Receiver that doesn't process analog input

[Pogre]

Between the separate dac and wasted time this sounds like an expensive and fruitless endeavor. We see so much money and energy wasted chasing inaudible numbers. It bothers me because I'd rather folks donate it to me for all the good it does and I'll get the most expensive speakers I can afford...

 

[Bucknekked]

Between the separate dac and wasted time this sounds like an expensive and fruitless endeavor. We see so much money and energy wasted chasing inaudible numbers. It bothers me because I'd rather folks donate it to me for all the good it does and I'll get the most expensive speakers I can afford...

@PENG , @TLS Guy , @Pogre
I got nothing from a purely technical point of view I can add to this discussion. I think the technical stuff got displayed pretty well in a format even I could get the gist of. For me, I can sum it up with "its probably not worth the time and effort".

I would look at the problem differently and from the point of view that the OPs desire was to have perfect fidelity with what was recorded. I read some very fine articles recently on just what a myth that is because the sound of the orchestra is really an illusion we create with our playback systems. It can never be "perfect" because the original recording isn't even perfect. We can't match the original because what we recreate in our homes is an illusion, not some ideal version of the audio truth.

This isn't philosophy. Its physics. The recording engineer with his equipment (@TLS Guy would be an expert voice here) can't capture a perfect record of what was played by the musicians. It will be his version of the illusion and subject to many sonic imperfections. We then re-create an illusion in our homes. There is no perfection. We either enjoy the illusion we create, or we get on the upgrade train and keep buying hardware until we run out of money or tire of the game. Or we do things like the OP is trying to do...............

 

[PENG]

Curious, any other brand/model ranges you could offer in this respect? How much does it matter how the volume control works? Is setting of delay/level not using dsp?

I was just responding to the OP's main question about processing, not about the A to D thing, though he did make a statement (not a question..) about A to D for volume control. That's not always the case. If you look at Denon/Marantz block diagram on level control you will see that there are two routes. One involves the ADC and the DSP, the other goes direct to the volume control IC that is an analog volume control IC, albeit digitally controlled, but I don't see any ADC involved. So while the Owner's manuals and the service manuals don't explicitly say so, one can deduce from the block diagrams that if pure direct/direct is selected, since there won't be any need for DSP, the analog input signal would be routed to bypass the ADC/DSP block. Again, since D&M's literature has not made things abundantly clear, I could only say it is merely a reasonable assumption on my part that in pure direct/direct mode, when there are no dsp functions involved (this much was confirmed in the manual), there should be no need to route the analog input signal to the ADC path. For the 7.1Ch analog inputs, it is a much clearer case though, to the point I would say it does not get double converted or processed by the DSP engines.

Hopefully we don't need to debate the same for digital inputs, direct, pure direct or not.

 

[PENG]

Curious, any other brand/model ranges you could offer in this respect? How much does it matter how the volume control works? Is setting of delay/level not using dsp?

Missed that you asked about other brand/model.. I assume there are more, for example NAD is another one. Below is from the owner's manual of the T758 V3.

"7.1 CH INPUT • Connect to the corresponding analog audio output of a multichannel source component such as a DVD-Audio or multichannel-SACD player or external multichannel decoder (disc copy protected formats only allow analog signal transfer). Typically, these sources will produce 5.1-channel output, in which case the Surround Back jacks are left unconnected. The signal present at these jacks can be heard by selecting Source 7 (7.1 CHANNEL INPUT is defaulted to this Source). • There is no bass-management or other processing (other than master-volume control) available to this 7.1 channel input. "

So again, that addresses the OP's question on "further processing...."

 

[TLS Guy]

@PENG , @TLS Guy , @Pogre
I got nothing from a purely technical point of view I can add to this discussion. I think the technical stuff got displayed pretty well in a format even I could get the gist of. For me, I can sum it up with "its probably not worth the time and effort".

I would look at the problem differently and from the point of view that the OPs desire was to have perfect fidelity with what was recorded. I read some very fine articles recently on just what a myth that is because the sound of the orchestra is really an illusion we create with our playback systems. It can never be "perfect" because the original recording isn't even perfect. We can't match the original because what we recreate in our homes is an illusion, not some ideal version of the audio truth.

This isn't philosophy. Its physics. The recording engineer with his equipment (@TLS Guy would be an expert voice here) can't capture a perfect record of what was played by the musicians. It will be his version of the illusion and subject to many sonic imperfections. We then re-create an illusion in our homes. There is no perfection. We either enjoy the illusion we create, or we get on the upgrade train and keep buying hardware until we run out of money or tire of the game. Or we do things like the OP is trying to do...............

That is exactly the issue and the way it is.

When Peter Walker was at the helm, he stated that the best that could be achieved was listening though a window into the concert hall. For once he was wrong, as now you can recreate at least a believable acoustic sense of space. In fact I think better than that, as there are venues I know, and at least this system with the latest technology can get awfully close. It certainly is an amazing experience. I can vouch for the fact you can create the illusion that the space is much bigger than it is and give a sense of the type of building it is.

 

[AcuDefTechGuy]

Keep in mind...
For a multi-channel processor or AVR, to control multi-channel volume levels within close tracking tolerances (+/-0.2 dB) the signal is digitized..

Just my $0.02...

You mean the volume in increments of 0.5dB?

Like -30.0, -29.5, -29.0, etc.

 

[TLS Guy]

Missed that you asked about other brand/model.. I assume there are more, for example NAD is another one. Below is from the owner's manual of the T758 V3.

"7.1 CH INPUT • Connect to the corresponding analog audio output of a multichannel source component such as a DVD-Audio or multichannel-SACD player or external multichannel decoder (disc copy protected formats only allow analog signal transfer). Typically, these sources will produce 5.1-channel output, in which case the Surround Back jacks are left unconnected. The signal present at these jacks can be heard by selecting Source 7 (7.1 CHANNEL INPUT is defaulted to this Source). • There is no bass-management or other processing (other than master-volume control) available to this 7.1 channel input. "

So again, that addresses the OP's question on "further processing...."

The key words are "other than volume control". I have not found a receiver or pre/pro, and may be I have missed one, that has anything other then a volume control that rotates other than over 360 degrees. Further, when I use the volume control remote, I hear no motor moving an analog control. So the volume control is obviously not analog. If it was I would advise everyone to run a mile from it. Now there are really no analog controls of the quality of yesteryear. Parasound tried in a two channel preamp amp and have caught one Hell of a cold!

 

[PENG]

The key words are "other than volume control". I have not found a receiver or pre/pro, and may be I have missed one, that has anything other then a volume control that rotates other than over 360 degrees. Further, when I use the volume control remote, I hear no motor moving an analog control. So the volume control is obviously not analog. If it was I would advise everyone to run a mile from it. Now there are really no analog controls of the quality of yesteryear. Parasound tried in a two channel preamp amp and have caught one Hell of a cold!

I suggest you read the schematics yourself, just the block diagram will do. I think it is on page 50 of the AV8805's service manual. That page looks practically the same for the 7704/05, and the corresponding Marantz and Denon AVR. I suggest the AV8805 only because it seems to be the only one downloadable from Marantz. The NJU72343 appears to be some sort of a digitally controlled volume control IC, not an analog discrete circuit board, but an IC, MSI class (medium scale integrated).

In the block diagram, you will see that the line analog input has two alternate paths.

Path 1. line in to 2 multiplexor switches NJU72750, then to vol IC NJU72343.

Path 2. Line in to the same 2 switches, but from output of the 2nd one, it gets routed to the AK5358, a very mediocre ADC, and then to the AK4490 DAC (the lower grade AK4458 for your AV7705) and then to the vol IC NJU72343.

Now, think about this, what's the point for the analog input signal to go through ADC, then DAC, if only to go through another ADC step in the vol control chip? That would be totally ridiculous and illogical. Further, what's the point to use a flag ship AK4490 DAC if it is preceded by the low grade AK5358 ADC?

I have great respect for M Code for his insider insights, but he is not always right about everything, neither am I obviously.

You can Google for the data sheet of the NJU72343, but the similar but higher grade analog vol control IC used in some Arcams have better documentation that explains the inner working much better than the NJU's. Same operating principles anyway so the one for the CS3318 should be a better one to read.

https://statics.cirrus.com/pubs/proDatasheet/CS3318_F1.pdf

 

[M Code]

You mean the volume in increments of 0.5dB?

Like -30.0, -29.5, -29.0, etc.

No... I mean tracking error between channels...

Just my $0.02...

 

[ssmaudio]

Good God! I didn't realize that this would stir up a hornet's nest.
Look, bottom line: all I care about when setting up a streaming rig for multi-ch DSD downloads. (Maybe DSD Is the worst thing ever, but I like the sound that comes out, so what can I say?) This requires a DAC to connect to a receiver and I want that DAC to be the last processor before the speakers. That's it, dude!

Anyway, calling Marantz and looking at the schematic of the Marantz SR 7012 (thanks to Peng!) I can see that the incoming analog inputs are sent directly to the speakers. This is what I wanted. So now I have a way to connect an Exasound to a receiver to my speakers. And Audirvana on my PC as the front end, because it does the album management well including liner notes.

Thank you to all (including the raging ones) for your opinions.

 

[PENG]

Good God! I didn't realize that this would stir up a hornet's nest.
Look, bottom line: all I care about when setting up a streaming rig for multi-ch DSD downloads. (Maybe DSD Is the worst thing ever, but I like the sound that comes out, so what can I say?) This requires a DAC to connect to a receiver and I want that DAC to be the last processor before the speakers. That's it, dude!

Anyway, calling Marantz and looking at the schematic of the Marantz SR 7012 (thanks to Peng!) I can see that the incoming analog inputs are sent directly to the speakers. This is what I wanted. So now I have a way to connect an Exasound to a receiver to my speakers. And Audirvana on my PC as the front end, because it does the album management well including liner notes.

Thank you to all (including the raging ones) for your opinions.

One of the issue is the internet.. Anyone can post things as though they were facts and taken as facts by many. Often enough, hearsay got perpetuated to the point they became normalized and recognized. Since you are/were an EE, I'll throw this likely unpopular example (I assume).., the so called Watts RMS. This incorrect term has now been fully adopted by most audio amp manufacturers, go figure!!

Now on the very topic of volume control that you brought up (I guess unintentionally..), I can see the confusions created by use of so different terminologies such as digital volume control, analog volume control, digitally controlled analog volume control etc..

 

[PENG]

I’d like to know which AVRs convert Analog to Digital in Direct Mode.

Also about the Analog-to-Digital Conversation with the Volume.

Or is this just another hearsay.

As I mentioned before, there appeared to be enough evidence that the D&M receivers, at least the very old ones and the latest ones would likely route analog input signals to bypass the ADC/DSP blocks if direct or pure direct modes are selected. Examples of the evidences are: a) the block diagrams clearly shows two signal paths, one does not involve the ADC AK5358 chip and b) the volume control IC is the NJU72343, positioned right at the end of the signal chain for Denon, and just ahead of the HDAM for the Marantz. There is no build in ADC in the NJU72343.

For the Yamaha RX-A, I am not sure, there appeared to be some possibilities that analog input signals (stereo RCA) would be put through A to D somehow such as if/when DSP/YPAO is engaged. Unless I missed, I did not see a dedicated ADC chip shown in any of the schematics or block diagrams but there may be a stereo ADC build in with another IC such as the PCM9211 So again, I really don't know and wouldn't even want to take an educated guess.

Since you have a direct line to Yamaha, I would appreciate it if you could try to get an answer from them. Again, please insist you want an authoritative response, not one from their level one support I assume.. It is not about sound quality imo, but about someone's curiosity.

Below is from the volume control IC BD34703KS2 LSI chip's datasheet:

https://www.datasheets360.com/pdf/-5225953889880620514

The chip was used (and may still be used) in some RX-A models for volume control.