Signalyst DSC1

[savan]

My choice for rpi4 power supply, xl4015 as a predregulator to form low dropout votage for TPS7A8500 with opa209 feedback, enough for rpi4 : )

 

[savan]

Special attention to vcc, gnd, signal line, shielding layers, not a final, need to do some fine diff traces at the dac input/output

The same must do for dac output fronend
The same for dac input frontend -> ct7302 / ct7601... A lot of work : )

 

[savan]

Some pictures from old development concept. Initial version was with yellow transformers, last two pictures is evaluation without yellow transformers, added tone control, bluetooth, fm radio... a lot of wires around and too bad layout, even with all that things I'm getting 17.9 enob which is a good result for too bad implementation and layout around with long wires : ) Now developing dual mono, half the size of dev version.

 

[savan]

Main pcb around 115x160mm. CT7302, CT7601, Bluetooth, DSC2, dual mono (diff i/v, diff to se, mfb, tone control, se to diff), J.D. Super Regulator with inline dc filter. J.D. regulator will be suplied by xl4015 buck from torus transformer. Supply for output frontends will be suplied by discrete J.D. regulators +-15V, it will be supplied from smps aux.

 

[jeroen_d]

You can see the input level in my measurement. Unfortunately I am not able to use higher input level with reliable results. The distortion of the sound card used becomes dominant. With -10dBFS I get different results with different DACs. At -3dBFS they all start to measure the same.

What was the input level? To get comparable results you should use -3dBFS level.

 

[jeroen_d]

Hello,

Is there anyone who can say if it's worth switching from dsc2 to dsc3? What differences are there? Also speaking of the DSC2, what differences are there between the yellow and black transformers?

I've both in possession and DSC2 is not used anymore. DSC3 sounds much more polished, real high end.

 

[savan]

Anybody sugest me capacitors for tone control? My choice for bass level is MKP1839447404 and looking for good capacitors for treble level, thinking for https://www.solomusicgear.com/product/emerson-paper-in-oil-tone-capacitor-0-015uf-green-and-cream but its soo expensive, do you have idea for cheaper one?

 

[bohrok2610]

You can see the input level in my measurement. Unfortunately I am not able to use higher input level with reliable results. The distortion of the sound card used becomes dominant. With -10dBFS I get different results with different DACs. At -3dBFS they all start to measure the same.

If your ADC has high distortion near full scale a notch filter would help. Most dacs have low distortion at -15dBFS so it is more informative to use an input level that is closer to full scale.

 

[savan]

Digital VCC/DGND ruting, one over other, inside lajers 2 and 3, that will form some capacitivity and in the same time less supply noise. Top layer and bottom layer is master gnd/shild connected at the vcc out capacitor in star connection. Analog frontend for dsc diff is on their own potential and have their own isolated supply, that remain to be ruted. Top layer is signal layer. Working on this ten days, its moving finaly, the hardest and most important part is done. Some track can't be routed, I don't want to force route them over/through some important lines, bottom dsc, so I installed u_fl connectors and going to route them coaxialy. Gpio functions from ct7601 and I no need external circuity to control BTon and ISOUSBon, two wire trought i2c whole main pcb control : ) Very hard layout! Pcb size 115x162mm, well done! : )

Picture 2, i2c controled relay based digi pot, 8 steps, for tone control.

 

[savan]

Enlcosure around 360x260mm , and this is layout. Time for designing enclosure : )

 

[wengtech]

Hello,
i want to buy hqplayer software,
are there any discounts for diyaudio members here?

Thanks
Peter

 

[savan]

Ready for soldering

 

[Embehu]

I have a pair of jensen transformer, it’s je 123-s. I’m quite headache when looking for infor that these ones can be use as output transformer for dsc dac or not?
Some say yes, some say no. (Actually I still haven’t had this dac yet)
So anyone here tried it before? Please tell me is this possible? Or I have to choose the edcor or Chinese one with exactly 10k 1:1?

Many thanks!
Trung

 

[Markw4]

You could try 1:1 and see what you think. Its probably not going to be optimal in various ways, but it might be acceptable enough. Have to try it and see.

OTOH, if you want to try something more high-end maybe consider: https://www.lundahltransformers.com/wp-content/uploads/datasheets/1588.pdf

 

[savan]

Today work, hand soldering, J.D. main regulator and other regulators soldered and tested, well done. The rest now is easy : )

 

[savan]

Tone control pots, relay based, finished today, my hope tommorow main pcb will be almost done, missing some parts like isousb211 for ct7601 usb and also i/v based on opa1633, those two ic will become available on 3rd quartal this year so I'm unable to finish project completely : ( In the meantime enclosure will be finished and everything else.

 

[savan]

Done until receve some missing parts, time for enclosure and designing CM4 based mediaserver/control pcb with their power supply and also back panel inputs. Enclosure is on the way from 19th, hope receive them in 10 days.

 

[ghitus]

Congrats, beautiful work!

Gaetano.

 

[savan]

Power suplies designed for this project
https://www.diyaudio.com/community/threads/super-regulator.247281/post-7600060
https://www.diyaudio.com/community/threads/super-regulator.247281/post-7600121

In rev 3 this one definitive https://www.diyaudio.com/community/threads/super-regulator.247281/post-7537194 .Rev 3 will go up to 1kw using Hypex Nilai, our frontend will go white : )

 

[rzaglinskij]

Done until receve some missing parts, time for enclosure and designing CM4 based mediaserver/control pcb with their power supply and also back panel inputs. Enclosure is on the way from 19th, hope receive them in 10 days.

Looks fantastic.
Is it possible to get pcb’s and scheme?