RC232 documentation
I quickly searched Behringer web site and DCX2496 documentation but didn´t find any good reference how to control the device via RS-232 serial port. What commands and parameters are available, what are their format and how to use them? I am not using available PC software but self-made microcontroller SW.
Do you have this information?
My aim is to build preamplifier based on Atmel microcontroller. It buffer and raise level of selected audio input so that DCX input dynamics can be optimally used. After DCX has filtered the signal this same preamplifier has volume control. It is 6-7bit discrete attenuator based on relays and resistive network so that channel balance stay always constant. Possible lowest bits can be adjusted inside DCX.
With this preamplifier I would also like to adjust channel balance etc. and do it by sending commands to DCX via RS-232 serial port and do fine channel balance tuning digitally inside DCX. Also be able to switch between different settings like different EQs when using loudness or other -modes. Different settings could be useful for different audio inputs: CD, tv and radio sources need to be EQed differently. Also loudness during night time would be useful feature.
All these settings could change automaticly when I change a audio source or level with my preamp. No need to touch DCX. Preamp´s microcontroller would send required commands to DCX via serial port.
I quickly searched Behringer web site and DCX2496 documentation but didn´t find any good reference how to control the device via RS-232 serial port. What commands and parameters are available, what are their format and how to use them? I am not using available PC software but self-made microcontroller SW.
Do you have this information?
My aim is to build preamplifier based on Atmel microcontroller. It buffer and raise level of selected audio input so that DCX input dynamics can be optimally used. After DCX has filtered the signal this same preamplifier has volume control. It is 6-7bit discrete attenuator based on relays and resistive network so that channel balance stay always constant. Possible lowest bits can be adjusted inside DCX.
With this preamplifier I would also like to adjust channel balance etc. and do it by sending commands to DCX via RS-232 serial port and do fine channel balance tuning digitally inside DCX. Also be able to switch between different settings like different EQs when using loudness or other -modes. Different settings could be useful for different audio inputs: CD, tv and radio sources need to be EQed differently. Also loudness during night time would be useful feature.
All these settings could change automaticly when I change a audio source or level with my preamp. No need to touch DCX. Preamp´s microcontroller would send required commands to DCX via serial port.
APi, if you send me an e-mail I will send you a pdf file with the commands the DCX uses.
Some helpful DCX user posted them once but I cannot remember where....
Ergo
ergo.esken AT mail.ee
Some helpful DCX user posted them once but I cannot remember where....
Ergo
ergo.esken AT mail.ee
Re: RC232 documentation
http://freerider.dyndns.org/anlage/dcx2496remote_txt - Editor.pdf
If you like you could download it from my website:APi said:
http://freerider.dyndns.org/anlage/dcx2496remote_txt - Editor.pdf
audio-kraut,audio-kraut said:
my hires digital output board is now also tested, documented and up and runnung for Pioneer DV-585A and DV-588A. Maybee this may be an option for you. The unit is quite unexpensive and worth a try! See http://freerider.dyndns.org
Charly
First impressions
On the strength of this and other threads I purchased a DCX2496 which arrived on Friday. After making some XLR to phono leads with attenuation, I put it in and was surprised how easy it is to integrate into my system.
After messing about with crossovers and EQ for a couple of hours I got down to some serious listening and can say that it is a keeper. The ability to seamlessly integrate the different speakers is excellent.
I'm currently running it with a Goodmans 201 powered with a valve amp and no crossover or eq from the DCX, i.e straight through. The bass is a 15" in a U dipole powered by SS amp and using the crossover with a Butterworth second order low pass filter and lots of eq, and a supertweeter crossing again with a Butterworth second order high pass. All OB dipole.
Advantages are that I've now got really good bass and smooth treble with no sibilance and flat to 20KHz, bass is flat to about 32Hz but I need loads of eq to get much below that and from what I've heard it's not needed. Bass is fast deep and not at all boomy. I've been able to compensate for a room mode sucking out at the listening position at about 70Hz.
There is a little loss of detail but only really noticeable, strangely, on bad recordings. I don't particularly notice this on well recorded material. There is some noise, a low level mush that I hope is because I've got the volume control on the input and only 1 or 2 bars lit on input signal strength.
KYW has answered a question for me here http://www.diyaudio.com/forums/showthread.php?postid=756350#post756350 which may be of interest to others looking to modify the DCX. I'll have a go in a few weeks when I've plucked up the courage to attack SMD components
As ever, thanks to all the folk who post here
your insights are invaluable to audio heathens like me.
Kevin
On the strength of this and other threads I purchased a DCX2496 which arrived on Friday. After making some XLR to phono leads with attenuation, I put it in and was surprised how easy it is to integrate into my system.
After messing about with crossovers and EQ for a couple of hours I got down to some serious listening and can say that it is a keeper. The ability to seamlessly integrate the different speakers is excellent.
I'm currently running it with a Goodmans 201 powered with a valve amp and no crossover or eq from the DCX, i.e straight through. The bass is a 15" in a U dipole powered by SS amp and using the crossover with a Butterworth second order low pass filter and lots of eq, and a supertweeter crossing again with a Butterworth second order high pass. All OB dipole.
Advantages are that I've now got really good bass and smooth treble with no sibilance and flat to 20KHz, bass is flat to about 32Hz but I need loads of eq to get much below that and from what I've heard it's not needed. Bass is fast deep and not at all boomy. I've been able to compensate for a room mode sucking out at the listening position at about 70Hz.
There is a little loss of detail but only really noticeable, strangely, on bad recordings. I don't particularly notice this on well recorded material. There is some noise, a low level mush that I hope is because I've got the volume control on the input and only 1 or 2 bars lit on input signal strength.
KYW has answered a question for me here http://www.diyaudio.com/forums/showthread.php?postid=756350#post756350 which may be of interest to others looking to modify the DCX. I'll have a go in a few weeks when I've plucked up the courage to attack SMD components
As ever, thanks to all the folk who post here
your insights are invaluable to audio heathens like me.Kevin
Re: First impressions
the volume control has to be BEHIND the DCX2496. Having it in front of the unit you loose a lot of resolution (may bits) and get the noise you are talking of.
I use a passive volume control bedind the DCX2496 and it works like charm. Look here:
http://freerider.dyndns.org/anlage/CP-2500.htm
Kevin,KevinTams said:
the volume control has to be BEHIND the DCX2496. Having it in front of the unit you loose a lot of resolution (may bits) and get the noise you are talking of.
I use a passive volume control bedind the DCX2496 and it works like charm. Look here:
http://freerider.dyndns.org/anlage/CP-2500.htm
Re: Re: First impressions
Konnichiwa,
While I agree that it is usually better if it can be done that way, I would take exception to claims that it CANNOT be sucessfully be located ahead of the DCX.
We know each output of the DCX offers around 112db dynamic range. If we consider the -112db point equal to 10db absolute SPL in room at the listening position and if we retain a 6db headroom for the DCX output stage we have the potential for completely clean 116db peaks at the listening position, while any "loss of resolution" remains below the quietest rooms noisefloor. In fact, I'd be happy to make -112db = 20db SPL in room at the listening position which gives us up to 126db peaks on the listening position, assuming our speakers can hold up.
So, if you make sure to correctly match the Sensitivities of the Drivers and Amplifiers driven from the DCX crossover you can attenuate the signal (analog) ahead of the DCX with no real penalty sonically.
It is all in correct level matching, something that is 2nd nature to anyone from a pro audio background....
Sayonara
Konnichiwa,
oehlrich said:
While I agree that it is usually better if it can be done that way, I would take exception to claims that it CANNOT be sucessfully be located ahead of the DCX.
We know each output of the DCX offers around 112db dynamic range. If we consider the -112db point equal to 10db absolute SPL in room at the listening position and if we retain a 6db headroom for the DCX output stage we have the potential for completely clean 116db peaks at the listening position, while any "loss of resolution" remains below the quietest rooms noisefloor. In fact, I'd be happy to make -112db = 20db SPL in room at the listening position which gives us up to 126db peaks on the listening position, assuming our speakers can hold up.
So, if you make sure to correctly match the Sensitivities of the Drivers and Amplifiers driven from the DCX crossover you can attenuate the signal (analog) ahead of the DCX with no real penalty sonically.
It is all in correct level matching, something that is 2nd nature to anyone from a pro audio background....
Sayonara
Has anybody quantifed the level of performance loss by attenuating a spdif signal say from a PC via the volume control of some program like winamp etc.
ie: the PC is a juke box feeding spdif to the DCX..
Cheers
ps i can easily send the analog input of my DCX into clipping (red lights on ) via my Yamaha preamp -just crank it up...
ie: the PC is a juke box feeding spdif to the DCX..
Cheers
ps i can easily send the analog input of my DCX into clipping (red lights on ) via my Yamaha preamp -just crank it up...
Konnichiwa,
Well, much will depend. If the Output of your Soundcard in the digital domain is 48KHz/16Bit then using the digital domain volume control is a bad idea, the same holds true if you use generic volume control algorythms.
If you have the right DSP in your PC you could in fact do extensive re-eq, volume control and many other things digitally, but you would have to bypass a lot of the build in stuff and likely winamp would not be the right player for this to work.
Ciao T
george a said:
Well, much will depend. If the Output of your Soundcard in the digital domain is 48KHz/16Bit then using the digital domain volume control is a bad idea, the same holds true if you use generic volume control algorythms.
If you have the right DSP in your PC you could in fact do extensive re-eq, volume control and many other things digitally, but you would have to bypass a lot of the build in stuff and likely winamp would not be the right player for this to work.
Ciao T
Re: Re: Re: First impressions
In practical terms, to be clear, does this mean setting the max output from the preamp so that the DCX input is just running into the red bars on full volume on music peaks, with the internal digital gains all set on 0dB?
Thanks for putting some numbers to the gains and sound levels, it's beginning to make some sense to me 😀
Kev
Kuei Yang Wang said:
In practical terms, to be clear, does this mean setting the max output from the preamp so that the DCX input is just running into the red bars on full volume on music peaks, with the internal digital gains all set on 0dB?
Thanks for putting some numbers to the gains and sound levels, it's beginning to make some sense to me 😀
Kev
Re: Re: Re: Re: First impressions
Konnichiwa,
Yes, pretty much so.
Adjust the coarse differences between amplifier input sensitivity and driver efficiency using attenuation in the analogue domain after the DCX. Use the digital attenuation only for fine tuning the system, leaving around 6db OUTPUT headroom.
I did in another thread some basic calculations illustrating how to do this, based on driver sensitivity and amplifier input sensitivity, cannot quite remember where that one went.
I would still change the DCX from 10V to 2.5V full scale levels all around and do the other mods discussed if it is mainly for domestic use.
Sayonara
Konnichiwa,
KevinTams said:
Yes, pretty much so.
Adjust the coarse differences between amplifier input sensitivity and driver efficiency using attenuation in the analogue domain after the DCX. Use the digital attenuation only for fine tuning the system, leaving around 6db OUTPUT headroom.
I did in another thread some basic calculations illustrating how to do this, based on driver sensitivity and amplifier input sensitivity, cannot quite remember where that one went.
I would still change the DCX from 10V to 2.5V full scale levels all around and do the other mods discussed if it is mainly for domestic use.
Sayonara
Re: Re: Re: Re: Re: First impressions
I saw the thread on sensitivity /gain matching but I couldn't use that with too much confidence as I don't know the sensitivity of my speakers and gain of my amps, so I used the "suck it and see" approach, using the attenuation in the ic cables that you outlined for balanced to SE and then changing the input resistors on the amps to get a better match. This will all be fine tuned as I progress.
I'll open the DCX in a few days and see how confident I am in making the changes you've outlined.
My pre is your DC phono into TX102's. If I rewire the TX102's to the +6dB setting would it drive the DCX at 20K input impedance?
regards
Kevin
Kuei Yang Wang said:
I saw the thread on sensitivity /gain matching but I couldn't use that with too much confidence as I don't know the sensitivity of my speakers and gain of my amps, so I used the "suck it and see" approach, using the attenuation in the ic cables that you outlined for balanced to SE and then changing the input resistors on the amps to get a better match. This will all be fine tuned as I progress.
I'll open the DCX in a few days and see how confident I am in making the changes you've outlined.
My pre is your DC phono into TX102's. If I rewire the TX102's to the +6dB setting would it drive the DCX at 20K input impedance?
regards
Kevin
Re: Re: Re: Re: Re: Re: First impressions
Konnichiwa,
Yes, BUT.... The worst case load on the Phonostage itself would now be 5KOhm.
HOWEVER, good news. The DCX has an input impedance notably higher than 20KOhm, so as long as the cable behind the TX-102 is low enough capacitance (as this also stepped up to be effectively 4 X what it is nomrally with the volume all up), there are no real worries about loading.
I'd say less than or around 100pF cable capacitance will be fine, not the limit is the loading on the Phonostage, not the TX-102 per se.
Sayonara
Konnichiwa,
KevinTams said:
Yes, BUT.... The worst case load on the Phonostage itself would now be 5KOhm.
HOWEVER, good news. The DCX has an input impedance notably higher than 20KOhm, so as long as the cable behind the TX-102 is low enough capacitance (as this also stepped up to be effectively 4 X what it is nomrally with the volume all up), there are no real worries about loading.
I'd say less than or around 100pF cable capacitance will be fine, not the limit is the loading on the Phonostage, not the TX-102 per se.
Sayonara
woa ..that was some fooookin long read ..
now i am seriously exhausted ..
with all that info ( old and new )
i am still a bit mixed up about this unit!!
quick things i need to know :
- If i use digital input , what is the connection type?
- will i be able to adjust the volume from within my computer ?? i never used digital output from my soundcard yet ..
I'd use this unit for :
digital output from computer -- >
setup crossovers and filters
analogue out to amplifier ...
Is this the correct use for this unit ?
Then about the DAC
has anyone found a direct upgrade ?
like a chip that can replace the ones on this unit
and gives better performance ?
( i can only do simple electronic stuff like changning parts, i do not have the knowledge to think about the change and analyse it )
Is there direct stuff to do on the PSU that will help the quality ?
now i am seriously exhausted ..
with all that info ( old and new )
i am still a bit mixed up about this unit!!
quick things i need to know :
- If i use digital input , what is the connection type?
- will i be able to adjust the volume from within my computer ?? i never used digital output from my soundcard yet ..
I'd use this unit for :
digital output from computer -- >
setup crossovers and filters
analogue out to amplifier ...
Is this the correct use for this unit ?
Then about the DAC
has anyone found a direct upgrade ?
like a chip that can replace the ones on this unit
and gives better performance ?
( i can only do simple electronic stuff like changning parts, i do not have the knowledge to think about the change and analyse it )
Is there direct stuff to do on the PSU that will help the quality ?
Konnichiwa,
XLR. Simply attach your coax cable to pin 2 & 3 of the XLR plug and solder a 220R resistor across the pins as well.
Yes, but most likely the volume control in your PC will not be a good idea to use. Much depends on the exact programs, devices and soundcard.
Yes, except the outputs are at Pro-Level (that is around 10V for digital full scale) meaning you need to apply attenuation (usually a LOT of attenuation) to the outputs prior to applying the signal to your amplifiers. The key to getting the most from Digital Crossovers and Equalisers is to get the level right, which can be trickey.
The DAC chip's on this unit are pretty decent and certainly not the limit in terms of performance, the analogue stages and powersupply need upgrading much more desperatly than the DAC (and ADC) chips.
Replace it with a low noise linear one, external to the DEQ (inside there is not enough space).
Sayonara
JinMTVT said:
XLR. Simply attach your coax cable to pin 2 & 3 of the XLR plug and solder a 220R resistor across the pins as well.
JinMTVT said:
Yes, but most likely the volume control in your PC will not be a good idea to use. Much depends on the exact programs, devices and soundcard.
JinMTVT said:
Yes, except the outputs are at Pro-Level (that is around 10V for digital full scale) meaning you need to apply attenuation (usually a LOT of attenuation) to the outputs prior to applying the signal to your amplifiers. The key to getting the most from Digital Crossovers and Equalisers is to get the level right, which can be trickey.
JinMTVT said:
The DAC chip's on this unit are pretty decent and certainly not the limit in terms of performance, the analogue stages and powersupply need upgrading much more desperatly than the DAC (and ADC) chips.
JinMTVT said:
Replace it with a low noise linear one, external to the DEQ (inside there is not enough space).
Sayonara
Does anyone know where I can get the schematic for the stock power supply in the DCX? The DCX Yahoo group has schematics for everything but. TIA
thank you Kuie for your informative replies ..again 🙂
though some basic question remains in my head ..
With digital output from my sound card i should be able to control the volume then that is all good..
but you mentionned that it might not necessailry be a good idea ? i remember reading here that software volume controls are not always good..could that be what you are pointing?
do you have any reading reference or advice on that matter???
i do not have time to make an external digital volume control or stuff like that...not much time available at all with the buisness 😛
For the digital input, this seems pretty simple ..
should this be supported by almost all sound cards with digital output ? no impedance problems ??
is there necessary shielding for difital connections like that??
For the pro level outputs..
i am only using Bryston amplifiers, does that count as pro ???
my amplifiers ( 4B ST ) don't have volume knob
will i have sound level problem ?
my 2b has the volume control, but i won't be using this
amplifier on my main system ..
and i guess that one adjusted. i don't want to have to fiddle with the volume on the amplifiers individually 😛
all my amps have XLR connectors ...
Did you guys found out a simple replacement for the DACs?? something that could be just resoldered there with minor modif and give good improvement ?
from akm website, the DACs used on the behringer are pretty much top notch ...
And for the power supply, do you have any simple advices on devices that i could use directly. ..
thanks again for your time ...
if this device does what i need
i'll be looking at the newwer creative X-fi cards to send out thedigital signals...
though some basic question remains in my head ..
With digital output from my sound card i should be able to control the volume then that is all good..
but you mentionned that it might not necessailry be a good idea ? i remember reading here that software volume controls are not always good..could that be what you are pointing?
do you have any reading reference or advice on that matter???
i do not have time to make an external digital volume control or stuff like that...not much time available at all with the buisness 😛
For the digital input, this seems pretty simple ..
should this be supported by almost all sound cards with digital output ? no impedance problems ??
is there necessary shielding for difital connections like that??
For the pro level outputs..
i am only using Bryston amplifiers, does that count as pro ???
my amplifiers ( 4B ST ) don't have volume knob
will i have sound level problem ?
my 2b has the volume control, but i won't be using this
amplifier on my main system ..
and i guess that one adjusted. i don't want to have to fiddle with the volume on the amplifiers individually 😛
all my amps have XLR connectors ...
Did you guys found out a simple replacement for the DACs?? something that could be just resoldered there with minor modif and give good improvement ?
from akm website, the DACs used on the behringer are pretty much top notch ...
And for the power supply, do you have any simple advices on devices that i could use directly. ..
thanks again for your time ...
if this device does what i need
i'll be looking at the newwer creative X-fi cards to send out thedigital signals...
Kuei wrote (as regards to RCA digital to AES/EBU digital XLR input to DCX)
Quote: "Simply attach your coax cable to pin 2 & 3 of the XLR plug and solder a 220R resistor across the pins as well"
To Kuei san: Sorry for primitive question, but please confirm that it means that the Pin on RCA (from DVD/CDP in my case) connects to Pin 2 XLR, Sleeve on RCA connects to Pin 1 & 3 together. 220 Ohm resistor across Pin 1 & 2.
Also, some people recomends Neutric adapter http://dv411.com/neutaestran.html - but it should not be necessary - right ?)
I am confused as usual
LageB
Quote: "Simply attach your coax cable to pin 2 & 3 of the XLR plug and solder a 220R resistor across the pins as well"
To Kuei san: Sorry for primitive question, but please confirm that it means that the Pin on RCA (from DVD/CDP in my case) connects to Pin 2 XLR, Sleeve on RCA connects to Pin 1 & 3 together. 220 Ohm resistor across Pin 1 & 2.
Also, some people recomends Neutric adapter http://dv411.com/neutaestran.html - but it should not be necessary - right ?)
I am confused as usual
LageB