ok, so i've completed the board according to BOM (my first ever diy electronic project, so i'll be amazed if it works).
i have the R-type transformer but there's no ground - only on the mains side. i only have 0-9V black, black; 0-9Vwhite, white; 0-15V yellow, yellow and 0-15V green, green
1. does the ground on the board get left unpopulated or connected to the chassis or something else?
2. of the coax cable, which should be connected to the gnd, the interior piece of wire or the surrounding wire?
thanks for all help along the way
i have the R-type transformer but there's no ground - only on the mains side. i only have 0-9V black, black; 0-9Vwhite, white; 0-15V yellow, yellow and 0-15V green, green
1. does the ground on the board get left unpopulated or connected to the chassis or something else?
2. of the coax cable, which should be connected to the gnd, the interior piece of wire or the surrounding wire?
thanks for all help along the way
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would a phono/RCA socket be the same as a digital coax socket? i've been looking on ebay for a coax socket/connector, but nothings coming up. this is what i'm looking at...NEUTRIK BLUE COLOURED GOLD PLATED NYS367-6 PHONO CHASSI | eBay
if so, i just connect the signal wire to the main rear connector and the outer braid to the sticking out flange, is this right? (apologies for poor terminology, i don't know what things a called)
if so, i just connect the signal wire to the main rear connector and the outer braid to the sticking out flange, is this right? (apologies for poor terminology, i don't know what things a called)
HOLY S**T, it only bloody works!!!
my first soldering project and it's singing away. just f***ing brilliant. massive thanks to clave (for all your efforts), erin (who pm'd me a link to this DAC in the first place), bcmbob for your assistance and to anyone else that helped so willingly.
i have built the 4396 DAC according to claves BOM. Clave, can you pm me your paypal address, i'd like to buy you a couple of beers for all your efforts with the BOM and the hours spent.
cheers again guys, peace
my first soldering project and it's singing away. just f***ing brilliant. massive thanks to clave (for all your efforts), erin (who pm'd me a link to this DAC in the first place), bcmbob for your assistance and to anyone else that helped so willingly.
i have built the 4396 DAC according to claves BOM. Clave, can you pm me your paypal address, i'd like to buy you a couple of beers for all your efforts with the BOM and the hours spent.
cheers again guys, peace
You're welcome.
I've simply shared what I did for myself.
There's no need of PP, we can have virtual beers
transformer floating ground
hey,
i've run into some odd issues using this along with my headphone amp.
my current setup derives the common ground by connecting the two out of phase secondaries as is mentioned several times throughout the thread.
i'm using a plastic chassis so there is no chassis ground tied to earth. the earth/safety wire of the transformer is hooked up to earth on the iec inlet.
while i can't rule out that the smps psu of the headphone amp is to blame (i'll be replacing it shortly with a sigma11 anyhow), here is what i'm seeing:
1. adjusting the pot on the headphone amp will cause a persistent high frequency whirring/phaser like sound that usually lowers in pitch and fades out
2. microphonic effects while moving the headphone cable
3. moving hand around the perceived magnetic field of the dac's r-core transformer, or close to the dc inlet or rca connectors causes a theramin-like effect that induces a sound of changing frequency/intensity in the headphones
4. touching the shield of the digital coax cable very slightly quiets a background hum.
5. (without dac connected to amp), touching the plastic case of the smps with one hand and the metal enclosure of the headphone amp with the other causes a lot of humming/white noise in the amp.
6. i see 30mv pp of noise on my scope while probing the output of the amp (again, without the dac connected). i see this same noise on the scope, with the smps powered up, but disconnected from the amp. the mv pp of the waveform increases the closer i put the dc output cable of the smps to the scope power cable. of course, the noise disappears if i unplug the smps from the wall.
i can't get any of the same odd noises/effects from the dac using it in the auxillary input of my a/v receiver.
i think the issue is probably with the smps of the amp (or another component in the amp), but would not having an earth referenced ground anywhere in the dac exacerbate these symptoms?
should i, as was suggested in this thread, connect earth/safety ground to the 0 pin of the dac's 12-0-12 connector along with the two out of phase secondaries?
not sure why this seems to have showed up suddenly in my setup. the only changes i've made recently are soldering up audio/coax rca with nerve audio hooked upwire/audioquest vsd-1 coax, and is that i've switched the positions of the brown/yellow leads from the r-core. maybe slight differences in the windings are now causing a higher potential on the dac's v common?
thanks,
-matt
hey,
i've run into some odd issues using this along with my headphone amp.
my current setup derives the common ground by connecting the two out of phase secondaries as is mentioned several times throughout the thread.
i'm using a plastic chassis so there is no chassis ground tied to earth. the earth/safety wire of the transformer is hooked up to earth on the iec inlet.
while i can't rule out that the smps psu of the headphone amp is to blame (i'll be replacing it shortly with a sigma11 anyhow), here is what i'm seeing:
1. adjusting the pot on the headphone amp will cause a persistent high frequency whirring/phaser like sound that usually lowers in pitch and fades out
2. microphonic effects while moving the headphone cable
3. moving hand around the perceived magnetic field of the dac's r-core transformer, or close to the dc inlet or rca connectors causes a theramin-like effect that induces a sound of changing frequency/intensity in the headphones
4. touching the shield of the digital coax cable very slightly quiets a background hum.
5. (without dac connected to amp), touching the plastic case of the smps with one hand and the metal enclosure of the headphone amp with the other causes a lot of humming/white noise in the amp.
6. i see 30mv pp of noise on my scope while probing the output of the amp (again, without the dac connected). i see this same noise on the scope, with the smps powered up, but disconnected from the amp
. the mv pp of the waveform increases the closer i put the dc output cable of the smps to the scope power cable. of course, the noise disappears if i unplug the smps from the wall.i can't get any of the same odd noises/effects from the dac using it in the auxillary input of my a/v receiver.
i think the issue is probably with the smps of the amp (or another component in the amp), but would not having an earth referenced ground anywhere in the dac exacerbate these symptoms?
should i, as was suggested in this thread, connect earth/safety ground to the 0 pin of the dac's 12-0-12 connector along with the two out of phase secondaries?
not sure why this seems to have showed up suddenly in my setup. the only changes i've made recently are soldering up audio/coax rca with nerve audio hooked upwire/audioquest vsd-1 coax, and is that i've switched the positions of the brown/yellow leads from the r-core. maybe slight differences in the windings are now causing a higher potential on the dac's v common?
thanks,
-matt
it appears that the LME49720 i was using turned into LFO's in this setup. odd, and unfortunate, because they're great op amps. i swapped 'em out for LME49860 and it seems much more stable.
i also earthed the 2 secondaries (the 0 in 12-0-12) at the board connector by running a lead to earth/safety on the iec inlet. i was pleased to see no sparks and no blown fuses
still, any idea why these op amps started oscillating like this? something to do with the impedance of the dac's output or...? touching the chassis/potentiometer on the amp variably induced or quieted the oscillations. fwiw the amp uses a virtual ground circuit (tle2426).
thanks,
-matt
i also earthed the 2 secondaries (the 0 in 12-0-12) at the board connector by running a lead to earth/safety on the iec inlet. i was pleased to see no sparks and no blown fuses
still, any idea why these op amps started oscillating like this? something to do with the impedance of the dac's output or...?
touching the chassis/potentiometer on the amp variably induced or quieted the oscillations. fwiw the amp uses a virtual ground circuit (tle2426).thanks,
-matt
it appears that the LME49720 i was using turned into LFO's in this setup. odd, and unfortunate, because they're great op amps. i swapped 'em out for LME49860 and it seems much more stable.
i also earthed the 2 secondaries (the 0 in 12-0-12) at the board connector by running a lead to earth/safety on the iec inlet. i was pleased to see no sparks and no blown fuses
still, any idea why these op amps started oscillating like this? something to do with the impedance of the dac's output or...?
thanks,
-matt
FWIW, I've read somewhere that using IC socketts with fast opamps could cause oscillation and could be controlled by adding decoupling caps across the +/- rails.