@miro,
I do beleive it was indeed simplier for most. At that time tjey did not care too much on how improve it by lowering the output impedance or play with the esr of caps with these regs. I would try to remove the 0.1 uF output cap on the PSU1 and increase the esr of the cap by chosing a lower value as 220 uF or non low esr at the output. You can keep very low esr at the input pin though like the little mkp and the low esr of the big smoothing cap that is near help a lot remembering all rhe cd playets I moded with those regs...nostalgia...
Some added a little resistor but an old lythic like the old nichicon VS serie did the trick when passed. Then a little decoupling was often enough near the load while they used all the time bad ceramics...sometimes when better inspired they used mkt. Philips blue ones were particulary good.
I do beleive it was indeed simplier for most. At that time tjey did not care too much on how improve it by lowering the output impedance or play with the esr of caps with these regs. I would try to remove the 0.1 uF output cap on the PSU1 and increase the esr of the cap by chosing a lower value as 220 uF or non low esr at the output. You can keep very low esr at the input pin though like the little mkp and the low esr of the big smoothing cap that is near help a lot remembering all rhe cd playets I moded with those regs...nostalgia...
Some added a little resistor but an old lythic like the old nichicon VS serie did the trick when passed. Then a little decoupling was often enough near the load while they used all the time bad ceramics...sometimes when better inspired they used mkt. Philips blue ones were particulary good.
Ok Miro, it does work 
. Unfortunately not as intended, since I found out, that the switched sockets switch the ground and not the pos. voltage. ??? No idea why. So I need an extra switch or I keep it for permanent external PSU.
Btw, my phone can deliver the needed 400 mA - for a short while. I was surprised by that.
Thanks and have a good day
I like this little DAC very much.
. Unfortunately not as intended, since I found out, that the switched sockets switch the ground and not the pos. voltage. ??? No idea why. So I need an extra switch or I keep it for permanent external PSU.Btw, my phone can deliver the needed 400 mA - for a short while. I was surprised by that.
Thanks and have a good day
I like this little DAC very much.
Hi Miro, this is the socket I mean. It has got a three pole arrangement. When no plug is attached, two of the three pins are internally connected. In case of an attached powerplug, this connection is opened and just one of the two is connected to the plug. My plan was to connect the USB power to the DAC part via the 2 connected pins, when no external psu is used and have it automatically disconnected in case of external power. Unfortunately this is onyl true for the barrel (outer) contact, not for the inner pin. As usually the middle pin is used for +V and the barrel connector (outer) for grnd. So if I wanted to use it as intended, I had to change the polarity of the plug.
Usually I listen via PC to this dac, and in this case the 400mA over USB is not a dealbraker, yet sometimes I take the DAC with me, when I am listening to music from the phone and then the 400 mA empty my phone too quick for my taste. That is why I bought a powerbank in order to power the DAC part.
Usually I listen via PC to this dac, and in this case the 400mA over USB is not a dealbraker, yet sometimes I take the DAC with me, when I am listening to music from the phone and then the 400 mA empty my phone too quick for my taste. That is why I bought a powerbank in order to power the DAC part.
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Sorry, I can't find any brand on the capacitors. I use those leftovers in my stash.
Could it be some mouser generic caps?
@ernesternest I see the socket. You can create Y USB cable by connecting 2 USB cables together (one will carry both (data and power) and the second only power from the powerbank) 🤔