Also, it seems as though the transformer coming with the DAC isn't 12-0-12, it's 15-0-15.
Therefore, I could get something like this
Universal R Core Transformer for Tube Pre-Amplifier new - eBay (item 250614623647 end time Aug-11-10 05:50:54 PDT)
and save $5.... Probably not worth it, but I was wondering if there are any other options...
But I think I am realizing that all of these ship from china, and therefore, all of them are going to have exorbitant shipping charges attached to them. The most I could hope to save is $10 max.. and it's probably not worth putting more time into figuring out.
Therefore, I could get something like this
Universal R Core Transformer for Tube Pre-Amplifier new - eBay (item 250614623647 end time Aug-11-10 05:50:54 PDT)
and save $5.... Probably not worth it, but I was wondering if there are any other options...
But I think I am realizing that all of these ship from china, and therefore, all of them are going to have exorbitant shipping charges attached to them. The most I could hope to save is $10 max.. and it's probably not worth putting more time into figuring out.
Another option would be a single 15-0-15 and a pre regulator circuit tapped off of one leg to drop it down to 9V or so to feed the dig section. The reg circuit would cost around $4 and you would need about a 50VA trafo. The one you found is only around 10VA.
I got the empty adapter for the PCM1798/94,but how do I find out the pinconfiguration of the DAC board/adapter.I mean I know the pinlayout of the DAC chip,just wanna check the adapters layout is right against the main DAC board.Any one have a layout on this?I messaured voltages of the CS4398 adapterboard,but all I get is voltages I don´t get what is what,I2S and more.
Hi Ryssen,
is your adapter a general one from SSOP to DIP or is THE adapter for PCM1798/94 for the DAC board of this thread?
Can i know where do you get it?
Thanks
Andrea
I can tell you that the 4398 daughter board traces jump all over the place, so if your new board is generic there is no way it will work. If you got it from one of the Chinese dac suppliers you would hope they gave you the right one. You might have to ring out every trace to be sure.
I got it from snow468@gmail.com he sells this DAC board that whe are using.
They look like this:
I know sommeone did use one in this thread with output trafos,so they do work with this board.I guess I will have to try follow the traces on the adapters,because I wanna know what the pins are for,unless snow knows it...
They look like this:
I know sommeone did use one in this thread with output trafos,so they do work with this board.I guess I will have to try follow the traces on the adapters,because I wanna know what the pins are for,unless snow knows it...
I got it from snow468@gmail.com he sells this DAC board that whe are using.
They look like this:
I know sommeone did use one in this thread with output trafos,so they do work with this board.I guess I will have to try follow the traces on the adapters,because I wanna know what the pins are for,unless snow knows it...
I did use it.
Your daughter board is the right one. You had to solder a capacitor and SMD resistor, and of course PCM1798 or 1794 (and NOT 1792 or 1796).
I'll post some pictures later.
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I have ordered 2 LL1572 from Lundahl,I will get them in second week in august.I will use aresistor as I/V.
I even found some schema on a discrete I/V /output I might try later on.
I even found some schema on a discrete I/V /output I might try later on.
Are you sure about that number, those are digital pulse trafos.
Spencer, a forum member, used to sell jfet I/V board kits for very reasonable prices. You might see what he has to offer these days.
Spencer, a forum member, used to sell jfet I/V board kits for very reasonable prices. You might see what he has to offer these days.
Opps, the trafos should be LL1571,recomended by Lundahl.
I will se if spencer has any boards..
I will se if spencer has any boards..
pcm1798 board
That reminds me something...
Actually, I removed several parts from the pcm1798 adaptor (including the opamps under the board) and put few wires to make a direct drop-in for the DA converter.
Look at the picture:
pin19 to R-
pin20 to R+
pin23 to L+
pin24 to L-
That goes directly to the same outputs (ref CS4398 adaptor) on the DA converter board.
You can load the transformers at the output or the input (better results in my setup but takes 4 resistors instead of 2). Take a look at my findings on a previous post (same title: pcm1798).
Pierre G.
That reminds me something...
Actually, I removed several parts from the pcm1798 adaptor (including the opamps under the board) and put few wires to make a direct drop-in for the DA converter.
Look at the picture:
pin19 to R-
pin20 to R+
pin23 to L+
pin24 to L-
That goes directly to the same outputs (ref CS4398 adaptor) on the DA converter board.
You can load the transformers at the output or the input (better results in my setup but takes 4 resistors instead of 2). Take a look at my findings on a previous post (same title: pcm1798).
Pierre G.
I got it from snow468@gmail.com he sells this DAC board that whe are using.
They look like this:
I know sommeone did use one in this thread with output trafos,so they do work with this board.I guess I will have to try follow the traces on the adapters,because I wanna know what the pins are for,unless snow knows it...
Attachments
Is it simply a matter of stripping the board of the parts on the top, removing opamps and soldering the wires as shown or does something else need to be done that is not shown in the pics?
Also - can these adapters be ordered with with PCMxxxx already included or do the chips need to be ordered separately and then soldered?
Thanks for the pics,by the way is there a ground connection on the adapter,to solder the I/V resistors to.
Snow sells the Pcm1798 on adapter,the Pcm1794 he did not have,so I boght an empty adapter and bought a 94 else where on ebay.
You must keep us informed of your progress. I would love to see a direct comparison between the 4398 and a current out chip. From what I have read, getting the I/V conversion right with trafos is very difficult and time consuming. I'm sure you have made a good decision by trusting the trafo manufacturer's recommendations. Compared to them we are all just a bunch of hackers.
I did a direct comparison between CS4398 and PCM1798, and... there is no any comparison. PCM1798 is a way better in every aspect. I'm impressed.
Some pictures:
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.
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.
An externally hosted image should be here but it was not working when we last tested it.
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I just ordered adapter board with PCM1798.
As usual you can expect a barrage of questions to follow as soon as I receive it.
As usual you can expect a barrage of questions to follow as soon as I receive it.