A NOS 192/24 DAC with the PCM1794 (and WaveIO USB input)

[kartick]

Thanks @dddac

So this way, right? V-violet (15), w- white (0), V- violet(15).

 

[67339]

Hello,
I meshed up the choke numbers. I have a few LL2771 ( 5 or so), have two LL2733.
But Doede was talking about the LL2773 which is real high current choke.
If you ask Lundahl to adjust the airgap to 425 mA ( little margin) you will need for the new DDDAC you will get a 750mH with 0,44 ohm dcr.
I wil ask Doede if he likes to try a 400mA LL2771 which will have lots of mH but also 2,8 ohm dcr.
Greetings Eduard
P.s chokes are not that expensive , they last for ages as well

 

[dddac]

Yes Kartick, that is correct

 

[dddac]

Dammit, I just see the posts in between and that the transformer has two separate windings. To create a center tap, it is more likely you need to connect one grey/white and one violet wire… best check is to do this and measure if you have 15 volt in between end 30 between the outer wires

 

[dddac]

Like this Link to info

 

[dddac]

See the polarity connections to create a center tap ?

 

[kartick]

I hadnt seen your message and went ahead as per your previous suggestion. I checked the voltage without connecting the supply to the dac first. All worked fine actually. I could use the trimmer to bring the voltage up to 12.5V and it has been 30minutes since i first powered it on and it has maintained the required voltage properly. Nothing overheating as well. Then i connected the psu to the dac and it played fine without any issues. Should i correct anything now? Do i need to shutdown the psu?

 

[G600]

No you're fine.
You have a center tap transformer

 

[kartick]

Many thanks @G600

 

[dddac]

Good to hear my fear was unnecessary and things work fine !

 

[kartick]

But thanks for being extra vigilant for my case @dddac

 

[dddac]

Sure you are welcome Kartick

 

[Appy]

I have a problem with playback from 24bit/96khz via RPI5 i2s (Volumio) to DDDAC1794. Only noise. 16bit/48khz plays well. With RPI4 no problems via i2s.

 

[dddac]

Mmm, too often when Problems like this occur , I See Volumino involved. No idea why, but somehow there are always some kind of unintended issues… can you switch back to 16 bits in Volumino? By the way, i have got several feedback, that the old RPI 3B gives best results overall….

 

[Appy]

Thanks Doede
Yes, 16bit works fine, but that is not the intention. By the way, I tried Gentooplayer, same problem.

 

[dddac]

Well, I know for 100% sure, that the dddac works with 24 bits. It is hard for me to comment on players and hardware platforms I am not familiar with / have experience with? Hopefully another user has some insight?

 

[Smartdriver]

I have a problem with playback from 24bit/96khz via RPI5 i2s (Volumio) to DDDAC1794. Only noise. 16bit/48khz plays well. With RPI4 no problems via i2s.

Ditch the Rpi5 and follow Doede's hint on a Rpi3b, you can get them secondhand without any problems

 

[G600]

It's a way to deal with it, Smartdriver.
But I'm pretty sure it's a dumb software issue inside a config file.
Another constructive way is to dig, and communicate the solution afterwards

 

[mbrennwa]

To determine if it's a hardware thing (with the RPi5?) or a software thing, please try something different than Volumio on the same RPi. Ropieee maybe?

 

[Smartdriver]

It's a way to deal with it, Smartdriver.
But I'm pretty sure it's a dumb software issue inside a config file.
Another constructive way is to dig, and communicate the solution afterwards

You're probably right but, if you see this video by the respected Hans Beekhuyzen you stick with the nimble Rpi3b.

Bigger and/or newer isn't always better