SMSL SU-1 design idea

Jump to Latest
#162
Too tiny.
 

Attachments

  • image.jpg
    image.jpg
    1 MB · Views: 161
#164
Isn’t that normal!? It is source selection. Why would USB have to be active when choosing the optical input?

Maybe old fashioned as I never use computer audio. They usually seem to create more issues than they solve 🙂
 
Last edited:
#167
Let's say I'm watching TV at the moment, using optical in. I start my streaming PC in the background.
The streaming software will fail to start because the configured USB DAC is missing. 🙁
I asked in other forums, it seems only professional devices keep their USB on.
 
#168
Why would one watch TV and start a streaming pc in the background? Maybe I do not fully understand but I fail to see doing 2 things simultaneously is worthwhile. With old fashioned analog source selection one also did not want the other sources bleeding through when a certain source was selected (this is carved in memory, analog heritage) and the other sources were therefor usually shut down. In situations with an audio player instead of a PC this will also not be an issue I guess. IMHO the behavior of SU-1 is what can be defined as pretty normal and not as an issue. It can also easily be solved with a second SU-1, changing the sequence of power on/off or source selection, not connecting either one of the sources to the DAC etc. 🙂 Maybe too much features are asked of a simple low cost device. Maybe it is just a follow up issue by own choice for PC audio.

Anyway, if this is a desired key parameter or a showstopper one better chooses another device.
 
Last edited:
#170
jean-paul said:
Maybe old fashioned as I never use computer audio
Click to expand...
Do you use it only with coax in ? Then there is absolutely no point in making any power supply changes for XMOS, SPDIF goes to 9211 directly. It is powered by 3.3V regulator near XMOS crystal. Maybe here will be sense to put here TPS7A2033 or something good for it, because this transceiver make clock for AKM and also has PLL in it (with external RC filter), also need to check decoupling caps around this chip, it seems that there are fewer capacitors than in the datasheet.
 
#171
Cutting USB buspower and adding a linear PSU is the mod with single largest effect (besides output transformers) regardless of which input is used. Bonus is that it has 230V instead of yet another ugly adapter.

I am sorry but your statement “no point” is not right.

BTW I don’t use it at all. Building it was a pastime while healing from disease. Like most of the stuff I build. Build & learn & improve skills. Mechanical, esthetical, performance wise.

I should finish it but I have a nasty waterdamage in my house that eats my time.
 
Last edited:
#172
What output trafo did you use?

If one make a good 5V source and hook it in via USB (which I did and thought it was an improvement) - is that still bad? Did you skip over any power related things behind the USB power inlet of the unit and then hooked up what voltage - if so.. ?

//
 
#174
hi guys,

i am tempted to buy one of these su-1 and put a dip socket in place place of the opamp, Anyone knows what the other 8soic iC is next to the OP stage opamp?

by the way, one of the best reg i tested for audio devices, whatever they may be, is the lm317 with some additional current bias (around 300mA). Also putting a small around something like 20uH air inductor afterwards improves the sound even further.

the absolute best i tried is salas shunt but it's only good for 5V and above. I use the simplest circuit salas made for the shunt portion.... and for the ccs beforehand, i use the one with the bjt that sets the current with the reference Vbe voltage and the mosfet as pass transistor. This is subjective, but i tested a heap of them regulators. My favs. regs. may measure not best but sound the more like music to my ears.
 
You must log in or register to reply here.
Top Bottom