FETaudio discrete I/V
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PCM1794A DAC for Sale / PCM1794
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You could save time by buying the PCM1794a dac board that comes with the discrete output.
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PCM1794A DAC for Sale / PCM1794
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Paint
1. Size the pdf view to fit on your screen. You may want to make a few screens out of it to get it nice and big.
2. Press your "print screen" button to copy the view to the clipboard.
3. Paste the clipboard into Windows Paint accessory.
4. Save as a jpeg
5. Crop, resize to 11 inches wide, compress to 200kb, ect, with Irfanview or PhotoShop.
1. Size the pdf view to fit on your screen. You may want to make a few screens out of it to get it nice and big.
2. Press your "print screen" button to copy the view to the clipboard.
3. Paste the clipboard into Windows Paint accessory.
4. Save as a jpeg
5. Crop, resize to 11 inches wide, compress to 200kb, ect, with Irfanview or PhotoShop.
I could save time and money by focusing what I have now for the CS4398 DAC....discrete regulator all parts, digital input tranny with BNC connection, corrected PLL values, upsampling board and some best of all Onetics output traffos just for the CS4389
BTW spencer's board way far from my budget as a second project....
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If you need transformers for your DAC:
http://www.diyaudio.com/forums/swap-meet/174219-digitec-transformers-sale.html#post2313419
http://www.diyaudio.com/forums/swap-meet/174219-digitec-transformers-sale.html#post2313419
anbody had this happen?
I emailed Ian,at gigaworks about a schematic for his high end DAC and now I am a BLOCKED bidder from His site on ebay,beat that,lol!!!!!
Touchy
I have same problem!!
I can't buy anything from his site
I have +100 feedbacks on ebay, only positive...
Snow
You can email snow468@gmail.com who is the original designer of the board to ask if she will sell you what you want. She doesn't always list on ebay but has stock to sell and accepts paypal and ships fast.I have same problem!!
I can't buy anything from his site
I have +100 feedbacks on ebay, only positive...
I have same problem!!
I can't buy anything from his site
I have +100 feedbacks on ebay, only positive...
Manual here for you. It's for the V9 DAC and be warned some of the schematic doesn't match the board -
https://dl-web.dropbox.com/get/HiFi...ormation/CS4398 DAC2 192KHz.pdf?w=e53b30d1
Upsampler issue with 192KHz files
Hello Dears,
today I downloaded some sample file from my favorite audiophile hirez label:
Unipheye Music
I got a 24/192 file and a 32/192 among others. I had never listened to native 192KHz stuffs. I tried the 24/192 and I had problems. I source the gigawork from the spdif output of my Esi juli@. I work under linux but I also tried win7+JRMC14 and had the same problem.
The sound came at very low level and it was full of noise...like an FM radio out of sync, a sort of brown noise. So I thought it was my ESI card, but its output was OK. So I removed the upsampler from the gigawork and everything worked ok... by the way these files sound really great!
So when a 192Khz stream is passed to the the upsampler it gets into troubles, ans I wonder why? I thought that the upsampler should have operated as bypass when a 192Khz stream was played, but instead something wrong is happening.
It could also be that by upsampling board has some problem. I hope somebody out there can try this and give me feedback.
Cheers
Pietro
Hello Dears,
today I downloaded some sample file from my favorite audiophile hirez label:
Unipheye Music
I got a 24/192 file and a 32/192 among others. I had never listened to native 192KHz stuffs. I tried the 24/192 and I had problems. I source the gigawork from the spdif output of my Esi juli@. I work under linux but I also tried win7+JRMC14 and had the same problem.
The sound came at very low level and it was full of noise...like an FM radio out of sync, a sort of brown noise. So I thought it was my ESI card, but its output was OK. So I removed the upsampler from the gigawork and everything worked ok... by the way these files sound really great!
So when a 192Khz stream is passed to the the upsampler it gets into troubles, ans I wonder why? I thought that the upsampler should have operated as bypass when a 192Khz stream was played, but instead something wrong is happening.
It could also be that by upsampling board has some problem. I hope somebody out there can try this and give me feedback.
Cheers
Pietro
Trans I/V hum
My transformer I/V with PCM1798 is running good at 42R per leg into Edcor MXL8CS which are 1:8 so the voltage level isn't bad. Maybe about 6-8db less than the cap direct out of one leg of the CS43122 which is plenty loud direct into my amp with digital volume control wide open. I could use another 6db from the I out chip so changing to the 1794a should get me there even with the low resistance. The 43122 is really very good. Very detailed. The 1798 is also very detailed and may have a more natural sound. The sound is promising but I have a low hum I can't get rid of. Any ideas? Disregard the cap and transformer options that are visible at the left of the board in the photo. The PCM1798 module no longer has any signal connection out of the riser pins after removing the original signal resistors, caps and opamps. I originally had "A" ground on the input center tap and on the - leg of the single ended outputs. Then I tried floating the ground on the outputs but the hum remains. The 43122 has zero hum (just a slight hiss that I will need to work on) on the same board.
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EDCOR - MXL8cs
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My transformer I/V with PCM1798 is running good at 42R per leg into Edcor MXL8CS which are 1:8 so the voltage level isn't bad. Maybe about 6-8db less than the cap direct out of one leg of the CS43122 which is plenty loud direct into my amp with digital volume control wide open. I could use another 6db from the I out chip so changing to the 1794a should get me there even with the low resistance. The 43122 is really very good. Very detailed. The 1798 is also very detailed and may have a more natural sound. The sound is promising but I have a low hum I can't get rid of. Any ideas? Disregard the cap and transformer options that are visible at the left of the board in the photo. The PCM1798 module no longer has any signal connection out of the riser pins after removing the original signal resistors, caps and opamps. I originally had "A" ground on the input center tap and on the - leg of the single ended outputs. Then I tried floating the ground on the outputs but the hum remains. The 43122 has zero hum (just a slight hiss that I will need to work on) on the same board.
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EDCOR - MXL8cs
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Attachments
hi,
Do you have a scope?Or a laptop,you can download a scope program and use the sound input with a probe to test your signal,I would shorten as many wires as possible and use the scope to determine the freq. of the hum and start looking,check PS first and maybe move the transformers away from the board,or shield them in a metal can grounded to the CT,If ps is smooth,then start at input and trace it through till you find it ,you can connect a wire to ground and "make "ground checks as you go ,something will change the sound and you will know you're in the area of the problem,
try it and see what happens,Good hunting!!! alot of good grounding techniques on this forum....
Do you have a scope?Or a laptop,you can download a scope program and use the sound input with a probe to test your signal,I would shorten as many wires as possible and use the scope to determine the freq. of the hum and start looking,check PS first and maybe move the transformers away from the board,or shield them in a metal can grounded to the CT,If ps is smooth,then start at input and trace it through till you find it ,you can connect a wire to ground and "make "ground checks as you go ,something will change the sound and you will know you're in the area of the problem,
try it and see what happens,Good hunting!!! alot of good grounding techniques on this forum....
Is the 42R is the optimum value for most traffos or just for the Edcor?
Will the pcm works with 1:1?
buzz
I moved the the ps transformer around and it is radiating a little. That is just something I had laying around. I will have to get a better one. That is not the cause of the buzz though. The noise increases when I touch any of the grounds such as the top of the filter caps or the transformer shields. But not when I touch the RCAs for the trannie outputs which are now floating. It doesn't hum at all with the CS43122 in action and the output going out the other side through the caps or 1:1 transformers.
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I moved the the ps transformer around and it is radiating a little. That is just something I had laying around. I will have to get a better one. That is not the cause of the buzz though. The noise increases when I touch any of the grounds such as the top of the filter caps or the transformer shields. But not when I touch the RCAs for the trannie outputs which are now floating. It doesn't hum at all with the CS43122 in action and the output going out the other side through the caps or 1:1 transformers.
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gee nobody home???? http://www.auctiva.com/stores/viewstore2.aspx?id=556676&itemFilter=1&page=home
Store
Are you looking for Gigawork?
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gigawork shop items - Get great deals on DAC Kits, Amplifier Kits items on eBay Stores!
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Are you looking for Gigawork?
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gigawork shop items - Get great deals on DAC Kits, Amplifier Kits items on eBay Stores!
.
Download the 8421 datasheet and study it. Internally it does some complicated things that are beyond my knowledge base. It does mention problems with truncation distortion when the input format is not correctly set to match hi rez inputs, and it does not go into bypass mode automatically.
No tap
Still searching for the hum in the trans I/V of the 1798. I removed ground from the primary center tap. The hum remains but the conversion is still intact. A center tapped trans will only be necessary if you implement the load on the secondary side such as Rakk which opens up more options for trannies. I then connected ground back onto the minus leg of the single ended secondary and the hum went away. For one power on cycle. I think? I swear it was gone. Then it was back. Oh well. Listening over the hum, The CS43122 with a simple one leg cap out is better anyway. Maybe a mono mode PCM1794a with a class A I/V would beat it but that is a lot more complicated for multiple channels of an active cross.
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Still searching for the hum in the trans I/V of the 1798. I removed ground from the primary center tap. The hum remains but the conversion is still intact. A center tapped trans will only be necessary if you implement the load on the secondary side such as Rakk which opens up more options for trannies. I then connected ground back onto the minus leg of the single ended secondary and the hum went away. For one power on cycle. I think? I swear it was gone. Then it was back. Oh well. Listening over the hum, The CS43122 with a simple one leg cap out is better anyway. Maybe a mono mode PCM1794a with a class A I/V would beat it but that is a lot more complicated for multiple channels of an active cross.
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