 
The source of the humming is important, because if it coming from all the speakers your system have a problem with power supply probably, or if it coming from the Sub or other speaker(s) alone that will narrow down the choices.
 
(look like the question I have answered have been deleted meanwhile)

the humming I have is from the sub alone. if I remove the Coil. no more hum. I tried to isolate with rubber but still seems to want to hum. only replacement might be the cure. for a better quality coil. also is it possible for the coil humming connected with pop when using fans or lights?

 

[ramachandra]

The core of the transformers usually made from sheets of iron to eliminate certain problems of the solid core. The core of the toroid transformer in the Z-5500 supposed look like a big rolled up spring just as on the image.
 

 
Normally it is kept together really tight and if it get lose this is what happen: https://www.youtube.com/watch?v=lUt8rE9tYo0 There are people who can make and repair transformers, and if you are lucky enough there is somebody close to your are to fix it. I do not know the pops, look like some sort of ground problem to me.

 

[XenonMB]

my humming is coming from all the speakers and is unaffected by the volume control on the pod. that's why i concluded its the filter caps (10k and 4.7k). Pretty much all the posts and advice i read online said thats the symptoms for those failing or being defective. i got mundorf MLytic 10k and 4.7k 63V as replacement. they have a pretty good reputation here, but as i said the humming is exactly the same as before so i'm not sure whats causing it, and the burnt cap is all i could see so far that is obviously defect

 

[scratje]

Hello All,
 
I want to introduce myself to this community.
 
I'm new here but follow this thread for over one year now with deep respect to Ramachandra for your very nice and detailed thread.
I own a Z5500 system since 2005 with great pleasure but want it to be more hifi audio, since i only use it for music and watching 5.1 movies in combination with a vintage pioneer A91D stereo amp and this is a truly high-grade amplifier.
 
I am not totally new to soldering ic's, recapping and upgrading (i did it to my A91D) so last sunday i decided to go for the first and second mod.
 
First i tried to order from Mouser (their Dutch branch) but they charge €40 for shipping below a total order of €150. (the distance between them and my home is less than 70km!!)
After some searching i found Digikey in the States and they charge no shipping costs to the Netherlands above $100, so i orderd all of my Silmic 2 (lots of spare ones)  and opa 1612AID from them, which will arirve tomorrow so that's really really fast.
The 2 Elna for Denon 10000uf 50V and  Nichicon KG Super Through TYPEIII 4700uf 50V will ship from China and are expected to arrive within a month but In the meantime i can start with the control pod and see(hear) if all has gone well.
 
For now i'm very excited to begin modding, so wish me luck an i will keep you all posted  

 

 

[scratje]

Today i received all the components from DigiKey and started right away with desoldering the opamps from the control pod.
For desoldering i used desolder wick en after that i reheated each pin seperately and gently lifted it up wiht a needle.
I discovered that the opamps were superglued to the circuit board so removing them was a little bit tricky but they all came off without damaging the circuit board!
After that i solderd the new OPA1612AID opamps and tested the analogue outputs and digital optical input and so far so good with nice sound improvement already  

 
Tomorrow  i will start recapping wih the silmic 2 and hopefully it goes as well as the opamps!
 
 

 
 
 
 

 
 
 
 

 
 
 
 
 
 
 
Update:
 
Today i did the recapping wiht Silmic 2 in the control pod and everything is working nicely!
Sound is very good for now and next i will go for the recapping and new opamps in the sub.
For now i'm very statisfied

 
 

 
 
 

 
 
 
 
 

 

[scratje]

Ramachandra, one question for you please.
I noticed that in the list of capacitors, you mention 2 pcs 10uF 16V for the volume control but in the image you mention 2 pcs Elna Silmic 2 - 22uf 16v.
I soldered 2 pcs 22uf 16v and all is working fine so can it do any harm?
 

 
 
 
 
Today i started with the sub and just like member X172, i too have a different version with a seperate circuit board for the opamps.
I changed the opamps and all capacitors on this board and tested the sub with great result and a big inprovement to the sound!
Later on i will recap the mainboard and make preparations for the Main filter capacitors which are still underway.
 
 
 
Pics from my version of the circuit board with seperate board for opamps
 

 
 

 
 
Operation succesfull

 

 

[ramachandra]

Mouser only charge 20€ from the UK to Ireland, and below 70€ no cost for shipping. Digikey, Farnell more expensive here. In Hungary maybe Farnell is the cheapest.
Sometimes I wonder why there is so few options out there to get the bigger Elna for Audio filter capacitors, or any kind of Cerafines. I bet the the DENONs only factory surplus like the Elna Kenwood, Elna Pioneer and not made for the public to purchase. We are lucky because few seller have them mostly on eBay and affordable, plus the sound is well compensate the shipping time. By the way, good to see your precise work, I'm looking forward to your updates.

 

[ramachandra]

"I soldered 2 pcs 22uf 16v and all is working fine so can it do any harm?" There is no Z5500 here around to check, but as i remember it is part of to the tone control. If there is no negative side effect on the sound no reason to worry.

 

[scratje]

  "I soldered 2 pcs 22uf 16v and all is working fine so can it do any harm?" There is no Z5500 here around to check, but as i remember it is part of to the tone control. If there is no negative side effect on the sound no reason to worry.

 
Thank you for your reply.
I have checked a pic from the original circuit board and there are two pcs of 10uf 16v on it.
 

 
 
Thank you for your compliments about my precise work so far!

 

[scratje]

Finally ready now recapping the mainboard and very pleased with the beautifull sound.
The only thing i maybe will not do is to recap the main filter caps because it is very risky to remove them without damaging the main board.
Tried to cut away the glue and used the desolder wick but they will not come loose in any way.
Perhaps it is possible to cut the caps from above and disassemble them so i can reach the connection pins inside the caps but when this does not work i will be stuck with a useless mainboard!!
If according to Ramachandra the improvement from recapping the main filters is about 15% i don't think taking the risk is wise and for now the Z5500 has a huge improvement in sound quality already.
 
Very happy with this great tutorial and deep respect for Ramachandra's work!!
 
I'm using a X-Fi extrem music card now and in the near future i will be replacing it by a Creative sound blaster ZxR, so maybe there will be more improvement in sound quality