Hifimediy direct out cs4398 DAC

[puredyne]

This is a general purpose isolator for balanced/unbalanced conversion... Hopefully the signal is coming out high enough for a direct amp connection... I've payed 122.16 Pounds for two OCC wired Transformes.

Datasheet: Sowter Type 3603
OCC Option: SOWTER TRANSFORMERS OCC OXYGEN FREE WIRE

 

[fandersen]

Is there a specific model of transformer that is highly recommended at reasonable price?

I used a set of Jensen JT-11-DMCF transformers. Not the cheapest but they work really well with CS4398. The Experience with this DIY DAC thread has a lot of discussion of various transformers from cheap to expensive for a CS4398 based DAC.

 

[Ahlek]

I used a set of Jensen JT-11-DMCF transformers. Not the cheapest but they work really well with CS4398. The Experience with this DIY DAC thread has a lot of discussion of various transformers from cheap to expensive for a CS4398 based DAC.

Thank you very much for the link. So far I like the sound of the DAC very much and hope to maximize its performance.

 

[MurphyUHF10]

Hi There,

I ordered mine a couple of days ago and am greatly looking forward to this DAC!!

I have read this entire thread from start to finish, and am now up to date

Ta
CM

 

[OlavHaal]

My Dac arrived.....

Hi all!

Today my sweet little NewDac came in the post - thanks to HiFiDIY for perfect boards - and I look forward to listen to Hi-Res files on this Less-is-More kind of doing digital sound. Just now I am listening to Christe Winn on 24/96 Wav files on my old DacMagic(with OpAmps and filters). My B1-Pre has only 2 transistors and my SITLamp has ONLY 1 transistor(Sony 2SK82). Think it will be even more musical with this sc4398dac(hope so).
But first I have to go 14 days offshore to my telecom-schedule. Have to wait till beginning of october for to get it singing.

Best to all

 

[nakamoomin]

Got mine today too.

Busy comparing the tiny HifiMeDiy USB DAC to the ODAC at the moment. Will report back here once I get the Direct-out DAC up and running.

 

[puredyne]

I've tested for a few hours... State Of Art Sound, streamed from my HDSP@LinuxBOX! ...This DAC is real love, thanks a lot!!!

 

[OlavHaal]

Hi Puredyne...

I've tested for a few hours... State Of Art Sound, streamed from my HDSP@LinuxBOX! ...This DAC is real love, thanks a lot!!!

Thanks for your report - I wonder if you have tried the DAC with oversampling, since as your photo shows you are running Non-Oversampling for the moment. And if you could say what you prefer of the 2 possibilities?

Best

Olav

 

[puredyne]

Hi OlavHaal, Via Jack Server the hardware upsampling is totally unnecessary, all system streams are eventually summed and resampled by the server.

 

[MurphyUHF10]

I've tested for a few hours... State Of Art Sound, streamed from my HDSP@LinuxBOX! ...This DAC is real love, thanks a lot!!!

I have the same transformer (from HiFiMediy?)..
What rating mains fuse have you chosen??

Ta
CM

 

[puredyne]

@MurphyUHF10, I need to know the same tipp !! I only had a 1A fast type at home.
@hifimediy, can you suggest a possible fuse rating and type, fast or slow? ...I would like to try and install the output transformers. Should the two Output Caps be removed?

 

[hifimediy]

Hi, PSM15 PSU use a 15VA transformer, so you can choose about 0.1A/220V or 0.2A/110V fast type fuse. When output transformers are used, you can keep the output caps but use the balanced output, the output caps are useless then.

 

[MurphyUHF10]

Hi, PSM15 PSU use a 15VA transformer, so you can choose about 0.1A/220V or 0.2A/110V fast type fuse.

Thanks!!

Also,, when using "Direct out" it's ok to just leave the -Ve output (for both L + R) un-connected / floating..??

I notice the Coupled output simply uses +Ve output and leaves -Ve un-used..?? Is this correct??

Ta
CM

 

[hifimediy]

Thanks!!

Also,, when using "Direct out" it's ok to just leave the -Ve output (for both L + R) un-connected / floating..??

I notice the Coupled output simply uses +Ve output and leaves -Ve un-used..?? Is this correct??

Ta
CM

Yes right.

 

[MurphyUHF10]

Yes right.

Thanks,, that sounds easy enough!

As I plan my enclosure, I intend to mount 4 RCA's on the back, 2 for "coupled" and 2 for "direct out".. That way I can easily choose, depending on which pre/power amp I want to use

Is it ok to leave Zero volts (GND) floating?? Or must it be tied to Chasis-Earth??

Thanks
CM

 

[hifimediy]

Thanks,, that sounds easy enough!

As I plan my enclosure, I intend to mount 4 RCA's on the back, 2 for "coupled" and 2 for "direct out".. That way I can easily choose, depending on which pre/power amp I want to use

Is it ok to leave Zero volts (GND) floating?? Or must it be tied to Chasis-Earth??

Thanks
CM

The GND of RCA is better to be floating to chassis-earth but connected to GND on board, and choose a ground point on board connect directly to chassis.

 

[puredyne]

I tried only with a single-ended tube amplifier & full range monitors ... these OCC wired transformers add to the detail an unexpected musicality... I'm really satisfied with the grade of enjoyment achieved with this DAC !!! ....in the future I'll take one more DAC Board to test and compare the valve output stages. My dear friend Uwe, a German engineer who designed other good converters very transparent and natural around the Cirrus Flagship... advised me how to connect the Sowter 3603:

Primary (1&2) four R301 from the CS4398.

XLR:
Trafo 5 open,
Trafo 4 & 6 to XLR 2 & 3,
Trafo 2 to XLR1 & to Case GND.

RCA:
Trafo 5 open,
Trafo 4 to RCA Signal,
Trafo 2 & 6 togather to RCA GND & Case GND.

 

[MurphyUHF10]

The GND of RCA is better to be floating to chassis-earth but connected to GND on board, and choose a ground point on board connect directly to chassis.

Thanks!

Yes, I meant to say if the "power supply" GND (Zero Volts) needed to be connected to Chasiss-Earth, not the RCA GND (shield)..

What about those on here I have seen using plastic cases?? What do they do??

Ta
CM

 

[OlavHaal]

How to do ???

Primary (1&2) four R301 from the CS4398.

XLR:
Trafo 5 open,
Trafo 4 & 6 to XLR 2 & 3,
Trafo 2 to XLR1 & to Case GND.

RCA:
Trafo 5 open,
Trafo 4 to RCA Signal,
Trafo 2 & 6 togather to RCA GND & Case GND.

Hi Puredune!

You didn`t use the balanced output?

As I read your scheme, you have 4 pc 301 ohms resistors on both the + and the - lines. Then you have trafo 5 open, and 2 and 6 together connected to RCA-ground. And 4 goes to RCA-signal(pluss).
But then you must take the signal out before the 2,2 uf capacitors - and route that same signal to the transformer?
Have I got it right - and must I use 301 ohms resistors if I use the J3-output(balanced).
Seems like there are many different combinations for how to couple the transformer. I want to try it later - but with a passive B1 and a 8watt SIT(selfmade) - I want to use the extra gain from the balanced output.
And HiFiMediy had a drawing earlier that was simple AND without resistors?

Anybody who can explain just a little - for a new dacbuilder with no transformer-knowledge?

Best

Olav

 

[OlavHaal]

Now I see....

Hi all and sorry for misunderstandings on my part.

After reading some other postings it suddenly flashed a light!! One will use the direct out with - Ve+ (right channel) and AGND(right channel) - then Ve+(left channel and AGND(left channel). Connect + to 1 and AGND to 3. For both channel! And the rest is like Puredune used for his Sowther 3603!
The only question that remains for this newborn Transformer man is: Can I use my 1kohm Takman metalfilm(I have 4) as primary load? And will it be serial or paralell?

Grateful for answer - anybody?

Best
Olav