Thanks Åke!
Going to take it apart and let you know. Need to have all the papers right first.
Going to take it apart and let you know. Need to have all the papers right first.
My Behringer DCX2496 is close to 15 years old and I see that it seems to look the same today , - has there been any upgrades over the years ? im considering replacing my amps with CROWN XTI and are curious if anyone knows how good the crown build in DSP is compared to the Behringer ?
Hi All,
I plan to get DCX2496 soon to replace my passive crossover in 3-way DIY loudspeakers. I read a bit about what is the best way to connect it and I decided to control volume between DCX and power amplifiers. Therefore I plan to use a surround processor/ preamplifier with 6-channel analogue inputs and outputs. After reading the OM of Harman Kardon Signature 2.0, which I plan to use, I found out that preamp channels have different frequency responses : front 20Hz-50kHZ+/-0.5dB, rear & centre 20Hz-30kHz +/-1dB, sub 10Hz to 100Hz +/-1dB. I was wondering if this limitation won't let me use this preamp just as a volume control. There are some old threads referring to using surround processors with DCX2496, but none of them mention results...
I plan to get DCX2496 soon to replace my passive crossover in 3-way DIY loudspeakers. I read a bit about what is the best way to connect it and I decided to control volume between DCX and power amplifiers. Therefore I plan to use a surround processor/ preamplifier with 6-channel analogue inputs and outputs. After reading the OM of Harman Kardon Signature 2.0, which I plan to use, I found out that preamp channels have different frequency responses : front 20Hz-50kHZ+/-0.5dB, rear & centre 20Hz-30kHz +/-1dB, sub 10Hz to 100Hz +/-1dB. I was wondering if this limitation won't let me use this preamp just as a volume control. There are some old threads referring to using surround processors with DCX2496, but none of them mention results...
Yes there has been some upgrades. The PCBs (particularly the DSP board) has been redone twice and the ADC chips have been changed from AKM AK5393/AK5383 (Ch-A,B/Ch-C) to Cirrus CS5381/CS5361. The Cirrus has better specifications. Other than that, the rest is mostly the same with only minor revisions due to parts obsolescence. The newer DCX2496s don't have the PCMCIA slot any more.
There is also a "new" model DCX2496LE (not so new any more), which is a cost-reduced version of DCX2496. Ch-C analog/mic input is missing on the LE, as is the AES or S/PDIF digital input on Ch-A. There is also no RS232 or RS485 serial port, so there is no way to program the unit with a computer. But what is there is essentially the same as the DCX2496.
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Measurement repost
Bentoronto has been griping in other threads that no one will show measurements of DCX mods. I posted mine here years ago, but even I can't find them in the thread now. :eye:
So here are a few from years ago. They should the stock output of the DCX2496 using the SPDIF inut vs the same unit with transformer outputs, SPDIF input. All that was done here was to replace the stock opamp output stage with a high quality 1:1 transformer.
The unlabeled is an IMD sweep, tho I don't remember how it was done.
Bentoronto has been griping in other threads that no one will show measurements of DCX mods. I posted mine here years ago, but even I can't find them in the thread now. :eye:
So here are a few from years ago. They should the stock output of the DCX2496 using the SPDIF inut vs the same unit with transformer outputs, SPDIF input. All that was done here was to replace the stock opamp output stage with a high quality 1:1 transformer.
The unlabeled is an IMD sweep, tho I don't remember how it was done.
Attachments
Thanks for posting. Glad to see data.
But I don't understand what the four illustrations represent and impossible to draw conclusions without an explanation of what's being illustrated.
As far as I can A-B here, the first two panels are quite similar.
What is the second panel showing? Are the levels the same? What is -60dB referenced to?
In the fourth panel, the transformer seems to have bigger (faulty?) outputs in the audible range but the stock unit has two sharp peaks north of 15kHz where nobody can hear much and only dogs can hear the harmonics.
Thanks.
B.
But I don't understand what the four illustrations represent and impossible to draw conclusions without an explanation of what's being illustrated.
As far as I can A-B here, the first two panels are quite similar.
What is the second panel showing? Are the levels the same? What is -60dB referenced to?
In the fourth panel, the transformer seems to have bigger (faulty?) outputs in the audible range but the stock unit has two sharp peaks north of 15kHz where nobody can hear much and only dogs can hear the harmonics.
Thanks.
B.
Here is a trace of mine. Run a few minutes ago. SPDIF input, just like Pano's.
The circuit includes REW in my elderly Mac Air, a cheapy SPDIF converter from eBay, beat-up old XLR to RCA plugs, about 4-lamps lit input to DCX, but only about 2-lamps output (in other words, not using anything like the full the dynamic range), some old volume controls, worn out old RCA cables, and connecting back to my Mac Air is a ADC I bought at the Salvation Army store used for $4 many years ago.
It is only fair to mention that in my rush to post, the ADC signal slightly overloaded the REW... so the DCX is only part of the errors in the FR and THD+Noise.
First of all, I won't waste your time showing the FR. Even with all those "heritage" bits and pieces, it is razor flat, 10 to about 20kHz (REW limit). Anybody expect different?
Attached below is the THD+Noise (out to like 9 harmonics) from an incredible 10 Hz to where REW poops out. For the math-challenged, "-88.7dB normalized to the fundamental" is .0037% THD+Noise. OK, that's the best case but seems good to me.
Can't think of errors here, but glad to learn if I've measured wrong.
I hope anybody who wants to post further to either side of this "DCX is crap" debate should do so using measurements, not gut feeling.
B.
The circuit includes REW in my elderly Mac Air, a cheapy SPDIF converter from eBay, beat-up old XLR to RCA plugs, about 4-lamps lit input to DCX, but only about 2-lamps output (in other words, not using anything like the full the dynamic range), some old volume controls, worn out old RCA cables, and connecting back to my Mac Air is a ADC I bought at the Salvation Army store used for $4 many years ago.
It is only fair to mention that in my rush to post, the ADC signal slightly overloaded the REW... so the DCX is only part of the errors in the FR and THD+Noise.
First of all, I won't waste your time showing the FR. Even with all those "heritage" bits and pieces, it is razor flat, 10 to about 20kHz (REW limit). Anybody expect different?
Attached below is the THD+Noise (out to like 9 harmonics) from an incredible 10 Hz to where REW poops out. For the math-challenged, "-88.7dB normalized to the fundamental" is .0037% THD+Noise. OK, that's the best case but seems good to me.
Can't think of errors here, but glad to learn if I've measured wrong.
I hope anybody who wants to post further to either side of this "DCX is crap" debate should do so using measurements, not gut feeling.
B.
Attachments
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I just did, using measurements. That you can't read them is something I can't help. Don't know what more to do.
I can "see" them just fine. I think readers of this thread will be able to judge for themselves based on post 4027 whether I know a thing or two about REW and distortion measurements.
I think it is fair to expect you to explain what it is you've posted. I gather your purpose was to demonstrate shortcomings of the DC2496 remedied by using a transformer output.
I'm glad to provide further details about my test and to answer any questions, esp from anyone who thinks razor flat from 10 Hz or that .01% THD+Noise (-80dB) is too distorted for their ears or that the DCX2496 needs mods to have good SQ.
B.
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I use the French RCA-mod. Don't know what the transformator mod does to the sound but the French mod sounds smooth /soft and big.
Maybe the next revision of REW will contain measurements of smooth/soft and big.
Funny, my unmodified unit already sounds exemplary smooth/soft and big.
B.
It's right there on the measurements Ben. Right in plain sight. That you can't understand them or that you want to brag about knowing REW is simply deflection on your part. There are horses, and there is water.
If the stock DCX is good enough for you, bravo! Why worry? But I, and many others have found worthwhile improvements with some easy modifications. Even some of the most die hard objectivists around here have found the improvements audible. The AKM DACs are quite good, IMO. You stick to your version, we're happy with ours. 😀
It's a problem that this doesn't have a main volume control, what alternatives are there or solutions? Ideally I'd use a digital input
I worried about the volume control problem for ages, and tried all sorts of analog methods to control 6 channels simultaneously.
In the end I gave up and simply used digital volume control from my media player. Not an option if you are spinning CDs. I did all the measurements and listening tests I possible could and found NO disadvantage to 24 bit digital volume control. It is no worse than analog volume control, and tracks better. Having found that the widest range I ever used was 10dB, it seems logical just to use digital. Of course my gain structure was set up correctly so that -10dB was all I ever needed.
In the end I gave up and simply used digital volume control from my media player. Not an option if you are spinning CDs. I did all the measurements and listening tests I possible could and found NO disadvantage to 24 bit digital volume control. It is no worse than analog volume control, and tracks better. Having found that the widest range I ever used was 10dB, it seems logical just to use digital. Of course my gain structure was set up correctly so that -10dB was all I ever needed.
It would be CD unfortunately. But I'd only need 4 channels at the moment, so not too bad. Not sure if this is ideal for me though, I don't have a windows pc and liked the fact that this is a "freestanding" unit. I don't think it has the EQ I need though to properly tame the subs, I use a Rane 1/3 octave graphic for sub duties at the moment that I've modified to 1/6 octave 😱🙄
I use this as vol control. The cool thing is that it is stand alone and pc-control. It is a little overkill but almost all usb soundcards have spdif in and out. I put a CD in the digital input and it follows the master pot.
That looks like two things. I thought technology was supposed to make our lives easier........
Even the miniDSP graphic is only 1/3 octave
Even the miniDSP graphic is only 1/3 octave
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With the DCX you get parametric EQ, which is great. Also shelf filters along with all the crossover slopes and delays. Very handy.
I have used the master gain on the DCX as a volume control, but didn't find it very user friendly, mostly because it was nowhere near my listening position. Who wants to get up to change volume? 😱
I have used the master gain on the DCX as a volume control, but didn't find it very user friendly, mostly because it was nowhere near my listening position. Who wants to get up to change volume? 😱
How many parametrics Pano? Sorry to ask basic questions, I've found manual on-line but have problems getting my head round it. This can be picked up quite cheaply now, do you think it's worth me having a play with?