5.1+ Processors with Best DACs/Preamps?

For the 5.3 system I want to build, my plan was to have JRiver feed Blu Ray disc audio to this MCH DAC via USB. https://www.oktoresearch.com/dac8pro.htm 

 https://www.stereophile.com/content/okto-research-dac8-pro-da-processor 

But like most DACs, the Okto’s balanced outputs only deliver ~ 4.1 volts, which KR found insufficient to drive his power amps (Benchmark AHB2, NAD C298) with DIRAC Live 3 enabled. Thus, all balanced outputs of this processor would need to supply a minimum of 10 volts/channel to offset DIRAC gain losses of almost 20db  https://www.sowter.co.uk/decibels.php , as KR mentioned in his review of the Topping Pre90. https://www.stereophile.com/content/topping-pre90-line-preamplifier

Unfortunately, there are no 8-channel preamps available, either from audiophile or pro audio brands. KR's fix was to buy three Topping preamps, which as shown in Fig. 3 its balanced outputs deliver very low distortion, and which virtually continues decreasing well beyond 10 volts.

https://www.stereophile.com/content/topping-pre90-line-preamplifier-measurements 

But stacking three Pre90 preamps doesn't seem the most elegant solution, and KR mentioned that struggling with the Pre90's crappy remote is no fun.  

So unless I find a reputable builder to affordably custom design a MCH preamp, the only alternative would be a MCH processor with a DAC section at least as good, but ideally far better than the Okto, and with all balanced outputs delivering at least 10 or 12 volts/channel.

If yes, how likely could its own master volume/mute remote control allow reducing all balanced outputs to ~ 5 volts or less without any loss of resolution and perceptible dynamic range?  

If yes, which model (s) would also have a pair of high quality potentiometers for selectively setting levels of the front and rear/side speakers-like the ones John Curl used for designing the JC-2 preamp https://www.partsconnexion.com/tkd-potentiomters.html , which JA raved about going head to head against his Levinson 380S? https://www.stereophile.com/solidpreamps/308para/index.html See p. 10-11. https://parasound.com/pdfs/JC2Manual.pdf

Theta Digital are the only MCH processors I’m aware of which might have DAC sections at least equaling the Okto DAC 8 Pro, though I doubt its preamp performance would match that of the Parasound JC-2.

Please suggest brands/models.

Ideally, such processors would also be customizable, allowing omission of video and unbalanced connectivity, thereby minimizing final cost.

Would something like this work as an alternative approach?

https://www.anthemav.com/products-current/type=av-processor/model=avm-70-8k/page=overview

9 hours ago, davide256 said:

Would something like this work as an alternative approach?

 

https://www.anthemav.com/products-current/type=av-processor/model=avm-70-8k/page=overview

They mention 10volts Output Max but the unit has like 15 XLR Outputs which are possibly all available for use at the same time. Then they only list the THD & SNR numbers based on a 4v Output. 

The other question would be what that 10v Max Output turns into when more than 2 XLR channels are used at once. Does it spread that Voltage across all the XLR Outputs evenly (ie...1.5v each??) or some variation of that depending on how many Amps are plugged in? Or, do all 15 XLR's get there own allocation of 10volts? I doubt its the latter but maybe I'm wrong. And if it did do that (each getting 10volts), why wouldn't you want to advertise it, that's a big selling point IMO, why not shout it out if that is the case.

The price would also bring me pause given the listed Specs or even more to the point, just the way the Specs are written alone. To fuzzy and broad which is a Red Flag IME/IMO.

But, I guess it all depends on what the buyer wants. I've never listened to this unit but just based on price and specs alone I can think of better options that are known goods (Like the cheaper Anubis previously mentioned).

2 hours ago, cjf said:

They mention 10volts Output Max but the unit has like 15 XLR Outputs which are possibly all available for use at the same time. Then they only list the THD & SNR numbers based on a 4v Output. 

 

The other question would be what that 10v Max Output turns into when more than 2 XLR channels are used at once. Does it spread that Voltage across all the XLR Outputs evenly (ie...1.5v each??) or some variation of that depending on how many Amps are plugged in? Or, do all 15 XLR's get there own allocation of 10volts? I doubt its the latter but maybe I'm wrong. And if it did do that (each getting 10volts), why wouldn't you want to advertise it, that's a big selling point IMO, why not shout it out if that is the case.

 

The price would also bring me pause given the listed Specs or even more to the point, just the way the Specs are written alone. To fuzzy and broad which is a Red Flag IME/IMO.

 

But, I guess it all depends on what the buyer wants. I've never listened to this unit but just based on price and specs alone I can think of better options that are known goods (Like the cheaper Anubis previously mentioned).

 

 

 

They make good gear. Can't say if their room compensation is a as good as Dirac but it certainly can make your typical box speaker sound far better even in

a bad room.

You could order the Octo Research DAC8 Pro with higher Outputlevel, if needed:

Quote

Choose a custom output voltage that matches your amplifier. Available in range from 1 to 12V RMS. Please specify the requested value in your order note.

11 hours ago, cjf said:

The other question would be what that 10v Max Output turns into when more than 2 XLR channels are used at once. Does it spread that Voltage across all the XLR Outputs evenly (ie...1.5v each??) or some variation of that depending on how many Amps are plugged in? Or, do all 15 XLR's get there own allocation of 10volts? I doubt its the latter but maybe I'm wrong. And if it did do that (each getting 10volts), why wouldn't you want to advertise it, that's a big selling point IMO, why not shout it out if that is the case.

This is bogus.  Audio line-level voltage outputs are not like power amp outputs which are constrained by the power supply.  I have never heard of stereo or multichannel line-level output voltages being affected by how many are active.

On 3/8/2023 at 6:26 AM, Kal Rubinson said:

This is bogus.  Audio line-level voltage outputs are not like power amp outputs which are constrained by the power supply.  I have never heard of stereo or multichannel line-level output voltages being affected by how many are active.

This and the rest below are all questions I would be very interested in knowing the answer to.

I guess I'm not sure how the size of the PS can't be involved if its the Source for all the components inside the box that require power to perform their function?

I'm also not sure how the XLR Output would be able to provide power in order to send the signal downstream to the next XLR Input of some other box if the Source PS was not involved?

If I assumed that the PS inside the Source box does play a role in the above functions then I would ask if the size of that PS would be limited in order to fit inside the box its going in?

My next question would then be, can I assume that the size of the PS would then have some relation to the amount of Output it can produce?

If the Source box had a 500w PS (As an example) and it must provide enough juice to power all the components and functions inside that Source box then I would be curious to know if the designer then needs to "divvy" up that 500w across all the components/functions inside the box while also reserving enough headroom as a safety margin as to not have the Source box run out juice before its job is done.

Continuing on with the above hypothetical, my next question would be, how much of that 500w is allowed to be used as Output voltage for the XLR Outputs? Is it unlimited (from 0-500w) or is it "capped" at some value in order to not allow them to hog up too much power from the original 500w and to allow the other components to continue functioning?

Lastly, if I assumed that their was some kind of "cap" on how much power an individual component could draw/use and we looked at the XLR Output function on its own I would be curious to know how that "allocation" is spread across, say, 8 simultaneous Outputs?

No significant power is needed.   Only voltage into a high impedance load.

Thanks to all for suggesting hardware AND for feedback on the very important concern of sufficient MCH balanced output voltage vs. electronic (non-acoustic) room correction-imposed gain losses. Of course, it's certainly prudent to ask Anthem Tech Support (or any processor, DAC/preamp brand) to verify that all balanced outputs will deliver at least 10 volts max out, however likely they are to supply distortion curves at output levels above 4 volts.

Measurements were done here. https://www.audio “science” review/forum/index.php?threads/anthem-avm70-review-av-processor.27316/

But I'm not sure which might be the distortion vs. output curve.

The SINAD curve?

In any case, I've upped my 5.3 processor or DAC/preamp budget to ~ $7K.

Question: Which, if any processors (Emotiva, Theta Digital, Anthem, Lyngdorf, Marantz, et al) has USB audio input, volume/mute remote, 10+ volts balanced outputs (ideally can be ordered with no ADCs)-and has DACs which can reduce intersample overs distortion, like Benchmark DACs? 

https://benchmarkmedia.com/blogs/application_notes/intersample-overs-in-cd-recordings?_pos=1&_sid=0eeb1f150&_ss=r

Are you doing any video?  IF not, then look at what @The Computer Audiophile and I have done with ATMOS systems.  I also think you would want a Sub Woofer in the system design.

I have the opposite problem with XLR voltages; my 24-channel DAC is Pro, and the Emotiva power amp is Home. I have 11 attenuators in my 7.1.4 system.

4 hours ago, bobfa said:

Are you doing any video?  IF not, then look at what @The Computer Audiophile and I have done with ATMOS systems.  I also think you would want a Sub Woofer in the system design.

 

I have the opposite problem with XLR voltages; my 24-channel DAC is Pro, and the Emotiva power amp is Home. I have 11 attenuators in my 7.1.4 system.

Nice hardware but I'd be staying with a 5.3 system; front pair/center/rear pair/3 or 4 subs. No extra (ATMOS) speakers.

MOTU has USB Audio input? Along with using the system for music, I'd be playing BD movie discs on my pc via JRiver, which would feed video via HDMI to my TV and output decoded DTS MA audio via USB to the MOTU. 

No video/audio syncing issues?

So your MOTU's balanced outputs exceed 10 volts/channel?

And MOTU attenuators let you set all levels?

Handheld volume/mute remote or only  via mouse? 

Can the MOTU be ordered without ADCs?

There is no video in my system at all. 

I have used both USB and AVB over ethernet

I do not know the voltage but the levels are set at Pro level

I am using external Passive Sure attenuators   The MOTU does have DSP level setting.  initial testing indicated that the hardware versions were better.

I do remote control with Apple Remote or with j-Remote on an iPhone or iPad. 

Are you really talking about 5.3.0.  that is a lot of subwoofers.  I do not understand the need for that.

There are many models from MOTO.  There is no issue with having the ADAT interfaces there.  I am actually getting ready to use some of them for external devices..

Bob

There is a lot to learn on these systems

52 minutes ago, bobfa said:

I am using external Passive Sure attenuators

You mean several of these attenuators? https://www.shure.com/en-US/products/accessories/a15as?variant=A15AS

A MOTU solution might/might not have worked for me IF I got internet service like most here.  

Apparently, ABU can assure syncing of video and audio via the internet, and thus between my smart TV and JRiver on my pc via MOTU. However, LOL, I get my internet via my iPhone 7 plus's wifi hotspot, so I have no router and won't be streaming content for quite some time.

Thanks for the heads up on J-Remote; wasn't aware of that. It might still work reasonably well for volume/mute via my hotspot, though supposedly still need my wireless keyboard for JRiver's BD player transport controls-likewise for Samplitude DAW, which I typically use for music file playback.  

In any case, the (dc coupled) balanced outputs on this model https://motu.com/products/avb/8a/specs.html are (presumably) each 20 dbu max output/channel, or ~ 7.8 volts, according to this chart. https://www.sowter.co.uk/decibels.php

But as MOTU has no onboard DSP, it's still questionable whether (undistorted) ~ 8 volt/channel would be enough to offset pc based DIRAC gain losses.

As for using multiple subs, I will be using three Rythmik or SVS powered sealed subs, as does Kal Rubinson, for smoother bass response. Lots of science shows this to be a valid approach. https://www.harman.com/documents/multsubs_0.pdf Also, see Earl Geddes and Floyd Toole's studies and practices on this.

55 minutes ago, bobfa said:

I am using external Passive Sure attenuators

You mean several of these attenuators? https://www.shure.com/en-US/products/accessories/a15as?variant=A15AS

A MOTU solution might/might not have worked for me IF I got internet service like most here.  

Apparently, ABU can assure syncing of video and audio via the internet, and thus between my smart TV and JRiver on my pc via MOTU. However, LOL, I get my internet via my iPhone 7 plus's wifi hotspot, so I have no router and won't be streaming content for quite some time.

Thanks for the heads up on J-Remote; wasn't aware of that. It might still work reasonably well for volume/mute via my hotspot, though supposedly still need my wireless keyboard for JRiver's BD player transport controls-likewise for Samplitude DAW, which I typically use for music file playback.  

In any case, the (dc coupled) balanced outputs on this model https://motu.com/products/avb/8a/specs.html are (presumably) each 20 dbu max output/channel, or ~ 7.8 volts, according to this chart. https://www.sowter.co.uk/decibels.php

But as MOTU has no onboard DSP, it's still questionable whether (undistorted) ~ 8 volt/channel would be enough to offset pc based DIRAC gain losses.

As for using multiple subs, I will be using three Rythmik or SVS powered sealed subs, as does Kal Rubinson, for smoother bass response. Lots of science shows this to be a valid approach. https://www.harman.com/documents/multsubs_0.pdf Also, see Earl Geddes and Floyd Toole's studies and practices on this.

What DSP do you use and how implemented?

36 minutes ago, nxrm said:

In any case, the (dc coupled) balanced outputs on this model https://motu.com/products/avb/8a/specs.html are (presumably) each 20 dbu max output/channel, or ~ 7.8 volts, according to this chart. https://www.sowter.co.uk/decibels.php

Could be.  Depends on your speakers' sensitivity, your amp's input sensitivity/gain, your room size and how loud to play your music.

1 minute ago, Kal Rubinson said:

Could be.  Depends on your speakers' sensitivity, your amp's input sensitivity, your room size and how loud to play your music.

Perhaps. That MOTU model's certainly affordable in the extreme. I just wish it was usable for me without need for a monthly wired ISP fee to operate the router.

27 minutes ago, nxrm said:

I just wish it was usable for me without need for a monthly wired ISP fee to operate the router.

???? Why?  Routers are cheap.

I do not understand why the MOTU would need an internet system.  I play local music all the time with no need for internet.  If you are running USB you do not even need a network to it.

If you are going to use AVB there is some additional complexity.  I will have an update on moving my system to AVB shortly.

I am not using Dirac.  There  is about 4 to 5 db of step down with the corrections.  I am using Accurate Sound software with AudioLense. This system corrects for the room, the speakers, bass offloading and first time of arrival with 65000 taps per channel.

We need to understand what you are actually building better to help.

You might want to study Dolby Labs systems designs for ATMOS Audio.  You can scale up and down to different speaker configurations using ATMOS.  You can use other multi-channel playback formats other than ATMOS

Bob

PS remember that most Pro audio systems only play PCM and many of them only to 24/192 if that is a problem for you.  ATMOS content is at 24/48.

Also remember I have no video, no AVR none of that in my system. it is AUDIO only.  My Primary playback is from Apple Music ATMOS and yes that will need an Internet connection most of the time.  (not local files). I also use a MAC for the same reason.  

Bleeding - edge!

2 hours ago, Kal Rubinson said:

???? Why?  Routers are cheap.

????? Of course, though I misread the connectivity requirements for  MOTU, perhaps quite fortuitously.

7 minutes ago, nxrm said:

????? Of course, but doesn't MOTU need an ethernet connection (via CAT cable) for the pc to transmit MCH audio via the router the MOTU box? To do that isn't an ISP service required?

1.  Dunno.  Could be.

2.  Unlikely.

2 hours ago, bobfa said:

I do not understand why the MOTU would need an internet system.  I play local music all the time with no need for internet.  If you are running USB you do not even need a network to it.

 

 

Okay, so you're saying that I can output a PCM signal with 5 surround channels and 3 subwoofer channels via USB directly to this?

https://motu.com/products/avb/8a/specs.html

2 hours ago, bobfa said:

If you are going to use AVB there is some additional complexity.  I will have an update on moving my system to AVB shortly.

 

But do I actually need this AVB thing?

Assuming you're familiar with the highly popular JRiver player https://jriver.com/

and as I mentioned here numerous times, I will often use this system to play BD movie discs on my pc via JRiver. The graphics card's HDMI will send the video to my TV and the movie's DTS-MA,  decoded to PCM, via USB to the MOTU.

So the question is will there be any video/audio syncing problems?

no idea

9 minutes ago, bobfa said:

no idea

I guess JRiver and MOTU support and/or users at forums would know this for a fact-I hope.