Yamaha Pure Direct

I just got a new Yamaha Aventage receiver. What is the purpose of this ? Does the pure direct mode work thru the HDMI and 2 channel analog connections ? Thank You

 

From the manual....

"Use Pure Direct mode to enjoy the pure high fidelity
sound of the selected source. When Pure Direct mode is
enabled, this unit plays back the selected source with the
least circuitry."

In practice, it disables the LED panel and I gather uses all available power for amplification of the signal in use. The remote still works. It will work through HDMI and analogue inputs.
Any sound processing (eg Dubly Pro Logic etc) will not work. It will still process multichannel signals through HDMI, I think.
It makes a slight but noticeable improvement to the sound on my fairly humble setup.

 

thanks. Have read quite a few positives about the Pure Direct mode

 

Pretty sure it will also work with S/PDIF input. Suck it and see, as my granny used to say.

 

The Pure Direct mode on my Yamaha AVR is intended for 2 channel analog connected source components - such as a TT or the RCA outputs from a CDP or SACD player.

Pure Direct maintains an analog path from the outputs of the source component all the way thru the AVR with NO A/D, NO DSP/AutoEQ, and no backend D/A to the output stages and to your speakers.

However, there is a catch - 2-channels only cuz the path is from a 2-channel source component, so there is no sub channel.

If you have a source component where the DACs are 'better' than those in the AVR, then Pure Direct will let you hear the source DACs and not the AVR DACs since there is no internal A/D - D/A conversions in the AVR.

 

Sounds like a cool feature.

 

I've just checked,on my Yamaha r-s300,sub can be heard,with or without Pure Direct.It is an active sub,connected via single RCA cable.

 

That last paragraph is normal enough and any deviation from this in a receiver would render it unfit for regular usage.
Source component with a DAC is connected by rca cables to the avr receiver. Audio coming in via RCA automatically bi passes the receiver's DAC
That rca analogue audio can be processed but it is a dud receiver design if the processed sound was the default setting.

Pure Direct sounds like a fancy name for stereo mode.
On my HK AVR 5550 (which I bought when I had more hair and less grey) I can turn off all sound processing with pressing just one button, the stereo button on the remote. Then, audio coming via digital input -> receiver's DAC -> analog stereo output, (sub is activated if chosen).
Audio coming in via RCA can be processed only if you choose.

I note that on the later HK avr receivers (hdmi models), this remote control facility is no longer available. Instead of pressing just one button on the remote to get analog stereo from a digital audio input, the user has to go through a few hoola hoops of menus to select stereo every time.
So, if you have a source like a Sky sat box, with a mixture of HD and Analogue, it is a nightmare to use.
I was astonished to see how such a user friendly design, so simple and straightforward, had been skewed senseless. But I see that this also happened with many other user control features.

 

We don't have A/V Yamaha, but their 2 Channel stuff it worked like:

old mid 90's and newer A-S700 "Pure Direct" - cuts out the tone, balance and loudness controls. Essentially making the signal path as short as possible and with as few interfering components.

On the new CD-S700 CD player, "Pure Direct" kills the LCD display altogether, and cuts S/PDIF output. Arguably increasing definition and reducing noise.

The A-S700 has another button called "CD Direct" which does all what "Pure Direct" does, but also engages CD input only with a Op-Amp circuit that changes how gain is applied. It does make a difference, quite a big one really, that tightens everything up.

I should hope that the A/V units work similarly, using the "Pure Direct" should kill a lot of processing and yield a better sound quality. It may be the case that is is just for 2 Channel mode however.

I seem to recall an article where Bob Clearmountain was mixing Roxy Music's Avalon for 5.1 and he had a Sony A/V amp, and said that it kept putting in sub channel info when he purposefully mixed without it. So he had to make compromises for the gear people would be using.

http://www.soundonsound.com/sos/aug03/articles/roxymusic.htm

 

OK, I just did a little experimentation, and Yamaha pure direct mode will output stereo and multichannel analogue sources, plus PCM over HDMI in stereo or multichannel, as well as S/PDIF in stereo. It will also process DTS multichannel over S/PDIF.

Not sure about DSD or DTS over HDMI because my crappy universal DVD player won't put out DSD and you have to frig around with it too much to get DTS to work over HDMI.

According to the manual, tone control, sound programs and Yamaha's fancy multichannel speaker balancing software are disabled in pure direct mode.

 

Here is the audio block diagram for the RX "family" of Yamaha AVRs:


As you can see and what I hear on my AVR - if the source component is *analog* and you engage Pure Direct, then the path bypasses all Digital domain processing and effects - which includes no sub (well, at least on my AVR - I don't got no sub for a TT in Pure Direct).

If the source component is connected digitally - then the signal path is already in the digital domain and the sub signal may be present.

 

Yamaha AVRs do have a different feature button called "Straight" - which works for both analog and digitally connected source components and supposedly bypasses some of the video and other 'processing' related circuitry. It down mixes multichannel sources to 2-channel but also keeps the sub output active.

 

Greig, I have a Yamaha HTR 6290B 7.1 surround receiver. I'll check when I get home today from work, but I thought that mutli-channel SACDs and DVD-A discs play multi-channel through the Pure Direct function.

 

My Pure Direct mode works with DSD. When in Pure Direct mode the display goes off but when you move the volume the display comes on for a second and you can see the DSD light will be on if accepting a DSD signal.

 

Thanks for all the info.

 

I beleive, in a nutshell, Pure Direct sends the signal through without any additional decoding or effects added in the receiver.

For example: I THINK, If the source has a LFE channel then it will be sent through and be heard.

On the other hand, if your source has no LFE (.1) channel but you have a LF crossover set within the receiver so everything under, say 80Hz, goes to the sub it will be disabled and there should not be any signal going to the sub (0.1) channel.

I think, therfore I, err, nevermind.

 

Also all video cuircitry turned off.

 

That's how mine works. I use bass management and it disappears when I am in Pure Direct mode. Also, if you use the automatic setup with the microphone, the EQ settings it does aren't used in PD mode.

 

Like Granny Clampett?

 

I did some experimenting today and pretty much confirmed what you stated for my Yamaha in Pure Direct.

I used the multi-channel Dire Straits "Brothers in Arms" and a standard CD copy.

My Oppo 83 was connected both HDMI and optical to my AVR: HDMI to the BD input and the optical to the CD input.


For the multi-channel SACD:
In "Pure Direct" via HDMI - all channels played L/R/C/SL/SR/ and the sub when I selected BD on the AVR.

However, when I switched the AVR to be on the CD input, when I selected "Pure Direct" I only heard the Left and Right speakers - no sub.

For the standard 2-channel redbook CD:
In "Pure Direct" for either HDMI or CD inputs selected at the AVR - only the Left and Right speakers were active - no sub.

Makes sense.

 

My Denon stuff also has that sort of feature. Direct mode so it is only music.
On my Denon 4806 receiver.

 

Just testing Bob Dylan - Love And Theft SACD 5.1. The surround mix is playing through the Pure Direct mode.

 

I like it. Have been experimenting with it.

 

Another observation: when switching to Pure Direct while using AM radio (remember that?), the sound switches from front left/front right dual mono to centre speaker only.

 

I had a Yamaha CD player 20 years ago that had a feature like this. I forget what they called it back then.