Thanks!
I'm trying to figure out if chassis mount XLR sockets should be installed on DCG3 chassis and the power amp chassis in the event that they will become useful.. If star quad cable can be implemented with RCA's and 4V balanced dac has no advantage with unbalanced DCG3 then I guess I will not use any XLR connectors..
I'm trying to figure out if chassis mount XLR sockets should be installed on DCG3 chassis and the power amp chassis in the event that they will become useful.. If star quad cable can be implemented with RCA's and 4V balanced dac has no advantage with unbalanced DCG3 then I guess I will not use any XLR connectors..
With unbalanced DCG3 you can still add a chassis XLR female pair allowing for a convenience input I guess. Connecting it in a typical way pin 1&3 tied like in XLR RCA adapters. But opting to manage balanced/unbalanced interfacing in the cables wiring only is the most versatile way in general. Since there are cases you would want to optimize the wiring differently. https://www.ranecommercial.com/kb_article.php?article=2107
Before I´ll do a second attemt implementing a muses 72320 volume control a couple of quick measurements using an SSL2+ audio interface. -6dbFA and 0dbFS. Volume pot is a bourns 20k log for the time being.
The 1khz tone was fed with another soundcard. I guess quite a bit of the thd is from that.
Feeding with same soundcard I got a lot of distortion. Gnd loop I guess.
.
Is it healthy?
The 1khz tone was fed with another soundcard. I guess quite a bit of the thd is from that.
Feeding with same soundcard I got a lot of distortion. Gnd loop I guess.
.
Is it healthy?
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Hello here.
I would like to post my findings here also with some measurement's...
It was for me a looong journey, because i bought the Behringer UMC 202HD, and it was not very good stock that is...
Well well well, i saw the thread here on diyA https://www.diyaudio.com/community/threads/behringer-umc-202hd-for-measurements.341309/ and i began to investigate stuff.
First thing i did was user @alfredr 's very nice lowpass-filter.
The output get's cleaned up a lot, when using this little thing... thank's @alfredr
Sine 1KHz with and without his filter... pictures tells everything here.
Very good... i now own a good sinewave generator
Along my journey i fighted a lot with noise, spikes and hum, having still not so very good measurements.
User @YashN did a very good mod, with some direct input, i also did... Thank's @YashN.
But still fighting with spikes and noise i stumbled over @MagicBus 's balanced protoboard. (never tested i guess)
Along with some trial and error's i finally got it up and running.
Showing good result's
THIS is along with Victor's 1KHz osc ::
And finally i'am able to do some real world DUT!
Salas DCG3, protobuild build with help from Salas on non original homedrawn pcb's in 2016.
Rebuild into another chassis lately, with remote ESP32 controlled stuff.
A nice OLED... to add noise .. No just nice to have!
So having it all setup, looking like this ::
Modded Behringer & Victor's osc..
So i did some measurement's on my DCG3...
There are allway's things to improve, but i'am satisfied with it as is. - No hum, no nothing at full volume with my +91dB spk.
I attached a FFT shot i took today at -6dB as Salas reference from first page of this thread.
Salas's looking better, but we are talking noise, and stuff below 100-110dB.
I'am sure the mains hum which are reaching ~110dB are proberly the enviroment it is in during test.
But the Behringer is now very prone to noise, i can even have the laptop psu in the mains outlet, without any noticable things on FFT.
The THD number's are near Salas's numbers so i think it's good, and the noisefloor of the Behringer must be way "under" the DCG3 (~150dB)
One thing more... The Victor's are very usefull when i measure my poweramp's. With internal generator i get nasty spikes and stuff, but with Victor's i got very very good results. Funny thing is, that measureing this DCG3 actually gives some little better numbers with internal generator, except from the 2. harmonics witch are very low.
Finally i have a great gear for doing protobuild's and making allready good gear better (turning trafo's, moving internal wiring, gnd scheme etc...) such things
can be seen live with this great toy!
Thank's everybody for the help, and sry. for the long post Salas!
EDIT:: DCG3 was loaded with 10k resistor during test.
Jesper.
I would like to post my findings here also with some measurement's...
It was for me a looong journey, because i bought the Behringer UMC 202HD, and it was not very good stock that is...
Well well well, i saw the thread here on diyA https://www.diyaudio.com/community/threads/behringer-umc-202hd-for-measurements.341309/ and i began to investigate stuff.
First thing i did was user @alfredr 's very nice lowpass-filter.
The output get's cleaned up a lot, when using this little thing... thank's @alfredr
Sine 1KHz with and without his filter... pictures tells everything here.
Very good... i now own a good sinewave generator
Along my journey i fighted a lot with noise, spikes and hum, having still not so very good measurements.
User @YashN did a very good mod, with some direct input, i also did... Thank's @YashN.
But still fighting with spikes and noise i stumbled over @MagicBus 's balanced protoboard. (never tested i guess)
Along with some trial and error's i finally got it up and running.
Showing good result's
THIS is along with Victor's 1KHz osc ::
And finally i'am able to do some real world DUT!
Salas DCG3, protobuild build with help from Salas on non original homedrawn pcb's in 2016.
Rebuild into another chassis lately, with remote ESP32 controlled stuff.
A nice OLED... to add noise
.. No just nice to have!So having it all setup, looking like this ::
Modded Behringer & Victor's osc..
So i did some measurement's on my DCG3...
There are allway's things to improve, but i'am satisfied with it as is. - No hum, no nothing at full volume with my +91dB spk.
I attached a FFT shot i took today at -6dB as Salas reference from first page of this thread.
Salas's looking better, but we are talking noise, and stuff below 100-110dB.
I'am sure the mains hum which are reaching ~110dB are proberly the enviroment it is in during test.
But the Behringer is now very prone to noise, i can even have the laptop psu in the mains outlet, without any noticable things on FFT.
The THD number's are near Salas's numbers so i think it's good, and the noisefloor of the Behringer must be way "under" the DCG3 (~150dB)
One thing more... The Victor's are very usefull when i measure my poweramp's. With internal generator i get nasty spikes and stuff, but with Victor's i got very very good results. Funny thing is, that measureing this DCG3 actually gives some little better numbers with internal generator, except from the 2. harmonics witch are very low.
Finally i have a great gear for doing protobuild's and making allready good gear better (turning trafo's, moving internal wiring, gnd scheme etc...) such things
can be seen live with this great toy!
Thank's everybody for the help, and sry. for the long post Salas!
EDIT:: DCG3 was loaded with 10k resistor during test.
Jesper.
Attachments
Congratulations for your FFT gear efforts. You have additional electronics inside the preamp that probably radiate some. But your harmonic spikes are still below audible and your THD+N number is still very good. Shows your measurement gear is very quiet. Not adding enough own noise.
*With power amps I also find difficulties with SE loop from own generator and external does better. But not when the power amp has balanced input. What I found works better for RCA input power amps from audio interface electronically balanced TRS jack output, is coax cable wired as tip to RCA hot, sleeve to RCA cold, ring no connection.
*With power amps I also find difficulties with SE loop from own generator and external does better. But not when the power amp has balanced input. What I found works better for RCA input power amps from audio interface electronically balanced TRS jack output, is coax cable wired as tip to RCA hot, sleeve to RCA cold, ring no connection.
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Did some more measurements. This linestage is very sensitive to internal signal cabling. Got some spike every 100hz from the former measurement. By turing/moving on signal_in coax cable these almost disappeared.
BTW: I am not sure how much of the harmonics is caused by the dac/adc in the measurement setup. Probably quite alot. A decent oscillator is by far the best to use but I think this is good results anyway. This is at 0dbFS.
BTW: I am not sure how much of the harmonics is caused by the dac/adc in the measurement setup. Probably quite alot. A decent oscillator is by far the best to use but I think this is good results anyway. This is at 0dbFS.
This is a very clean result for harmonic noise. I can't right away tell you if the THD numbers are spot on vs my prototype because I need to know what is your card's zero dBFS input level in VRMS first. What is it?
Regarding higher order small harmonic spikes they usually crop up from DAC and ADC above about 400mV RMS in such audio interfaces. Without averaging they tend to just lurk in the grass.
Regarding higher order small harmonic spikes they usually crop up from DAC and ADC above about 400mV RMS in such audio interfaces. Without averaging they tend to just lurk in the grass.
You are debugging down at -130 dBFS level with single ended signal. Just looking at it the wrong way it could change behavior. How a weak magnetic field crosses a signal route is what you are probably tweaking.
Salas, Interesting in your thoughts on an active crossover in the path DCG3 VS Mezmerize.
I'll be experimenting with Xkitz Crossovers when they arrive in the mail. With the extra gain stage of active xovers, I was wondering if a DCG3 signal will see degradation in this set-up and maybe a Mez is a better choice with its unity gain along with possible other reasons? The build plan includes dual chassis so DC for Mez would come from a dedicated PSU which could be an upgrade to its on board PCU.
Thanks in advance!
I'll be experimenting with Xkitz Crossovers when they arrive in the mail. With the extra gain stage of active xovers, I was wondering if a DCG3 signal will see degradation in this set-up and maybe a Mez is a better choice with its unity gain along with possible other reasons? The build plan includes dual chassis so DC for Mez would come from a dedicated PSU which could be an upgrade to its on board PCU.
Thanks in advance!
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