Hi Quang Hao,
in the last version (2 PCB) you have changed the SSHV for the I/V stage, it´s the same of the D3a Pre.
There are lot of changes during the thread, I am a little unshure what I have to buy.
Also the dimension of the power transformer is for me ??????, after Tangmonster have had a lot of problems with the PS of the D3a Pre.
You show different tubes for use, but the need also different B+, 200V - 270V, the SSHV can regulate it without changing nothing of parts?
Perhaps Salas can give a little help here.
I think it would be a good idea show a new atual BOM and schematics with all values verified.
Klaus
Quanghao... Here is one...
PLEASE NEW THREAD AND NEW BOM
It's very confusing having differrent projects all in one thread. Threads are free! It makes sense! Let's do it already!
Quanghao, you have a great project here and I'm not trying to be difficult... I'm only asking that you start a new thread because this thread is getting confusing with all the different interations of this project all being discussed in one place. I don't think I'm the only one asking for this either.
As far as typos in the BOM just look back a few pages.
Thanks!
As far as typos in the BOM just look back a few pages.
Thanks!
Hi all!
I have open new topic about DAC-END 2 up dat, I call DAC-ASH , it mean Andrea-Salas-Quanghao
You see in this link: http://www.diyaudio.com/forums/quan...99-dac-ash-dac-end-2-up-date.html#post2274329
The comments of you is what I always look forward and thank you immensely.
I have open new topic about DAC-END 2 up dat, I call DAC-ASH , it mean Andrea-Salas-Quanghao
You see in this link: http://www.diyaudio.com/forums/quan...99-dac-ash-dac-end-2-up-date.html#post2274329
The comments of you is what I always look forward and thank you immensely.
Quanghao:
In post 1785 for Salas HV IC1 is listed as a 9160. I believe it should be a IRF9610.
Also for the zener (4172) you have recommended other options as this number is hard to find.
My SalasHV is running well powering my E182CC board
Best
Bob
Hi Guys,
Ive a question- has it ever happened to any of you that one of the dac elements close to AD1865 gathered 50 Hz transformer noise that was audible in the speakers? i know that my transformer is too close to the pcbs but the guy i bought it from assured me its screened. When I put in optional chokes, its even a bigger nightmare- noise is audible at 9 oclock. Its less noisy when I put in a piece of steal between the transformer and pcb where the chokes and wires joining pcbs are. Thx for help
Ive a question- has it ever happened to any of you that one of the dac elements close to AD1865 gathered 50 Hz transformer noise that was audible in the speakers? i know that my transformer is too close to the pcbs but the guy i bought it from assured me its screened. When I put in optional chokes, its even a bigger nightmare- noise is audible at 9 oclock. Its less noisy when I put in a piece of steal between the transformer and pcb where the chokes and wires joining pcbs are. Thx for help
Attachments
If your transformer is a nickle core device, you will have to take some extraordinary measures to overcome hum, regardless of screening. The core is a great antenna.
Separate .060 thick cold rolled steel box, annealed to Marstenite / Osteonite temperatures will buy you -120 db of external field rejection. Nickel and copper plate will extend that off into RF land.
Buy Ralph Morrisons book "Grounding and Shielding Techniques" to learn how to implement fully shielded boxes.
Of course, you could also start turning the transformer, rotating it in three axis and raising and lowering, to see if there is a null field plane you can use. Alternately begin changing the location of AC carrying wires with relation to the transformer.
Thing to know and use about EMF is that it is an infinite field, but you can shove it and form it by using ferrous materials with little permeability, as in the CRS above, or mu metal for high perm attachment . Think in 3D above all.
Separate .060 thick cold rolled steel box, annealed to Marstenite / Osteonite temperatures will buy you -120 db of external field rejection. Nickel and copper plate will extend that off into RF land.
Buy Ralph Morrisons book "Grounding and Shielding Techniques" to learn how to implement fully shielded boxes.
Of course, you could also start turning the transformer, rotating it in three axis and raising and lowering, to see if there is a null field plane you can use. Alternately begin changing the location of AC carrying wires with relation to the transformer.
Thing to know and use about EMF is that it is an infinite field, but you can shove it and form it by using ferrous materials with little permeability, as in the CRS above, or mu metal for high perm attachment . Think in 3D above all.
Oh! That is the transformer!
It is very near the chip and tube! Not good!
You can try take it go out the chassis, and test again!
you use 5687! so the SSHV need low current, R1 ( R set current) = 56R, it is ok!
An measure the voltage drop on R 56R, And V: 56 = mA ( toltal current)
I've had a problem 
The DAC stopped working yesterday. I pulled it apart and the power supply for the DAC (the salas shunt). has gone a cropped on the digi supply.
The 2 resistors have got extremely hot. So hot they melted my poor solder join. So I resoldered them back together and it's working again.
However the resistors are very hot to the touch. Also the 3 dropper LED's are only illuminating occassioanlly. Sometimes they don't come on at all. Other times they come on for maybe 2 minutes, then they go out.
The other parts of the shunt are operating fine (the ana. side).
Any idea's anyone?
The DAC stopped working yesterday. I pulled it apart and the power supply for the DAC (the salas shunt). has gone a cropped on the digi supply.
The 2 resistors have got extremely hot. So hot they melted my poor solder join. So I resoldered them back together and it's working again.
However the resistors are very hot to the touch. Also the 3 dropper LED's are only illuminating occassioanlly. Sometimes they don't come on at all. Other times they come on for maybe 2 minutes, then they go out.
The other parts of the shunt are operating fine (the ana. side).
Any idea's anyone?
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