CS4397 dac

janos, the reason why you say your dac might be harsh sounding is that it may be running on a AC power supply...my experience of batteries is that they "soften" or take the harsh edge of everything....I have another dac not so heavily modded and I have no experience of listening fatigue at all, in fact I have a very hard job getting away from the hifi .I am even now looking at how to run a cd player of battery, it is not impractical if you use one with a large amp hour...If you connect a 6volt battery to the dac tho watch out for your sepc oscons they will be rated to 6volt ,most probably, and a new battery gives 6.5v...use a touch bulb to drain the battery down a little

Check please 1st: Is the original 5 V input of the board disconnected? If yes, give a +5 V input to the 7 pins inlet (pin is labeled, situated inside a white framed part which is close to the opt/sb/koax).

Also, check the R24 resistor (it is close to the optical inlet). You should see +5 V at the resistor (at the end closest to the label U3). Could sbody provide me please a full schematic of the board, where the parts are clearly labelled/seen?

janos I have tried to add the schematic to the post but its not having any of it,,,,google "lampizator lampucera" then scroll down the page ...but I am sure the diagram is not correct....check your mail as well

there is 5 volts at r24 and yes pin 7 on the power connector strip has 5volts

I have been comparing the working dac board to the one that has gone wrong....I think the receiver chip is malfunctioning....i have checked until i am blue in the face for silly mistakes but can find none....however the working dac has 1.65v dc on pins 10,11,12 of the 4397 chip...the silent board has 3.3 volts on 12 and 0.0v on 10 and 11......these receive data from the reciever chip so unless it has something to do with the mute or reset functions...the receiver chip must be blown.....luckily they are cheap on ebay not so true for the dac chip.....so I await the post

on my working dac it is impossible for me to measure the voltage on the "mute" pin 15 of the cs4397 chip....the silent dac reads 4v dc.....is this too low?Could anyone take a reading on theirs' ? I am sure the problem is in this area I have been really clean and tidy modding the board there is no reason for anything to be damaged....its got to be something not set up right

Hi all, I am inspired by this thread. Having recently come out of the closet and declared myself a tweaker (is there a better descriptor) and not just a builder of kits I am embarking on a lampucera based stand alone DAC. I am also perversely attracted to tubes and can see no harm in Lampization of this unit instead of usual opamp. I have not seen much discussion of this in this thread though and have not spotted it elsewhere.

I would like to replicate the boxed version here:

http://tapa.tk/mu/51818184-7ad8-ada1.jpg

So far I have ordered lampucera (on the fabled slow boat from china) and bits for basic board mod sans opamp. I now want to get rest of build list together and ordered for a bodger session in coming weeks.

The schematic on the site (http://www.lampizator.eu/LAMPIZATOR/LAMPUCERA/CD DAC Lampucera lampizator.html)
shows a single tube whereas the final boxed version is clearly two tubes.

http://tapa.tk/mu/51818184-7bc6-2648.jpg

I am not sufficiently confident to work out what he has done here although I am wondering if the dual tube version is balanced, if so how does the wiring differ. Thoughts and guidance on this appreciated.

Has anyone else ventured down this route? As I said I do love my valves and am keen to bolt a couple in here....

Oh and while I am on does anyone know of a good source of nice chassis? Thanks

I have seen pics recently of someone in the UK who has done this mod, but at the moment I can't remember where it was!

I have one of these Dacs, but have not done this mod (yet!)

Rob.

I was mistaken it was a Lampizated Beresford 7510

http://www.theartofsound.net/forum/s...ght=Lampizator

Thanks for searching for the nearly link Puffy,

revoli.

That's ok mate

Puffin.

http://www.diyaudio.com/forums/group...ional-pcb.html

http://i73.photobucket.com/albums/i2.../Tubizator.jpg

the board beat me...cannot figure it out....so sat some ams 1117-3.3s on some panasonic fcs and chanced adding two extra 3.3s on my first board....pin 6 on the receiver and the 3.3 voltage to the dac ...I had originally added 7 seperate supplies using LT317. I dare not mess with this board any more than that...Too early to comment on sound

Revoli...I use a srpp stage on my lampucera and I am astounded by the sound quality ...I have not ever heard any "high end" kit but I have not heard anything yet that produces sound like this...its crazy...to me its high end....its worth all the hassle....I have a quad 99 with a bursen op amp ....I have left the bursen set up in the cd player so I can compare ...the quad has a dac of the same stable as the lampucera...it cannot compete.... now I just run the sp/dif signal from the player into the lampucera....you will find you get a extremely powerful signal and big dynamics no listening fatigue :I love it

Hi,
Have been seeing many posts by leo and others. May I request Leo or anyone else to point out the most useful mods.
The ones below seem reasonable - any opinions?

Regards
vinod

Quote:

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Originally Posted by FireFly

General rules: use short leads, where high frequeny is present. Increase capacitor values for analog power supply lines, nothing very critical here.
For digital supply lines, big values are NO NO. It will "slow down" music, details will be lost, dynamic will suffer. Very low ESR is not always very good.

My mods (look to real PCB, not shematic):

C19: replace with 220-3300μF, low ESR. Bigger value is not always better, my choice is 470μF Sanyo green. Will try Panasonic FC 1000μF.
C1: leave SMD, bypass with 0.1μF MKP
C21: replace with 100-220μF. MUST be smaller value from C19. My choice is 100μF Oscon
C15: leave SMD, bypass with 0.1μF MKP
C14: (wrong marked as C41): leave SMD, bypass with 0.33μF MKP
C17: replace with 470μF Oscon
C10: leave SMD, bypass with 0.33μF MKP
C3: leave original, not worth replacing. Intended only for reset. Or replace with any value 10-220μF. No effect on sound.
C18: important, replace with your best cap, BG or Oscon or....., value 150-220μF. My choice is 220μF Oscon
C11: leave SMD, bypass with 0.33μF MKP
C2: replace with 100μF Oscon
C5: leave SMD, bypass with 0.33μF MKP
C20: replace with 470μF Oscon
C13: leave SMD, bypass with 0.33μF MKP

Next 5 capacitors have big impact on sound

C9: very important. Capacitor MUST have small dimensions & very short leads & very low ESR & low inductance. Use your best MKP 0.1μF or ceramic, value 10nF-100nF. Big lytic, tantalum or polyester is NO NO, sonic spectrum will be distorted, unbalanced. My choice is small ceramic 100nF (0.1μF), glued & sealed with big drop of hot melt glue or wax, to prevent microphonic effect. This is negative side of ceramic capacitor.
MKP's have no microphonic effect, but they pick up high frequency noise from receiver chip CS8416 and will remove upper part of sonic spectrum (some of high frequency will be lost & bass will have some kind of boombox effect, not very precise). Leave SMD, use ceramic or MKP as bypass (see text above).

C25, C16: very important. C25 is connected to pin FILT- and C16 is connected to pin FILT+.
Please look to datasheet
[IMG]http://shrani.si/f/2e/Ff/4jXHB5xE/dacafter5.jpg[/IMG]

C25: replace with 10μF-47μF. Bigger value=better ripple rejection, but you will loose high frequeny details & dynamic. Sound will be some kind of "slowed down"& unsharp. If you increase C25 value, you should decrease C16 value, they are correlated. It is very very difficult to find balance.
Without C25, transparency is the best, with very good details, but also bright & kind of harsh on highs.
My choice is 10-22μF, if C16 is 100μF.

C16: replace with 100-220μF. Bigger value=better ripple rejection, but you will loose high frequeny details & dynamic. Sound will be some kind of "slowed down". Same as for C25, but even bigger impact on sound. Bigger capacitor= bigger boombox:confused: My choice is 100μF, if C25 is 10-22μF.

I like open transparent system with good highs and open vocals and my bass speakers are very good in bass range (3 x bass driver). For tube amp with less bass, try to slightly increase C26 and C16. Please experiment by yourself & choose visely :lolsign:

C12: C12 is bypass for C25. Leave SMD, bypass with 47nF (0.047μF) MKP. Tantalum or lytic is NO NO, please no big value, it will add to capacitance of C25 and change performance.

C8: C8 is bypass for C16. Leave SMD, bypass with 47nF (0.047μF) MKP. Tantalum or lytic is NO NO, please no big value, it will add to capacitance of C16 and change performance.

Op-amp mods (already described before by Leo)

R8, R9, R14, R17: replace with 30K matched resistors, to remove DC on op-amp pin 1 and 7.
C32, C33, C34, C35: replace with 100-220pF polystyrene (styroflex) capacitors. It is tricky here to find right balance :)
C32, C33: 100pf = great details, but bright sound. 220 pf = less details, muffled sound. My choice is 180pF.
C34, C35: replace with 100pF

C27, C28, C30, C31: remove capacitors and bypass pins with wire (already described before)
C6, C54: remove capacitors and bypass pins with wire (already described before)

Another trick: If you like vocals, please try to add some capacitance to C36 and C38. Leave SMD, bypass with 220pF-560pF polystyrene (styroflex) capacitor. My choice is 440pF (2x220pF in parallel) :eyebrows:

With these mods, DAC will sound very analitic, with very good bass and highs, exceptionaly good mids, very musical, a lot od details. Maybe a little on bright side.

Some info on caps:

http://shrani.si/f/3E/wQ/1QvwKk0J/capac.jpg



Happy modding & sorry for my English, it is not my native language

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Hi Vinod,

Its been a long time since I've touched this dac, I've tried a lot of things since then so my memory is a little rusty. If its the small dac board same as in the first post of the thread I'd sort the outdated PLL filter out on the CS8416 and then sort the messed up output section, I just altered a few values to clean things up C32,C33,C34,C35 and R8,R9,R14,R17 (details in first post) or you can try this way as posted by Anders http://theartofsound.net/forum/showp...&postcount=424
Change spdif input coupling cap (think its C9 from memory ) to a 0.1uf MKP1837 . Should get you started :)

Thanks Leo. Will try. The board is probably quite old but this is my first try on DACs. Doesnt sound bad as is.
Question on the mods. I assume the components to be changed are the ones as seen on the pcb?
There are a few schematics floating around specially on lampiztor site but does not really match the pcb I think

Rgds
Vinod

Hi,

The DAC is finally working. Did most of the suggested mods. Removing the C32,33 made a big diff I think.
There is a small problem - getting some odd sounds now and then. Maybe related to a repair I had to do on the Left side cap bypass - the pads went while soldering and had to use a small piece of wire to connect the DAC chip output directly to the opamp.

Anways, Iam not sure if this can be a long time investment. May try the buffalo DAC next.

Thanks to Leo and Firefly..

Rgds
Vinod

Hi Vinod,

If you run a wire from the dacs output to the op-amps input for the left channel you'll be missing out parts of the filter in the output stage, if the filter is still in circuit for the right side it'll sound odd .

Leo,

My statement was not quite right. I took the output of the DAC and connected it to the pad with the resistor leading into opamp.
I think the odd ticks I hear every 30 mins maybe oscillations. May need to put in the 150pf cap. I removed c32,33,34,35. The mods I did included
changing resistors to 30K, removing the caps leading into opamp and out of it.
Also put in 1500 and 100uf for c19 and 21. Iam using toslink now.
I may put in the new values for the PLL.

Sounds good enough now so not sure if these mods will be value add.

Regards
Vinod