Mr White's "Opus", designing a simple balanced DAC

[DarrenWadsworth]

Transformer help

I got how to wire the toroidal transformer for use in powering my cd-rom controller. I plan on using an R-core for the OPUS. Before I destroy the LCPS could someone tell me which wires I should connect to which LCPS inputs? Which wires I connect to which AC source? Neutral? Hot?

An externally hosted image should be here but it was not working when we last tested it.

Thank you
Darren

 

[megaman12]

Hi guys,

I was just testing out the ASRC module, and by accident all three bypass pins were connected. After that I couldn't hear any music. Could I have blown out something in the ASRC module?

 

[BrianDonegan]

Re: Transformer help

I got how to wire the toroidal transformer for use in powering my cd-rom controller. I plan on using an R-core for the OPUS. Before I destroy the LCPS could someone tell me which wires I should connect to which LCPS inputs? Which wires I connect to which AC source? Neutral? Hot?

An externally hosted image should be here but it was not working when we last tested it.

Thank you
Darren

For 120V mains, you join the Red and Green leads together and to one mains connection, and the Yellow and Orange leads together and to the other mains connection.

For the LCPS, use the White and Black secondaries; White/White/Black/Black in that order.

If you are not using the Blue and Brown secondaries (18V), be sure to tie them off so they do not short.

 

[orthoefer]

Re: Transformer help

I got how to wire the toroidal transformer for use in powering my cd-rom controller. I plan on using an R-core for the OPUS. Before I destroy the LCPS could someone tell me which wires I should connect to which LCPS inputs? Which wires I connect to which AC source? Neutral? Hot?

An externally hosted image should be here but it was not working when we last tested it.

Thank you
Darren

That's an interesting looking transformer you've got there. Where did you get it? Another nice thing about your transformer is that you can use the 18 V secondaries to power the LCBPS for the Ballsie.

 

[DarrenWadsworth]

Thanks Brian!

I got that from Diyclub

I read where the r-core type has lower noise etc for audio applications.


Darren

 

[DarrenWadsworth]

When I connected the Toroidal I bought from Twisted Pear, my DMM show the output voltage as 17.5vac.

Was supposed to be:

(115V+115V prim. / 15V+15V 25VA sec.)

Did I connect it wrong?

I'm using it for the cd-rom controller which the maker just told me that 17.5 could be too much for the voltage regulator.

He recc 12v but told me that 15 would be ok. I guess 17 is too much.

Any Ideas?

Thank you

Darren

 

[BrianDonegan]

That's the unloaded voltage, but could also be that your mains voltage is a little high. What kind of vreg is it?

 

[DarrenWadsworth]

I would have to look after work. If I give you the part number would that help? This thing produces 12 and 5 volts for the cd-rom.

An externally hosted image should be here but it was not working when we last tested it.

Do you think maybe its the one by the rectifier diodes?

Or?

Darren

 

[BrianDonegan]

Looks like an LM7812 and 7805. They can handle the voltage, but probably not without a heatsink. Maybe you shoudl try a different trafo.

 

[DarrenWadsworth]

Rather than buy another another expensive transformer (and wait for shipping), could I just mount a heatsink for those? Ill check on the part number when I get home tonight.

Darren

 

[MrMajestic]

Our plan is to make another receiver based on the WM8805 to allow up to 8 S/PDIF sources.

Do you have a timeframe of the new receiver bóard? This would be a great addition to the lineup no doubt.

 

[DarrenWadsworth]

Looks like an LM7812 and 7805. They can handle the voltage, but probably not without a heatsink. Maybe you shoudl try a different trafo.

I verified that the VREG next to the rectifier diodes is a 7805. You're good!

Would it fry it if I attach bend it up and attach a generic TO220 heat sink (which I can get locally) to that VREG? What about the other non-heatsinked part?


If you could reply today it would be great as I am going to try to get the whole thing running by tonight.

Thanks, very much.

Darren

 

[BrianDonegan]

You should be able to do that easily. It can;t hurt to do both devices. Make sure you insulate the heatsink from the tab of the device (mica or other insulator).

 

[megaman12]

--------------------------------------------------------------------------------

hi,

I've been using the opus dac through usb for a few days now. I was only using it on my main computer, which is running Vista, and it's been running fine. Today I tried plugging in the usb into 2 windows xp computers, but all i get is static and heavy interference with the music. Anyone have this problem?

 

[Russ White]

I use the module with XP regularly.

Have you switched back to your Vista PC? Was it still fine?

Cheers!
Russ

 

[megaman12]

Yeah it's still fine, not sure what's going on. But this is with 2 XP computers so I know its not just the computer.

 

[BrianDonegan]

I regularly swap between XP (home laptop and desktop), 2003 Server and Vista (work desktops) without any problems.

Same USB cable? TI recommends the PCM2707 be supplied with a cable 6 feet (~2m) or less.

 

[megaman12]

The cables about 1m long, and I've tested the same cable on both the xp computers and vista computers.

 

[megaman12]

Ok, so now this gets wierder. I just tried it on another Vista computer and it does the same static and noise thing. The 2 xp and vista computers are all laptops, whilst the vista that works is a desktop. Does this make any difference?

 

[Russ White]

No, I use mine on a few different laptops.

It should make no difference.