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