Since about 2004 a Behringer DEQ2496 has been a central device in my stereo providing overall EQ in the analogue "processor loop" of the amplifier.
Although I do make use of some of the other features on occasion (like the excellent stereo width processor) I primarily use it for its PEQ features for room mode correction, and while I'm actively doing speaker development I use the PEQ and GEQ modes for temporary correction while working with crossovers etc.
It's outlived an amplifier and some of my previous speakers and is still in daily use, however it's starting to show it's age a little and I have had a few problems with it over the years.
When it was only a few years old the power supply blew up but that turned out to be a loose screw that shorted out on one of the power rails and blew a couple of diodes in the power supply - since repairing that it has only had one other fault in 17 years until now, and that is the bypass relays for the analogue inputs/outputs have been problematic.
About 6 years ago I started to notice that the output level on the right channel was intermittently down a little on the left channel - enough that I could notice a stereo imbalance, something on the order of 1dB.
Usually flicking it into bypass mode and back (switching the bypass relays a few times) would fix it but it would return a few days/weeks later.
Eventually after concluding the relay contacts were faulty in one relay (and only in the engaged mode, not the bypass mode) I replaced the bypass relays with new good quality relays and all seemed well for a few years - the intermittent shift in stereo balance between the two channels stopped happening.
In the last year I noticed things were not right with the stereo balance again and after doing some careful measurements with ARTA between left and right channels I've noticed there is now a 1.5dB error between the channels with the right channel having a lower output than left once again.
However this time it doesn't seem to be the relays as they are still relatively new and switching the relays in and out makes no difference like it used to with the old ones.
Further, there is a difference in frequency response between the two channels - the bad (right) channel has noticeable low frequency roll off such that at treble frequencies the right channel is down about 1.2 dB, in the midrange about 1.5dB and in the bass down around 1.8dB.
In analogue bypass mode both channels are identical.
This suggests the problem could be coupling capacitors between the DAC and the signal path to the relays which have lost a lot of capacitance. I had a very similar problem with my previous amplifier where the miniature electrolytic/tantalum (can't remember which) coupling caps in certain stages of the pre-amplifiers started going faulty causing loss in signal level in one channel and a slightly sloping up frequency response, so very similar symptoms to what I'm seeing here.
However with a surface mount design and no circuit diagram it's hard to tell where the coupling caps might be, what value they might be or whether it even has any for that matter.
So has anyone done any modifications/repairs to the analogue stages of the DEQ2496 (mine is a Revision 1 running firmware 1.4 not the later revision 2) or have a circuit diagram for the analogue stages that would help me troubleshoot this a bit further ?
Unfortunately I don't have a good working scope at the moment which makes it quite a bit harder for me to troubleshoot this sort of problem, although I could do some measurement with my ARTA setup.
As a workaround I've had to put the device in dual mono mode so I can increase the gain on the right channel and also slightly tweak the frequency response however I'm not very happy about this as it makes adjusting the PEQ's less convenient and I can't get an exact frequency response match between channels.
As it's getting long in the tooth now can anyone suggest any other units that don't cost a fortune that have comparable functionality to the DEQ2496 ? I'm still very happy with it if this level imbalance problem didn't exist, so am I better to just try to repair it again ?
Some of the EQ systems that I've seen people using aren't nearly as flexible in terms of user interface and functionality as the DEQ2496, surprising given how old it is now. So I'm not even sure what there is available today that's comparable in functionality yet affordable.
I've certainly had my money's worth out of it over 17 years!
Although I do make use of some of the other features on occasion (like the excellent stereo width processor) I primarily use it for its PEQ features for room mode correction, and while I'm actively doing speaker development I use the PEQ and GEQ modes for temporary correction while working with crossovers etc.
It's outlived an amplifier and some of my previous speakers and is still in daily use, however it's starting to show it's age a little and I have had a few problems with it over the years.
When it was only a few years old the power supply blew up but that turned out to be a loose screw that shorted out on one of the power rails and blew a couple of diodes in the power supply - since repairing that it has only had one other fault in 17 years until now, and that is the bypass relays for the analogue inputs/outputs have been problematic.
About 6 years ago I started to notice that the output level on the right channel was intermittently down a little on the left channel - enough that I could notice a stereo imbalance, something on the order of 1dB.
Usually flicking it into bypass mode and back (switching the bypass relays a few times) would fix it but it would return a few days/weeks later.
Eventually after concluding the relay contacts were faulty in one relay (and only in the engaged mode, not the bypass mode) I replaced the bypass relays with new good quality relays and all seemed well for a few years - the intermittent shift in stereo balance between the two channels stopped happening.
In the last year I noticed things were not right with the stereo balance again and after doing some careful measurements with ARTA between left and right channels I've noticed there is now a 1.5dB error between the channels with the right channel having a lower output than left once again.
However this time it doesn't seem to be the relays as they are still relatively new and switching the relays in and out makes no difference like it used to with the old ones.
Further, there is a difference in frequency response between the two channels - the bad (right) channel has noticeable low frequency roll off such that at treble frequencies the right channel is down about 1.2 dB, in the midrange about 1.5dB and in the bass down around 1.8dB.
In analogue bypass mode both channels are identical.
This suggests the problem could be coupling capacitors between the DAC and the signal path to the relays which have lost a lot of capacitance. I had a very similar problem with my previous amplifier where the miniature electrolytic/tantalum (can't remember which) coupling caps in certain stages of the pre-amplifiers started going faulty causing loss in signal level in one channel and a slightly sloping up frequency response, so very similar symptoms to what I'm seeing here.
However with a surface mount design and no circuit diagram it's hard to tell where the coupling caps might be, what value they might be or whether it even has any for that matter.
So has anyone done any modifications/repairs to the analogue stages of the DEQ2496 (mine is a Revision 1 running firmware 1.4 not the later revision 2) or have a circuit diagram for the analogue stages that would help me troubleshoot this a bit further ?
Unfortunately I don't have a good working scope at the moment which makes it quite a bit harder for me to troubleshoot this sort of problem, although I could do some measurement with my ARTA setup.
As a workaround I've had to put the device in dual mono mode so I can increase the gain on the right channel and also slightly tweak the frequency response however I'm not very happy about this as it makes adjusting the PEQ's less convenient and I can't get an exact frequency response match between channels.
As it's getting long in the tooth now can anyone suggest any other units that don't cost a fortune that have comparable functionality to the DEQ2496 ? I'm still very happy with it if this level imbalance problem didn't exist, so am I better to just try to repair it again ?
Some of the EQ systems that I've seen people using aren't nearly as flexible in terms of user interface and functionality as the DEQ2496, surprising given how old it is now. So I'm not even sure what there is available today that's comparable in functionality yet affordable.
I've certainly had my money's worth out of it over 17 years!
Last edited:
all 4 of my behringers have failed
Howdy, Funny i havent been here for over a decade and the first post i see is someone bitching about their DEQ2496
Yup just like you i bought my DEQ2496 and DCX2496 back in 2005 and enjoyed their amazing features as the heart of my main hifi and built a 2 x 3 way active array all eq and time aligned with the le cleache method, even built and managed a second system for a friend
But yeah things started going at about the 7 year mark. Yup all of the powersupplies have failed at various times, yup i have repaired them, yup they are all showing their age, yup i had firmware loading problems, yup they have all failed again, yup the second failures were much worse and knocked out stuff on the main boards, yup i dont know what to do,
So out of 4 all DEQ are now cooked and i have one DCX that is cobbled together from parts driving my shop system. If it lets go that will probably be it. The new prices for a unit i bought 15 years ago is sickening and now 96k is old hat.
Might go active analogue now im fulll circle back into analogue and DSD128
I do have some power dupply pinouts lying around they use a basket of voltages to drive the digital and analogue suprised no one here has made a replacement. Their powersupplies are trash and im sure everyone is pissed all these units are failing like this. cant bear to throw them out.
-k
Howdy, Funny i havent been here for over a decade and the first post i see is someone bitching about their DEQ2496
Yup just like you i bought my DEQ2496 and DCX2496 back in 2005 and enjoyed their amazing features as the heart of my main hifi and built a 2 x 3 way active array all eq and time aligned with the le cleache method, even built and managed a second system for a friend
But yeah things started going at about the 7 year mark. Yup all of the powersupplies have failed at various times, yup i have repaired them, yup they are all showing their age, yup i had firmware loading problems, yup they have all failed again, yup the second failures were much worse and knocked out stuff on the main boards, yup i dont know what to do,
So out of 4 all DEQ are now cooked and i have one DCX that is cobbled together from parts driving my shop system. If it lets go that will probably be it. The new prices for a unit i bought 15 years ago is sickening and now 96k is old hat.
Might go active analogue now im fulll circle back into analogue and DSD128
I do have some power dupply pinouts lying around they use a basket of voltages to drive the digital and analogue suprised no one here has made a replacement. Their powersupplies are trash and im sure everyone is pissed all these units are failing like this. cant bear to throw them out.
-k
Sorry to hear the problems you've had with yours. At 17 years old with daily use I think mine is doing fairly well. I'm certainly not bitching about it.
While the power supply did blow up (two main rectifier diodes) I found a screw that belonged on the main PCB wedged under PCB near the power connectors which had almost certainly shorted out one of the main supply voltages.
This happened when it was approx. 3 years old and the power supply has been fine since. This might be because it is left turned on 24/7 rather than being switched on every day so is not subject to frequent power on surges.
The right channel relay contacts seemed to go intermittent at around 10 years old but I put up with it for a few years as flicking it to bypass and back would fix it for a week or so, but I eventually replaced the relays.
The fault it has now I suspect is dried out / low capacitance coupling capacitors - I've found a post over on avsforum where someone had the same problem and they replaced all the coupling capacitors (and also the opamps, although I don't think that was part of the problem) and fixed it.
I haven't had any problems with firmware on mine, I upgraded it from 1.2 to 1.3 then 1.4a when it came out and it has been on that firmware ever since.
In the 17 years I've had it it once lost all the saved presets but aside from that it hasn't given me any trouble on the digital side.
If I can fix the channel imbalance just by recapping I'm happy to do that and use it a bit longer.
While I'd like something more modern I really don't know what else is available with equivalent functionality that isn't very expensive.
While the power supply did blow up (two main rectifier diodes) I found a screw that belonged on the main PCB wedged under PCB near the power connectors which had almost certainly shorted out one of the main supply voltages.
This happened when it was approx. 3 years old and the power supply has been fine since. This might be because it is left turned on 24/7 rather than being switched on every day so is not subject to frequent power on surges.
The right channel relay contacts seemed to go intermittent at around 10 years old but I put up with it for a few years as flicking it to bypass and back would fix it for a week or so, but I eventually replaced the relays.
The fault it has now I suspect is dried out / low capacitance coupling capacitors - I've found a post over on avsforum where someone had the same problem and they replaced all the coupling capacitors (and also the opamps, although I don't think that was part of the problem) and fixed it.
I haven't had any problems with firmware on mine, I upgraded it from 1.2 to 1.3 then 1.4a when it came out and it has been on that firmware ever since.
In the 17 years I've had it it once lost all the saved presets but aside from that it hasn't given me any trouble on the digital side.
If I can fix the channel imbalance just by recapping I'm happy to do that and use it a bit longer.
While I'd like something more modern I really don't know what else is available with equivalent functionality that isn't very expensive.
Last edited:
>A professional user usually renews his hardware every 4 to 7 years
Well thats just it, a huge swarth of hobbiests and non proffesionals bought them to be the centre piece and brains of their system expecting them to last, at the time they were the most expensive hifi componets i had ever purchased.
>completely normal for the devices to fail at some point due to component aging.
My reel to reel tape machine would like to have words with you.... and besides these were not high power devices, the power supplies were just pushing some TI DSP Chips, AKM A/DAC and a few op amps. FFS my plasma TV from the same age is still running fine but these aint (despite repairs). Its a pretty sad state of affairs.
Well thats just it, a huge swarth of hobbiests and non proffesionals bought them to be the centre piece and brains of their system expecting them to last, at the time they were the most expensive hifi componets i had ever purchased.
>completely normal for the devices to fail at some point due to component aging.
My reel to reel tape machine would like to have words with you.... and besides these were not high power devices, the power supplies were just pushing some TI DSP Chips, AKM A/DAC and a few op amps. FFS my plasma TV from the same age is still running fine but these aint (despite repairs). Its a pretty sad state of affairs.
Personally I don't think 4 to 7 years before failure is normal for electronic equipment of any sort. Hell, even the main LCD TV in our house is 6 years old now.
My stereo amplifier is not far short of 30 years old, (early 90's) and while I can see some signs of a repair to one of the output stages from before I picked it up second hand a few years ago I think that is par for the course for approaching 30 years old. Even the volume control is still scratch free. (which is surprising to be honest)
I would expect a minimum of 10-15 years from most types of electronic equipment that is designed well and is in daily use. With some recapping a lot longer than that should be possible.
Last edited:
DEQ2496
Hi
I am usng DEQ2496 and DCX2496 with passive out stages, I really think it improves soundquality and is very simple to do, I think....
I also measured with REW although the standard output is not bad, passive has the edge...
Cheers, Tom.
Hi
I am usng DEQ2496 and DCX2496 with passive out stages, I really think it improves soundquality and is very simple to do, I think....
I also measured with REW although the standard output is not bad, passive has the edge...
Cheers, Tom.
Passive output DCX2496 and DEQ2496
Hi
In the DCX2496 I took out the complete outputboard, I only use digital in, now directly connected from BNC to mainboard and 6 channel out over 1 Kohm and 5,6 µF MKP caps in series and 3,3 nF in parallel, mounted on a piece of aluminium L Profile, connected with a bought small connector with cables.
In the DEQ2496 cut the output cables from the main pcb to the output pcb and redirected over the build in board with about the same configuration as in the DCX, used high quality MKP caps, I removed the AUX output Jacks, made 2 Cinch outputs there, also made a SPDIF connector (where wordclock input was) and made a direct connection to the digital input on the flatband cable on the main pcb.
Hi
In the DCX2496 I took out the complete outputboard, I only use digital in, now directly connected from BNC to mainboard and 6 channel out over 1 Kohm and 5,6 µF MKP caps in series and 3,3 nF in parallel, mounted on a piece of aluminium L Profile, connected with a bought small connector with cables.
In the DEQ2496 cut the output cables from the main pcb to the output pcb and redirected over the build in board with about the same configuration as in the DCX, used high quality MKP caps, I removed the AUX output Jacks, made 2 Cinch outputs there, also made a SPDIF connector (where wordclock input was) and made a direct connection to the digital input on the flatband cable on the main pcb.
