I know there are smiliar threads, but this is after recap and new opamp.
I had so much trouble with the smd i took to to get it done.
First off i played it , was no sound, though cd was changing tracks etc and functioning so i assumed no power issues.
I took the board out and found using the ohm selector on the multimeter, one bridge wasnt working so fixed that.
Now i get clean sound from the left and right , i describe that as static /distortion. When i get a chance tomorrw. I will search for any dry joints. Again multimeter gave it all the clear on the ohm.😕
I tested another Technics player with out the earth to the case, and it was fine, as the new RCAs are grounded , not to the case.
Any other suggestions would be helpful
pics of the mod 😀 Looks stunning
PSU computer style cable removed, 24awg Neotech copper 600V
PSU Nichicon KZ. FG SilmicII
AUDIO SECTION: DAC Elna Cerafine opamp/output Elna SilmicII and ES Nichicon
I had so much trouble with the smd i took to to get it done.
First off i played it , was no sound, though cd was changing tracks etc and functioning so i assumed no power issues.
I took the board out and found using the ohm selector on the multimeter, one bridge wasnt working so fixed that.
Now i get clean sound from the left and right , i describe that as static /distortion. When i get a chance tomorrw. I will search for any dry joints. Again multimeter gave it all the clear on the ohm.😕
I tested another Technics player with out the earth to the case, and it was fine, as the new RCAs are grounded , not to the case.
Any other suggestions would be helpful
pics of the mod 😀 Looks stunning
PSU computer style cable removed, 24awg Neotech copper 600V
PSU Nichicon KZ. FG SilmicII
AUDIO SECTION: DAC Elna Cerafine opamp/output Elna SilmicII and ES Nichicon
An externally hosted image should be here but it was not working when we last tested it.
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I know it sounds obvious but "static after cd mods" means it has to be something you have done. You need to check for stray solder blobs and damaged or broken print. Also check all component values are correct. Check all the rails correct too.
Thanks Mooly, the opamp and output area i increased the voltage 10v to 50v, but same capacitance? but that should not matter. The board i bought in to get the smd done, i bought it out of the player to cut costs, so the guy wasnt able to test it. I feel, the problem must be my soldering, i had to bridge some, so there might lie the problem 🙁 hope to have sorted soon cause sounds great even on the crap computer speakers, as i feared to hurt my speakers 😀
😕
I re did some soldering and re did a bridge on one cap, i had to actually take it to the next point, a resistor and a rail, but tested fine with ohm meter, but again same old same old , right channel, maybe a bit less audiable this time as bad as before, left is perfect. I wonder if the opamp is faulty, but then i doubt that as the left is fine,
Could it be going up 10v to 40v is too much. I have other Silmic going in the mail, they are 16v, i could use them and also the 10v to 50V on the ES, i have a 25v one as a spare.
out goes the board again
Thanks Willi yes I did look over the caps, only ones i am not sure are the BPs, but direction isnt important with them.
I re did some soldering and re did a bridge on one cap, i had to actually take it to the next point, a resistor and a rail, but tested fine with ohm meter, but again same old same old , right channel, maybe a bit less audiable this time as bad as before, left is perfect. I wonder if the opamp is faulty, but then i doubt that as the left is fine,
Could it be going up 10v to 40v is too much. I have other Silmic going in the mail, they are 16v, i could use them and also the 10v to 50V on the ES, i have a 25v one as a spare.
out goes the board again
Thanks Willi yes I did look over the caps, only ones i am not sure are the BPs, but direction isnt important with them.
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Voltage rating of the caps won't cause any issue (as long as they are high enough rated to begin with)
If the left channel is OK then it sounds like a blob or a break somewhere around the right channel DAC/processing. It won't be an opamp (99.999% sure on that)
If the left channel is OK then it sounds like a blob or a break somewhere around the right channel DAC/processing. It won't be an opamp (99.999% sure on that)
Hi Mooly thank you, Yes since its so clear and fine on the left, i realise it must be the right, sure the soldering on the opamp is good cause I had it done. Maybe a rail, I didnt look around the DACs themselves so will trace all over it tomorrow. Caps for P990 arriive soon, Leaving those opamps, so the P350 might beat it with the LM4562 😀
put it back together after touching up solder, moving one lead away from the track, cleaned it up and still bag right channel😕🙁 , but the channel that works the left is so so nice
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
The only way you will fix this is by logical fault finding.
Have you checked the DC voltages around the opamp, one channel vs the other to see if that shows anything ? And make sure you haven't dropped a solder blob somewhere on the PCB around one of the DAC's
If you can't find anything from that then look at disconnecting the DAC outputs and cross linking left and right to try and prove whether the problem really is in the analogue stages or whether its further forward around the DAC.
Have you checked the DC voltages around the opamp, one channel vs the other to see if that shows anything ? And make sure you haven't dropped a solder blob somewhere on the PCB around one of the DAC's
If you can't find anything from that then look at disconnecting the DAC outputs and cross linking left and right to try and prove whether the problem really is in the analogue stages or whether its further forward around the DAC.
Thanks Mooly, I don t think my multimeter can detect DC. I will check everything again, you mean the PCM56 DAC? I wonder if its around the PSU area or around the 4558 opamp area, check the whole thing over tomorrow. Maybe the very fine traces on the opamp are not exactly touching on the right side. I was worried it was my briding work near the opamp where I lost most of the traces, but i joined the cap with wire to both the rail and resistor
P990 is done with caps, including new PSU caps, i trying out the Elna R20
P990 is done with caps, including new PSU caps, i trying out the Elna R20
DC ! Any meter can read dc voltages. Check the output pins of the opamp and see if the dc voltages are similar L vs R.
You could try recording the sound direct from the line output (using Audacity ?) to see if that gives us any clues.
You could try recording the sound direct from the line output (using Audacity ?) to see if that gives us any clues.
Hi Mooly,
You mean the audio output, so you can hear the distorted sound? I can do that.
As for measuring i set it to 200, and on the left ( using the output cap, since opamp is beneath the board, it gave 6.4, however i can measure the other cap its it bridge and can get to the pins.
Could i removed them and then measure from the pads? I shall do this tomorrow as its stormy this afternoon
You mean the audio output, so you can hear the distorted sound? I can do that.
As for measuring i set it to 200, and on the left ( using the output cap, since opamp is beneath the board, it gave 6.4, however i can measure the other cap its it bridge and can get to the pins.
Could i removed them and then measure from the pads? I shall do this tomorrow as its stormy this afternoon
Yes, just compare DC voltages on the left vs right circuitry. Left opamp output vs right and then work all the way back to the DAC output seeing if anything shows up.
I took the board out again, and checked it, a heatsink thing was a bit loose, whether that will be it, not sure. Storms atm, so I dont risk using the previous vintage gear now. I will have to remove caps so i can run wires up to test it. I followed the track, it seems the BPs are the output caps, hard to tell which is + or -, so will use the place of the Silmic close to the opamp. The DAC area seems ok.
Hmmm
I couldn't retrieve your file. Why why why are these file hosting sites total garbage. It wants to install download managers and all sorts of malware.
I did suspect as much so tried it first on an older PC. There is no obvious way to download your file on its own. Its all pop ups/pop unders and junk and malware. I'm having to restore that PC from an image back up to be sure nothing installed silently.
Use Dropbox or compress a few seconds of the to an MP3 128kbs and attach it directly to the forum as an attachment (zipped folder)
Sorry 🙂
I couldn't retrieve your file. Why why why are these file hosting sites total garbage. It wants to install download managers and all sorts of malware.
I did suspect as much so tried it first on an older PC. There is no obvious way to download your file on its own. Its all pop ups/pop unders and junk and malware. I'm having to restore that PC from an image back up to be sure nothing installed silently.
Use Dropbox or compress a few seconds of the to an MP3 128kbs and attach it directly to the forum as an attachment (zipped folder)
Sorry 🙂
Hi Mooly, sorry about that, I thought it was an okay one. I know popups are crazy, like this site i like to get movies alluc, gosh the files to watch the movies so much pop ups.
Its in wav, so get it mp3
Its in wav, so get it mp3
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OK, that sounds very odd, not quite what I was expecting tbh although it doesn't sound like an analogue fault but rather a problem around the DAC for that channel. When you analyse the file its just broadband noise.
Did you compare voltage readings on the left and right opamps (because if the voltages are different then that too can point to a problem around the DAC... you would then need to look at the DAC voltages of L vs R)
Did you compare voltage readings on the left and right opamps (because if the voltages are different then that too can point to a problem around the DAC... you would then need to look at the DAC voltages of L vs R)
🙁 that is bad if the DAC, but I did find that the PCM56P-J is still available at mouser. I could only read a cap on the good side close to the opamp, it gave 6.4. Do i remove the caps so can check? the voltages from the cap solder pads?
How do i measure the DACs? i find the ouputs for the PCM56, i have the PDF for the new replacements
http://www.mouser.com/ds/2/405/pcm56-406133.pdf
Another idea, could i desolder the dacs and change channels?
How do i measure the DACs? i find the ouputs for the PCM56, i have the PDF for the new replacements
http://www.mouser.com/ds/2/405/pcm56-406133.pdf
Another idea, could i desolder the dacs and change channels?
I still think your fault is man made... remember it all worked before the mods... so its unlikely to be a true failure of a semiconductor. Without a scope all you can do is be methodical and try and find some major discrepancy. That means measuring all the DC conditions around the DAC's and output stage. Play a CD and go around every pin on the DAC's and write the voltages down and compare. Any obvious differences one vs the other ?
Maybe this is going to be one to chalk up to experience......
Maybe this is going to be one to chalk up to experience......
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