Any full digital amp project(s) that may rival NAD C390DD?

[soundcheck]

Hi.

MiniDsp also offers TAS5706 based amps at 60$.
You might be able to match these with the USB streamer.



I'm also still looking for a high quality multichannel SPDIF IF to feed my FDAs.

The only mulitchannel SPDIF interfaces that were acceptabe to me was an Oppo BDP extension board and the RME AES card.

But the overall pricetag kept me away from getting these.

Cheers

 

[wgscott]

Hello,
New to this board. Please point me to the highest performing Digital Amp project(s) that might rival a NAD C390DD or Lyngdorf amp; those that output PWM. Thank you

I have the exact same question. I also listened to the NAD C390DD at home for a couple of months, and found it very clear, precise and detailed, but when I put my DIY Class D Audio amp back in place, I was shocked by how much better having twice as much power sounded. (My room is big and my speakers are fairly inefficient).

I was also a bit disappointed about how much energy the NAD consumes even when idle, compared to my DIY class D amp.

Hence, I would like to try to build my own version...

 

[riotubes]

any one able to audition the NAD D 7050 yet?

The specs are:
- 2 x 50 watt
- 24-bit/192kHz digital-to-analog converter for playback of high-resolution digital music
- asynchronous USB input for connecting a computer (up to 24-bit/96kHz resolution)

Would it have been that much more expensive to build 32-bit/386kHz capability for the spdif and usb?


If and when folks listen to this, I'd be curious about comparisons to the C390DD (which I've auditioned).

 

[pdemarco]

Also minidsp offers the icePower 125 with the dsp.

PWR-ICE125 | MiniDSP

It has a digital input, can be controlled through Ethernet. A very interesting candidate.

 

[egberttheone]

The Zetex chip is not available for DIY(not even the datasheet), I have build a full digital amp (I2S to PWM) based on a TI chip and it sound awesome and is very efficient.
I have also build this amp with the sta308 and it had a high noise floor.

Edit: I think Zetex offers the best performance at the moment.

 

[egberttheone]

I found this also: looks very intresting. DDFA®: CSRA6000? & CSRA6001?

 

[riotubes]

In March 2012, CSR acquired UK-based capabilities in digital class D audio amplifier technology from Diodes Inc of Plano, Texas, trademarked as DDFA (direct digital feedback amplifier). Diodes, Inc. acquired Zetex who developed DDFA.

This is the technology inside the NAD C390DD, the device I referenced when starting this thread. Perhaps CSR will make this available to DIY? I'm still curious about the NAD D 7050 which has the same trickle down technology.

 

[craig in SD]

any one able to audition the NAD D 7050 yet?

The specs are:
- 2 x 50 watt
- 24-bit/192kHz digital-to-analog converter for playback of high-resolution digital music
- asynchronous USB input for connecting a computer (up to 24-bit/96kHz resolution)

Would it have been that much more expensive to build 32-bit/386kHz capability for the spdif and usb?


If and when folks listen to this, I'd be curious about comparisons to the C390DD (which I've auditioned).

I got turned on to the direct digital concept through Soundcheck's blog and posts here and elsewhere, and purchased a D7050 last week, after having heard a C390DD at a local showroom a couple months back. Since they were in different setups and different rooms, I obviously cannot compare head to head, but the sound quality is very similar: silent, black background; deep, precise soundstage. I purchased a Wadia 151 also with the intent of comparing and keeping the one I preferred. My preference is definitely the NAD--fuller bass and deeper soundstage in my setup. I wish I had some way to measure the performance objectively. (Might still try out a NuForce DDA-100 for comparison too, not sure. I might just decide to keep the NAD, stop comparison shopping, and enjoy the music.)

My equipment: Monitor Audio Silver 5i, SB Touch, Blue Jeans Cables digital coax.

I'm very, very pleased with the D7050, and happy to answer questions. I don't have a lot of time to dive into a detailed post right now, but will try to respond to any questions in a day or two. I'm also on Audio Asylum and Audio Circle, if you want to move the discussion (since this isn't really a DIY topic.)

 

[oon_the_kid]

Hi riotubes,

It is unlikely that you will get a digital amp or any other amp to sound like your 300B. For the simple reason that you are running a high efficiency (probably) full range. The key is the output impedance of your amplifier. Tubes will have significantly higher impedance.

You can read in firstwatt.com. articles by nelson pass particularly on F1 amplifier. If you are using a solid state amp with generous amount of negative feedback, you will be overdamping your speakers and they will sound thin. You can reduce this by adding a resistor in series with the output. Prob around 1 to 10 ohm. Get a mundorf or parallel a few vishay dale. Meaning to try that with my t amps but didn't have the time.

Oon

 

[bobistev]

I got turned on to the direct digital concept through Soundcheck's blog and posts here and elsewhere, and purchased a D7050 last week, after having heard a C390DD at a local showroom a couple months back. Since they were in different setups and different rooms, I obviously cannot compare head to head, but the sound quality is very similar: silent, black background; deep, precise soundstage. I purchased a Wadia 151 also with the intent of comparing and keeping the one I preferred. My preference is definitely the NAD--fuller bass and deeper soundstage in my setup. I wish I had some way to measure the performance objectively. (Might still try out a NuForce DDA-100 for comparison too, not sure. I might just decide to keep the NAD, stop comparison shopping, and enjoy the music.)

My equipment: Monitor Audio Silver 5i, SB Touch, Blue Jeans Cables digital coax.

I'm very, very pleased with the D7050, and happy to answer questions. I don't have a lot of time to dive into a detailed post right now, but will try to respond to any questions in a day or two. I'm also on Audio Asylum and Audio Circle, if you want to move the discussion (since this isn't really a DIY topic.)

Hi Craig,

Is the 7050 using the Zetex technology? Any chance you can post photos of the unit internals?

 

[craig in SD]

Hi Craig,

Is the 7050 using the Zetex technology? Any chance you can post photos of the unit internals?

No photos of the internals. But a number of NADs specs for this unit are line item reproductions of the CSRA6000/CSRA6001 specs. See, for example, THD+N. The functions built into this chipset are ideal for producing an amp with the features of the D7050--e.g. unused amplifier outputs can be used for headphone or line level analog outputs (D7050 has one of each, and is on the low end of the available power range for this IC), and bluetooth streaming. I would wager good money this is what's inside. Is anyone else making such a good fit for this product?

 

[craig in SD]

NAD D 7050 Network Receiver with Bluetooth®

Well, now, it appears CSR is advertising that their direct digital technology is in the D7050, so I guess that clears it up...

 

[kerkula]

NAD drank the Apple juice

I was just about to by the 7050. It looks like a great product. I am sad to say, unless you own an Apple product (iphone or ipad) you really can't use this amp. You need one of these devices to configure the wi-fi or adjust the subwoofer output. NAD won't support any sort of android interface. There are probably reasons for this. The obvious one is that not only does one need to drop $999 for this amp but you also need to find spare cash to buy an ipad or iphone. Seems like a mistake to me. I really want this amp but not on those terms.

My hunt for the right FDA continues.

Kerkula

 

[von Ah]

That is seriously disappointing.

 

[kerkula]

Android app now available

NAD finally got around to it and made an android app available. I bought the d7050 and am enjoying it. It needed to break in over the course of a month. It sounded very good out of the box but doing even better now.

As for the app it is identical to the apple version which means not much. I suspect there's more functionality lurking in those chips than we are allowed to see.

cheers,

kerkula

 

[audiolic]

I havn't listened the NAD amp.

Though I listened to the NAD M51 (also DDFA ) + a class D amp at a friends place.
That combination sounded awesome.


I do run a tweaked DDX320 for quite some time ( which left my TP Buffalo plus Class-D amp behind)


I've done some tweaking on the DDX320 FDA. (You'll find an FDA article on my blog and discussions in the HifiMeDiy vendor forum.)

Without that tweaking it the DDX is IMO an average performer.
You probably are better of buying one of those 200-300 FDAs.

With my tweaks the DDX is IMO a great sounding device and pricewise
a steal. My mods didn't cost much. At a total of 150 $ (includes the LiPoFe batteries) a DAC incl. amp at this quality is hard to beat.



CSR with DDFA seems to offer a developments/evaluation board soon ( there's another thread over rhere @DIYA). That might be interesting.

NAD will also launch a new product line in July. Those FDAs will be called D7050 D3020. They come with USB input - DLNA/UPNP and wireless (7050) as well as bluetooth APX.
I'd say that these devices are gonna be very interesting. Keep the fingers crossed that they managed to built in even better soundquality then their older devices.
I'd be very tempted to try the big one.

hi there, do you know if your tweaks has been applied to new ddx320 2.2 version

 

[soundcheck]

Some of them.

The battery supply which made a big difference in my case they skipped for obvious reasons.

However. The DDX320 is no longer sold. Now they sell a (or better two) USB-FullDigitalAmps which are based on the same technology. I havn't tried the new device myself though.




Cheers

 

[AudioLapDance]

UD20 and UD80 both use the Savitech SA9023 USB receiver and then pass on I2S (with control I2C on the side) to PWM STA335 20W (UD20) or STA328 80W (UD80)

Anyone know where to find the SA9023 datasheet?

Just about to mod my UD20






UD20 20W STA335
View attachment sta335bw.pdf


UD80 80W STA328
View attachment STA328.pdf

PS oh ya, check out the un-used features of these kinds of chips (and that's 2007/8)

STA533BW
Features
■ Wide supply voltage range (5 to 24V)
■ 4 Power Output Configurations – 2 channels of ternary PWM (stereo mode)
(2 x 20 W @ 8 Ω, 18 V) – 3 channels - left, right using binary and LFE
using ternary PWM (2.1 mode) (2x10W + 1x20 W @ 2 x 4 Ω, 1 x 8 Ω, 20 V)
– 1 channel PWM output (parallel-mode) (1 x 40 W) – 2 channels of ternary PWM (2 x 20 W) + stereo lineout ternary
■ 2.1 Channels of 24-Bit DDX®
■ >94dB SNR and Dynamic Range
■ Selectable 32 KHz to 192 KHz Input Sample Rates
■ I2C control with Selectable Device Address
■ Digital Gain/Attenuation +48 dB to -80 dB in 0.5 dB steps
■ Soft Volume Update
■ Individual Channel and Master Gain/Attenuation
■ Dual Independent Limiters/Compressors
■ Dynamic Range Compression or Anti-Clipping Modes
■ AutomodesTM
– 15 Preset Crossover filters
– 2 Preset Anti-Clipping Modes
– Preset Nighttime Listening Mode
■ Individual Channel and Master Soft and Hard Mute
■ Independent Channel Volume and DSP Bypass
■ Automatic Zero-Detect Mute
■ Automatic Invalid Input Detect Mute
■ 2-Channel I2S Input Data Interface
■ Input and Output Channel Mapping
■ 4 x 28-bit User Programmable Biquads (EQ) per channel
■ Bass/Treble Tone Control
■ DC Blocking Selectable High-Pass Filter
■ Selectable De-emphasis
■ Sub Channel Mix into Left and Right Channels
■ Advanced AM Interference Frequency Switching and Noise Suppression Modes
■ Selectable High or Low Bandwidth Noise Shaping Topologies
■ Variable Max Power Correction for lower fullpower THD
■ Selectable Clock Input Ratio
■ 96 KHz Internal Processing Sample Rate, 24 to 28-bit precision
■ Thermal Overload and Short-circuit Protection embedded
■ Video Application: 576 x fs input mode supporting
■ PSSO-36 Slug Down package.

from:

http://www.diyaudio.com/forums/class-d/256281-noob-all-one-digital-audio.html#post3940046

 

[audiolic]

i need coax digital input..

 

[Yves Smolders]

FWIW - I know it's not what you are looking for, but the combo of NAD M51 (or NAD C 510, almost same as M51) with Ncore amplification behind it is pretty amazing. It's not a pure PWM amplification, but it's the best thing I've heard driving B&W 802 diamond speakers, short of the top of the range devialet. M51 is discontinued and being dumped at low prices