Depends on what you feed, I suspect. You have shown a difference amplifier, which does remove the DC, but it also can add its own output offset voltage (dependent on the opamp used). Most off-the-shelf amplifiers will have some series capacitor somewhere in the input circuitry, so this offset will effectively be removed.
If your amp is using a non-gapped amorphous core input transformer (like mine), this circuit will saturate the transformer.
Hi i have a question of going from XLR out to RCA in,
do you recommend this solution?
Balanced Wiring (3.9kΩ & 1.9kΩ)
And when fireing up DCX does the last used preset start?
do you recommend this solution?
Balanced Wiring (3.9kΩ & 1.9kΩ)
And when fireing up DCX does the last used preset start?
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Ok thank's Pulse! Does that solution activate a digital attenuation and some bit loss?
If i understand oehlrich right, all kind of volume adjustments happen in the digital part
I consider also this solution to bypass output stage during this method: passive output stage for DCX2496 It seems very nice! Would the output be ~10dBV (0.32V RMS)? If so, does this solution activate the digital output attenuation?
Thank's
If i understand oehlrich right, all kind of volume adjustments happen in the digital part
I consider also this solution to bypass output stage during this method: passive output stage for DCX2496 It seems very nice! Would the output be ~10dBV (0.32V RMS)? If so, does this solution activate the digital output attenuation?
Thank's
No output option?
All,
I would like to know if the following is feasible.
Remove the complete output of the DCX2496, connect the dac outputs directly to the xlr connectors (no filtering of the DC voltage etc.) and replace the output with input transformers in my amp (see picture).
The advantages would be:
- very few parts (no caps) in the sound path.
- fully balanced until my single ended amp.
- DC voltage eliminated (though at the other end of the cable)
- expensive but few parts..... so very fair price!
All this inspired by the application note by Jensen transformers on connecting balanced and se equipment.
Thank you for your input.
Peter
All,
I would like to know if the following is feasible.
Remove the complete output of the DCX2496, connect the dac outputs directly to the xlr connectors (no filtering of the DC voltage etc.) and replace the output with input transformers in my amp (see picture).
The advantages would be:
- very few parts (no caps) in the sound path.
- fully balanced until my single ended amp.
- DC voltage eliminated (though at the other end of the cable)
- expensive but few parts..... so very fair price!
All this inspired by the application note by Jensen transformers on connecting balanced and se equipment.
Thank you for your input.
Peter
Attachments
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Hi, it works only on the paper.
Change the output is not like change the bulb in a lamp.
The trafos works caring to the impedances seen by the primary and by the secondary. The ratio of the transformer is the key of this matter. You cannot forget. Otherwise the trafo doesn't work properly.
In your suggestion you don't care about the impedance matching. By the trafo you reflecy to the primary the impedance of your amps by the ratio2 of the trafo.
It works only, probably doesn't "sound"; only if you are lucky and the amps match the output impedance of the DACs. Study the data sheets and you will understand.
Better if you place the trafo inside the DCX. Look for a trafo with a center tap, and you place a "stupid" RC cell on this center tap, 33-47uF/10K is a classic. 10K or different depending on your amps, and you have to change the uF.
This RC filter:
1) helps a lot to clean the signal ... even if close to 75-100KHz you can ear a sweeter sound with the cell installed
2) matches the input impedances of your amps.
It is a classic, purist, solution to the DAC matter. The datasheet almost of all DACs describe this solution.
Change the output is not like change the bulb in a lamp.
The trafos works caring to the impedances seen by the primary and by the secondary. The ratio of the transformer is the key of this matter. You cannot forget. Otherwise the trafo doesn't work properly.
In your suggestion you don't care about the impedance matching. By the trafo you reflecy to the primary the impedance of your amps by the ratio2 of the trafo.
It works only, probably doesn't "sound"; only if you are lucky and the amps match the output impedance of the DACs. Study the data sheets and you will understand.
Better if you place the trafo inside the DCX. Look for a trafo with a center tap, and you place a "stupid" RC cell on this center tap, 33-47uF/10K is a classic. 10K or different depending on your amps, and you have to change the uF.
This RC filter:
1) helps a lot to clean the signal ... even if close to 75-100KHz you can ear a sweeter sound with the cell installed
2) matches the input impedances of your amps.
It is a classic, purist, solution to the DAC matter. The datasheet almost of all DACs describe this solution.
Canever, Thank you for the reply.
Will study the RC filter solution this weekend! I will still need a receiver end at the amp side though ;-(
I did study the data sheets (does not mean I understand all of it ;-) of my amp and the Jensen application note (attached) on crystal voltage out DAC's as I understand that the AKM dac's on the Behringer have a similar DC output.
The amp boards have an input circuit I wanted to change (wanted to mod this part anyways) to match the load of the line + trafo.
Will study the RC filter solution this weekend! I will still need a receiver end at the amp side though ;-(
I did study the data sheets (does not mean I understand all of it ;-) of my amp and the Jensen application note (attached) on crystal voltage out DAC's as I understand that the AKM dac's on the Behringer have a similar DC output.
The amp boards have an input circuit I wanted to change (wanted to mod this part anyways) to match the load of the line + trafo.
DCX output
Hi,
You need to charge DAC output with around 1k Ohm
You need to filter RC as well
A lot of people who used output transformers directly had DAC failed in time...
I use Jan Didden DCX outputs (find in Pilgham shop), passiv and activ, and all my amplifiers have input transformers inside chassis).
That is the best CMRR way. I remoove the input cap in amplifier replacing by transformer.
Pilgham Audio - DCX passive upg.
I modified up today around 15 DCX, all mods I appreciate were with Didden way; never use,please, selectronic mods! All of them are bad for different reasons,trust me. i tryed a lot of mods...
For input transformers You need tu use them with max 1 feet cable long to amplifier. (CMRR 30dB) that is the worse solution after lonely adapter cable.
But If You need to use transformers close to DCX, all in a separate box for example, not the best but better solution is to use output transformer as JT-11-EM .(CMRR 60dB max)
JENSEN TRANSFORMERS, INC. - LINE OUTPUT TRANSFORMERS
Finally, If You need to adapt pro level (from DCX outputs, no mods) with consumer level (RCA input amplifier) You need to step down 12dB with 4:1 input transformer as JT-10KB-D (CMRR up to 120dB!)
For my part, ragarding this point, I did that for DCX input since I remooved (of course) the E/S daughter board and have XLR pro level outputs from my preamplifier. I use Cinemag transformer that I made made (CM25101) to feat with the AK4393, means You need a midle point on secondary to analogique ground of AK.
For DCX output,Your choice will be the best with input transformer in chassis of amplifier (end line always) with JENSEN JT11-P-1,well known, almost for me
(CMRR around 107dB!)
I use the PCB version (1HPC)
JENSEN TRANSFORMERS, INC. - LINE INPUT TRANSFORMERS
my 2 cents
FRED
Hi,
You need to charge DAC output with around 1k Ohm
You need to filter RC as well
A lot of people who used output transformers directly had DAC failed in time...
I use Jan Didden DCX outputs (find in Pilgham shop), passiv and activ, and all my amplifiers have input transformers inside chassis).
That is the best CMRR way. I remoove the input cap in amplifier replacing by transformer.
Pilgham Audio - DCX passive upg.
I modified up today around 15 DCX, all mods I appreciate were with Didden way; never use,please, selectronic mods! All of them are bad for different reasons,trust me. i tryed a lot of mods...
For input transformers You need tu use them with max 1 feet cable long to amplifier. (CMRR 30dB) that is the worse solution after lonely adapter cable.
But If You need to use transformers close to DCX, all in a separate box for example, not the best but better solution is to use output transformer as JT-11-EM .(CMRR 60dB max)
JENSEN TRANSFORMERS, INC. - LINE OUTPUT TRANSFORMERS
Finally, If You need to adapt pro level (from DCX outputs, no mods) with consumer level (RCA input amplifier) You need to step down 12dB with 4:1 input transformer as JT-10KB-D (CMRR up to 120dB!)
For my part, ragarding this point, I did that for DCX input since I remooved (of course) the E/S daughter board and have XLR pro level outputs from my preamplifier. I use Cinemag transformer that I made made (CM25101) to feat with the AK4393, means You need a midle point on secondary to analogique ground of AK.
For DCX output,Your choice will be the best with input transformer in chassis of amplifier (end line always) with JENSEN JT11-P-1,well known, almost for me
(CMRR around 107dB!)I use the PCB version (1HPC)
JENSEN TRANSFORMERS, INC. - LINE INPUT TRANSFORMERS
my 2 cents
FRED
Hi Fred, do you have references for this, it's not a problem I was aware of.
Fredsonqc
I am running direct out + and - signals from AK4939 to the primary of JT-11-EM (and exiting SE thru RCA). No other components (no resistor, no cap...). It works , so far. Are you saying that this is potentially wrong? Pls explain. I am not doubting you, just asking what is the correct way.
I am running direct out + and - signals from AK4939 to the primary of JT-11-EM (and exiting SE thru RCA). No other components (no resistor, no cap...). It works , so far. Are you saying that this is potentially wrong? Pls explain. I am not doubting you, just asking what is the correct way.
DCX's AK direct transformer output ???
Hi,
Yes It works! but...
I guess the problem guys had became because charge viewing by AK4393 (no 4939) was not 1k Ohm, depends also of course of amplifier input R value.
I do not know exactly when and why It was hapened because It's not my situation;
The other way of investigation should be the overload when switching on amplifier, depend on security with different amplifier (so many situation with so many amplifier I guess);
Another way became perhaps because no filtering at output ADAC and maybe some ground current appears.
So, usually It works, sometime It breaks down...
In doubt, my advise not to follow that issue...
Jan Didden did a great job with his firstly passive DCX output, and with that E/S new board, studying well how to feat with AK4393, and his mods maks the phase outputs better as well than original.
You are not obliged to mount the total kit, basis is enough as well.
my 2 cents
FRED
Hi,
Yes It works! but...
I guess the problem guys had became because charge viewing by AK4393 (no 4939) was not 1k Ohm, depends also of course of amplifier input R value.
I do not know exactly when and why It was hapened because It's not my situation;
The other way of investigation should be the overload when switching on amplifier, depend on security with different amplifier (so many situation with so many amplifier I guess);
Another way became perhaps because no filtering at output ADAC and maybe some ground current appears.
So, usually It works, sometime It breaks down...
In doubt, my advise not to follow that issue...
Jan Didden did a great job with his firstly passive DCX output, and with that E/S new board, studying well how to feat with AK4393, and his mods maks the phase outputs better as well than original.
You are not obliged to mount the total kit, basis is enough as well.
my 2 cents
FRED
It is of course AK4393 - sorry for the typo.
Based on what I think I learned about the DAC-transformer direct-out (from Jensen information prior to purchasing the trafos, also from the pool of knowledge from this forum) I made the simplest connection. Balanced V-out direct to the primary, no filter bcs the transformer blocks the DC by design, and the correct type of output transformer. The impedance of the transformer, the one that the DAC "sees" is actually depending on the next device' input impedance - it "reflects back" that into the primary, or so I understand.. In this case the next device is an active multi-channel volume controller with an input of 50 K so I guess the DAC "sees" a much bigger impedance than 1 K ... And it works OK. But after reading your posts I am doing a reality check. Anybody else to chip in?
Based on what I think I learned about the DAC-transformer direct-out (from Jensen information prior to purchasing the trafos, also from the pool of knowledge from this forum) I made the simplest connection. Balanced V-out direct to the primary, no filter bcs the transformer blocks the DC by design, and the correct type of output transformer. The impedance of the transformer, the one that the DAC "sees" is actually depending on the next device' input impedance - it "reflects back" that into the primary, or so I understand.. In this case the next device is an active multi-channel volume controller with an input of 50 K so I guess the DAC "sees" a much bigger impedance than 1 K ... And it works OK. But after reading your posts I am doing a reality check. Anybody else to chip in?
The primary of the following transformer passes any DC imbalance around the transmit circuit.
It does not block that DC.
The transformer prevents the DC reaching the stage after the transformer.
Any DC imbalance in the primary circuit will lead to increased distortion as a result of increased saturation of the transformer.
It does not block that DC.
The transformer prevents the DC reaching the stage after the transformer.
Any DC imbalance in the primary circuit will lead to increased distortion as a result of increased saturation of the transformer.
Hi!
Is there a way to switch between my own presets from the remote?
I manage only to get what i think is the "stock" presets.
With the "Load internal presets" It wants me to locate a file on the computer.
Is there a way to switch between my own presets from the remote?
I manage only to get what i think is the "stock" presets.
An externally hosted image should be here but it was not working when we last tested it.
With the "Load internal presets" It wants me to locate a file on the computer.
You can erase one by one all the stock presets (it's easier with the DCX than with the remote). Then you save the result on your PC as "empty session". You just have to recall this one everything you need to create a new family of settings for a new speaker, a new room or whatever.
Don't forget to save before loading a new one...
Don't forget to save before loading a new one...