Hi folk!
I'm currently developing an dedicated linear PSU for the DEQ/DCX which will replace the original PSU. I personally have a DEQ2496 and I'm looking for more details on the DCX. If a DCX owner can help?
I like to know the "working" voltage for the DCX inside the PSU in use with a close 95% use of the DSP board. To do this, you need to inject a signal on the input at 0dB et mesure voltages at the red points (see the inclosed pictures).
The dedicated board is 80 x 90 mm. The board will use 2 toroid transformers (2x9v or 2x7v, and 2x15v) or may be later a custom made transformer with all voltages. The size of these kind of transformer is 62x34mm. Can someone check if the board and the 2 transformers will fit in the DCX? (without the original PSU as well).
The board and the 2 transformers fit well in the DEQ2496.
More info on this thread:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=102277
Stephane
.
I'm currently developing an dedicated linear PSU for the DEQ/DCX which will replace the original PSU. I personally have a DEQ2496 and I'm looking for more details on the DCX. If a DCX owner can help?
I like to know the "working" voltage for the DCX inside the PSU in use with a close 95% use of the DSP board. To do this, you need to inject a signal on the input at 0dB et mesure voltages at the red points (see the inclosed pictures).
The dedicated board is 80 x 90 mm. The board will use 2 toroid transformers (2x9v or 2x7v, and 2x15v) or may be later a custom made transformer with all voltages. The size of these kind of transformer is 62x34mm. Can someone check if the board and the 2 transformers will fit in the DCX? (without the original PSU as well).
The board and the 2 transformers fit well in the DEQ2496.
More info on this thread:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=102277
Stephane
.
Attachments
This is the results of the Swedish jury(one of them)
Meters on RED,
14,83v
-15,10v
8,97v
0
0
5,00v
3,37v
Sorry bad pic,The RED line is 120mm,The GREEN is 140mm,The YELLOW is 40mm.So unless you/we find some trafos that are about 55mm large,there is either to move the DSP board or mount the trafos where the original PSU is and the new PSU board on the other side of the DSP board,any other solutions?
Meters on RED,
14,83v
-15,10v
8,97v
0
0
5,00v
3,37v
An externally hosted image should be here but it was not working when we last tested it.
Sorry bad pic,The RED line is 120mm,The GREEN is 140mm,The YELLOW is 40mm.So unless you/we find some trafos that are about 55mm large,there is either to move the DSP board or mount the trafos where the original PSU is and the new PSU board on the other side of the DSP board,any other solutions?
A custom made toroid will be the best but it's expensive for one unit or two.
It seems that 2x9v will be too high. The LM7505 on the DSP board will need a dissipator. I'll try tomorrow with a 2x6v transformer (2x7v do not exist in 15va). I'm pretty sure that the board will work with 2x6v but the LM7805 on the DSP board may be not. Too low end regulator.
Thanks.
It seems that 2x9v will be too high. The LM7505 on the DSP board will need a dissipator. I'll try tomorrow with a 2x6v transformer (2x7v do not exist in 15va). I'm pretty sure that the board will work with 2x6v but the LM7805 on the DSP board may be not. Too low end regulator.
Thanks.
Can't you work around a transformer of Amveco? Look for type 70050 at there webpage.
http://www.amveco.com/Low_Profile_PC.htm
Regards
http://www.amveco.com/Low_Profile_PC.htm
Regards
Hi
I have a general question about 2496 and CD players. Most here prefer to plug their 2496 with digital cable.
I'm thinking about purchasing an AMC 1100 preamp(has max output of 8V) and use analog output into 2496.
But what about CD player what kind of level should the CD player be that it's not overkill for unmodified 2496?
I have a general question about 2496 and CD players. Most here prefer to plug their 2496 with digital cable.
I'm thinking about purchasing an AMC 1100 preamp(has max output of 8V) and use analog output into 2496.
But what about CD player what kind of level should the CD player be that it's not overkill for unmodified 2496?
Hi,
my standard output CD player drives the input stage way beyond all the red LEDs on. I had to run the gain at the front end down at +8db to just clip the signals and probably a bit lower (+6db or +7db) to avoid all clipping of the input signal (if my memory is correct). This would indicate that 1Vac would drive the DCX to clipping, but I suspect an even lower signal (maybe 500mVac) could also drive the DCX to clipping. The maximum input signal is 9.75Vac.
my standard output CD player drives the input stage way beyond all the red LEDs on. I had to run the gain at the front end down at +8db to just clip the signals and probably a bit lower (+6db or +7db) to avoid all clipping of the input signal (if my memory is correct). This would indicate that 1Vac would drive the DCX to clipping, but I suspect an even lower signal (maybe 500mVac) could also drive the DCX to clipping. The maximum input signal is 9.75Vac.
Hi AndrewT and thanks for your reply.
So the CD player does not need to be anything special in signal output?
I had in mind this CD player
http://www.tnt-audio.com/sorgenti/cambridge-d500se_e.html
So the CD player does not need to be anything special in signal output?
I had in mind this CD player
http://www.tnt-audio.com/sorgenti/cambridge-d500se_e.html
Ryssen said:This is the results of the Swedish jury(one of them)
Meters on RED,
14,83v
-15,10v
8,97v
0
0
5,00v
3,37v
An externally hosted image should be here but it was not working when we last tested it.
Sorry bad pic,The RED line is 120mm,The GREEN is 140mm,The YELLOW is 40mm.So unless you/we find some trafos that are about 55mm large,there is either to move the DSP board or mount the trafos where the original PSU is and the new PSU board on the other side of the DSP board,any other solutions?
i want to make a new psu too and i wonder the 2 pins with 0v are the same or one is the ground for symmetric 15v and the other is the ground of the rest?
back said:
back said:
Please go to this Topic to do not duplicate talk.
http://www.diyaudio.com/forums/showthread.php?threadid=102277
.
DCX2496 clipping on the output
I have a DCX2496 and a SRC2496. When i run cd player through the SRC2496 the DCX is clipping on the bass output (low left and right) no matter how little gain i am setting. The cd player is run with S/PDIF out to S/PDIF in on the SRC, the signal is then routed with AES/EBU out from the SRC to the digital in on the DCX. I can see that the input on the DCX is clipping too. The other components that i have routed through the SRC is not clipping on the DCX. Is it too high outputgain on the cd player? what to do?
I have a DCX2496 and a SRC2496. When i run cd player through the SRC2496 the DCX is clipping on the bass output (low left and right) no matter how little gain i am setting. The cd player is run with S/PDIF out to S/PDIF in on the SRC, the signal is then routed with AES/EBU out from the SRC to the digital in on the DCX. I can see that the input on the DCX is clipping too. The other components that i have routed through the SRC is not clipping on the DCX. Is it too high outputgain on the cd player? what to do?
To raise this thread a little from dust again.....
I updated my website to be much more easy to update and edit and also made a small study of issue that has been raised in DCX2496 mailing list a few times.
Many have questioned if the clock upgrade "works" also if SPDIF input is used. Well look the link below - I think that is proof enough.
http://esken.net/ergo/blog/?page_id=33
Regards,
Ergo
I updated my website to be much more easy to update and edit and also made a small study of issue that has been raised in DCX2496 mailing list a few times.
Many have questioned if the clock upgrade "works" also if SPDIF input is used. Well look the link below - I think that is proof enough.
http://esken.net/ergo/blog/?page_id=33
Regards,
Ergo
Hi Ergo,
does that link show that you are sending a jitter contaminated signal into DCX and it comes out de-jittered?
Could you post a standard DCX for comparison?
How much work have you done on the DCX?
How much better is it than the standard model?
Could you list the modifications in order of value (sound improvement) for money?
does that link show that you are sending a jitter contaminated signal into DCX and it comes out de-jittered?
Could you post a standard DCX for comparison?
How much work have you done on the DCX?
How much better is it than the standard model?
Could you list the modifications in order of value (sound improvement) for money?
Yes basically the graph shows that the signal going into DCX through SPDIF comes out with less jitter than in the source signal.
Actually I have a unmodified DCX at work - I will try make same measurement with that one
******
I will try to put some of the mods I have done to my site, but to give some idea of things I have tried:
*SPDIF input upgrade with COAX connector and coax wire going right to the PCB, terminated with 75 ohm resistor and transformer changed to Scott digital transformer suggested by Jocko - unfortunately I do not have definitive measurements on this as it was 3 years ago and I did not know as well as now how to measure this... but it makes me "feel good" that the SPDIF is actually properly terminated and does no pass through
XLR connector - Relay - PCB trace - flat cable - PCB trace again - and unknown quality transformer + WRONG 110 ohm termination
*Tent XO upgrade - soundstage clearly gains in 3D feeling and instruments get their "air" around them.
* passive out with first order RC filter
* passive out with RLC filter - do not try as the coils will pick up way too much RF and output noise floor gets worse no matter what you do
*passive out with Lundahl transformers (for 2 channels) - good sound but also hard to realize due to size of transformers and it's hard to shield them from RF inside the unit
*6 channel ALPS volume in output as shunt regulator - too much signal is lost and the ability to drive load gets worse and bass sound suffers clearly.
*RC after DAC -> decoupling cap -> 6 channel ALPS volume in normal connection -> single OP134 per channel analog stage with individual regulators for each opamp - this gave a very good sound + the volume control right inside the DCX.
*Replaced all caps in switching power supply
*Replaced el. caps around DAC-s with Oscons.
*Currently I have moved the same 6ch volume + single opamp stages into separate "preamplifier" box and the DCX has gone back to original mod of RC passive filter + cap for decoupling. I wanted to use the same analog stage with Echo Layla24 when emulating the crossover with LspCad. So that is the reason I moved it out...
*********
As you can see I have tried many many things and mostly just making 2 channels at a time while keeping some other 2 channels with other mod. This has given me the ability to keep reference more or less.
The definite good mods are
*clock upgrade
*passive RC+C output (assuming you have a good preamp after DCX and the latter can also cope with some more RF than usual as the first order filter in DCX passive mod gives less RF rejection than the original or usual filters in CD-s.
**********
In the to do list I still have the upgrade of the DAC +5V power supply. I do not want to make it by just replacing the regulation in current 7805 position. I want to get closer to the DAC chips themselves. But there are some technical size limitations doing that and I have not found an elegant enough and small enough solution that would be able to supply about 200mA that the three DAC-s would require and at same time allow installation to very near the DAC-s. The tent shunt unfortunately does not have enough current capability - otherwise would be a good choise.
Ergo
Actually I have a unmodified DCX at work - I will try make same measurement with that one
******
I will try to put some of the mods I have done to my site, but to give some idea of things I have tried:
*SPDIF input upgrade with COAX connector and coax wire going right to the PCB, terminated with 75 ohm resistor and transformer changed to Scott digital transformer suggested by Jocko - unfortunately I do not have definitive measurements on this as it was 3 years ago and I did not know as well as now how to measure this... but it makes me "feel good" that the SPDIF is actually properly terminated and does no pass through
XLR connector - Relay - PCB trace - flat cable - PCB trace again - and unknown quality transformer + WRONG 110 ohm termination
*Tent XO upgrade - soundstage clearly gains in 3D feeling and instruments get their "air" around them.
* passive out with first order RC filter
* passive out with RLC filter - do not try as the coils will pick up way too much RF and output noise floor gets worse no matter what you do
*passive out with Lundahl transformers (for 2 channels) - good sound but also hard to realize due to size of transformers and it's hard to shield them from RF inside the unit
*6 channel ALPS volume in output as shunt regulator - too much signal is lost and the ability to drive load gets worse and bass sound suffers clearly.
*RC after DAC -> decoupling cap -> 6 channel ALPS volume in normal connection -> single OP134 per channel analog stage with individual regulators for each opamp - this gave a very good sound + the volume control right inside the DCX.
*Replaced all caps in switching power supply
*Replaced el. caps around DAC-s with Oscons.
*Currently I have moved the same 6ch volume + single opamp stages into separate "preamplifier" box and the DCX has gone back to original mod of RC passive filter + cap for decoupling. I wanted to use the same analog stage with Echo Layla24 when emulating the crossover with LspCad. So that is the reason I moved it out...
*********
As you can see I have tried many many things and mostly just making 2 channels at a time while keeping some other 2 channels with other mod. This has given me the ability to keep reference more or less.
The definite good mods are
*clock upgrade
*passive RC+C output (assuming you have a good preamp after DCX and the latter can also cope with some more RF than usual as the first order filter in DCX passive mod gives less RF rejection than the original or usual filters in CD-s.
**********
In the to do list I still have the upgrade of the DAC +5V power supply. I do not want to make it by just replacing the regulation in current 7805 position. I want to get closer to the DAC chips themselves. But there are some technical size limitations doing that and I have not found an elegant enough and small enough solution that would be able to supply about 200mA that the three DAC-s would require and at same time allow installation to very near the DAC-s. The tent shunt unfortunately does not have enough current capability - otherwise would be a good choise.
Ergo
Driverack 480/480T/4800?
Not to diminish the prowess of the DCX (maybe) but has anyone listened to a higher-end dbx? The ones listed in the title, PA and 260 models need not apply.., At least not for me, I use 2 DCX's to get my 2X4 and let the other 4 chs. hang for future subs....subs of I'm dreaming. lol So, anyone heard em?
Not to diminish the prowess of the DCX (maybe) but has anyone listened to a higher-end dbx? The ones listed in the title, PA and 260 models need not apply..,
At least not for me, I use 2 DCX's to get my 2X4 and let the other 4 chs. hang for future subs....subs of I'm dreaming. lol So, anyone heard em?audio-kraut said:
Price? Why would I ask about price in this context? Obviously these cost more, performance is the criterion, I thought that was clear.
Higher end as in not a PA or 260. Price? lol there is a guy on eBay that sells quite a lot of B-stock 480's for ~$1800 USD, more for 480T's with Jensens, and 4800's for ~$2800 US, and that is a big down cut from retail. Just looking for LISTENING impressions, and again, PA and 260 models need not apply.
FWIW, the 4800 retails for ~$5000 USD. Just wondering if it has the sonic cred to command that price compared to a stock, or even modded DCX.
I am not interested in the sonic creds, what are the features that might justify a price like that?
I have looked longingly at the deqx at a little over 3 grand, which may be justified as it allows a slope of >300db/octave and incorporates an auto deq. So - what makes the dbx so outstanding.
BTW - not interested in sonics as I am quite satisfied with the ones the dcx unmodded exhibits. So - don't care if they are "supposedly" better in any dbx unit, as I am not likely to hear a difference.