I know that there are a lot of schematics on diyaudio for the D1 but I just want a simple one. I have searched and found JFET ones and modified ones, I want the original one. I am looking for a schematic for the D1 I/V stage and SE conversion without the DAC or supporting stuff. I do not know 100% which circuits are for the volume control, I/V, receiver, etc. so a simplified schematic or link to one would be a boon. I want to use this with a Twisted Pear Buffalo DAC which uses the ESS Sabre DAC chip. Thus I would like suggestions for proper compnent values as well and I will include the data sheet for the DAC in this post as well. Thanks in advance and please be patient with me, I am new to this.
Now I just have to wait and see what Mr. Pass says about the Audio Nirvana Cast Super 12 drivers, enclosures, and FW amps to drive them.
CSS Sabre data sheet:
http://www.4shared.com/file/39002019/8023812b/ES9008_DataSheet.html
Now I just have to wait and see what Mr. Pass says about the Audio Nirvana Cast Super 12 drivers, enclosures, and FW amps to drive them.
CSS Sabre data sheet:
http://www.4shared.com/file/39002019/8023812b/ES9008_DataSheet.html
I asked Khundude to contact me so we could discuss how to modify the D1 to be suited for the D1 I/V. I have made a few tries over at the groupbuy thread but haven't made it work as intended yet.
I guess to make it work it would be simple to lower the gain of the D1 and maybe raise the bias (or the I/V resistor).
Also I think that if the buffalo sees a to high input impediance it will go in to voltage mode instead of current mode.. This may also be a problem. But I'm not shure, so if someone could fill in maybe
I guess to make it work it would be simple to lower the gain of the D1 and maybe raise the bias (or the I/V resistor).
Also I think that if the buffalo sees a to high input impediance it will go in to voltage mode instead of current mode.. This may also be a problem. But I'm not shure, so if someone could fill in maybe
I too would love to try this as an output for my buffalo - to be honest though I lack the knowledge required to suggest changes and so on. Can the buffalo be modified to put out the right amount to suit the D1?
Anyway, someone back up the thread referred to a group buy for the D1? Where would that group buy be? - I can't find it here?
Fran
Anyway, someone back up the thread referred to a group buy for the D1? Where would that group buy be? - I can't find it here?
Fran
Hi Fran,
The groupbuy finished a few weeks ago, sorry. The layout was made by Zei.
I have had mine playing for a few days according to the original schematic and it do sound good to me. only the output is a bit high thou.. I'm sure there is alot more to tweak to get opimal performance.. Russ have tried a similar circuit called Haiku. He talked about "input bias" should be 1.65V. But I too have not the knowledge to do this..
What do you use today as I/V, Fran?
Best regards
The groupbuy finished a few weeks ago, sorry. The layout was made by Zei.
I have had mine playing for a few days according to the original schematic and it do sound good to me. only the output is a bit high thou.. I'm sure there is alot more to tweak to get opimal performance.. Russ have tried a similar circuit called Haiku. He talked about "input bias" should be 1.65V. But I too have not the knowledge to do this..
What do you use today as I/V, Fran?
Best regards
Yunick said:
Variac said:
Here's a thread where I sim'd the standard D1.
http://www.diyaudio.com/forums/showthread.php?postid=1329559#post1329559
-David
woodturner-fran said:
It's a wee bit easier to mod the D1 than the DAC.
The D1 should be adaptable to most any DAC current output, you probably just need to tweak the resistor values. The IRF610s aren't wimpy little FETs and could handle more current if need be (properly heatsinked). The lower resistors (R26/R33) control the current bias (~9ma). The upper ones (R27/R34) control the voltage gain. The combo of the upper and lower resistors sets the DC voltage bias point (~15V) of the input to the voltage followers (Q2/Q5) (VOL+/VOL-). I'd probably try to keep that 15V bias point.
So, if the Buffalo puts out twice the current of the PCM63 of the original D1 (I don't know much more the Buffalo puts out) then to cut the gain in half, cut the upper resistors by half, to 750. If that's all you do your VOL+/VOL- bias point becomes 22.5 volts. To lower that back down to 15V cut the bottom resistors by half to 1.65K, which will raise the current bias to 18ma.
Don't know how it will sound, but it seems Nelson tends not to object to more current through a FET.
No, I haven;t tried it in voltage mode. The IVY is good - and better than just good when I added in the 10nF caps. That was what opened my eyes to what was possible with this DAC.
I will find out a bit more about the voltage mode and have a listen. I'm using it single ended so just need to sort that out and then I will listen in. I believe I need to add a resistor somewhere to make it go to voltage mode. Have to research this as I don't know much about it.
Fran
I will find out a bit more about the voltage mode and have a listen. I'm using it single ended so just need to sort that out and then I will listen in. I believe I need to add a resistor somewhere to make it go to voltage mode. Have to research this as I don't know much about it.
Fran
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