Ryssen said:I changed opamps on the AUX out from JCR4580 to LM4562 yesterday.
I think it was a downgradesmaler sound stage life less etc.
So now I am locking for 3 JCR4580 to change back to.
please,they seems to be hard to find.
Thinking on the shipping etc.
That is very strange, since the lm4562 is the one of best sounding opamp IMO.
But the decoupling in the deq2496 is SO POOR that just changing opamp is not good enough. If you check the opamp supply pins, you will find only "ONE ceramic cap" decouple 4 opamps (at least that is what I found).
I think at the very least you should put a small film cap directly accross the +/- pins for each opamp before pulling those lm4562 out.
And if possible, add good e-cap for the +/- 15V entering into the output stage board.
shanyau said:
If you check pins 15 & 16 for the ak4114, it gives spdif output. It is very possible that they go to the AES output. Check out the ak4114 datasheet.
I have bypass the AES input and directly use pin 44 for direct spdif input.
I add a BNC input with a digital tranny and a cap and then into pin 44.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=121818&highlight=
stef1777 said:Hi Folk!
I've built a new clock for the DEQ2496. I wrote a web page with some pictures if you want to have a look. Sorry, for the moment, the text is in French. It's the same principe, I've used in the v1 miniCLOCK but this time with a small low ppm SMD TCXO.
An externally hosted image should be here but it was not working when we last tested it.
Hi stef1777, lots of good info on your web page. I am very tempted to try out your clock mod.
A note about the cap update. I found that adding a good cap across ak4393 pin 17&18 and the ground of c32 ceramic cap improves the sound a lot. You might want to try that, I found the decoupling of the dac is poor ( pin 17 & 18 should be separately decoupled).
I use Oscon sepc grade with good result.
ChuckT said:
Hi!
I've also done that. The caps is missing if we compare the DEQ design with the AK4393 datasheet. Look on my web page (http://www.awdiy.com/index.php?page=various-deq-caps-mods). Myself, I placed the caps on C33.
An externally hosted image should be here but it was not working when we last tested it.
Concerning, the op-amp on the Analog board. Add 10uF caps on IC11 and IC12 is fine too. But don't use LM4562 at DAC output. Bad sound (too metallic and analytic).
For the clock, I've ordered 30 pcb. They will be available in 2/3 weeks. The beta clock seems to works fine in my own DEQ. I will also try it inside a DCX. The final version will also have a 10uH at + input.
Stef...
One more note about changing caps.
It might not be a good idea to put ultra low esr caps like Oscon immediately after those 3 pins regulators like 7805 or lm317 as they might oscillate.
Good info below.
http://www.tnt-audio.com/clinica/regulators_noise1_e.html
It might not be a good idea to put ultra low esr caps like Oscon immediately after those 3 pins regulators like 7805 or lm317 as they might oscillate.
Good info below.
http://www.tnt-audio.com/clinica/regulators_noise1_e.html
Big question for me!
Hello guys, I have a specific question on DEQ2496's features and I'm thinking maybe here I'll get the answer.
I intend to use the AUX analog out to delay a subwoofer with about 15ms. But, in the same time, I want to be sure that the digital out remains undelayed.
My concern is generated by the fact that AUX and digital outs are treated everywhere in the user manual as one block. And the Main analog out as the second block. Any of the first or the second block can be delayed one after the other but it is not clear if the delay is refering only at the analog outs or include also the digital out.
Hope you've got my point. Thank you very much!
Hello guys, I have a specific question on DEQ2496's features and I'm thinking maybe here I'll get the answer.
I intend to use the AUX analog out to delay a subwoofer with about 15ms. But, in the same time, I want to be sure that the digital out remains undelayed.
My concern is generated by the fact that AUX and digital outs are treated everywhere in the user manual as one block. And the Main analog out as the second block. Any of the first or the second block can be delayed one after the other but it is not clear if the delay is refering only at the analog outs or include also the digital out.
Hope you've got my point. Thank you very much!
Hi,
Unless I remember wrongly, on the I/O menu, thrid page delays, you can choose to apply them to AUX (default) or MAIN.
When I choose MAIN, if I use the analog (main) outs I can hear the changes when changing delays settings, but when I use the digital outs, I have to choose AUX for the delay settings to be heard (and working).
So, as far as I see, and if I have got the point
, you need to do it the other way around: plug your SW to the MAIN outs, delayed, and main system to the AUX (digital) out, undelayed.
Btw Stef, I am a fan of your work on the Behringer
I have one of mines now open (for whatever reason it had a DC output over 200mV on one channel and blew my Beta22 amplifier and my K701 headphones the damn thing) and will do some modding to it... I have some Lundahls around and looks like this will be the starting point (passive DAC out, this will keep me far from DC outs too).
Unless I remember wrongly, on the I/O menu, thrid page delays, you can choose to apply them to AUX (default) or MAIN.
When I choose MAIN, if I use the analog (main) outs I can hear the changes when changing delays settings, but when I use the digital outs, I have to choose AUX for the delay settings to be heard (and working).
So, as far as I see, and if I have got the point
, you need to do it the other way around: plug your SW to the MAIN outs, delayed, and main system to the AUX (digital) out, undelayed.Btw Stef, I am a fan of your work on the Behringer
I have one of mines now open (for whatever reason it had a DC output over 200mV on one channel and blew my Beta22 amplifier and my K701 headphones the damn thing) and will do some modding to it... I have some Lundahls around and looks like this will be the starting point (passive DAC out, this will keep me far from DC outs too).
Reducing the DEQ's analogue output level?
Just got a DEQ2496 with firmware v2.4 and I have been very pleased with the new-found control it gives me.
I have it connected between my preamp (Denon Pro DNA-7100) and power amp (Hypex UCD400HG) using the analogue XLR connections.
I find the output of the DEQ too high, so that at max listening levels, the input signal peaks are barely hitting -25dB on the VU meter. As I understand, this is way below the level for ADC to work at its best (ideally close to 0dB). I've already reduced the Gain setting in the Utility by -15dB and set the back button to 12dB
I've been able to reduce by a further 15 dB or so by turning the gain setting on the DYN menu for both channels to -15dB (with Threshold and Ratio at minimum). Does this in any way affect the audio beyond gain reduction?
Is there any other way to reduce the DEQ's voltage output by 20dB (including simple hardware changes that will not degrade audio quality?).
Just got a DEQ2496 with firmware v2.4 and I have been very pleased with the new-found control it gives me.
I have it connected between my preamp (Denon Pro DNA-7100) and power amp (Hypex UCD400HG) using the analogue XLR connections.
I find the output of the DEQ too high, so that at max listening levels, the input signal peaks are barely hitting -25dB on the VU meter. As I understand, this is way below the level for ADC to work at its best (ideally close to 0dB). I've already reduced the Gain setting in the Utility by -15dB and set the back button to 12dB
I've been able to reduce by a further 15 dB or so by turning the gain setting on the DYN menu for both channels to -15dB (with Threshold and Ratio at minimum). Does this in any way affect the audio beyond gain reduction?
Is there any other way to reduce the DEQ's voltage output by 20dB (including simple hardware changes that will not degrade audio quality?).
Preamp after DEQ
The easiest thing you could do, at least temporarily to find out how it would sound, is to put the DEQ before the preamp. This would also allow you to try it with the digital in. Having volume control after the DEQ is the key to getting the best sound out of it so as to get the input level to just peak the meters at your desired listening level in order to maintain the maximum resolution in the analog to digital conversion. You may also need volume control before it as well to get the right input level. I use the SRC2496 in front of my DEQ as it has an analog input level control that the DEQ lacks but then again, I don't listen to my turntable or tuner much any more so analog source quality isn't a big priority for me. I mainly use the digital in. Beyond this you would need circuit mods inside the Behringer.
Just got a DEQ2496 with firmware v2.4 and I have been very pleased with the new-found control it gives me.
I have it connected between my preamp (Denon Pro DNA-7100) and power amp (Hypex UCD400HG) using the analogue XLR connections.
I find the output of the DEQ too high, so that at max listening levels, the input signal peaks are barely hitting -25dB on the VU meter. As I understand, this is way below the level for ADC to work at its best (ideally close to 0dB). I've already reduced the Gain setting in the Utility by -15dB and set the back button to 12dB
I've been able to reduce by a further 15 dB or so by turning the gain setting on the DYN menu for both channels to -15dB (with Threshold and Ratio at minimum). Does this in any way affect the audio beyond gain reduction?
Is there any other way to reduce the DEQ's voltage output by 20dB (including simple hardware changes that will not degrade audio quality?).
The easiest thing you could do, at least temporarily to find out how it would sound, is to put the DEQ before the preamp. This would also allow you to try it with the digital in. Having volume control after the DEQ is the key to getting the best sound out of it so as to get the input level to just peak the meters at your desired listening level in order to maintain the maximum resolution in the analog to digital conversion. You may also need volume control before it as well to get the right input level. I use the SRC2496 in front of my DEQ as it has an analog input level control that the DEQ lacks but then again, I don't listen to my turntable or tuner much any more so analog source quality isn't a big priority for me. I mainly use the digital in. Beyond this you would need circuit mods inside the Behringer.
Scott, thanks for your suggestions. I've yet to hear how the set sounds with the DEQ pre-preamp so I'll give it a try one day - my gear is snuggly nestled in my sideboard and re-connections are not to be lightly attempted
Yes there are advantages to having the DEQ between the source & preamp. This way it can do its work entirely in the digital domain too without doing the ADC thing.
However, my preamp is actually a 7.1 pre pro so I have several digital sources to be EQ'd - a CDP, NMT (media server), DVDP and digital radio tuner. Or maybe get a multi s/pdif selector box (is there such a thing?)
There's yet a third way - I've connected my pre pro's optical O/P into the DEQ and used the DEQ's Gain Setting as volume control! The volume levels are actually quite feasible for my setup - moderately loud, louder or deafening
This could eliminate the preamp for a single digital source stereo setup I'd still like to know what the hardware mod would be like to attenuate the DEQ's ouput.
Please resend schematics of digital output DEQ2496
Hi,
I see that the digital part of DEQ2496 clearly lacks transparency.
Even if the bypass is activated!. Yet DEQ2496 uses AK4114 receiver, very good receiver 192khz. Is this a problem of jitter??
Please repost the image of the digital part of DEQ2496 especially the digital part: deq_digout.JPG
Thank you in advance
Cordially
Hi,
I see that the digital part of DEQ2496 clearly lacks transparency.
Even if the bypass is activated!. Yet DEQ2496 uses AK4114 receiver, very good receiver 192khz. Is this a problem of jitter??
Please repost the image of the digital part of DEQ2496 especially the digital part: deq_digout.JPG
Thank you in advance
Cordially