Your Thoughts: Upgrading my setup from a NAD 758v3

[Althezad]

First post on this forum. Let me say I'm grateful this forum exists it has proven to be a treasure trove of valuable information.

I'm making this post to share the next step in my hifi journey. I trust some of you will have opinions to share and maybe some of your guidance may steer me out of trouble.

For a couple of years now I've had a NAD 758v3 receiver, I've thought it was the bee's knees, and Dirac room correction has been super cool. However recently I've started noticing distortion on certain when playing solo piano tracks. So I went digging and I've learned a few things.

1. Piano is actually quite difficult to capture and reproduce faithfully
2. The NAD 758v3 was measured on this forum last fall and objectively measured poorly

So I'm looking to improve the Music capabilities of my hifi setup.

The challenge will be an elegant solution that allows me to keep the AVR (I do subjectively like the sound of the NAD 758v3 95% of the time).

So here is what I'm thinking:
New Gear:

• minidsp SHD (Haven't ordered this yet. The SHD stands out for two features, 1. Dirac which I enjoy and 2. Analog Inputs)
• Standalone amplifier (actually already have a 2x NC502MP unit on order from VTV amplifier, I've read the threads about some QC kerfuffles but decided to go with someone in North America)

The setup will be as follows:
The NAD 758 L/R Preamp Outs will connect into the miniDSP SHD analog inputs.
Connect the miniDSP SHD XLR from Output 1 & 2 of the miniDSP SHD to a Y Splitter into Inputs 1/2, 3/4 of the amplifier which will then Bi-Amp my speakers.
Speakers are Martin Logan Motion 40s

This will allow me to use the miniDSP as a preamp to switch into either "Movie" mode using the processing of my NAD or into "Music" mode use the DAC inside the miniDSP.

I wanted to get your thoughts and critiques on this setup. Will this work? Is there a more elegant solution that isn't exorbitantly priced?

Thank You

 

[Althezad]

Wanted to provide an update as the amplifier from VTV Amplifier arrived today. I got the 2xNC502MP providing 4 channels at 500W.



I hooked it up to my NAD T758v3 pre-outs, using an RCA to XLR into an XLR Y-Splitter.


I played a piano track still using the NAD's internal HDMI DAC and the distortion I was hearing through my NAD was gone!!
I'm a tad surprised that the distortion was coming from the Amplification section and not the DAC.

VTV Amplifier First Impressions
As I have read a thread from a customer who experienced poor quality from their VTV Amplifier, I was definitely hesitant in my purchase.
However, my amplifier is put together neatly, with all the external connections being snug. I do not intend to open up the amp to examine the internals, but (based on the exif data) I believe the picture uploaded on the VTV Amplifier's e-commerce is my unit.

I managed a couple of hours of listening today, and the amplifier definitely sounds different from the amplification section in the NAD. In addition to not distorting, I was right away drawn to details in orchestral tracks that I had not heard prior. The amplifier sounds nice. Really looking forward to continuing listening over the next weeks.

After an hour of listening the amplifier does get warm but not uncomfortably hot.

A small thing I dislike is there is a bit of a speaker pop on the power-off.

...

With the distortion gone .. what the heck am I going to do with that miniDSP SHD?

 

[Althezad]

The Journey Continues
I received the miniDSP SHD in the mail the other day. If you told me a year ago, I'd spend several hours trying to identify why I have a dip in my subwoofer crossover .. I'd have called you mad, but that was yesterday evening. Going to continue with this over the weekend.

NC502MP Power-Off Pops
So I've realized that the loud pop that occurs from NC502MP modules when they are shut down is not good for my mental health. I've reached out to Warren of VTV Amplifier for a return of the amplifier (ugh, return shipping from Canada is gonna hurt) and am looking at other similarly (same ball-park at least) priced options.

So at this point in the upgrade journey, I am about to be, stuck with a DSP ... and my old 758 amp.

 

[Althezad]

A couple of learnings today. I connected the MiniDSP SHD out to the Analog In on the 758 AVR, set it to Analog Bypass mode, and played some piano tracks. It sounded as distorted as before. This confirmed my prior finding that the amplification section is what impairs the audible qualities of the AVR.

Out with the NC502MP in with the NC500
Based on some googling, it seems like the power-off pop of the NC502MP is a known issue. As someone dipping their toe into figuring out a setup using a DIY build, it would have been valuable to have a "buyers guide" of the common amplification modules as well as the known pros/cons.

That's water under the bridge at this point. Warren has agreed to swap my amplifier out for an NC500 based unit. He assured me that they do not suffer from the same loud pops. I'll keenly await its arrival and keep my fingers crossed that this holds.

 

[Althezad]

Three weeks of logistics and some $$ later, the NC500 amplifier has arrived from VTV.

I asked Warren to build me an NC500 stereo unit with the VTV Custom Buffer Boards, no fancy bespoke Opamps at this time, just TI LM4562s. I figured it would be nice to have the ability to swap out and upgrade opamps later on down the line.

Just as with the prior unit, this one seems well constructed with no loose external bits.

How Does it Sound
First, the most important part is that there NO thump on power off! Just the click of a relay.

The VTV NC500 unit sounds better than my NAD. I want to say the prior NC502MP bi-amp setup I had before was more "punchy," but really, I'd be kidding myself if I could compare such nuances three weeks apart. It sounds good. I will need to let my ears burn in a little bit to the sound of the new amp.

The Hookup
I was able to hook everything up to meet my objectives of essentially having a "Music Mode," which bypasses the NAD758v3, and a "Movie Mode," which utilizes the NAD758v3 as a surround processor. A picture is worth a thousand words, so have a look.



A cool bit here is that turning on the TV triggers the NAD 758v3 to turn on via CEC, which turns on the VTV amp over the 12v. So all I need to do is turn on the SHD, and things are playing.

Some Thoughts:

• I still need to do room calibration via Dirac. I'll likely have to do this twice, once on the SHD and once on the NAD, to get the timings correct.
• It would be nice to find a single remote solution for all this. A shame the MiniDSP SHD has no way to trigger it to wake from standby.
• Long term, it may be a sensible upgrade path to get rid of the NAD entirely.
• First, I would upgrade to something like a 3 channel 1ET400A amp for the center and two rear channels.
• Then I would be able to replace the NAD with an entry preprocessor. (Not sure if an "entry" preprocessor bracket exists but think Yamaha CX-A5200)

 

[Althezad]

A Frustration:
I have now lived with the above setup for a while. It sounds great, but a small frustration is switching between watching a movie and listening to music. The digital music signal has the MiniDSP SHD at about -30 on the volume control. A movie requires routing through the NAD to decode the surround. The NAD's volume is set to -14, anything higher, and it seems to like to kick on its fan. A noise of a different kind which I want to avoid.

While plenty loud on the speaker's the NAD drives (C/RR/RL), I have to turn up the MiniDSP SHD to about -10 to make all the speakers equal. I played around with the NAD's speaker output levels in software, but this seems to be the best I can come up with. It sure would be nice to have just one volume control.

Cables
Since my speakers are a fair foot and a half from the wall, I decided to upgrade the aesthetic of the speaker cables. Look at these monsters that arrived from Aliexpress. These must certainly be able to handle at least four times the music throughput of my previous cables. This results in a more expansive sound stage, more dynamics, deeper bass extension, and music, which is now more revealing, detailed, textured, and articulate. /sarcasm

But really, they sound the same but look great.


(Off-brand gaming handheld for scale)

(At least 4x the sound throughput.)

Next Steps
I think the next step is to get my other three channels onto their own amplifier. Eyeballing the PASCAL T-PRO1 3x250w from VTV.

 

[bibi2000]

Wanted to provide an update as the amplifier from VTV Amplifier arrived today. I got the 2xNC502MP providing 4 channels at 500W.

View attachment 104287

I hooked it up to my NAD T758v3 pre-outs, using an RCA to XLR into an XLR Y-Splitter.

View attachment 104291
I played a piano track still using the NAD's internal HDMI DAC and the distortion I was hearing through my NAD was gone!!
I'm a tad surprised that the distortion was coming from the Amplification section and not the DAC.

VTV Amplifier First Impressions
As I have read a thread from a customer who experienced poor quality from their VTV Amplifier, I was definitely hesitant in my purchase.
However, my amplifier is put together neatly, with all the external connections being snug. I do not intend to open up the amp to examine the internals, but (based on the exif data) I believe the picture uploaded on the VTV Amplifier's e-commerce is my unit.

I managed a couple of hours of listening today, and the amplifier definitely sounds different from the amplification section in the NAD. In addition to not distorting, I was right away drawn to details in orchestral tracks that I had not heard prior. The amplifier sounds nice. Really looking forward to continuing listening over the next weeks.

After an hour of listening the amplifier does get warm but not uncomfortably hot.

A small thing I dislike is there is a bit of a speaker pop on the power-off.

...

With the distortion gone .. what the heck am I going to do with that miniDSP SHD?

Its very encouraging! I have a T758V3 as well, After upgrading my speaker to 2 LS50 Meta & one T-Rel Mini the sound was "good" but distortion appears with complex sound stage.
It becomes obvious that my AVR reach its amps limit with 8 ohms speakers, To get more confort with the speaker I pre-order the forecoming Boxem NCx500 stereos power amps (also because I like the product concept...).
I am also thinking about the Minidsp & WiiM Plus as remplacement for the processor, but I don't know that it is worth effort or 2.1 only? what is your opinion? Subjective opinion welcome !

 

[bibi2000]

Its very encouraging! I have a T758V3 as well, After upgrading my speaker to 2 LS50 Meta & one T-Rel Mini the sound was "good" but distortion appears with complex sound stage.
It becomes obvious that my AVR reach its amps limit with 8 ohms speakers, and to get more confort with the speaker I pre-order the forecoming Boxem NCx500 stereos power amps (also because I like the product concept...).
I am also thinking about the Minidsp & WiiM Plus as remplacement for the processor, but I don't know that it is worth effort or 2.1 only? what is your opinion? Subjective opinion welcome !

 

[Althezad]

Its very encouraging! I have a T758V3 as well, After upgrading my speaker to 2 LS50 Meta & one T-Rel Mini the sound was "good" but distortion appears with complex sound stage.
It becomes obvious that my AVR reach its amps limit with 8 ohms speakers, To get more confort with the speaker I pre-order the forecoming Boxem NCx500 stereos power amps (also because I like the product concept...).
I am also thinking about the Minidsp & WiiM Plus as remplacement for the processor, but I don't know that it is worth effort or 2.1 only? what is your opinion? Subjective opinion welcome !

I think the NCx500 based power amps are going to make quite a positive difference.

A reasonable thing to do when you get the amps is to try running the L/R pre-outs from the NAD to your new amplifiers. I do this when I watch 5.1 content, and even though the processing is still done on the NAD, I have noticed an audible improvement over using the NAD's amplification.

 

[bibi2000]

Hi Althezad,

Thank you for your return. I will start by this first steps and eventually later upgrade other aspects (first Little room optimization as our sofa is sticked to the wall).
I am looking forward for the Boxem units by end of January and I will report the subjectives improvements (I assume that the Boxem will not requires more than 1V pre-out as I am listenning @ low level and their is enough juices with NCx500).

Cheers

 

[bodhi]

What is happening here? You have LS50 metas and a REL shoebox and you are dealing with distortion problem with a more powerful power amp?

Sorry to tell you this but you are in for more expensive upgrade.

 

[bibi2000]

Hi Bohdi,

Yep, its bit a bit irrational
The REL shoebox is giving a nice flat bass response between 35Hz to 80 Hz. It is Really ok for me and complementary to LS50 Meta (I am not looking for 20-35Hz boom boom range).
The "little" issue with the T758's vs. Kef LS50 is a "small" loss of medium/trebble soundstage with a 8 ohm speaker compare to my previous 4 ohm for orchestral music.
I played with the LS50 directivity by playing with the usual 20-30° angle and it has given nice result but no sufficient to me (irrational).
After the amp and beyond T758's Dirac great jobs, as our Parisian living room is a 5m*6m "brick" , I will add some sound absorbers to reduce the concrete <-> concrete reflection. For the Bass, our room's corners are stuffed with books & furnitures... No place for the bass trap and again the bass are really good the Dirac calibration.
Later and eventually for the joy of $ spending I will upgrade the T758/pre-amps by a MiniDSPFlex digi/DACs or a nice new "audiophile" AVR (looking for 2024's new line ups with DIRAC ART).

 

[bibi2000]

Update:
After buying a MiniDSP SHD studio, I did just directly to the following set up :
tv -> (Optic) MiniDSP SHD Studio (Coax) -> Topping E70V -> (XLR) BOXEM A 5517/N2 -> Kef LS50 Meta
(Coax) -> Khadass Tone -> T-rel Mini Mk3
Few words: It is just game changer. The NAD T758 was good, this upgrade is just great for my ears
I stay in 2.1 with a few DIRAC tuning, the next step will be the room treatement.