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Discussion Starter · #1 ·
While talking on the telephone today with a Yamaha tech on an unrelated matter, I later asked about how the Pure Direct mode is implemented on their receivers. As many here know from past threads, there have been discussions about whether Pure Direct is purely analog or not.

The tech said that all Yamaha receivers, both AV and stereo models, will always digitize any source component connected to an analog input (that is, via the RCA jacks). Also, any source component connected to any digital input will always be re-digitized by the Yamaha receiver.

In short, Yamaha receivers digitize everything--there is no analog-only path available to the user.
 

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That is typically true of Denon AVRs as well, they digitize everything coming in via analog. IF you look in a denon manual it says something to the effect that pure direct cuts off unused circuitry etc.. They make no claims of bypassing the analog to digital process. The only one that I'm aware of in AVRs that does bypass the conversion is Anthem.
 

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For sound quality this is probably overall better than an all analog solution since all the volume control and processing can be done in a single component. I'm guessing they just skip the processing for Pure Direct. Done properly A>D>A conversion can be transparent. Despite the recent resurgence in vinyl the bulk of audio people listen to starts digital so for mass market pricing making a whole new analog signal path and making sure it was noise free and sounds good is something they seem happy to leave to higher end boutique brands like Anthem mentioned above.
 

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Volume control (including level trim) is normally always in the analogue domain in receivers, done after the DACs. So that continues to work when an analogue bypass (or DSD direct) is in force. Other things like channel delays and bass management don't work.

I'd like a reference on the Denon above - when did this change? My 4308 certainly has analogue bypass. My current supposition is that as the analogue bypass must exist for the multichannel input (either that or 8 ADCs, and the bypass is cheaper), they can re-use it for the 2-channel inputs. Receivers without multichannel input might not have the bypass.
 

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Volume control (including level trim) is normally always in the analogue domain in receivers, done after the DACs. So that continues to work when an analogue bypass (or DSD direct) is in force. Other things like channel delays and bass management don't work.

I'd like a reference on the Denon above - when did this change? My 4308 certainly has analogue bypass. My current supposition is that as the analogue bypass must exist for the multichannel input (either that or 8 ADCs, and the bypass is cheaper), they can re-use it for the 2-channel inputs. Receivers without multichannel input might not have the bypass.
I"ve had two Denon AVRs in the past, both newer than the 4308, and both make the same claim in the manual, 'cuts off unused circuitry'. No mention of bypassing digital conversion. One of the Denon's I had, a 1909, did have ex in RCAs, but that wasn't selectable bypassing of digital conversion but inputs to bypass all processing from another processor. The last one I had had dropped those type inputs, that was the 3311ci.

From a 3311 ci manual:

3143345

This mode is for playback in higher sound quality than in “Direct playback” mode.
• The following circuits that affect sound quality are set to off.
• Main unit’s display circuit (The display is turned off.)
• Analog video input/output circuit
• Surround back signals or front height signals are not created. • In this mode, the following items cannot be adjusted.'
• Tone (vpage 70)
• Dynamic EQ® (vpage 71)
• RESTORER (vpage 73)
MultEQ® XT (vpage 71)
• Dynamic Volume® (vpage 72)
My anthem makes the following statement in their manual:

  1. PROCESS ANALOG AUDIO INPUT
    If changed to No, digital conversion and signal processing are bypassed. Only level adjustments will be available.
The 4308 was a fantastic AVR, I started to buy one used before I bought my 3311ci. I agree that it doesn't make a lot of difference.
 

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I wouldn't take what the manual says too literally - they're often confusing and contradictory. I suspect they don't want to be pinned down on what exactly "direct" does and give themselves wiggle room to change it from receiver to receiver...

My 4308 knowledge is based on having read and researched quite a lot on its systems over the years, and experimenting with its behaviour myself. So I was interested to know if something really had changed in Denon system design. I know they've been having to skimp on power amp quality to fit in more channels, but from what I'd read basic architecture is still the same. As long as they're still models with 7.1 analogue input I'd be surprised if they'd killed only the 2-channel bypass but kept the multichannel bypass.

Oh, I think we might have been talking slightly at cross purposes - I was thinking of "direct", where you've been talking about "pure direct". In the 4308 both Direct and Pure Direct do the analogue bypass. The Pure Direct doesn't change any signal paths beyond Direct - it does indeed just cut out unused circuitry as you say (analogue video systems, HDMI video unless using HDMI input, front panel display, GUI, not sure what else).
 

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In short, Yamaha receivers digitize everything--there is no analog-only path available to the user.
Rather necessary for YPAO, parametric equalization, surround effects, and the rest of the DSP functions of an AVR.

Analog-to-digital and then digital-to-analog for the power amplifiers are transparent transformations in this day and age. Source impurity and what the speakers are doing to the audio, not to mention listening environments and hearing limitations, have far greater effects on audio integrity.
 

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While talking on the telephone today with a Yamaha tech on an unrelated matter, I later asked about how the Pure Direct mode is implemented on their receivers. As many here know from past threads, there have been discussions about whether Pure Direct is purely analog or not.

The tech said that all Yamaha receivers, both AV and stereo models, will always digitize any source component connected to an analog input (that is, via the RCA jacks). Also, any source component connected to any digital input will always be re-digitized by the Yamaha receiver.

In short, Yamaha receivers digitize everything--there is no analog-only path available to the user.
Im not sure if thats true what the tech told you and I chalk it up to not asking the right questions. If the mains are set to large, leave YPAO off and turn on Pure Direct, and have analog inputs, then the signal remains in the analog domain. If the inputs are digital, then they get converted to analog first. I confirmed this for the Rx-A3060, RX-V1800/1900, and RX-V1075 models over the phone with a Yamaha tech.
 

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This, from the TSR-700 manual, which presumably is identical on all models for the PURE DIRECT function:

  1. TSR-700
  2. ENJOYING SOUND
  3. Enjoying unprocessed playback
Enjoying higher quality playback (Pure Direct)


The unit allows you to enjoy the high-quality playback with reduced noise. Various processing modes and some circuitry (such as the front display) other than the basic playback function is suspended.


Each time you press PURE DIRECT, the direct playback mode is enabled or disabled. When the Pure Direct is enabled, “PURE DIRECT” lights up on the front panel.

NOTE

  • When the Pure Direct is enabled, the following functions are not available.

  • Selecting sound programs

  • Using the zone function

  • Operating the on-screen “Setup” and “Option” menus

  • Viewing information on the front display (when not in operation)

So, since YPAO is part of SETUP, clicking on PURE DIRECT enables "unprocessed playback" and disables YPAO and all DSP functions, which makes sense. BASS and TREBLE (TONE controls), which are not part of SETUP, are likely also implemented in DSP.
 

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Discussion Starter · #11 ·
Im not sure if thats true what the tech told you and I chalk it up to not asking the right questions. If the mains are set to large, leave YPAO off and turn on Pure Direct, and have analog inputs, then the signal remains in the analog domain. If the inputs are digital, then they get converted to analog first. I confirmed this for the Rx-A3060, RX-V1800/1900, and RX-V1075 models over the phone with a Yamaha tech.
What I stated in post 1 was precisely what the tech at Yamaha said: All sources (analog and digital) connected to any input are digitized by their AV and stereo receivers. He was adamant, when I pressed him about it, that no source input remains analog. That includes the use of the Pure Direct mode.

Note that we were not discussing older generations of Yamaha receivers, which, presumably, may be different.
 

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What I stated in post 1 was precisely what the tech at Yamaha said: All sources (analog and digital) connected to any input are digitized by their AV and stereo receivers. He was adamant, when I pressed him about it, that no source input remains analog. That includes the use of the Pure Direct mode.

Note that we were not discussing older generations of Yamaha receivers, which, presumably, may be different.
Hey Alex. I understand what you posted is what the Yamaha tech told you. Im simply disagreeing with him as the Yamaha tech I spoke too offered a different version. Analog inputs remain in the analog realm. Digital inputs gets turned into analog and remain in analog after that.
 
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