I have no artifacts that can be heard in my present setup
Part of the problem is I am currently using a "saved from a garage sale receiver" for a preamp - but I heard nothing when I was using a Nakamichi that died on me. The nak was no slouch.
I am basically an _analogue_ person, and am of the general opinion that an active tube line stage sounds better than passive.
So I'm hoping that in trade-offs that using the active preamp will offset the negatives from the extra dac/adc step -
I knew from the start that the Behringer may well be an intermediate step for me. Frankly, it has sounded better than I thought it would. Simply, that I am going for higher resolution sound than I am likely to get out of it. It was a gamble that for me has turned out as a most pleasant surprise. Important to me at this point in time, it gets me listening and to a further point of system development where I can continue with other things and make various A/B comparsons. I've got to get more of my system completed before I'll know how much of a "veil" there is with the Behringer.
Owning one, to me there is no question but that digital crossovers are the way to go. So the real question to me when I reach that step (after finishing GM70 amp and sorting the horn setup out) will be - should I mod the Behringer or sell it untouched and buy something with higher resolution.
Right now there is so much interest in this thread and so many people working on the Behringer that I'm thinking there will be a very good chance of coming out on top with the mods -
If not, at the rate I'm going there will likely be another generation of the Behringer or driverack out there by the time I finalize - the length of time to debug the preamp has been very frustating and disappointing but I'm hopeful that I'm over the hump. _big grin_
regards
Ken L
Part of the problem is I am currently using a "saved from a garage sale receiver" for a preamp - but I heard nothing when I was using a Nakamichi that died on me. The nak was no slouch.
I am basically an _analogue_ person, and am of the general opinion that an active tube line stage sounds better than passive.
So I'm hoping that in trade-offs that using the active preamp will offset the negatives from the extra dac/adc step -
I knew from the start that the Behringer may well be an intermediate step for me. Frankly, it has sounded better than I thought it would. Simply, that I am going for higher resolution sound than I am likely to get out of it. It was a gamble that for me has turned out as a most pleasant surprise. Important to me at this point in time, it gets me listening and to a further point of system development where I can continue with other things and make various A/B comparsons. I've got to get more of my system completed before I'll know how much of a "veil" there is with the Behringer.
Owning one, to me there is no question but that digital crossovers are the way to go. So the real question to me when I reach that step (after finishing GM70 amp and sorting the horn setup out) will be - should I mod the Behringer or sell it untouched and buy something with higher resolution.
Right now there is so much interest in this thread and so many people working on the Behringer that I'm thinking there will be a very good chance of coming out on top with the mods -
If not, at the rate I'm going there will likely be another generation of the Behringer or driverack out there by the time I finalize - the length of time to debug the preamp has been very frustating and disappointing but I'm hopeful that I'm over the hump. _big grin_
regards
Ken L
Harm? Depends.
I'm using the behringer with Urei coaxial speakers that I'm modifying.(I added a super-tweeter so they are 3 way speakers now) .
I can not insist enought how important is to use the full resolution of the unit, otherwise you'll get a grainy and veiled sound.
Last night I went to a friend's house that was blaming his unit for grainy sound. When I arrived I noticed he was injecting a -10db signal into it, And also the volume was in the preamplifier, BEFORE the Behringer. So most of the time, the signal meters of the unit were barely lit. That's too low a signal. You'll loose resolution, and in digital that's a no-no. The cure was to inject a healty signal thru it and then, attenuate the output with a passive potentiometer between the output of the Eq and the input of the power amp. The sound was great after that. He couldn't believe it.
Currently I'm using 6 gainclones after the Behringer. They have a gain of 22 times, so injecting a +4db at the amps inputs is way to hot. I could lower the gain of the amps but this is not recommended.Sound suffers.
The solution was to add internally a couple of resistors to atenuate the signal (14 db in my case) and now I can use most of the resolution of the unit. The sound is clearer, no hiss or noise.
I think the Rane unit is better, but at the price of the Behringer, I'd say is money well spent.
I'm still testing my new triamplified speakers+Behringer+GClones combiination. I still have problems at the crossover points and I couldn't make the phase control do anything meaninfull. Also, the auto align feature does not work propely, but otherwise everything else is great.
cheers
Ric
I'm using the behringer with Urei coaxial speakers that I'm modifying.(I added a super-tweeter so they are 3 way speakers now) .
I can not insist enought how important is to use the full resolution of the unit, otherwise you'll get a grainy and veiled sound.
Last night I went to a friend's house that was blaming his unit for grainy sound. When I arrived I noticed he was injecting a -10db signal into it, And also the volume was in the preamplifier, BEFORE the Behringer. So most of the time, the signal meters of the unit were barely lit. That's too low a signal. You'll loose resolution, and in digital that's a no-no. The cure was to inject a healty signal thru it and then, attenuate the output with a passive potentiometer between the output of the Eq and the input of the power amp. The sound was great after that. He couldn't believe it.
Currently I'm using 6 gainclones after the Behringer. They have a gain of 22 times, so injecting a +4db at the amps inputs is way to hot. I could lower the gain of the amps but this is not recommended.Sound suffers.
The solution was to add internally a couple of resistors to atenuate the signal (14 db in my case) and now I can use most of the resolution of the unit. The sound is clearer, no hiss or noise.
I think the Rane unit is better, but at the price of the Behringer, I'd say is money well spent.
I'm still testing my new triamplified speakers+Behringer+GClones combiination. I still have problems at the crossover points and I couldn't make the phase control do anything meaninfull. Also, the auto align feature does not work propely, but otherwise everything else is great.
cheers
Ric
¡Hola Ricren! Can you ?
Hi, can you explain more about the full signal into and attenuated after the Behringer. I'm planning to buy the thing but would like to use it with existing Rotel preamp - then behringer - then 2 Rotel power amps for bi-amping.
If I attenuate after the behringer say fixed -30dB, what happens when playing at lower volumes (input to behringer steered by the preamp pot). Will I have those resolution loss problems?
¡Saludos desde bélgica señor porteño¡
Hi, can you explain more about the full signal into and attenuated after the Behringer. I'm planning to buy the thing but would like to use it with existing Rotel preamp - then behringer - then 2 Rotel power amps for bi-amping.
If I attenuate after the behringer say fixed -30dB, what happens when playing at lower volumes (input to behringer steered by the preamp pot). Will I have those resolution loss problems?
¡Saludos desde bélgica señor porteño¡
Bonjour Jean,
This entire thing about proper levels is simpler than it seems to be.
I understand what you want to do: Your audio chain would be:
Preamp with volume control->Behringer->Amp.
That would work reasonably good, but is better if you can send to the Behringer a hot signal at all times and put some kind of volume control after the crossover.
There’s a thread at this site about the DIY Apox volume control kit that you could consider. Many people have built it and they are happy.
If you can compromise somewhat, you can live with the volume control BEFORE the crossover, like I do.
BUT if you do so, you’ll have to optimize the levels in your audio chain. How do you optimize?
1-Make sure the output of the preamplifier is hot enough for the crossover. Most likely, your Rotel is a –10 device with RCA outs, right? Let’s assume it is. So the signal that outputs is a bit low for the 2496, which is a +4 device (Actually, almost 12 db low!). You need to amplify the signal at least 4 times (11.8 db). If you fail to do so, your signal to noise ratio will be worse in exactly 12 db! And you also loose those 12 dbs of resolution.
Would you dare to modify the output stage of your preamp?
2-After the Crossover you are going directly to the power amps, right? I assume that your system
ream+ crossover+ power amps are all close together, right? So you do not need balanced lines. You just use pin 2 and 1 on the XLR out of the Behringer and go unbalanced to the amp.
Are they consumer devices (-10) or pro devices (+4)? If they are expecting a –10 signal, you need to provide attenuation; this can be done cleanly with a couple of resistors at the input connector of every amp. You do not even need to open them, Give me more detail of your amp and I can suggest the resistor values.
In a few hours I’m leaving on summer vacations. I’ll return by the end of January, if you have any questions I’ll be more than happy to answer them in a few days.
Cheers
Ric
This entire thing about proper levels is simpler than it seems to be.
I understand what you want to do: Your audio chain would be:
Preamp with volume control->Behringer->Amp.
That would work reasonably good, but is better if you can send to the Behringer a hot signal at all times and put some kind of volume control after the crossover.
There’s a thread at this site about the DIY Apox volume control kit that you could consider. Many people have built it and they are happy.
If you can compromise somewhat, you can live with the volume control BEFORE the crossover, like I do.
BUT if you do so, you’ll have to optimize the levels in your audio chain. How do you optimize?
1-Make sure the output of the preamplifier is hot enough for the crossover. Most likely, your Rotel is a –10 device with RCA outs, right? Let’s assume it is. So the signal that outputs is a bit low for the 2496, which is a +4 device (Actually, almost 12 db low!). You need to amplify the signal at least 4 times (11.8 db). If you fail to do so, your signal to noise ratio will be worse in exactly 12 db! And you also loose those 12 dbs of resolution.
Would you dare to modify the output stage of your preamp?
2-After the Crossover you are going directly to the power amps, right? I assume that your system
ream+ crossover+ power amps are all close together, right? So you do not need balanced lines. You just use pin 2 and 1 on the XLR out of the Behringer and go unbalanced to the amp.Are they consumer devices (-10) or pro devices (+4)? If they are expecting a –10 signal, you need to provide attenuation; this can be done cleanly with a couple of resistors at the input connector of every amp. You do not even need to open them, Give me more detail of your amp and I can suggest the resistor values.
In a few hours I’m leaving on summer vacations. I’ll return by the end of January, if you have any questions I’ll be more than happy to answer them in a few days.
Cheers
Ric
More good reading there.. I've been giving this x/o more thought today.
Ken,
Are you building a tube pre that turns the unbalanced -10Db signal into balanced +4Db ?
Sounds interesting.
Another option for the home theater crowd is a high end processor that outputs balanced (or digital)
I suppose another option would be to use 3 stereo stepped attenuators after the unit with some big jumps in ,say, 5 positions such as -12Db,-9Db, -6Db, -3db and 0Db. Then you could switch to a 'listening range' and use the input pre to fine tune.
Cheers,
Rob
Ken,
Are you building a tube pre that turns the unbalanced -10Db signal into balanced +4Db ?
Sounds interesting.
Another option for the home theater crowd is a high end processor that outputs balanced (or digital)
I suppose another option would be to use 3 stereo stepped attenuators after the unit with some big jumps in ,say, 5 positions such as -12Db,-9Db, -6Db, -3db and 0Db. Then you could switch to a 'listening range' and use the input pre to fine tune.
Cheers,
Rob
maybe a log step attenutator control with 6 multiple contact reed/gold relays?
64 values..... one single control knob for all the six channels, so you only need extra relays for more channels?
I think there are also chips available with passive resistror-networks/dividers controlled by a binary value..... maybe compact enough to build inside the processor
64 values..... one single control knob for all the six channels, so you only need extra relays for more channels?
I think there are also chips available with passive resistror-networks/dividers controlled by a binary value..... maybe compact enough to build inside the processor
dokter dB said:
Sounds great, probably beyond my skill though
I'm not good with electronics.... I thought about contacting the chap who made the 'cheap stepped attenuators' in the other thread to see if he could knock up a 'one dial does all' type affair.
I'm hoping somebody who has direct experience of the unit, and op-amp based x/o's will chime in with their opinions before I buy one/ go on and build an opamp x/o instead.
cheers
Rob
Rambling reply about what I'm doing _grin_
Nope.
Building a Dowdy designed unbalanced Transformer Volume Control Boat Anchor pre-amp. Using a pair of
http://www.sowter.co.uk/attens.htm
Started 2 years ago, the Dowdy Llama has rebuilt and been debugging since probably before the Behringer hit the market.
I have limited technical knowledge and am only able to solder from point A to point B as is on a schematic, While I had to ask Jim questions, hopefully I didn't have to ask him too many _grin_
I am a proponent of digital crossovers more than I am a supporter of the Behringer per se.
I know little about gain matching, impedance matching, etc.
However, I know what I hear ( and don't hear). I am somewhat at a loss to understand why I have had no problems with the DCX 2496, yet others seem to have a wide variety.
I believe as I go further along, I am likely to hit some type of veil (hopefully minor) as I put higher resolution equipment into the path. I'll just have to deal with it when I find it.
OTOH, except for the preamp, I am reasonably high resolution now with a VAC 30/30, SACD and Azurahorns.
Soooo, for now I'm just along for the ride, watching the thread _big grin_.
Was upgrading drivers to PM5's but hit a snag there.
Seriously hoping to get everything jelled in 3 or 4 months. _big grin_
Regards
Ken L
PS I'm not exaggerating about the integration with one of these things - hard to believe how well you can do.
PPS if I were to put attenuaters after the Behringer I would put four or six of the Sowters on a Shallco ganged switch.
RobWells said:
Nope.
Building a Dowdy designed unbalanced Transformer Volume Control Boat Anchor pre-amp. Using a pair of
http://www.sowter.co.uk/attens.htm
Started 2 years ago, the Dowdy Llama has rebuilt and been debugging since probably before the Behringer hit the market.
I have limited technical knowledge and am only able to solder from point A to point B as is on a schematic, While I had to ask Jim questions, hopefully I didn't have to ask him too many _grin_
I am a proponent of digital crossovers more than I am a supporter of the Behringer per se.
I know little about gain matching, impedance matching, etc.
However, I know what I hear ( and don't hear). I am somewhat at a loss to understand why I have had no problems with the DCX 2496, yet others seem to have a wide variety.
I believe as I go further along, I am likely to hit some type of veil (hopefully minor) as I put higher resolution equipment into the path. I'll just have to deal with it when I find it.
OTOH, except for the preamp, I am reasonably high resolution now with a VAC 30/30, SACD and Azurahorns.
Soooo, for now I'm just along for the ride, watching the thread _big grin_.
Was upgrading drivers to PM5's but hit a snag there.
Seriously hoping to get everything jelled in 3 or 4 months. _big grin_
Regards
Ken L
PS I'm not exaggerating about the integration with one of these things - hard to believe how well you can do.
PPS if I were to put attenuaters after the Behringer I would put four or six of the Sowters on a Shallco ganged switch.
Petter said:
That's not entirely true. In many instances the peak values of a filtered signal - be it LP, HP or BP - can be higher than the peak values of the signal going in. It has to do with phase shift of the IIR filters.
I most of the time have to lower the outputs of a processor to prevent clipping when processing a digital file that has 0dBFS samples in it (pretty much all CD's released in last 10 years), even if all I do is apply a cut. Just a DSP math thing.
Another note. Going from one DAC to three can only make things worse, because your system THD and noise is tripled.
This is not a case of stacking DAC to improve specs.
Henckel said:
Now that i have a unit in my own possesion i can confirm that the Behringer dont have a noise floor of -40dB. it goes all the way down to -90 dB when using the digital input.
I can also add that the digital input can lock onto 44100, 48000, 88200 and 96000 Hz 16 and 24 bit.
The unit clips at -0,4 dB gain on the digital input when used in a pure linear mode. I.e no Crossover or EQ. - Thats strange. The visual LED on the output lits up at a gain at +0,2dB. So take care the Clip indicator must never lit !
Now looking for a 6 channel volumen control based on PGA 2310 so that i can maintain full dynamic on each channel and still have the option to attenuate the indivdual channels in order to compensate for amp/speaker sensitivity.
Br
Morten
something like this looks great for a post-dcx2496 volume control, except for the price....
http://colemanaudio.com/sr51.html
http://colemanaudio.com/sr51.html
batdorf9 said:
http://www.sowter.co.uk/dacs.htm scroll down to and click on 9335
How about six of these?? Except for the price _grin_
They are generally sold for use in control rooms, I beleive.
six 9335's would be roughly $1000 US with freight.
Of course, the equation is a little out of balance - in that if you're gonna spend that kind of money you would be better to buy something other than the Behringer _big grin_
Regards
Ken L
Well, I am in same boat as many here, that is to say that I have the DCX2496 and am also I need of a post-crossover volume control. I think I have a solution that does not break the bank and also should work very well.
By the way the DCX2496 is sonically transparent if used properly, - i.e. the input levels are within 3-5 dB from the absolute maximum. I run tests by putting the DCX in the tape loop of Bryston BP-25. With levels equalized to within 0.1 dB in listening Blind Tests none of the 5 people I had here could tell if the DCX was in the loop or not. My speakers are home-made 3-way dipole with active EQ and distortion of less then 0.7%.
The volume control I am building now is going to have 16 channels and will be controlled by a simple universal infra-red remote. It is based on a commonly available Alps motorized potentiometer. Here is what I am doing.
I bought 10 dual motorized pots from allelectronics.com. They are 10k linear and are also of a very high quality sporting a nearly 1 inch resistive element. I intend to hook them up to a motor control circuit through a relay matrix. The motor control circuit has a sensor and takes its commands from a hand-held common remote. The relay matrix allows me to switch in and out any or all potentiometers with a simple push of a button on my remote.
The design uses 8 dual pots, so there are 16 channels. The 0 to 9 numbered pad on the remote is arranged as follows,- push 0 and all pots ore off, push 9 and all pots are on, toggle 1 through 8 and the 8 pots are toggling On to Off and back. The control is rather simple.
There two problems that had to be solved for this scheme to work. First, what if the motors are not 100% identical? Then the rotational speed of different pots may be different. This problem is solved by experimentally looking for the slowest pot and adjusting the speed of other pots with resistors placed in series with the motor, - a fairly easy procedure. In the end you can have all 8 pots rotating with identical speed.
The second problem is tracking. Nominally each pot is 10 k, but when you measure them it is not quite so, besides you cannot really expect a perfect tracking even between the 2 resistive wafers in a given dual pot. To solve this I need linear pot that can be turned into a log pot by introducing a resistor between the wiper and ground. This resistor will dominate the overall resistance of the pot-resistor combination since this resistor must also be about 6.7 times smaller then the value of resistance of the linear pot. By using a common 1% value, this resistor will force all pots to have nearly identical tracking.
In the end all pots will be concealed in the enclosure. I intend to have 8 LEDs on the front panel that will indicate which pot is currently on. This scheme also gives a measured capability to do a kind of balance control between 8 channels. However, all in all it is an inexpensive Master Volume control. I also intend to buffer all inputs and outputs. The total cost is low since the pots can be had for $3.50 each if you get ten of them.
I am using 2 DCX2496 in my Home Theater which is an 8 channel system with active 3-way fronts and 2-way rears. All in all I need 14 channels, - that includes my 2 Center channels and 2 side channels.
Anyway, what do you guys think of this Master Volume control?
Vadim
By the way the DCX2496 is sonically transparent if used properly, - i.e. the input levels are within 3-5 dB from the absolute maximum. I run tests by putting the DCX in the tape loop of Bryston BP-25. With levels equalized to within 0.1 dB in listening Blind Tests none of the 5 people I had here could tell if the DCX was in the loop or not. My speakers are home-made 3-way dipole with active EQ and distortion of less then 0.7%.
The volume control I am building now is going to have 16 channels and will be controlled by a simple universal infra-red remote. It is based on a commonly available Alps motorized potentiometer. Here is what I am doing.
I bought 10 dual motorized pots from allelectronics.com. They are 10k linear and are also of a very high quality sporting a nearly 1 inch resistive element. I intend to hook them up to a motor control circuit through a relay matrix. The motor control circuit has a sensor and takes its commands from a hand-held common remote. The relay matrix allows me to switch in and out any or all potentiometers with a simple push of a button on my remote.
The design uses 8 dual pots, so there are 16 channels. The 0 to 9 numbered pad on the remote is arranged as follows,- push 0 and all pots ore off, push 9 and all pots are on, toggle 1 through 8 and the 8 pots are toggling On to Off and back. The control is rather simple.
There two problems that had to be solved for this scheme to work. First, what if the motors are not 100% identical? Then the rotational speed of different pots may be different. This problem is solved by experimentally looking for the slowest pot and adjusting the speed of other pots with resistors placed in series with the motor, - a fairly easy procedure. In the end you can have all 8 pots rotating with identical speed.
The second problem is tracking. Nominally each pot is 10 k, but when you measure them it is not quite so, besides you cannot really expect a perfect tracking even between the 2 resistive wafers in a given dual pot. To solve this I need linear pot that can be turned into a log pot by introducing a resistor between the wiper and ground. This resistor will dominate the overall resistance of the pot-resistor combination since this resistor must also be about 6.7 times smaller then the value of resistance of the linear pot. By using a common 1% value, this resistor will force all pots to have nearly identical tracking.
In the end all pots will be concealed in the enclosure. I intend to have 8 LEDs on the front panel that will indicate which pot is currently on. This scheme also gives a measured capability to do a kind of balance control between 8 channels. However, all in all it is an inexpensive Master Volume control. I also intend to buffer all inputs and outputs. The total cost is low since the pots can be had for $3.50 each if you get ten of them.
I am using 2 DCX2496 in my Home Theater which is an 8 channel system with active 3-way fronts and 2-way rears. All in all I need 14 channels, - that includes my 2 Center channels and 2 side channels.
Anyway, what do you guys think of this Master Volume control?
Vadim
A solution that seems to be working well for some people is using AV receivers for the amps and volume controls. They don't need to have the latest processing but they need clean amp sections when used with the straight-through multichannel analog inputs. As long as they are physically close together, 2 or more receivers can maintain volume sync with a single infrared remote control so the number of synchronized channels is basically unlimited. Cheap and easy.