Almi's Logitech Z-5500 Mod (High-End upgrade for the speaker system)

[ramachandra]

I think you already know what to use. If you try better then Nichicon FW the sound will be more refined. The way towards the higher grade is:  FW=> KA=> FG=> KZ
http://www.hificollective.co.uk/components/nichicon.html
The OPA1604 just need the lowest fine melting point solder you can get, and plenty of soldering paste. Good solder is a key to succeed.
This is my priority and not ultimate list to use capacitors around OpAmps from the material point. Construction, brand, function also play a significant role and may change it:
-Polystyrene film capacitors have excellent sound characteristic in general. Mostly out of production usually difficult to source.
-Silver Mica is sound cleaner then any film capacitors, but piercingly harsh if used alone, a mixture of 50% film and 50% Mica is a good ratio.
-Polypropylene KP, MKP film is great for signal path. Easy to get, a bit expensive.
-Polycarbonate KC, MKC film is hard to come by this days.
-Polyethylene Terephalate PETP. Like my favorite K73-16.
-Polyester KT, MKT, MMK, MKS film the most common film capacitors, good for PSU less attractive for applications on the signal path.
If the ceramic caps are there to filter out high frequency radio garbage, better to leave them, or try to use polystyrene or mica and see what's happen.

 

[A-Force]

i have a very big confusion on what mkp/mkt should i buy. i ve read the internet that the vishay 1837 are very good as bypass caps but on mouser the closer capacitance that is available is 0.1uf. is it ok if i order this for bypass 22uf caps on z5500? maybe you have another recomendation. also what to put in the 1uf position near regulators? and on the preamp the 0.22uf what is your recomendation? there are a lot of diffrent caps to choose from mouser and i don t know what to put where... please help. my head is going to explode with so many datasheets i ve read

 

[ramachandra]

The Vishay MKPs good caps indeed, i often get them with DAC KITs.
Film capacitors have more linear frequency response compared to the electrolytes still not perfect, and as the capacitance of the capacitors increase the ability to transmit the higher frequencies is usually suffer, and building something up from multiple caps is usually result more transparent sound, or bypassing the big cap with smaller cap(s) help the higher frequencies. I can not dig up a good chart at the moment to explain how capacitance and frequencies related. So basically the 0.1uF will work, just don't let pass as much from the lower frequencies as the 0.22uF. If you want more you can add for example 0.68uF or between. The point is to not change the original value significantly and something is better then nothing. Under 0.01uF the benefit is arguable in this position.
 
"also what to put in the 1uf position near regulators?" Nothing special, use any good brand MKT cap you can get.
 
"and on the preamp the 0.22uf what is your recomendation?" For the Zobel network there are so many to chose from. Try any good brand MKT or better MKP axial film, or K73-16. If you looking for something special the 160V K42Y-2 PIO is working like a crap filter, really make bad recordings enjoyable, but not the best for bass.
 
Here you can find how other people rate film caps on the signal path by listening, i put this list here for everybody who want to try something else then my recommendation, or looking for something fancy 0.47uF caps to do the "Third mod":
http://www.humblehomemadehifi.com/Cap.html
http://www.enjoythemusic.com/diy/0411/capacitor1.htm
http://www.head-fi.org/t/284863/orgy-of-capacitors-the-cap-thread
http://jimmyauw.com/tag/jensen/

 

[MasterCATZ]

http://s16.postimg.org/65in4mcb9/CAM00012.jpg
 
what would I check to find the cause of the tda7294 blowing
 
for ages my z5500 were making crackling / popping noises so i decided to have a peak inside to see if any caps looked sus , I did not notice anything, During this I have PC's volume down low and the speakers on boost to try and heat soak it  , for some reason the noise was not being made ..
 
after 30 mins i gave up flipped the power switch and reassembled the back plate with 4x screws and then turned the mains back on , the SUB / speakers were making a large humm sound and it blew before I got to switch the power back off , I am unsure what the hell I could have possibly have done as I made no changes to it at all
 
one possibility it could have had something to do with not turning them off before killing the  power  and some state of chip was wrong when I provided mains power back to it ? I am unsure what the controller was doing at the time no idea if it switched on or was in standby mode
 
or the popping noise was from that chip and it finally gave in after heat soak ?
 
also how would one get a NON FAKE tda7294 ?
 
211784-0000-A2
Logitech Z-8 REVA2
 
*edit*
 
on another note which speaker would that tda7294 chip have handled ? sub ?
also if i removed the tda7294 would it be safe to attempt turning the system back on for testing? or would that cause more IC's to self-destruct ?

 

[A-Force]

for the bypass caps what whould you sugest? vishay 1837 0.10uf ( http://www.mouser.com/ProductDetail/Vishay-Roederstein/MKP1837410011/?qs=sGAEpiMZZMv1cc3ydrPrFx9ULflYAhdyMVWtY4Esfn0%3d )  or something like this, that is 0.22uf ( http://www.mouser.com/ProductDetail/Vishay-BC-Components/BFC241642204/?qs=sGAEpiMZZMv1cc3ydrPrF6b39BhxIu4vKrkO7Tq9Sd4%3d ).  is z5500 capable to work properly at a crossover 80hz without drawbacks with better speakers or the amp is designed only for 150hz??? i say this because when i set crossover to 30hz for example there is no bass from the satelites. also is there a limit in how low can the woofer go(subsonic filter in the amp) because i m thinking in replacing the woofer with 2!!! better ones in series from car audio that can go easily down to 20hz. so insead of having 2 z5500 subs, i m thinking to have 4subs 4ohms each one of them in order to get best room acoustic and better spl!! i also read that tda7294 is capable of 4ohms but is the design of the amp let us use 4ohms speakers insead of 8ohms?do you think its a good idea to make proper enclossures for car audio speakers and use them? i have this question because they are very cheap. i bought the second best, 6x9 speaker from pioneer, (5 way speaker 450w peak, 90rms that goes down to 35hz) in a street price and they are truly awsome, but in home cinema speakers, the price for something similar is waaaay higher. i guess you pay the sound signature :-/ 

 

[ramachandra]

MasterCATZ
 
I do not know what went wrong. The chance for the TDA to blow straight after you opened up the Z5500 by coincidence is low, i believe.
If you want to fix it yourself you have no choice just turn it on after careful checking. First try it for 1 or 2 second and listen, and and hope nothing else blow up and no funny sound.
For genuine TDA try Mouser, probably Farnell and Digikey just as fine too. Judging according to the color of the wire the Front Left got the damage, if all same in the older version.
 
A-Force
 
Get the 0.22uF Vishay MKP.
The TDAs can do 20Hz and I'm not familiar with the limits set in the pod, or the existence of subsonic filter in the amp.
Instead of 4 Sub maybe you can do better with four 3 ways speaker with a direct cable connection. The four Sub still mono and can improve only a segment of the frequencies. My relative sad with the four small two way JBL sats he have almost no need for the Sub. I'm sure if the Zobel network is properly set to the new speakers (or left out) he even can get better result.

 

[A-Force]

i guess vishay 416 is better than 1837...what is zobel network?

 

[MasterCATZ]

Thanks for the reply ,
 
how ever now thinking about it I did reconnect a speaker that might have been front right and at the time I was worried that maybe I possibly used an AV lead and not the speakers lead  downside to RCA plugs can no longer remember if it was Yellow / Red / White nut I feel the plug was towards the top area
I think the wire codes changed as I think the IC was towards the middle more
I'll take a full shot later on
 
TBH I never looked into it much further after IC blew I just ordered 2x from ebay for testing  then read about the fakes online and made the post, the IC looked like the larger of them so I thought possibly the sub or centre
 
( which are the speakers the popping sound might have been coming from its been a while since I last used the set so memory was a bit foggy )
 
I might try and fire it up tomorrow with the fried  IC removed and see what happens

 

[scratje]

Finnished!

 
My third mod of the Z5450 is now complete and working.
I did replace all the components i talked about before exept for the quad channel opamp.
Not wanting to risk damaging the very tiny solder pads because i don't have the proper solder iron for this smd work, i left this opamp for what it is.
The mod works perfect and the sound is great and allmost as good as the Z5500
I now have to weld a 25mm aluminum spacer because of the Elna for denon's hight.
 
So now i have two modded Z5500 and one modded Z5450 ..................

I will keep one Z5500 and the others are for sale so let's see what fans of modded systems will pay for them!
 
For now i'm done modding these systems and maybe i will do the Creative X-Fi extreme music soundcard mod in the near future to complete my music experience.
 
Thank you Ramachandra for this great thread and all others for contributing!
 
 

 
 
 

 
 
 

 
 
 

 
 
 

 
 
 

 

[ramachandra]

A-Force
 
"i guess vishay 416 is better than 1837" Only listening can tell that for sure, good specifications alone no guaranty.
"what is zobel network?" The 5pcs 220nF caps in series with resistor on the preamp panel is the Zobel network. The function is to protect the TDA Amps from feedback suppression. The rest is explained well on this forum: http://forum.diyspeakers.net/viewtopic.php?f=2&t=1364 For example if you want to hook up new speakers for the surround and you know enough information about them, easy to set the network to the new requirements. Online calculators are exist.
 
 
MasterCATZ
 
Maybe no harm to change the C506  just to be sure, TDA failures often linked to aging bootstrap caps.
 
 
scratje
 
Nice Job! Good to see those big DENONS on board. I was interested what is inside the Pod and tried find images, but none of them good enough to see the components. Probably very similar to the Z5500 Pod. People time to time asking me to do a mod for them, i can direct them towards you if you have the time and spirit.

"and maybe i will do the Creative X-Fi extreme music soundcard mod in the near future to complete my music experience" U will not be disappointed. +50% improvement. The risk is somewhat there to damage the SMDs by heat, but this cards are dirt cheap this days. About 22€ as i recall included shipping on eBay. Sometimes i had seen them in bulk from the US.

 

[scratje]

Thanks Ramachandra

 
First i want to point out that soldering the Denons onto the board needs a little bending of the leads to fit.
The spacing is ok but the total diameter of the Denons is a bit more than the original caps so to avoid overlapping, you have to bend the leads a little to bring them off center, one to the left and one to the right!
The leads are very thick so there is no harm bending them.
 
At first i thought the control pod had no opamps but at your request i opened it again and found out that there are also three quad channel NJM2060 in there.
The layout is different from the Z5500 control pod and i am not sure which capacitors are in the signal path.
Ik guess the 47uf 25V, 22uf 10V and 22uf 16V around the opamps and analogue inputs are the ones to replace and caps around the volume control chip JRC NJW 1150.
 
Opening the pod is easy.
First remove the foot which is fitted onto the bottom (pull it off).
After that you see six screws which need to be removed.
Than you can lift the upper side off the pod and than push the main cable in and pull the under side down to get the circuit board free.
 
 
I took the time to do a layout image of the pod so you can see what's in there...........................

 
 
Layout

 
 
 
The heat plate in the upper right corner can be removed.

 
 
 
 

 
 
 

 
 
 

 
 
 

 
 
 

 
 
 

 
 
 

 

[ramachandra]

Thank you for the good photos.
 
In the Pod of the Z5500 there are 6 OpAmp, here 3 quad doing the same job probably. Cost effective, not the audiophile way.
Same DSP, Codec, volume control, the Zilog Z8F microcontroller is new, i can not read the code on the Cirrus chips, but i guess the same too.
Interesting, the connectors are soldered manually and some other components. We had seen cleaner PCB i guess.
No SMD electrolytes so even the Codec can see some new Elnas and Os-Con on the digital part.
 
I think this Pod wanna feel the heat.

 

[scratje]

Ramachandra,
 
Here a new pic of the layout.
 
two Cirrus logic CS5351KZZ a/d converter http://datasheet.octopart.com/CS5351-KZZ-Cirrus-Logic-datasheet-55585.pdf
a Cirrus Logic CS42526CQZ 6channel codec http://datasheet.octopart.com/CS42526-CQZ-Cirrus-Logic-datasheet-53453.pdf
a Cirrus Logic CS8421CZZ 32-bit, 192 kHz Asynchronous Sample Rate Converter http://datasheet.octopart.com/CS8421-CZZ-Cirrus-Logic-datasheet-42648.pdf
 

 
I think it will not hurt to recap all the caps around these chips so i will order them

 
I found a nice webshop in the UK, HIFI Collective, and they have a lot of caps http://www.hificollective.co.uk/componentshome.html
The shipping costs to the Netherlands are low and no customs so far from the last order i have made.
 
By the way, pics showing the sub with 25mm aluminum spacer.........
 
 

 
 
 

 
 
I'll be back

 

 

[ramachandra]

So the CS5351KZZ ADC is the same.
 
The hificollective has also a good selection from the fancy film caps i have linked above. I think it is a bit expensive at the moment, thanks to the weak euro. Well, it depends on the quantities really.
 
Making thing from metal is not a challenge for you obviously, it is look like part of the original setup. I like the precisely cut corners, i do not think mine can turn out this good in the shed.

 

[A-Force]

hi i m thinking to take out the back of the woofer with the amp and make a new box for the amp only ( both amps because i have 2 z5500) and make one box for the 2 amplifiers. inside the woofer there is something else beside the speaker i think is the power tranformer. When i make the new box is there something to consider about the position of the transformer for example do i have to place it away from the amp or there is no problem to place it near by? The 2 transformers from the 2 systems is there a prob if they are one next to the other? Any advises apriciated!! Thx in advance!!