@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.
Good evening Miro, I would like to apply an external 5v socket for the EASY DAC. I have a socket with a built in switch, that pass through the usb power, if no plug is in the socket.
I would be happy if you showed me the locations for ground and 5V in from the external PSU.
Thank you 🙂
I would be happy if you showed me the locations for ground and 5V in from the external PSU.
Thank you 🙂
To be a bit more precise, I would like to power the PCM chip by USB, for example a phone, and all other things by external 5v. Is this possible?
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.
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.
Miro is it possible for me to adapt your PSU1 to 24v bipolar by using 7824 + 7924 and a 24v transformer as long as all the caps are rated properly? Or does this require new calculations for smoothing cap values?
I believe the Pass IV stages run mostly around 24v
I believe the Pass IV stages run mostly around 24v
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.
Attachments
Last edited:
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) 🤔
Hey guys!
Maybe, it's a wrong place to ask this question.
Is it possible to buy this empty PCB board somewhere in Europe?
Maybe, it's a wrong place to ask this question.
Is it possible to buy this empty PCB board somewhere in Europe?