DAC 2496 (AK4393) DAC KIT With CS8416+AK4393+5532

Jump to Latest
MaHo

MaHo

Member
Joined 2011
help please

Hello

I am begginer, I found this thred and bought this kit . The PCB is half done. But I have some questions about PSU.

I want to use 2 trafos first 2x15V 15 VA and second 2x9V 15 VA.
Is 15 VA enough for this aplication?
Can I use both secondaries of 9V trafo conected in paraller for 0-9 input?
I am from Europe /230V/ how to count fuse and which type /fast, slow.../?
How to conet signal grond to chasis, which „hole“ on PCB should I conect with chassis?
And what is best solution to conect signal ground to chassis? /use termistor? use bridge rectiflier? direct conetion?.../

Thanks a lot
Martin
 
50AE

50AE

Member
Joined 2011
MaHo, The seller states that a traffo with more than 10W can be used, so it should do fine.

Guys, there's something I don't understand. The DAC works for USB and SPDIF input, right. But if USB will be used, how do I get the USB to give a 24/96 signal? I heard USB is limited to 16/44. Is this true? Is it possible to get 24/96 from USB and how?
 
E

erin

Member
Joined 2006
MaHo said:
Can I use both secondaries of 9V trafo conected in paraller for 0-9 input?
I am from Europe /230V/ how to count fuse and which type /fast, slow.../?
Click to expand...

Probably just use one secondary for 0-9 input and leave the other winding not connected.

Without measuring current, try 75mA fast fuse, if it blows, increase fuse to 100mA, if it still blows, increase until it does not blow. This is the easiest way.
 
C

col_s

Member
Joined 2008
MaHo said:
Hello

I am begginer, I found this thred and bought this kit . The PCB is half done. But I have some questions about PSU.

I want to use 2 trafos first 2x15V 15 VA and second 2x9V 15 VA.
Is 15 VA enough for this aplication?
Can I use both secondaries of 9V trafo conected in paraller for 0-9 input?
I am from Europe /230V/ how to count fuse and which type /fast, slow.../?
How to conet signal grond to chasis, which „hole“ on PCB should I conect with chassis?
And what is best solution to conect signal ground to chassis? /use termistor? use bridge rectiflier? direct conetion?.../

Thanks a lot
Martin
Click to expand...

Since we are being asked about safety issues here..

Each transformer should have its own appropriately sized fuse on the mains side of the transformer (inline with the "active" wire). The reason for this fuse it to protect the transformer from exceeding its current rating and catching on fire if there is a short internally or on the secondary side. The rating of the fuse should match the rating of the transformer, and is usually included in the datasheet for the transformer.

Further fuses can be used on the secondary side to protect the devices that you will be powering. These should be sized for the load. Your can measure the current drawn using an ammeter and then size the fuses on the secondary appropriately.

I think a lot of people probably leave the signal ground floating. You should take a wire from the connector where the transformers connect to the PCB ground. This is the local "star" ground point. Run this back to the chassis ground.

some information on grounding/earthing for safety, and earth loop breaking.

Earthing (Grounding) Your Hi-Fi - Tricks and Techniques
Power Supply Wiring Guidelines
 
V

Veggiel

Member
Joined 2010
col_s said:
Since we are being asked about safety issues here..

Each transformer should have its own appropriately sized fuse on the mains side of the transformer (inline with the "active" wire). The reason for this fuse it to protect the transformer from exceeding its current rating and catching on fire if there is a short internally or on the secondary side. The rating of the fuse should match the rating of the transformer, and is usually included in the datasheet for the transformer.
Click to expand...

I have a problem with my fuse everytime I try to start the DAC my fuse blows. I'm using a 20va 2 x 15v transformer primary 230v, with a fuse rated at 80ma fast blow.

Can somebody help me with this isue?
 
Last edited:
T

Trebla

Member
Joined 2005
I have a problem with my fuse everytime I try to start the DAC my fuse blows
Click to expand...
.

It's probably just the inrush of current when the thing is switched on.
Try a time delay(slow blow) fuse, which should allow for this. I wouldn't use a fast blow anyway.
Alternatively, just try progressively bigger fuses till it works, so long as you are confident that the wiring is okay
 
C

carlmart

Member
Joined 2001
preciseaudio.com
I took the dive and bought a semi-assembled DAC4396 kit from eBay. Ordered only the pcb with the SMD parts and no through-hole parts. If I am going to change them anyway, so why pay for them?

For the passive parts I will use 1% PRP resistors for everything, except those around the output chip, which might be 0.1% matched PRPs or specific 0.1% types.

For the film capacitors, Wima FR2 or polystyrenes. I am not sure what to use on the electrolytic local bypasses. Oscon types, Sanyo or Nichicon LF, should be good, at least for the digital ICs.

For the regulated power supply I plan to build an external pcb. At first it should be built with 3X7 chips, properly filtered in the adj leg and using no low-esr capacitors at the output. 3X7s do not like low-esr caps at their output.

On a second stage, I should try a Sulzer/Jung regulator on the output IC.

As there will be a socket for that chip, I will try several dual chips I have and maybe some singles on adapter.
 
C

carlmart

Member
Joined 2001
preciseaudio.com
But can't you assemble an electronics kit? Or did you buy the assembled kit?

There will be things much more important than connecting the transformer to the board.

Also you will dealing with potentially dangerous electric hazards, as you will connecting the board to AC supply.

If you are not experienced on this it can be very risky. Can't you find someone who can do this for you?
 
Greg Erskine

Greg Erskine

Member
Joined 2002
Paid Member
FOXYE said:
I have the assembled kit, i need to know where to connect the 18V [red] and 0V [black] in the pcb.
Click to expand...

Hi FOXYE,

If you are using a single transformer there is a small link that is required on the underside of the PCB. It should be obvious as it is close to the power in terminals.

You need 15-0-15 VAC (3 wires) transformer. If you use 18-0-18 VAC it will work but I suspect the 12 V regulators will get extremely hot and probably burn. Mine get hot especially the positive regulator (55 to 60 degrees) on 15-0-15 VAC.

regards
 
C

carlmart

Member
Joined 2001
preciseaudio.com
FOXYE said:
I have dual 18V transformer, can I connect it to the converter?
Click to expand...

i need to know where to connect the 18V [red] and 0V [black] in the pcb.
Click to expand...

Do you have a single or a dual transformer? You need a dual transformer for this kit.

If the regulators get hot, particularly the 7809, you will need to attach a heatsink. The size of it will depend on the extra current dissipated for 18v AC. I don't know which are the current requirements of this kit.

The place where 7809 is seems to show that it was likely heatsinking it would be necessary. Perhaps just a small aluminium plate would do it.

Greg: your 7X12 regs also get hot? If so, then heatsinking them would be tricky.
 
You must log in or register to reply here.
Top Bottom