Behringer DCX2496 digital X-over

[mige0]

Originally Posted by Gary P

At this time the system is using the gain control VST from BlueCat audio controlled via MIDI to control the system volume. Seems to work well but I'll setup the system using Nyquist EQ as the gain control and see if I can hear any difference. I spend a lot of time listening to music at low levels so good performance at higher attenuation levels is plus.

Gary

I'm interested if you come to the same findings and conclusions !


Michael

[mige0]

Sy
thats why I'm not a scientist - there would be no time left for the good things in life...


My results, conclusions, simus, and measurements shown are valid nevertheless, as can been looked up elsewhere (or measured by yourself - if you take the effort)

Michael

[sendler]

Originally Posted by planet10

Replacing the switcher with an analog supply is a pretty standard mod. For those in North America, Michael Mardis does that using special made (& very special) O'Netics transformers.

dave

The transformers are used to couple the analog output directly out of the dac chip, eliminating all of the active analog stages in the DCX. Other people use caps. I don't know of too many people replacing the switch mode power supply. I scoped mine once and found it to be dead silent at the 200uV limit of my cheap scope. Radiated emissions are noticeable with the lid off but seem to be fully contained within the shielding partitions once the lid is reinstalled. SMPS technology is quite mature now and has sonic advantages over linear supplies especially for power amps. I have just switched to MeanWell SMPS for my power amps and will never look back. The SMPS make the amps sound more powerful and much faster.

[mige0]

Originally Posted by sendler

I have just switched to MeanWell SMPS for my power amps and will never look back. The SMPS make the amps sound more powerful and much faster.

Which ones do you use ?
I've looked up MeanWell page and found them to supply a extraordinary wide palette of SMPS - but nothing dedicated for audio ?

Did you need any additional filters at AC side or DC side ?

Michael

[sendler]

Originally Posted by mige0

Which ones do you use ?
I've looked up MeanWell page and found them to supply a extraordinary wide palette of SMPS - but nothing dedicated for audio ?

Did you need any additional filters at AC side or DC side ?

Michael

I have switched to a modified version of these amps which sound amazing if you are willing to run a less intrusive output filter.
2*100 watt @ 4ohm TK2050 Class-D Audio Amplifier Board_Sure Electronics' Webstore
See the mod thread here.
http://www.diyaudio.com/forums/class...00-tp2050.html
I have finally found a great sounding off the shelf, shielded inductor and am doing listening for the final values of the filter as we speak. Look at my photo gallery to see some of the coils I have tried.
These power supplies are a fantastic deal.
36V DC 9.7A 349.2W Regulated Switching Power Supply_Industrial Power Adapter_Boxed Industrial Power Adapter and Chargers and Transformers_Measure Power Adapters_Sure Electronics' Webstore
No mods necessary. I'm using single rail but they should be able to run +- as the outputs can float.
Once I get my amps together I want to try a twin DCX version of this with T-Line subs.
http://www.diyaudio.com/forums/multi...ml#post2040924

[mige0]

Thanx for description and links !

[Pano]

Hey Gary, good to see you here! Love the avatar.

A nice digital volume control would be great. At the moment I use the digital input only so use the volume control in my player. It's done in 32 bits then converted to 24 or 16 bits as I choose. So far, it's working great for me. I'm willing to be proved wrong - that there is a better way.

I've been working with an ESS DAC chip that has 24 bit digital volume control. It also seems quite nice. Being an 8 channel chip, it could run the whole DCX. But it's probably easier to use a drop-in AKM chip with volume control.

[planet10]

Originally Posted by Legis

is the analog transformer going to actually increase THD% from the original design?

I don't care. THD is a meaningless spec as far as sonics go.

A transformer will certainly change the nature of the distortion. Being passive it is certainly going to generate far less higher order harmonics.

dave

[SQLGuy]

Originally Posted by Legis

What about those input and output mods, is the analog transformer going to actually increase THD% from the original design?

Not only that, but many of the transformers commonly used for this have less primary impedance than the 1K Ohm minimum output load that the DAC is rated for. Overloading the DAC probably incurs some noticeable changes in the sound that some may find an improvement.

[Legis]

I received my DCX yesterday. I have tested it for multiple hours and came to a conclusion that it is very, very transparent. And believe me it is not because I had bad/low resolution system or something like that.

DCX takes power from pre-amp socket of Bada LB-5600 power filter and I also put a ferrite in the end of the power cord. The power cord itself is shielded (tinned copper foil, 82% coverage) 3x1,5mm2 HQ cable.

IC's are from Monoprice, which are low resistance and inductance, shielded quality cables. My XTZ AP100 power amps have XLR inputs as do the EAW CAZ1400 sub amplifiers. Only unbalanced connection is from pre out of XTZ Class A 100 D3 --> DCX. There I use RCA male --> XLR male adapter and double shielded, air insulted low capasitance, resistance and inductance RCA IC.

As speaker cables I use Ecoflex 15, which is 3/5" thich coaxial cable with very good techinical specs. (center connector is like 5awg thick, very low resistance, capasitance and inductance cable).

I have put some money for the system and tried to optimize it in many aspects. This being said, I do not hear any corruption from DCX in the signal path, as odd it might sound.

DCX adds hiss a little, but I can't hear it from the listening position. What comes to sound quality, hiss would be the only thing I would like to improve in DCX. Hiss itself does not degrade the sound (maybe in very low listening levels it would), but it would be nice if DCX would ntt add any hiss since my set has very low noise floor (Bbarely audible with ear at the tweeter).



What comes to DCX's other features, I noticed that only way to mess the sound is to use auto-align. Does your DCX also give different delay-settings every time with auto-align?

According the auto-align, the woofer of RX6s is 1 metre/3,3 feet away from midrange and tweeter? I know that analog x-over can cause phase shifting, but wouldn't that be too much and not taken into account when designing the speaker? I listened to this setting and of course it sounded different, and at least to my ear it sounded not so good than all drivers with same delay. Lower midramge was not so present, maybe because midrange/woofer and woofer were not in the same phase (RX6s use 2,5way desing). The I ran A-A again, and result differed quite good from the first settings. 3rd run of A-A and again different result. 3 different runs, 3 different settings. Distance difference is like 0,5-1 metre, while the mic and speakers have stood still.

Where is the problem? Used mic is Behringer ECM8000 measurement mic.