View Full Version : CS4397 dac
fordgtlover
28-10-2008, 13:25
Just noticed , Q1 emitter should go to R3
You can alter the gain by adjusting the emitter resistors on the differential pair
This circuit is based on this http://home.quicknet.nl/qn/prive/ra.vdsteen/pdfs/SACDenhancer_evo3.pdf
Thanks Leo. I've made that change.
I had intended to have a few boards made, but the Aussie dollar is in the toilet at the moment so It's quite expensive to have the boards done. I'm looking at other options at the moment.
Here is the final stereo board layout I ended up with. Board size is 50mm x 80mm
http://img224.imageshack.us/img224/9429/os31rn3.jpg
http://img224.imageshack.us/my.php?image=os31rn3.jpg
Hello FordGTlover.
May I suggest the next website for your pcb ?!
a quick price calculation was about 4 USD a pcb.
http://www.makepcb.com/
have fun ! and remember, i am interested in a board or 2 also
Naqua
Filterlab
28-10-2008, 19:10
I've just been reading through this thread, and I absolutely love the fact that we have some hardcore knowledgeable electronics engineers on here, gives the DIY section massive credibility (even if I haven't a sodding clue what you're all talking about). :lol:
I didn't expect my thread to be so popular:smoking:
Thanks Leo. I've made that change.
I had intended to have a few boards made, but the Aussie dollar is in the toilet at the moment so It's quite expensive to have the boards done. I'm looking at other options at the moment.
Here is the final stereo board layout I ended up with. Board size is 50mm x 80mm
http://img224.imageshack.us/my.php?image=os31rn3.jpg
I wouldn't pay too much, this was intended to be cheap;)
Other option is to etch your own board, you could use the layout here on page5 as its single sided http://home.quicknet.nl/qn/prive/ra.vdsteen/index_en.html
You are an electrical engineer? I am in 1st year in college planning on majoring in either mechanical or electrical... then I can understand more of the complicated things you talk about lol.
fordgtlover
29-10-2008, 08:22
Hello FordGTlover.
May I suggest the next website for your pcb ?!
a quick price calculation was about 4 USD a pcb.
http://www.makepcb.com/
have fun ! and remember, i am interested in a board or 2 also
Naqua
I just had a quick look, and it look like a great deal. I'll do a bit more poking around, but I think you may have found me a winner.
I wouldn't pay too much, this was intended to be cheap;)
Other option is to etch your own board, you could use the layout here on page5 as its single sided http://home.quicknet.nl/qn/prive/ra.vdsteen/index_en.html
I agree. I don't want to pay too much. I have never etched a board, and I suspect others are in the same boat. I wanted to give myself and others the opportunity to get the best out of this little DAC for a reasonable price. The place Naqua linked to looks very cheap. :)
StanleyB
29-10-2008, 09:27
I wanted to give myself and others the opportunity to get the best out of this little DAC for a reasonable price. The place Naqua linked to looks very cheap. :)
I have been following this thread, and you are doing a great job.
When you are finally finished, let me know how much it all cost. Then I can loan you one of my DAC to compare the two...
Stan
fordgtlover
29-10-2008, 10:41
I have been following this thread, and you are doing a great job.
When you are finally finished, let me know how much it all cost. Then I can loan you one of my DAC to compare the two...
Stan
Thanks for the words of encouragement, and the kind offer.
Cheers
Rob
On another note, I think I'll resize the board slightly to the same size as the DAC to allow it to be 'stacked' on top.:)
Filterlab
29-10-2008, 10:52
I didn't expect my thread to be so popular:smoking:
Over 19,000 views and counting. :)
I don't think it would better your dac Stan, it would be interesting though if the guy compared them
Just remember this thing is cheap and good option for those wanting to get into diy without having to spend much, I paid under 30 quid for the dac board:lol: seems the prices have gone up a bit though:doh:
So far I've kept it under 80 quid
will this work as an output cap?
http://www.parts-express.com/pe/pshowdetl.cfm?PartNumber=027-222
will this work as an output cap?
http://www.parts-express.com/pe/pshowdetl.cfm?PartNumber=027-222
I've never tried them, anything like that would be suitable, obviously you have to remember the high voltage film and foil type tend to be pretty large physically.
Try to keep bare leads as short as you can to help prevent any noise pick up with them being unshielded
Hello,
I have made the mod Leo suggested for the r8-r9-r14-r17 to 30k 1% and c32-c33-c34-c35 to 150pf.
I am measuring 5mV left and 23 mV right. I thought it would be closer to 0 mV. However i am measuring from pin 1 and pin 7 of the opamp to AG. This with the standard output-caps and r28 r29 still in the circuit. Does that explain the offset i'm measuring. (coupling caps between dac and opamp are bypassed)
If not, what can i do to kill the offset (apart from placing output caps).
Thanks in advance for eveyones help. It is a nice DAC indeed.
Here's my question. Alot of people buy capacitors to improve their sound. They replace their input caps from the amplifier with a better one. My amp has 3.3uf input caps stock. Do I have to remove those to add in the capacitor that I showed you? And what are the benefits of the input cap on the DAC?
Thank you leo
How long did it take for you guys to get your ebay dac board? Did anyone buy from the gigaworks guy?
Hi,
I ordered from gigaworks twice.
It's all good. Fast response, good packaging.
Took about a week to arrive (in the netherlands is where i live)
Naqua
Tripmaster
30-10-2008, 22:30
Not foolish, just a little too eager;)
The original values for most of the decoupling caps was 100uf, the value isn't really critical so anything around 100-220uf should be ok
BTW, first easy thing to try is swapping C25 to a 10uf or 22uf cap, it looks like you have a big Oscon there, 150uf is too big for the CMOUT pin in my opinion, thats for the dacs internal bias
If that don't help much try changing just the other oscons and tants to general purpose 100-220uf, its worth leaving those two panasonic FM/FC caps until last and see what its like without the oscons and tants, we need to find a point where you start to hear improvements and then work from there
Very nice job on the Shigaclone :smoking:
Hi Leo
I played with C25 today. I managed to find a 10 and 22uf cap in my parts bin. The 10uf cap didn't improve the bass but seemed the sharpen the sound slightly. However, the 22uf cap might have improved the bass slightly...its hard to tell. I am putting a parts order together tonight so I should have the 100uf general purpose caps in a few days.
I will report back...
Thanks for the compliment BTW :)
Richard
Hello,
I have made the mod Leo suggested for the r8-r9-r14-r17 to 30k 1% and c32-c33-c34-c35 to 150pf.
I am measuring 5mV left and 23 mV right. I thought it would be closer to 0 mV. However i am measuring from pin 1 and pin 7 of the opamp to AG. This with the standard output-caps and r28 r29 still in the circuit. Does that explain the offset i'm measuring. (coupling caps between dac and opamp are bypassed)
If not, what can i do to kill the offset (apart from placing output caps).
Thanks in advance for eveyones help. It is a nice DAC indeed.
A few things could be causing the offset
It helps to match all the resistors in the differential stage, if say the + side doesn't mirror the - side it can cause drift
If you use the supplied op-amp which I think is based on a NE5532, these are bipolar input and tend to have some dc offset on the output, you could try a jfet input stage op-amp to see if it helps
My dac measures less than 2mv's on the output, I matched all output filter resistors for the +/- output
Here's my question. Alot of people buy capacitors to improve their sound. They replace their input caps from the amplifier with a better one. My amp has 3.3uf input caps stock. Do I have to remove those to add in the capacitor that I showed you? And what are the benefits of the input cap on the DAC?
Thank you leo
yes, you remove the caps to be replaced, if you leave the old ones in the new ones are then in parallel with the old ones and it will double the value
The only cap on the dacs input is for the SPDIF input which is used for blocking DC, this is a digital signal, the standard ceramic capacitor is a bit microphonic , ideally a physically small cap should be used here which is low inductance low microphonic
You don't have to change the input spdif cap, its just a bit of fine tuning, I wouldn't use anything with a bigger than 5mm leg spacing
Hi Leo
I played with C25 today. I managed to find a 10 and 22uf cap in my parts bin. The 10uf cap didn't improve the bass but seemed the sharpen the sound slightly. However, the 22uf cap might have improved the bass slightly...its hard to tell. I am putting a parts order together tonight so I should have the 100uf general purpose caps in a few days.
I will report back...
Thanks for the compliment BTW :)
Richard
Let us know how you get on;)
I may build one of those transports later too!
Tripmaster,
Since you are playing around with the caps on CMOUT...
In the datasheet for the DAC eveluation board there's 2 resistors of 1k to cut the 5v into 2,5v and connect it to CMOUT.
In the note's it says they are for PCM modes. I suppose its because CMOUT has to be typically (according to the datasheet) at 1/2 VA.
Maybe it's something to try also ? I havn't tried it yet.
My mod list to date is as follows:
Mod1 Standard board with coupling caps (betwee DAC and output stage) and mute chip bypassed.
Result: OK i guess, dont knw exactly
Mod 2 C20, C25, C16, C17 -> 100uF 16v OSCON
everything else rest standard as is.
Result: Bass ok good soundbalance
Mod3 C3,C18 -> 220uf 16v Philips
C19 -> 1000uf 16v general purpose
Result: Bass shy, vocals to bright
Mod4 C25 10uF 16v general purpose
C19, 100uF 16v Oscon
Result: Vocals little better, still bass shy
Mod5 30k and 150pf around opamp
Result: Not determined yet, still have offset.
Seemed Bass getting downhill with Mod 3 and after.
Let you know if i'm getting somewhere.
I have to wait for parts, got a few ELNA SILMICII and Pana FC on the way.
Stay tuned.
Naqua
PS LEO: Thanks for your suggestion, i will try matching the resistors first, then changing opamp to opa627's i have here.
I seem to remember reading somewhere that the CMOUT mod brings out more detail. Could be worth trying.
I've tried the CMOUT mod, tbh I'd try it after you feel the caps etc are right
You notice people start getting problems with bass etc once they start swapping the decoupling caps;)
Just be patient, I think a lot of the problems is the layout and that supplied psu, its easy to results in instability
Remember this board is cheap, don't expect it give giant killing performance, it won't IMHO but what it can do is give a very good sound on the cheap
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
http://shrani.si/f/2e/Ff/4jXHB5xE/dacafter5.jpg
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
leo, on your instructions for modding, you bridged the chip below the board. What does this do?
Tripmaster
01-11-2008, 11:14
leo, on your instructions for modding, you bridged the chip below the board. What does this do?
It bypasses the chip. Leo thinks the DAC sounds better without. I removed the chip completely as a last resort. If you do add a blob of solder to those points make sure you lightly scratch the surface so you get a good solder joint. I didn’t and ended up burning off the pad!
Tripmaster
01-11-2008, 11:30
Wow! thanks for those comprehensive lists.
I removed all of the Oscons and Tants and replaced with general purpose caps, but now the LED doesn't light up! I have checked the PS and I am still getting the correct output.
I am going to check the board for continuity in my lunch break and see if I can find the fault(s). The trouble is I have soldered and re-soldered so many times resulting in a lifted a solder pad or three! I have always managed to find the track by scratching away the black coating.
An ill fated project from the start ;)
I am debating whether to buy another board or try something else.
Does anyone have a spare DAC PCB they would like to sell?
Leo, you mentioned you may be planning another DAC project...any news?
Richard
Leo, you mentioned you may be planning another DAC project...any news?
Richard
;) http://theartofsound.net/forum/showthread.php?t=1152
I think best thing to do with the cheapo CS4397 would be to do the output filter mod (30k + 150pf) bypass the smd chip bottom of board and sort the output coupling DC blocker caps first and see how it sounds.
I'd then try updating the PLL filter to the correct values (1N/3k/22N)
Maybe then try a better op-amp, obviously one that won't go unstable in this circuit
Then try the decoupling caps in stages so its easy to revert parts back if you don't like it.
Problem with passive parts like capacitors is that people have their own references , they can alter the tone of the sound and sometimes have undesirable effects in both sound and stability to the circuit
fordgtlover
01-11-2008, 12:12
Tripmaster,
Since you are playing around with the caps on CMOUT...
In the datasheet for the DAC eveluation board there's 2 resistors of 1k to cut the 5v into 2,5v and connect it to CMOUT.
In the note's it says they are for PCM modes. I suppose its because CMOUT has to be typically (according to the datasheet) at 1/2 VA.
Maybe it's something to try also ? I havn't tried it yet.
My mod list to date is as follows:
Mod1 Standard board with coupling caps (betwee DAC and output stage) and mute chip bypassed.
Result: OK i guess, dont knw exactly
Mod 2 C20, C25, C16, C17 -> 100uF 16v OSCON
everything else rest standard as is.
Result: Bass ok good soundbalance
Mod3 C3,C18 -> 220uf 16v Philips
C19 -> 1000uf 16v general purpose
Result: Bass shy, vocals to bright
Mod4 C25 10uF 16v general purpose
C19, 100uF 16v Oscon
Result: Vocals little better, still bass shy
Mod5 30k and 150pf around opamp
Result: Not determined yet, still have offset.
Seemed Bass getting downhill with Mod 3 and after.
Let you know if i'm getting somewhere.
I have to wait for parts, got a few ELNA SILMICII and Pana FC on the way.
Stay tuned.
Naqua
PS LEO: Thanks for your suggestion, i will try matching the resistors first, then changing opamp to opa627's i have here.
Naqua
Mine is similarly modded to your except for the following (possibly significant) differences C25 -> 10uf Oscon, C20 -> 330uf Oscon, C19 -> 1500uf MBZ and C21 -> 470uf pana FM. I am also running an OPA2107 opamp. I don't consider mine to be bass shy at all. I actually think it is pretty well rounded. Apart from the output stage that I am working on, I don't think I'll be making any other changes.
Here is my current configuration:
R2 3K
C3 10uF 10V Oscon
C8 .1uf Polypro
C9 .1uf Polypro
C10 .1uf Polypro
C11 .22uf MKT EPCOS
C12 .1uf Polypro
C13 .22uf MKT EPCOS
C16 100uF 16V Oscon
C17 100uF 16V Oscon
C18 100uF 16V Oscon
C19 Rubycon MBZ 1500uF
C20 330uF 6.3V Oscon
C21 470uF Panasonic FM
C22 22nF
C23 1nF
C25 10uF 10V Oscon
R8, R9, R14, R17 30K
C32, C33, C34, C35 150pF
Opamp OPA2107
Leo's bypass mod
C27,C28,C30,C31,C6,C54 Bypassed
L & R out C 2uF Obbligato PIO
L & R out R 51 Ohm Kiwame
It bypasses the chip. Leo thinks the DAC sounds better without. I removed the chip completely as a last resort. If you do add a blob of solder to those points make sure you lightly scratch the surface so you get a good solder joint. I didn’t and ended up burning off the pad!
So I can try it bypassed and not bypassed? Is this bypassing the OPAMP or just that chip? Cus i bought a nice opamp.. lol
JDmz.
It's just bypassing the chip. It normally mutes the output signal when there's no lock at the pll or when powering on.
Opamp stays in place
Tripmaster
01-11-2008, 22:34
So I can try it bypassed and not bypassed? Is this bypassing the OPAMP or just that chip? Cus i bought a nice opamp.. lol
Yes, just bypassing the chip.
Hi, I messed up the trace of C54 on the side of the right output. Do you know where I can find this? I just see a bare board... got it from using a desoldering braid
pic
http://i161.photobucket.com/albums/t202/aznracerx1989/th_IMG_3784.jpg (http://s161.photobucket.com/albums/t202/aznracerx1989/?action=view¤t=IMG_3784.jpg)
also,did you remove r28 and r29? mine has resistors there with 104 written on it
thank you
EDIT:
I used resistance checker and the RED's have 0. So I assume I can connect the YELLOW's?
It is weird.. I always thought current moves from - to +, why is it reversed?
C54 is connected to R output
are you sure? Doesnt it go negative to positive? so the left side of C54 goes to R output?
EDIT: I fixed it by doing what I described in the picture.. why is the capacitor connected backwards? + on +
negative side of C54 is connected to R output. Positive side of C54 is connected to op-amp output.
If you bypass pads with wire, both positive and negative pads are connected to R output.
Don't understand about capacitor connected + on + or backwards :lolsign:
Signal is always traveling from higher level to lower lever. At op-amp output is higher level (source of the signal), at RCA is lower level. Capacitor is between, positive side goes to higher level, negative goes to lower level, where is problem? :eyebrows:
Anyway, using lytic or tantalum for coupling is bad idea :scratch:, but it is cheap
Hi-res shematic
http://shrani.si/t/3F/9O/2G6LodNt/boardshema.jpg (http://shrani.si/?3F/9O/2G6LodNt/boardshema.jpg)
Mod update:
Mod6:
c19 pana 470uf
c21 oscon 100 uf
c3 10 uf gpo
c18 100 uf oscon
c20 470uf pana
c25 10uf pana
c16 100 uf oscon
c17 100 uf pana
Muddy bass - "air" ok "beeing there" not ok
Less detail, less dynamics
MOD7
c19 pana 470uf
c21 pana 150 uf
c3 10 uf general purpose
c18 100 uf oscon
c20 oscon 100uf
c25 10uf pana FC
c16 100 uf oscon
c17 100 uf pana FC
round bass, power dynamics, Detail and highs-ok
also tried opa21047AP was to heavy on the bass, less depth didn;t like it.
Next round -> elna SILMICII instead of Pana FC
tried all 3 types (Oscon, Panasonic FC, Elna Silmic II) during several days listening marathon :lol:
No big difference at all (the same values for all 3 types). Panasonic FC is the worst (less bass), Elna Silmic II and Oscon is equal, maybe is Oscon more stable in bass & mid region, but less details & less dynamic than Elna. Or just my imagination playing with me :lolsign:
Naqua:
Difference between your MOD6 and MOD7 is value for C20. Bigger value will "slow down" music, cause less details & muddy bass.
I increased C19 from 470μF to 1000μF. Changed C20 from 470μF to 220μF OSCON and changed C17 from 470μF OSCON to 100μF Elna Silmic II.
How come leo's board did not come with R28 and R29? I have resistors there. Should i remove those since I added in 30k resistors?
Hello, again.
I tried Leo's mod for the r's and c's around the opamp. (R's 30k C's 15-pf). But i am still getting about 25mv on each side (left +27mv and right -23mv).
tried matching the resistors: resistors went down from about 30,2k to about 29,9k dc output went up from about 25mv to 30mv. Fet based opamp also had no result.
Maybe it's the way i am measuring ?!
Ouput caps and r's are still in place and i measure between pin s1 and 7 from the opamp to ground (middle) pin on the output connector. The DAC is not connected to an amp. Opamp is JRC5532.
Is this the correct way to measure the DC on the output or do i have to remove output caps and resistors first to get correct measurement ? Or do i have to connect the dac to an amp ?!
I would be pleased to hear from someone who knows and can help me eliminate the offset.
Thanks in advance !
Naqua
@Naqua
your measurement is correct. Pin 1 and 7 from op-amp to ground. I am using 30 K resistor (matched set) and my offset is 1 mV left side and 2 mV right side.
Use matched set od 4 resistors. You need to buy 10 or 20 resistors & use your multimeter to match 4 of them. If you are using coupling capacitor, capacitor will block DC, no need to worry about some DC offset left. And C's are not 15pF, they are 150pF.
Resistors are responsible for DC offset, no capacitors. Capacitors+resistor are RC filter.
@JDMZ
why to remove R28 and R29? Look again on board shematic I posted, what will you accomplish with this action?
Thanks Firefly! I'm glad somebody else can help answer questions , I think the manufacturers of this dac should be paying us:lol:
I've noticed a few of the dac boards had R28/28 missing, maybe they just forgot to fit them on some batches
Thanks Firefly,
To resume i understand correctly:
I'll try to macht 4 resistors of 30k. My multimeter just has 1 digit after the decimal point. Will that be enough to match ??
Also my Resisitors are matched as follows:
30.0k 29.9k for left channel
29.8k 29.8k for right channel
I assume this is not matched enough then ?!
Is it better to have precision resistors of 0.5% or 0,1% tolerance or do i have to match them also.
Is it ok to raise the resistor value if it helps to eliminate the offset? (ie to 31k or 33k)
Thanks again
@Naqua
30.0K vs. 29.8K, is this matched? For me this is NOT matched. Maybe you can use 27K resistor and 5K multiturn trimmer in series to set offset to 0 mV :eyebrows:
If you change resistors, you will have to change capacitors values too. Stay with 30K resistors and capacitors 120-180pF.
Pic of multiturn is bellow
http://shrani.si/f/t/YV/3wOuhRIJ/multiturn.jpg
@leo
thanks, will try to help, but credits for major work goes to you :)
Thanks Firefly (and of course Leo) :)
Will try 0,1% 30k resistors first.
Then will try your multiturn option.
Thanks again (and again and again etc) :)
My opa hdam opamp has a ground wire. Can I hoook this to AG ground? between the two outputs? or one of those other grounds?
The output caps i used.. does not show polarity. Is this normal/ok?
Thank you
Some new things about op-amp output stage.
Look to shematic I posted on page 28
http://theartofsound.net/forum/showpost.php?p=22444&postcount=288
Capacitors C32 and C33 are connected as negative feedback. This is very very bad practice, to put capacitors as negative feedback, they are destroying trebles & fine high details. It is asking for trouble or like giving pacient a medicine, after he is already death :lolsign:
They must go out. I cut them from the my board.
And resistors R8 and R9 are also negative feedback. Too much negative feedback is poison for sound, like hitting a pacient with hammer to sedate him :lolsign:
Values must go higher, do decrease neg. feedback, I will make some tests & calculation and post results.
Capacitors C37 and C39 are part of RC lowpass filter for L and R channel, They have too big values, will make some calculations & tests and post results.
Also capacitors C44 and C51, near wide white power connector, with original values of 100μF. Values should NOT be increased, they should be decreased something like 47μF, to give sound more air. But this depends on your ears :lol:
So you are saying I should just desolder those two capacitors? Anyone know where the ground of my opamp can go? AG or the other ground?(or however many types there are)
Looking forward to your results!
Some news:
Capacitors C32 and C33 (original value 56pF) should go out. Op-amp will not oscillate without them :eyebrows:, they are killing highs.
Capacitors C34 and C35 (original value 1nF) should go out. Or minimal value of 100-150pF, as Leo suggested.
C44 and C51: desolder original 100μF, put 47μF.
C40 and C50: leave original SMD, bypass with 0.1μF MKP (small size)
Bottom side of the board:
Solder lytic capacitor 4.7μF or 10μF directly to op-amp legs 4 and 8 (4=negative, 8=positive) for decoupling. Use good quality cap.
This guy did tests and proved that it Improved the highs..
http://theartofsound.net/forum/showpost.php?p=18774&postcount=210
Removing those capacitors, are we replacing it with something else? Or just leaving it empty?
Hi
I'm Marco from Germany (sorry for my bad english).
My Kit arrived today.
I compared the "stock"-dac-kit with my CD-Player ( a Sony SCD-XE670).
The only difference I heared was that the DAC is a bit louder than my CDP.
I'm a bit disappointed. Is this normal in "stock"-state?
What is the first thing I could do to improve the Sound?
My equipment:
Sony CDP SCD-XE670
Amp: Rotel RA-931 (I use its headamp)
Sennheiser HD650
Thanks in advance
Marco
Hi Marco, from another Marco :)
Welcome to AOS. Where in Germany are you? My wife has relatives in Köln and Bergisch Gladbach.
Marco.
Where in Germany are you? My wife has relatives in Köln and Bergisch Gladbach.
Marco.
Hi Marco
I live in western Germany. About 100km to Köln and 10km to the Netherlands.
Hi Marco,
Are you anywhere near Euskirchen? My wife also has relatives there. We usually spend a week in Köln and a week in the countryside near where you are :)
I love Germany!
Anyway, we better keep the thread on topic ;) I just popped in to say hello.
Marco.
Hi Marco,
Are you anywhere near Euskirchen? My wife also has relatives there. We usually spend a week in Köln and a week in the countryside near where you are :)
Euskirchen is in the South of Köln. I live in the North (about 100km) of Köln.
I love Germany!
Me too! ;)
Anyway, we better keep the thread on topic ;) I just popped in to say hello.
Yes we should. I think the others are getting nerved by this.
So could anyone make a guide/tutorial or simply a list of what improved the sound? That would be awesome!
I read the whole thread (and also this (http://rockgrotto.proboards39.com/index.cgi?board=m&action=display&thread=1672&page=1) and this (http://www.head-fi.org/forums/f6/noodle-dac-ebay-special-354407/)) but I'm a bit confused because some mods are contradictory.
One persons changes Capacitor-A like this and another like that.
Thanks in advance
Marco
P.S.: There is actually no thread in our german hifi-forum. If I suceed with my mods, I will post one.
im gonna try firefly's mod when people start confirming it is good. Yea I am confused too. Leo has 4 capacitors around the opamp when firefly removes 2 of them. And he removes the resistor mods too. Leo hasn't been on in a while, but I will do the mod once he agrees with firefly lol.
Things like PSU's and type of op-amps can cause varying results, I personally don't like Oscon caps in a lot positions yet some others do, as with everything else its best to try it out, if you don't like it, just rip it out;)
I've not tried removing the caps in the op-amps feedback positions yet.
I'm currently using AD826 which can be a little touchy so requires a bit of care
Soon as I get time I'll remove the caps and have a look on the scope
If you remove the the caps and notice excessive brightness this can be a sign of HF distortion caused by ringing, some op-amps shouldn't cause any issues so should be fine
I have capacitors like this except 4uF on my outputs. http://www.parts-express.com/pe/showdetl.cfm?Partnumber=027-200
It does not show polarity.. can it go any way?
Yes, either way.
Polyprops and other plastic types are not directional in the sense that electrolytics are.
I like to arrange things so that the start of the writing on the cap is at the input side.
im gonna try firefly's mod when people start confirming it is good. Yea I am confused too. Leo has 4 capacitors around the opamp when firefly removes 2 of them. And he removes the resistor mods too. Leo hasn't been on in a while, but I will do the mod once he agrees with firefly lol.
Let's do some math:
C34 and C37 together with R11 and R15 are forming second order lowpass filter.
Fc= 1 / 2*Pi*√R11*R15*C34*C37
With values of R11=6K8, R15=22K, C34=1nF, C37=1nF is cut frequency set at 13 kHz, as proved before by Jackenhack. See post
http://theartofsound.net/forum/showpost.php?p=18774&postcount=210
If you change value of C34 to 150pF as Leo suggested (and leave C37 at 1nf) then you will have cut frequeny at 33.6 kHz. If you change C34 value to 100pF, then is cut frequency at 41.148 kHz.
About feedback capacitors C32, C33 already Leo explained. Together with resistors R8 and R9 are forming kind of Bass Booster and decreasing gain of op-amp for high frequencies and limitting usable bandwith of op-amp.
Hello everyone,
I am still messing around to kill the offset.
So far i used 30k 0,1% resistors and measuring left 5.6mv and right -26mv
Checked and rechecked everything, used FET opamp but offset remains the same.
Measuring some voltages at the opamp i see some differences between left and right. Measurements are as follows:
Straight from the dac outputs everything 2,53v (left and right)
Left side inputs Opamp pin2: 1,448v and pin3: 1,445v
Right side input Opamp pin5: 1.434v and pin6:1.436v
Seems i am losing mvs left between dac output and left opamp inputs.
I removed the opamp and measured resistance as follows.
Left between dac output pin 19 and opamp pin2: 29,0k
Left between dac output pin20 and opamp pin3: 29,1k
Right between dac output pin24 and opamp pin6: 28,9k
Right between dac output pin23 and opamp pin5: 29,4k
Is there anyone who can help a relative noob to determine what to do to kill the offset ?
Resistors of 0,1% tolerance do not need to be matched or do they ?
They all measure 30,0k on my dmm.
Thanks in advance for your replies. !!
Naqua
@naqua
look on shematic & measure other resistors. They must match for L and R channel.
R15=R18=22K, R10=R12=6.8K, etc, etc, etc.
Today desoldered C36 and C38. On shematic, value is indicated "102", that is 1000pF or 1nF. I measured them and real value is 30pF, not 1000pF as indicated :doh:
I just removed c32,33,34,35.. I think the highs are more detailed now. With my klispch horns it seems a little bright, but clear. I don't have audiophile ears though haha.
@JDMZ
keep 2 small capacitors in spare. Some op-amps may start oscillating. In this case, solder capacitors C32 and C33 back. Very small value of 5pf will be enough.
I experienced this with some OPA op-amps.
I have a discrete opamp from audio-gd.com... Ahh crap i dont have 5pf capacitors. It still sounds pretty good though.
you need this 5pF just in case od cranky op-amp. Don't bother if everything is OK.
With Klipsch horns try this:
C34, C35: 680pF
C37, C39: 220pF
C36, C38: 680pF
experiment with C36 and C38, try values between 470pF and 1nF :eyebrows:
What do you recommend for capacitors? What type? Should I just get some ceramic ones like what I had? I bought them at digikey.com
Makgajwer
25-02-2009, 14:57
What I see is stagnancy in this tread ;-)))
So I must show something I built.
There is an external DAC based on the CS4397 DACboard and a CD player with this DACboard built-in (Sony CDP-XA20ES). Both porojects have tube output stages instead of original opamp based stages:
http://www.audiostereo.pl/zalaczniki/1216755_1.jpg
http://www.audiostereo.pl/zalaczniki/1216755_2.jpg
http://www.audiostereo.pl/zalaczniki/1272131_1.jpg
http://www.audiostereo.pl/zalaczniki/1272131_2.jpg
Nice work!
Where did you get the case?
Also is thetube pcb your own or is it one you brought?
Makgajwer
25-02-2009, 15:39
The cases You can buy at http://www.modu.it/
The tube pcb is not my own project, I bought them from my acquaintance.
This is my first post on this message board.
Have followed this thread for some time now, and have modded a few of these small DAC kits during the past couple months.
Someone on another forum suggests connecting pin 20 on the CS8416 chip directly to a +5v source via a 47k resistor.
Has something to do with the PLL configuration when used in conjunction with the CS4397 chip.
Connecting pin 20 as noted above supposed to help lower jitter in this configuration.
Have any of you had experience with this.
I'm basically a parts swapping DIY guy, so the techinical stuff is way above my head.
Cheers.
Hello Makgajwer !
Would you share about the schematics you used in CS4397 output ?
Thanks
R.C.
Makgajwer
05-03-2009, 22:07
Preview
Quote:Originally Posted by Ciu
Hello Makgajwer !
Would you share about the schematics you used in CS4397 output ?
Thanks
R.C.
Why not?
http://www.audiostereo.pl/zalaczniki/1247665_1.gif
You must omit and bypass C2, it's drawing error.
And there is another (cheap) CD with this DACboard built in:
http://www.audiostereo.pl/zalaczniki/1295590_1.jpg
http://www.audiostereo.pl/zalaczniki/1295590_2.jpg
Makgajwer
05-03-2009, 22:08
Why the hell my attachments disappeared?
Makgajwer
05-03-2009, 22:14
once again
http://http://www.audiostereo.pl/zalaczniki/1296260_1.jpg
Hello
Thanks for the schematics...
Would you add values to components ?
I had a look to sowter 4603... accept offset DC from DAC (2.5v ?) on input without cap blocking ?
Thanks
R.C.
Makgajwer
12-03-2009, 23:36
Ah, yes, I forgot to add values.
C1 omit and bypass, it's drawing error
R1 and R2 forms divider. Choose values to set about 2V signal level at output.
R2- 220ohm if Ua is about 200V
R4 1meg or so
C3 2uF or so, polypropylene, teflon or paper in oil
Sowter needn't to accept an offset DC, because there isn't any offset DC between (+)out and (-)out from DAC. Both of them have +2,5V potential according to the GND. So there is NO differential DC voltage between them (unless CS4397 is fried).
Hello Makgajwer!
You are absolutely right about DC offset !
Thanks
R.C.
Makgajwer
25-03-2009, 16:55
Revised schematics
Not been in here for a while, life gets in the way! Just finishing connecting this DAC to my shigaclone cd player but I'm looking for a good quality connector between the dac and CD. I assume digital coaxial? I have a spare cable but if this is the best route then where do I get a decent socket for the board?
Cheers
Iain
I hard wired a 75R BNC socket to the pcb, the single phono socket on this dac board is really poor, it gave me regular drop outs on the spdif
Listening again to this dac a few days ago, its really quite a good little performer on the cheap once modified and a few of the circuit errors corrected
Sounds like a plan, putting an RS order in today but all will be delayed by easter, should have got round to it a while ago! I have a small problem that I need some help with. I have 0.5mv across the right output but 1.4V across the left.
I followed the nulling posts somwhere around post 96ish it has obviously worked on one channel but not the other, poor connection on one of the resistors? I'll read back through again but do you have any pointers as to where to look troubleshooting wise. I'm sure I had this at vitually zero last time I powered up. I could give up and pop some caps on the output but I'm trying to avoid this as I have protection on the amp and I want to keep the mods to a minimum in the signal path.
Cheers
Iain
Yes, I'd certainly check the joints, be sure all values are correct etc, somethings way out of balance on that channel giving you the high offset
Caps on the output will only get rid of the DC but you'll probably get a channel inbalance if theres a problem with the resistors
Did you try another op-amp just to eliminate the possible faulty chip?
Yes, I'd certainly check the joints, be sure all values are correct etc, somethings way out of balance on that channel giving you the high offset
Caps on the output will only get rid of the DC but you'll probably get a channel inbalance if theres a problem with the resistors
Did you try another op-amp just to eliminate the possible faulty chip?
That's a great suggestion, I found a spare opamp yesterday when having a garage tidy! I'll give it a try and report back. Joints look ok but tempted to dab them with an iron. It's lead free stuff and I fine it hard to spot bad joints with it.
Iain
Ok Iain:)
Failing that you could post a High res pic and I'll check over it, obviously harder to see things on a pic but may be worth a try just incase
ROHS solder , I hate the stuff!!! :steam: only time I use that is at work, my own gear is all lovely leaded ;)
Arse! Just broke the right hand side ( from above, phono and optical to left hand side) pad of C34 away from the board changing the opamp. Can't reconnect it as the pad has come away, is there any other point to connect this to or am I hitting ebay for a new board?
Iain
I don't think theres any need to scrap it
So to get this right the pads for C34 are damaged? Its going to be hard to explain how to fix, do you know how to read a schematic?
Yep, rhs pad gone. I'm not the greatest with schematics but try me, I can always ask questions!
By the way I suspect the leg of the cap on C34 was touching the cap next to it. I wonder if this was the cause of the higher voltage. All the resistors seem fine.
Appreciate your help, not really wanting to scrap this, would rather keep the pennies for a buffalo at some point.
Iain
Yep, rhs pad gone. I'm not the greatest with schematics but try me, I can always ask questions!
By the way I suspect the leg of the cap on C34 was touching the cap next to it. I wonder if this was the cause of the higher voltage. All the resistors seem fine.
Appreciate your help, not really wanting to scrap this, would rather keep the pennies for a buffalo at some point.
Iain
Hmm, ok, I'll try and edit the picture of original board to see if it helps;)
First we'll sort the pad problem then try and figure out the DC offset, BTW this is part of the op-amps non inverted input so if its shorted out you'll get an inbalance
Cheers Leo, don't kill yourself posting anything up now. I've had too much wine to go near a soldering iron tonight ;)
Iain
Too late, well for later see if this makes sense;)
http://i273.photobucket.com/albums/jj220/kingbusoms/dac11.jpg
http://i273.photobucket.com/albums/jj220/kingbusoms/dac22.jpg
http://i273.photobucket.com/albums/jj220/kingbusoms/dac33.jpg
This is presuming the board is same as mine:)
BTW the part numbers on the schematic are not quite right for the op-amp pins so to help try and save confusion I've drawn the pics.
One side of C34 goes from R11 to non inverted input of op-amp, the other side of C34 goes to ground.
If track is broken you can wire R11 to pin3 non inverted input (make sure correct end of that resistor is connected) , solder one end of the broken off C34 from R11 and the other end to C36 which goes to ground
Thanks Leo, great pictures. No cont between pin 3 and R111 so full repair done BUT in the process I managed to break the other pad on C36 Doh! I had a Wima bypass cap at that point (think it was a recommendation from diyaudio) and I knocked it and it was enough to lift the pad.
Really annoyed with myself, is there a fix for this, link to R10 and R15 from wayward end of bypass cap?? (towards opamp end of board). The modified pad is still in place.
Up until yesterday this board looked really nice!
Iain
Drawn on where C36 is connected to, right side (near C17) goes to ground.
Other side of C36 goes to R15 and R10
http://i273.photobucket.com/albums/jj220/kingbusoms/dac44.jpg
Fix done, bit of a lash-up but all back to how it was. Negligable mv on the left output. 1.4V on the right.
Iain
What voltages do you get on op-amp from
pin2 to ground?
pin3 to ground?
pin5 to ground?
pin6 to ground?
What voltages do you get on op-amp from
pin2 to ground?
pin3 to ground?
pin5 to ground?
pin6 to ground?
1 -8mv
2 1.42V
3 1.42V
4 -12V
5 1.42V
6 1.42V
7 1.42V
8 12V
Iain
ps. Sorry for delayed reply, been busy eating chocolate :)
you got a bad track ,joint or resistor I reckon
Look at the voltage reading of the differential out of the dac , + is 1.4v, - is 1.4v
Differential to line out this should give 0v
A clue, whats the DC offset out of that dodgy channel? you got one half missing;)
Don't go making yourself into a bloater with all that choccy :lol:
you got a bad track ,joint or resistor I reckon
Look at the voltage reading of the differential out of the dac , + is 1.4v, - is 1.4v
Differential to line out this should give 0v
A clue, whats the DC offset out of that dodgy channel? you got one half missing;)
Don't go making yourself into a bloater with all that choccy :lol:
Got to find it without breaking anymore pads, fun starts here I guess! So I should start looking on the knackered side. What's the best method here, pull up the schematic and compare points from the good side (as a reference) to the bad until I hit a difference?
Cheers
Iain
p.s. stopped with the choc and hit the single malt!
Got to find it without breaking anymore pads, fun starts here I guess! So I should start looking on the knackered side. What's the best method here, pull up the schematic and compare points from the good side (as a reference) to the bad until I hit a difference?
Cheers
Iain
Yes, I'd imagine if the DC offset is +1.4v it'll be the -1.4v side , I'm also supping so my brains not fully functional:o
p.s. stopped with the choc and hit the single malt!
Good choice:cool:
lol, I know the feeling. I can't work out which side is which now, it can wait as I'm not minded to burn or fry myself tonight!
Iain
lionking
04-05-2009, 13:09
Hello every one
that kit needs 12v transformer to work?
http://cgi.ebay.co.uk/High-Grade-24bit-192khz-DAC-with-fully-assembled-kits_W0QQitemZ120413813083QQihZ002QQcategoryZ3272Q QcmdZViewItemQQ_trksidZp1742.m153.l1262
Whats the best amount of VA to a transformer for this kit?
I am thiking of buying it and that transformer doesnt look
very nice!
362
Thanks
Those plastic encased transformers can suffer from mechanical buzzing which could prove to be annoying
You don't need huge current for this sort of application, some will argue larger VA is best and others will say its wasting money
When playing with this dac I used a 60vA toroidal because its what I had spare
Tripmaster
04-05-2009, 19:51
Hi Leo
This DAC has been getting a great write up over on DIYA. Have you ever tried using one of those transformers?
http://www.diyaudio.com/forums/showthread.php?s=&threadid=137976
Hi Leo
This DAC has been getting a great write up over on DIYA. Have you ever tried using one of those transformers?
http://www.diyaudio.com/forums/showthread.php?s=&threadid=137976
I can believe it getting quite a lot of attention, their cheap and sound pretty good once a few issues on the standard thing have been sorted out
I've not tried the transformers, tbh my objective with this dac was to keep it as a cheap project with decent performance
Of course thats not to say don't try transformers:eyebrows: I tend to try as many projects as I can and post results/opinions
Start cheap and folks can go further if they like
Hello,
My name is Ivo and I registered here just for this thread.
I was browsing that lampizator site and I stumbled across the DAC, I was intrigued and I had to order one. So I did. Googling brought me here.
Now I've had it for a couple of days and I've been modding it as per the standard stuff, I changed the opamp for a LM4562, I changed the PLL parts, I changed some of the caps for OS-CON, I kinda like the sound of those, and some for generic Low-ESR. I removed the coupling caps and I'm about to change the caps + resistors around the opamp to see if I can't get the offset voltage down.
I tried 0,22 uF wima bypass caps on some of those SMD ceramics, but it completely killed the sound, it became muddy and cluttered. I've since removed them and the awesome clarity is back.
I've got some Vishay/Roedenstein 0,1uF in the mail (the big-ish blue box caps) and I'm gonna see if those improve the sound any.
Well, nothing to add really, just wanted to say that I love this little gem of a DAC and I love the people here for all the information they've created.
I've got some Vishay/Roedenstein 0,1uF in the mail
Mace.
If you have ordered Vishay/ERO MKP1837 0.1uf, then make sure you put one in place of C9 (input). These were the best caps- in my opinion- for the job. I tested quite a few.
I found this to be the greatest single improvement, while i was upgrading.
Its tempting to replace and bypass loads of caps all at the same time. But not so easy to go back if you don't like the effect.
http://www.picstation.net/image-98E6_4A09F59E.jpg (http://www.picstation.net/share-98E6_4A09F59E.html)
Mace.
If you have ordered Vishay/ERO MKP1837 0.1uf, then make sure you put one in place of C9 (input). These were the best caps- in my opinion- for the job. I tested quite a few.
I found this to be the greatest single improvement, while i was upgrading.
Yup, those are the ones, the box-types.
Did you replace or bypass C9?
Its tempting to replace and bypass loads of caps all at the same time. But not so easy to go back if you don't like the effect.
Yeah it's true, I tried the Wima's on a bunch of those SMD caps (0604?), but I did not like the effect.
I have a 0,5mm tip on my iron and a steady hand, so removal was easy and non-destructive.
I'm expecting the caps by the end of the week, I'll post here about the effects.
Mace.
I left C9 in place while i was testing different bypass caps. This meant i had something to use as a reference. The best sounding bypass cap also turned out to be the best replacement for C9, which is no longer there.
Using the wrong cap here can really screw up the sound. Regardless of how many bypass caps are fitted further down the line.
If you find something that you think sounds better than the Vishay, let me know.
samoloko
29-05-2009, 10:21
one very big upgrade would be using audio transformer as a output stage
more Info at diyaudio
Leo have you tried It
one very big upgrade would be using audio transformer as a output stage
more Info at diyaudio
Leo have you tried It
Hi,
No not yet, I've been putting it off tbh for a while but it seems those who have tried them did like the results so its something I'll have to try out later to satisfy curiousity :)
A list of mods have been added to page1 to make it easier (list kindly done by member Raptor) , any further mods will probably be added there too
A list of mods have been added to page1 to make it easier (list kindly done by member Raptor) , any further mods will probably be added there too
That's awesome!
I have a quick question. It says R28 and R29 should be empty, but mine are populated, should I remove them?
That's awesome!
I have a quick question. It says R28 and R29 should be empty, but mine are populated, should I remove them?
Anyone? :please:
Anyone? :please:
I think those resistors go from output to ground (going from memory), if you use coupling caps after those I'd just remove them
I think those resistors go from output to ground (going from memory), if you use coupling caps after those I'd just remove them
Ok thanks.
I have K42-Y2 1uF PIO's in there, but no resistors in series with the output.
Then again I'm using a 4562 and not that AD you're using. :)
hi guys,
how 's everybody doing?
i was trying to mod the the dac with some cap upgrade but have accidentally lifted a pad....being a relative newbie! the lifted pad is c19 ( positive side of the cap)which is before the 3.3v regulator.
1. where do i tap the positive side of the cap which is connected to the +5v supply? i tried connecting it straight to the +5v supply but the regulator gets too hot and the led does not light up.
please help! thank you
nika
I don't have the dac here at the moment but will have a look when I get it back
thanks leo,
i can't wait to fix it.
hey fellas,
is there anybody interested in selling their unused cs4397 dac? i need one for my bedroom system.....i just need the dac board...
thanks
Can anybody help me, I have lifted the pads of C19. What should I do? Thanks in advance...
Mr Magoo
23-08-2009, 22:09
The power for the digital bits goes through the C19, the positive enters the AMS117 thingy on its right hand leg( as viewed from top). So what I did, having wrecked the same pad was this:
Soldered poitive leg of cap to input leg of AMS117, and connected that by a wire to the +6V. So the positive is now sorted.
Took a wire from the ground to the negative leg of the cap, and then a connected another wire to the ground side of C21.
The +6V and G are clearly marked on the PCB, I soldered the connections on the underside of the board. A tip here is that the cap is mounted firmly by only one leg, so use wire that is stiff enough to hold it in place.
I turned the thing on and nothing went bang or pfft and the LED came on.
I've found dealing with SMD pads and tiny work areas a real pain, so may get the larger version with through-hole parts.
You might want to get the PDF file for the CS4396 and CS4397 evaluation board
http://www.cirrus.com/en/pubs/rdDatasheet/cdb4396-1B1.pdf
Thanks for help Mr. Magoo. I gave up to work with this tiny fragile Chinese Dac board :steam:.
Many thanks to the contributors in this thread. The CS4397 DAC is my first attempt at a standalone DAC, and I've implemented a few of the mods detailed herein to what I think is very good effect. I've gotten spoiled on the quality of sound this little gem can produce.
I have a question regarding the Toslink socket. I'd like to get it off the board to make room for a possibly hair brained scheme to stack 2 CS4397s in a "Double DAC" for mounting in as small an enclosure as can be managed. Besides that, I'm not likely to ever need it and the thing seems to get in the way too often.
So, can the Toslink socket be simply removed, or does the circuit need to be terminated in some way if the socket has been pulled?
You can just desolder the socket.
I did it to make more room to work, especially when playing around with input caps.
Grazie. My CS4397s will soon be Toslink-less..
http://img40.imageshack.us/img40/9773/cs4397.jpg
I read all the post of this tread however I have not found any changes for the electrolites circled in red.
Shall I replace with better quality or better quality and bigger size?
Going by memory those larger 100uf caps are for the op-amp decoupling, feel free to change them
Any one manage to successfully input I2S directly to this DAC board?
I have input the appropriate leads from an I2S output in place and (I think) configured the chip for I2S input. Nothing. I really don't know that much about this so any thoughts would be helpful. The I2S board is the one from twisted pear.
The mistake i know i made was not to check the DAC board for operation before any mods (D'oh) and I did have to repair a bent and mis-soldered pin on the chip so maybe it is a board failure, but thought I would ask before I return the board to pre-mod configuration and see if it works at all. Thanks.
@ leo
Hi,
I read your Buffalo thread and so I am interested in your statement: Does this CS4397 DAC reach your Buffalo Mod?
Regards
Thomas
@ leo
Hi,
I read your Buffalo thread and so I am interested in your statement: Does this CS4397 DAC reach your Buffalo Mod?
Regards
Thomas
Hi Thomas,
No,imo its not as good as the modified Buffalo but not many other diy dacs I've tried so far are either :)
The CS4397 is capable of very good performance though with some work and has the advantage of being cheap
Hi to all members:
Anybody can help me please with this DAC Kit I´ve recently buyed at eBay.
After some searchs and readings, I decided to do some mods and now it did not work. The blue LED light up, that indicate it´s on, but no sound out :-/
Many thanks in advance for your help.
You will need to read this whole thread as there are lots about problems created when modifying these boards.
It starts around here :-
http://www.theartofsound.net/forum/showthread.php?t=315&page=18
Tripmaster
01-12-2009, 15:01
You will need to read this whole thread as there are lots about problems created when modifying these boards.
It starts around here :-
http://www.theartofsound.net/forum/showthread.php?t=315&page=18
Thanks for the reminder, I was trying to forget about this! :(
I wasn't going to "name names" but as you have identified yourself......:lol:
Tripmaster
01-12-2009, 16:31
I wasn't going to "name names" but as you have identified yourself......:lol:
My face says it all!
audio1st
07-12-2009, 09:26
But you did persevere and get it working..;)
:scratch:But Richard, I am confused with your transformer wiring though, did it come with pigeon English instructions, how is it working?
Your primaries are out of phase with each other and so secondaries have had to be wired out of phase as well. I would have thought your "light bulb tester" would have protested?
The norm is; L-1, N-4, link 2-3. and white-8,white-5 and black-6,7. Apologies if I have it wrong.:doh:
As an observation, it could have been easier to bypass the output caps and the "mute chip" with links under the board. Just remove the output caps and add new ones between board and phonos.
Barry,
Tripmaster
07-12-2009, 13:54
Hi Barry
The transformer came pre-soldered that way. I wasn't using a light bulb tester back then so I'm not sure if would have protested. Unfortunately the solder pads were so far gone the dac eventually packed up. I have considered getting another but I've been dabbling with various projects since and its always been put on the back burner.
I see you have been working on some new CD enclosure designs, looking good as ever!
http://theartofsound.net/forum/album.php?albumid=8
robertor
28-12-2009, 17:25
hi everybody,
this is my first post here and sorry for my bad english.
i have some problem with the lampucera DAC.
the optical toslink work fine but the coax seems dead.
no music but only rustling.:(
there is also a strong lowering of the light of the red led.
maybe the lampucera has passed in R.I.P.(Requiescat in pace = Rest in Peace)?
thanks for your help.
Makgajwer
28-12-2009, 17:53
R.I.P. = Rust In Pieces
:lol:
Hi Roberta, the RCA fitted for the input spdif on these dacs are extremely poor, I had problems with the ones I was modding, yours may be ok but I'd try replacing it just incase
The ones I modded did not have any led, I presume the led is the locking indicator for the CS8416
robertor
28-12-2009, 18:33
thanks for the very fast reply.
i have modified the lampucera following the fikus project.
i have never used the coax imput until 5 or 6 day ago because my cd player was unprovided of the digital output and the lampucera was connected by optical to my MacPro.
now i have the cd player with the coax out and the lampucera don't work:steam:.
thanks for suggest and i try to change the input connector.
very interesting the removal of output elko replaced with the film condensator close the output connectors.
p.s. for Leo: my name is roberto.
lionking
28-12-2009, 19:40
Hi everyone!
Anybody tried one cs4397 per chanel?
With two chinese cs4397 boards is it possible?
Thanks
Need some basic help. First let me state that my background is in mechanical engineering rather than electrical but I do like a challenge.
So far I’m using this dac stock with the supplied power supply. I was happy that it worked at all after I hooked it up. First problem I noticed was it is louder in one channel and I have to use the balance control on my preamp (lucky I even have one). So I have been looking here for a solution.
Could the different values of R8, 9, 14 & 17 cause this?
Later on I read about that someone had a bad voltage regulator, I figured that is easy to check so I did and the +5 volts is +5.1v the +12v is +11.81 but the -12v is -16.44v. Looks like a problem on the -12v to me but is it causing the channel imbalance? I measured at the first power supply connector relative to the AG pin.
Regards.
Rare Bird
28-12-2009, 23:44
Hi Alan ;)
What are you using the DAC for Computer?
Hi Alan ;)
What are you using the DAC for Computer?
Andre,
It's basically an experiment to see if you can cobble together these ebay parts into a usable audio component. Also to compare a modern DAC to the one in my Meridian 207 (TDA1541).
Rare Bird
29-12-2009, 00:17
Andre,
It's basically an experiment to see if you can cobble together these ebay parts into a usable audio component. Also to compare a modern DAC to the one in my Meridian 207 (TDA1541).
Alan:
If it's compooter use & just a trial why not use the onboard balance control on your media player compensate..
Andre,
It's not for computer I am testing in my main system. I can use the balance control there. But I want to find and fix the source of the problem. That is my experiment. To see if I can do this, with little help of course.
Rare Bird
29-12-2009, 01:18
Andre,
It's not for computer I am testing in my main system. I can use the balance control there. But I want to find and fix the source of the problem. That is my experiment. To see if I can do this, with little help of course.
Leo's yer man
http://theartofsound.net/forum/showthread.php?t=315
Need some basic help. First let me state that my background is in mechanical engineering rather than electrical but I do like a challenge.
So far I’m using this dac stock with the supplied power supply. I was happy that it worked at all after I hooked it up. First problem I noticed was it is louder in one channel and I have to use the balance control on my preamp (lucky I even have one). So I have been looking here for a solution.
Could the different values of R8, 9, 14 & 17 cause this?
Later on I read about that someone had a bad voltage regulator, I figured that is easy to check so I did and the +5 volts is +5.1v the +12v is +11.81 but the -12v is -16.44v. Looks like a problem on the -12v to me but is it causing the channel imbalance? I measured at the first power supply connector relative to the AG pin.
Regards.
It could be caused by a few things, example incorrect or drifted value resistor in the output stage, fb resistor etc, one channel of the dac chip output maybe faulty or maybe loaded down too much.
Also check the soldering especially around the dac chip
Is the input voltage to the left and right channel op-amp the same? (inverted and non inverted input not the supply)
The voltage regs feeds both channels so if one was faulty it would affect both channels
robertor
29-12-2009, 11:49
dismantled all the previous mods and installed for another time some new some old twek nothing changed.
if can help anyone where is the led i measure 3,4-3,5v with the optical input and 1,3-1,35v when there is the jump on coax input.
:scratch: but nothing.
thanks
Did you select the jumper/link in the socket for co-ax input?
robertor
29-12-2009, 13:08
hi leo,
where is the supply input socket(+5 -12 +12 etc etc) there is also the socket for the choice of input.
correct?
. . . like this(over view) 3 points.
one side coax and one side optical: correct?
when i jump the 2 legs for the optical input i find about 3-3,5v where is the led, when i jump the coax 1,2-1,25v in the same place.
robertor
29-12-2009, 16:32
today the last famous words of my lampucera have been: bzzz tick tock bzzzz and after the SILENCE.
i think once and for all dead.
thanks for support and sorry.
It could be caused by a few things, example incorrect or drifted value resistor in the output stage, fb resistor etc, one channel of the dac chip output maybe faulty or maybe loaded down too much.
Also check the soldering especially around the dac chip
Is the input voltage to the left and right channel op-amp the same? (inverted and non inverted input not the supply)
The voltage regs feeds both channels so if one was faulty it would affect both channels
Hi Leo,
Thanks for taking the time to help here.
Problem solved. You are gonna love this ……..….. it was the crappy pin connector on the cable from the board to the RCA, specifically the half on the cable.
Your suggestions stimulated me to action, so I looked up the datasheet to identify the input pins and off I went. This is how I measured the op amp input and output voltages. Please tell me if method is valid.
I used the stereophile test disc on track 20 repeating at constant volume. Measuring AC voltage from each individual pin to AG at the output RCA, all four inputs, pins 2, 3, 5 & 6, were equal at .057v and output pin 1 was .335v while pin 7 was .331v. Is 4mv difference significant?
So it’s not the dac or the op amp lets check the output at the RCA, there is a big difference l versus r which after all is the problem. Now where is it? I separated the halves of connector J6 and measured l & r outputs to AG and they were equal. Bingo problem isolated. So I pulled the pins from the other half and gave them an extra crimp and now all is well.
Coming back to the supplied power supply if my measured -16.4v is correct then somehow they make the -12v higher than the +12v, even though both are 12v regulators (7812 & 7912). Is that possible? Then -5v is derived by a drop across R23. Does that leaves -12v remaining or is there something else dropping it back to -12v?
Regards,
audio1st
30-12-2009, 12:57
Hi Alan,
The -16.4V is incorrect. I think that is the same voltage you would have before the 7912 reg..
Check the soldering of the 7912 regs centre pin (ground)..
Hi Alan,
The -16.4V is incorrect. I think that is the same voltage you would have before the 7912 reg..
Check the soldering of the 7912 regs centre pin (ground)..
Thanks Barry
The transformer datasheet confirms that 16.39v is the secondary no load voltage. My mistake was that the pin out of 7912 is different to 7812. For 7912 the center pin is the input. When I measure the correct pins the voltage is fine.
Regards,
samoloko
05-01-2010, 14:11
what Is the purpose of the bottom of pcb chip
what Is the purpose of coupling electrolytic caps between dac L+ L- R+ R- and OPA - could they be bypassed without any think to worry
I present for your perusal, and probable amusement :lol: my 1rst DIY audio project: The one, The only............... 2xUGLY-2xDAC.
Go here to :stalks:
http://s713.photobucket.com/albums/ww135/Mazeppa_photos/2xUGLY-2xDAC/
This thread and the Lampizator's site were my primary inspirations. Initial plan was just to get one working as delivered. SQ was better than anything I ever had, but it quit working in short order. Leo's comment about having trouble w/the stock RCA digital in jack reminded of another post about 75ohm BNC jacks & proper cable (I used RG/6u) being superior for digital signals. Implementation promptly brought the DAC back to life, and what's this? It sounds better!
You guys know how it goes now, the story begins to tell itself. Mod-itis has set in. Ok, I need to get the LM4562 optimized, and get that DC offset squared away, but first I'll poke a Lampucera in there to compare to the opamp version, and this, and that, and then something else...... but then I got spooked by how easy it is to mess this thing up. If you look closely at the tube DAC, you'll see where I had to go the CS4397 leg directly for one of the inputs to the 6n6p, yep lifted a track when removing C27. Man, that thing is like a hair. My cd playback was already so much better than anything I was used to, I was able to allow myself to divert to some long put off speaker projects.
Well, enough speaker projects are done that my attention is drifting back to the 2xUGLY-2xDAC. Think I'll start back w/some of the more fundamental stuff like getting some correct components in to fix the DC offset and enhance the digital lock in for the receiver chip.
My electronics expertise barely extends beyond being able to solder, but w/access to resources like The Art of Sound, I can do much more than I would have even considered otherwise. Thanks guys, not only am I having a ball with this thing, my system sounds better that I ever thought it would.
Questions, comments, jokes (funny ones) are very welcome.
Here's to you, boys! :cool:
Very nice!
One question though, what's the light dimmer for?
This all goes way over my head Mace, but one of the photo captions says "Yes, that's a household lighting dimmer. I didn't have an assortment of resistors to trim heater voltage, but had the dimmer laying around being useless."
Interesting project, Mazeppa.
Excellent stuff!
Most of my stuff starts off just bolted to a wooden chopping board often looking well ugly but allows easy modding
Very nice!
One question though, what's the light dimmer for?
This all goes way over my head Mace, but one of the photo captions says "Yes, that's a household lighting dimmer. I didn't have an assortment of resistors to trim heater voltage, but had the dimmer laying around being useless."
Interesting project, Mazeppa.
Tube filament and heater are supplied by individual xformers. Optimal heater voltage for 6n6p is 6.3v. My 115v/6.3v heater xformer yielded 7.6v in circuit as household supply is slightly over 120v. Lighting dimmer was placed in series w/the high side xformer winding to provide adjustment to desired 6.3v.
BTW: In comparing the opamp DAC to the tuber, one large difference I noticed was greater bass output from the tubed DAC. While shopping e-bay for some different 6n6p's for spares and trials for SQ differences, included in a pitch for his (a fella in Ukraine) wares, it was noted that 6n6p tubes accentuate bass frequencies. Hmmmmmm.
Leo, you mentioned trying the Lampucera, I believe. Could this (reported bass freq. enhancement) be the source of the coloration you noted?
BTWII: The tube DAC is much preferred so far, but I strongly suspect I've yet to hear the LM4562 at its best.
janos_904
19-01-2010, 18:29
Hi, I found Lukasz Fikusz's pages approx 4 months ago. There are many interesting stuff over there, and I decided to give a try to "Lampucera 1.0" project (because of the cheapest one :-)). After a while,, I bought a mini DAC board only, and upgraded the smd parts. The sound of the DAC is good, but the balanced version is even better, smooth, lovely, dynamic, analog like! I steal the signal from L-, L+, R-, R+ points, followed by GE 330 nF/850 V capacitors. The signal goes to a (DIY :-) Balanced Bride of Son of Zen preamp . Important, that the power source is an 6 V SLB (Sealed Lead) battery with special stab circuit giving regulated 5 Volts. On the picture the black labels shows one board made to my friend; the red substitutions are my one DAC. I also think to replace/add tantal caps to Wima-s and maybe to try the lamped version. János
Here's mine unmodified board..
http://ekke.kapsi.fi/temp/CS4397/cs4397_tn.jpg
http://ekke.kapsi.fi/temp/CS4397/cs4397_bottom_tn.jpg
Bigger versions here: Top (1.9MB) (http://ekke.kapsi.fi/temp/CS4397/cs4397.jpg) & bottom (1.5MB) (http://ekke.kapsi.fi/temp/CS4397/cs4397_bottom.jpg)
Now I just need to figure out what to do with it.. There seems to be some changes to 1. post like led and R28 & R29 and some additional components between CS-chips..
samoloko
26-01-2010, 14:21
I've changed the PPL filter for the CS8416 as I noticed it was the wrong values, it now locks onto the spdif much better and sounds better too.
Edit added 01/06/09
- R2 becomes (BC Components minimelf) 3k, C22 becomes 22nF, and C23 becomes (COG/NPO) 1 nF ((Read datasheet for reccommendations))
- R8,R9,R14,R17 to 30k WELL MATCHED
- C32,C33,C34,C35 to 150pf SMD or Polystyrene
- R28 and R29 should be missing.
- C3, C18, C11 can be left alone (Just pulling pins high)
- C12, C8, C13, C10, C14(C41) bypass with MKP 0.1uF
Leo
would you please explain
1) PLL values coming with dacs are wrong BUT some say that they are right for 32 - 44.1 KHz and the new values are right for 96 Khz mode ?
2) OPA filter values R8,R9,R14,R17 to 30k and C32,C33,C34,C35 to 150pf are correct for all OPA types Incl LM4562
3) R28 and R29 should be missing means that they have to be removed - why ?
4) C3, C18, C11 can be left alone (Just pulling pins high) - removed ? c18 Is 100/16 between c3 and c11
5) C12, C8, C13, C10, C14(C41) bypass with MKP 0.1uF - add a new cap or first remove smd cap ?
regards
Hey. Remove all r´s and c´s in the analog section and r23,c1,c4,d2. and cd4053 below, (neg. supply) and add 8 2.2K resistors. LM4562 opamp. ~2mv dc at output. Look at the PDF. Plays wonderfull. Anders.
Hi everybody. I have a CS4397 dac with the following mods: All electrolytics replaced with oscons at the digital section. Bypass the analog stage by removing C27,28,30,31 and connecting two scr mkp caps directly from the cs4397 (AOUTR-, AOUTL-) to the output RCAs. It was working great for weeks, but suddenly the following problem appeared: I get strong noise (like an impulse signal) when changing to the next track of a cd. During a track's playback everything is ok. Changing to the next track gives a strong noise, and the woofer gets displaced out to its limits, like dc is passing to the speakers for a very short period of time, which does not make much sense since i have dc blocking capacitors at the outputs.
While this noise is heard, i measure the chip's output dc falling from 2.5V to approx 2.0V dc and then it gets back to normal 2.5V. This is when measuring directly the output pins (AOUTR- for example). When i measure AFTER the dc blocking capacitors that i have added, the voltage is 0V dc (as expected) but when the noise happens the analog voltmeter indicates a negative voltage, like a negative impulse signal. Check the following video to see what i mean. I measure the voltage on my rca outputs (= after the dc blocking capacitor) and the needle is on 0V. I press the "next track" button and the needle moves to negative voltage for a while.
http://www.youtube.com/watch?v=Be4j2biZPgU
I measure the voltage on C3 and it remains stable when the noise happens. I measure on C25 and the voltage drops when i change track. If i change tracks many times continuously (pressing the next track button 2-3 times per second) the voltage drops more each time i change the track (like something sucks much current instantly) and when i stop changing tracks the voltage gets back to normal. I increased the C25 to 150uF and the voltage drop is quite smaller but the noise is still quite strong and the woofers pop out to their Xmax
I re soldered most of the connections (input rca, power supplies etc) with no improvement. The same happens when i connect the dac to my computer and play a sound file. At the beginning and the end of the file the "tsak" noise happens and the woofers stick out. It seems like when the spdif is initiated or stopped the noise is heard.
Any ideas what could be wrong?
and this is when measuring directly the chip's output: The voltage is stable at 2.5V (needle stays at the right corner, maximum of the scale). I press the play button on the cd and 3 impulse noises happen, and the voltage drops down to 2V for three times, and then the track starts playing.
http://www.youtube.com/watch?v=5FeucajR6is
fandersen
08-03-2010, 21:59
Hi all. Lots of good info on modifying this dac!
I was wondering if there are any recommendations for a replacement power supply for this dac, preferably diy?
janos_904
11-03-2010, 12:29
Hi DIY-ers, happy to post, that the sound of my mini DAC is improved further (see #417 ). The foil GE-s were replaced to 0.33 uF Mundorf Silver/Oil. It makes the total project pricier, but the song of mini’s turns to another league! I have very good results using Russian military silver mica KSZG caps right now: 100 nF/500 V. I found them very close (or better) to Mundorfs at lesser price! There is question showed up about the values of C25, C16. I replaced Yageo at C25 to Blackgates (2x10 uF) and left C16 (OsCon 150 uF). There was a nice, clear sound, and! deeper bass. But, during long listening I found the sound tiresome (if it is the correct word for). Lampizator’s advice was chosen; I put 100 uF OsCon at C25. I know, the value is much higher than the factory recommendation. The sound is very relaxing, nice, there is a bit less bass but easy to listen for 2-3 hours. It is not slowed down, as was mentioned earlier. Did you find similar results?
BlackKnight
18-03-2010, 18:40
Hi from a newcomer. :)
I hope that someone will give me a helping hand. After soldering a new C8 capacitor I noticed that there is no voltage on the soldering pads. The voltage should be the same as on pin 26 on CS4397 chip, right ?
janos_904
26-03-2010, 09:43
Hi, I am experienced using Mundorf Silver/Oil and KSG capacitors further. I think, despite of high respect of Mundorf S/O, they colors the sound a lot, KCG-s do as well, maybe not that much. There is a very important capacitor, namely C9 (DC blocking capacitor) just in SERIES in the signal path. I got some Russian military SSG-3 (CCГ-3) 126 nF/350 V Silver Mica’s from Vilnius. Because of their size, I made a new rout to receiver chip via a BNC terminal installed (do not forget there is a 75 ohm between signal to ground just before silver mica). I put 0,252 nF CCГ-3 silver Mica’s (C9). The result is surprisingly good (stunning). I highly recommend trying this tweak. János (to get CCГ-3, search on US e-bay)
belgiangenius
27-05-2010, 20:40
Any comments on whether this DAC really needs an output stage LPF to eliminate 400Khz noise that some people refer to?
anyone news about the plopping as described above? I do have the same problem when connected via toslink to my Ac Ryan mediaplayer.
Is there somethink we can change? looks like the dac is having problems to lock on the signal the mediaplayer provides.
please help!
Hi, I am experienced using Mundorf Silver/Oil and KSG capacitors further. I think, despite of high respect of Mundorf S/O, they colors the sound a lot, KCG-s do as well, maybe not that much. There is a very important capacitor, namely C9 (DC blocking capacitor) just in SERIES in the signal path. I got some Russian military SSG-3 (CCГ-3) 126 nF/350 V Silver Mica’s from Vilnius. Because of their size, I made a new rout to receiver chip via a BNC terminal installed (do not forget there is a 75 ohm between signal to ground just before silver mica). I put 0,252 nF CCГ-3 silver Mica’s (C9). The result is surprisingly good (stunning). I highly recommend trying this tweak. János (to get CCГ-3, search on US e-bay)
hi janos can you explain a bit clearer what you did with the silver mica on c9????I think I would like to give it a go but cannot understand what you have done...alan
Nice to see the modding is still going quite strong for these dacs, I've not used mine for a while (its currently on loan) so may have a bash at another
Just a note to the new members, can you please pop into the welcome section of the forum to keep the site owners happy :)
I can't remember all the part numbers for the dac but I presume C9 is for the SPDIF input coupling
I recently did a passive mod to this dac. Not bad.
Agree, not bad for a cheapie
Hi 'AndersN', 'Ekke', 'yiannis', 'fandersen', 'BlackNight', 'kput', 'hansr', 'belgiangenius' and 'janos_904',
Welcome to AOS :)
Could you please pop into the Welcome area and introduce yourself to our community by supplying your proper first name, basic geographical location, system details and music tastes, as this is the requirement for all new members joining AOS.
Cheers! :cool:
Marco.
fandersen
08-09-2010, 23:47
After successfully building one of these DACs -- thanks Leo, et al -- I ended up at diyaudio (http://www.diyaudio.com/forums/digital-line-level/137976-experience-diy-dac.html) to learn about bypassing the opamp with transformers. The diyAudio thread is very long but full of info on implementing transformers. I ended up installing Jensen JT-11p-1 transformers but there are lots of options. IMO, a worthwhile upgrade.
Hi 'fandersen',
Please see my post above and pop into the Welcome area and introduce yourself before posting any further on the main forum. You are joining a community here, not simply an information resource to use at your leisure.
This also applies to other new members who've posted here and haven't yet introduced themselves properly. I would ask that you observe the required protocol.
Thank you :)
Marco.
fandersen
17-09-2010, 04:25
Hi 'fandersen',
Please see my post above and pop into the Welcome area and introduce yourself before posting any further on the main forum. You are joining a community here, not simply an information resource to use at your leisure.
Yup, I did (based on your earlier post). I apologize for not doing this at the start but I think we all start by lurking a bit and then get wrapped up in the wealth of knowledge on the forum. I'm still very much a newbie in diy audio but learning quickly and hoping to one day contribute more than just my enthusiasm for this hobby.
After successfully building one of these DACs -- thanks Leo, et al -- I ended up at diyaudio (http://www.diyaudio.com/forums/digital-line-level/137976-experience-diy-dac.html) to learn about bypassing the opamp with transformers. The diyAudio thread is very long but full of info on implementing transformers. I ended up installing Jensen JT-11p-1 transformers but there are lots of options. IMO, a worthwhile upgrade.
Do you have any pics of these mods? Welcome by the way.
Rob.
fandersen
18-09-2010, 00:49
Do you have any pics of these mods?
I used an old CD player to house the DAC as I wasn't concerned about cramming everything into a small box. The CD player also had a decent power transformer that had an 8v output that I ran through a TREAD power regulator to give me a nice clean 5v for the DAC. Since I was bypassing the output stage I didn't have to worry about the 12v.
Initially I ran the DAC with an opamp, hence the mods that are still on the board for the output. The transforms are connected to the C27, C28, C30, and C31 connections. The input and output filters are based on Jensen recommendations for these transformers.
fandersen
18-09-2010, 00:51
Hmm.... the images didn't make it on the last post :scratch:
Hmm.... the images didn't make it on the last post :scratch:
Thanks for the pics. Might try it meself.
Rob.
janos_904
23-09-2010, 09:55
hi janos can you explain a bit clearer what you did with the silver mica on c9????I think I would like to give it a go but cannot understand what you have done...alan
Hi, Sorry for my post to be unclear. So, I made an a new spdif input for the DAC. The signal path is the following: BNC (RCA) inlet, Silver Mica in series, and the output leg of the capacitor soldered by a fine silver wire (or by copper) directly to the CS8416 Receiver chip signal input leg. I will make a photo, how it is looks like. After a test period and some advices, I decided to use 10 nF Silver Mica capacitor insteed. (0.01uF 350V 0.3% tol. Russian millitary SILVER-MICA capacitor). It makes a great job, the signal shape is not affected, I recommend it highly. Cheers, János
janos_904
23-09-2010, 10:05
Dear Leo, I recommend to re-play with this small board. First of all, please design separated (dedicated) 5V, and 3,3 V power supplies, using low noise power regulators. At the receiver chip in the 3,3 V line advicable to use Os-Con very low ESR polimer capacitors (SEP, SEPC). And the DAC rocks :-). May be you are the only one, who could compare this one to Buffalo. But just after the modds listed above. Cheers, János
Hi János ,
I have another one of these dac boards so will start modding it soon. I may even try the Paul Hynes regs with it :lolsign:
janos_904
25-09-2010, 13:01
Hi, here goes a photo to help to isolate power lines. It was taken from a polish diy forum. My polish is poor, but the label is may be not correct :-)! On the picture the labeled line goes directly to the Vref leg of the DAC chip. I disconnected it by a sharp blade, and soldered a new 5 V power inlet, according to the green arrow. Be careful, not to cut deep and wide, because of the ground is close. The +5 V analog of the DAC goes at the under-side of the board. It is good to separate too. Now, we can install and connect separated 5 V supply for DAC chip. Don't forget: the receiver still needs 5 V (3.3 V fits too, or not enough?), because to choose one of the spdif input (optical or coax).
janos_904
07-11-2010, 10:52
Hi, I have to correct my last post. So, both the DAC's analog power (number 28) and voltage reference (number 22) pins are connected by the very same via. That is the worst case for an a voltage out DAC. I guess, the only way to provide a nice VOLTAGE REFERENCE to the DAC is: simply lift up the reference pin, and connect it to our voltage reference source directly. The song of Cs4397 benefits a lot by dedicated (separated) voltage reference.
I have given every major power point to each chip its own, LT317 regulated power supply...thats 6 independent battery powered feeds. I have used silver mica on c9....the sound was at first harsh...I walked away for a few hours , started to sound shockingly good.....eventually I had to recharge my tripath amp batteries, I did not touch the dac board, but when I turned back on...NOTHING.....
1)all the pins on the chips that need voltage are getting what they require
2)have continuity from the digital input and analogue out puts
3)have signal entering the reciever chip
4)have 2.5v dc on the analogue outputs but no AC
5)cannot understand the transistor near c21. I suspect this as it has something to do with the mute function...On the circuit diagram it shows one pin of the transistor connected to pin15(dac), one pion connected to pin 14 of the reciever chip and one pin connected to ground...I cannot find any of my pins on that transistor connected to ground
can any one help...as it was initially working it must be just some stupid mistake I have madehttp://www.lampizator.eu/LAMPIZATOR/LAMPUCERA/CD%20DAC%20Lampucera%20lampizator.html
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
janos_904
27-11-2010, 14:45
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).
janos_904
27-11-2010, 15:06
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/showthread.php?t=6870&highlight=Lampizator
Thanks for searching for the nearly link Puffy,
revoli.
That's ok mate
Puffin.
http://www.diyaudio.com/forums/group-buys/156149-tube-i-zator-professional-pcb.html
http://i73.photobucket.com/albums/i239/saxonsex/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
vinodt1347
28-02-2011, 21:25
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
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
http://shrani.si/f/2e/Ff/4jXHB5xE/dacafter5.jpg
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
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/showpost.php?p=103231&postcount=424
Change spdif input coupling cap (think its C9 from memory ) to a 0.1uf MKP1837 . Should get you started :)
vinodt1347
01-03-2011, 21:58
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
vinodt1347
05-03-2011, 19:40
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 .
vinodt1347
07-03-2011, 20:51
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
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