Beastaudio's 2015 NC Get Together...

[dgage]

Thanks Shreds. Been wanting one for years. I ordered an Apple Watch today for my family to get me. Looks like they'll be getting me an oscope too.

[3ll3d00d]

I've been very curious of the AV7702's ability to handle high levels of re-directed bass without clipping the signal for a while now.  I was also curious to see if the OPPO (which has been proven to clip movie tracks with hot re-directed bass) http://data-bass.ipbhost.com/index.php?/topic/379-maxmercys-wcs-test-disc-beta-and-an-o-scope/?p=6640

would end up passing the clipped signal out of the HDMI port digitally since the problem is apparently in the OPPO's digital section.  I was relieved to find out that it didn't and if you attenuate the Marantz AVR's sub out or MVL by at least 10.5dB you will be for sure safe against clipping in a worst case scenario for a 7.1 track with re-directed bass. 

 

I just replied to someone who commented on this on avs and something (well 2 things actually) occurred to me while I replied.

 

Doesn't this mean the Marantz has zero headroom for bass mgmt? I mean you had to reduce by 10.5dB and the 7 WCS add up to 10.2dB on top of the LFE so you had attenuate the LFE by as much as you were adding to make room for it.

 

Doesn't this imply MV is applied before processing? I thought MV would be done in the analogue section after processing.

[Shredhead]

Sounds good Gage, you'll dig it.

 

That makes sense d00d.  Quite possible.  MV's haven't been in the analog section since the 90's with the motorized volume control.  If you ever test an AVR's (or any piece of gear with a remote control for the volume) noise floor, you will notice that it stays the same no matter what the volume is set to.  Where an analog volume control will attenuate the volume and the noise floor.  This is why with today's digital signal chains it is important to plan for a WCS scenario and push the maximum level out of each link in the chain before clipping happens to get the most dynamic range.

 

If I had more time with the Denon I could go to it's analog in's and outs and see exactly where it's breaking point is.  If it's analog pre's can handle more than 6Vpk we would confirm your theory. 

[3ll3d00d]

That makes sense d00d.  Quite possible.  MV's haven't been in the analog section since the 90's with the motorized volume control.  If you ever test an AVR's (or any piece of gear with a remote control for the volume) noise floor, you will notice that it stays the same no matter what the volume is set to.  Where an analog volume control will attenuate the volume and the noise floor.  This is why with today's digital signal chains it is important to plan for a WCS scenario and push the maximum level out of each link in the chain before clipping happens to get the most dynamic range.

 

If I had more time with the Denon I could go to it's analog in's and outs and see exactly where it's breaking point is.  If it's analog pre's can handle more than 6Vpk we would confirm your theory. 

I'm confused now then. I was under the impression the units that have a multichannel analogue input do not run them through an ADC and hence can't do anything other than apply channel trims and MV to them. Certainly this is the case on my AV7005 which removes all such options when using the analogue inputs & ISTR reading somewhere that confirmed there was no ADC on that chain. If the trims/MV were digital then it could not even implement those trims without converting those analogue inputs.

[MemX]

 

The rest of the afternoon and night we contined to SpecLab scenes of various Blu Ray's and even MemX's revisions which were awesome. I have GOT to get me that demo disk that he brought to the GTG! Very cool stuff. 

 

 

Wait a minute...  I was there?  Man that must have been a good trip, I don't even remember going!

 

 

[Shredhead]

Good point d00d.  I am aware of things like these for the analog control of 7.1 with a remote while keeping things analog for the advantage of keeping dynamic range intact: http://www.msbtech.com/products/MVC.php ,but I didn't think that most AVR's would have a similar thing in them due to how much it would drive up the cost.  I have no idea if the Denon has a master analog volume output.  If it does, that is another good thing going for the 7702.

[NWCgrad]

A Beast GTG, what is there to say? If you missed it, you missed everything there is to miss.

 

After years and years, I got to meet the Simonian. That was a highlight. Since we've been on the air since the late 90s, I was stunned to find out Scott first logged into a subwoofer forum when he was 16 years old. Fuckin' awesome to meet you, my friend.

 

After years and years, I finally got to meet Max Mercy. Dude walks in, and says, "Hey everybody, John S------." It went straight over my head. As the general convo continued, someone asked him his SN. "I'm maxmercy." BAM! Extraordinary man, pleasure to meet and glad to have had the opportunity to converse with at length. Many talents, many interests and much fun.

 

After years and years, I get to meet the ship's android, Data, as in Data_Bass, Musician, sub builder, measurements tech, latent hippie and all around interesting young man, Josh Ricci. We have many things in common, except that I'm a hundred and he (and the rest of the crowd) are young fellas. Enjoyed talking with and overhearing your other convos as the day progressed into night. Oh, hell yeah.

 

Rowdy Roddy Brandon. The Beast From Still Country. Always smilin', always accommodating, always making everyone glad they made the arduous trip. Superb upgrades to the HT, SQ extraordinaire, fabulous (now centered) seating, Atmos/DTS-X ready sound and balls-out low end. You're the man, my friend. No bout a doubt it.

 

Dave "Jersey Boy". Always a great convo with an interesting guy. I HAVE to get up there to the Jersey shore and make a couple of days of it. I'm positive it will be a trip to remember and hosted by another stellar example of the profession.

 

Steve... I hope NSA was listening in because we solved the world's problems in under an hour. Awesome stuff. Glad to see you and great to talk with you.

 

Dave. Awesome products. Wishing you all the best in that enterprise and always available to offer any accumulated knowledge I have that you may be interested in. But, the gratitude this trip goes to your detailed explanation of the health issue that's been most on my mind over the last month or so. Thanks for the heads up and the free testing. Really, it made the trip ever so much more enjoyable in that I could relax for the first time in a while.

 

Man, I forget the name of the new dad. He knows who I'm talking about. Great to see you again and kiss that beautiful little baby boy for me. Congrats on a job well done and for having an attitude that I envy and that inspires me to smile more often.

 

Adam. I can't expound here because it would take up too much virtual ink. It was a blast having you stay and making the trip up to the mountains and back with you. I had a lot of things weighing on me and took some of that out on you. Having a big lug to absorb some grief in stride is something I can't easily repay, if ever. Hey to you and yours. I hope the trip back got you home safe and sound and looking forward to getting up with y'all soon.

 

There was a new guy there and I forgot his name because I'm old. I hope he chimes in because it was great to meet him as well. Also, props to the maniacal car stereo dude who left Matt speechless with an altered heart rate and temporarily deaf. He was at the remote control late into the even when I happened to be sitting in front of one of Nick's HST-18s. My back still smarts a bit.

 

Nick. Wow. HT-18s. HST-18s. HS-24s. The new DS4-18. They, of course, were the stars of the show. I appreciate you more than you know. Sorry your old man couldn't make it. His absence made me the oldest guy there by too far a margin.

 

Paul. Machine head. The data makes the GTG a whole different event. Most importantly, as memories fade, the data remains. I LOVE watching SpecLab scrol the low end content in real time as we watch a flick or listen to hits. I watched intently as they screened John Wick because I've SL graphed those gunshots and remember the bandwidth to <3 Hz. The first time through, the low end response was rolled off just <15 Hz. After the SEQSS-V (working name: Dash V) was inserted and quickly tweaked, the SL graphs showed the huge increase in playback accuracy, adding 2-1/2 octaves to the presentation. I know sitting in the cubby hole patching cables, setting levels, measuring and matching gain, running loop throughs of the signal chain, separately and collectively, working in the dark with a pen light, naming and capping SL graphs as fast as they come and go on the big screen and ending the night with data that's as reliable as it gets... is an AWESOME feat.

 

Matt. Thanks for being there, packing my special diet needs food, lugging hardware, positive attitude and mingler-extraordinaire. I know this was your first GTG. You picked a great one. I hope you had a good time. I hope you make it out to more of them down the road.

 

The rest of the attendees will have to forgive me for the omission here, but rest assured I'll remember whomever it is eventually because everyone there was unforgettable.

 

To all of you mega pixel phone owners... No pics? You jaded bunch of meat heads.

Who needs the NSA? My wife was watching Directv and they called out the Empire State Building, when I changed pages on the website I was reading the banner ad was for the Empire State Building....amazing how fast they track our viewing and sync to ads. Down right scary...imagine how much they know about our habits.

[3ll3d00d]

Good point d00d.  I am aware of things like these for the analog control of 7.1 with a remote while keeping things analog for the advantage of keeping dynamic range intact: http://www.msbtech.com/products/MVC.php ,but I didn't think that most AVR's would have a similar thing in them due to how much it would drive up the cost.  I have no idea if the Denon has a master analog volume output.  If it does, that is another good thing going for the 7702.

this discussion reminded me of this series of articles -> http://hometheaterhifi.com/technical/technical-reviews/options-by-supplier-and-price/

 

parts 2 3 and 4 can be found at 

 

http://hometheaterhifi.com/technical/technical-reviews/audio-video-receiver-build-quality-part-ii-design-of-high-performance-avrs-and-pre-pros/

http://hometheaterhifi.com/technical/technical-reviews/avr-audio-video-receiver-build-quality-part-iii-component-choices-for-a-high-performance-design/

http://hometheaterhifi.com/technical/technical-reviews/avr-audio-video-receiver-build-quality-part-iv-the-emotiva-xmc-1-ssp-a-paradigm-of-a-pre-pro-implementation/

 

These articles explain in detail how volume controls, amongst other things, are implemented. This does place the MV after processing though so it makes me wonder what is going on in that AV7702 if cutting either the MV or SW trim enabled it to pass. Were you measuring RCA or XLR outputs?

[Shredhead]

Cool d00d.  I won't have time to read that for at least a couple of days.  That was measuring the RCA.  If I could spend some more time with the unit I think I could figure out what the deal is.  For the time being I'm just happy that there is a work around for passing an unclipped signal for hot re-directed mixes.  I just heard that this unit will definitely not be compatible with DTS X upgrades in the future so that's a bummer. 

 

Do you know for sure that the signal path never hits a dac on it's analog in's?  If so, will you please link me the source because I can't find anything on it specifically for Denon AVRs. 

[3ll3d00d]

 

Do you know for sure that the signal path never hits a dac on it's analog in's?  If so, will you please link me the source because I can't find anything on it specifically for Denon AVRs. 

I don't have a definitive statement from the manufacturer that I can reference. It was generally commented as a fact for my model (AV7005).

 

There are a few features that suggest this is the case;

 

- there is no processing of any nature available to the 7.1 multichannel inputs (no surround modes, audyssey, delays etc)

- it has independent channel trims (albeit not accessible via the OSD only the web ui, the OSD is broken in this regard... this was confirmed by marantz support) for the 7.1 MC inputs

- it behaves like a unity gain device (when the trim & MV is zero obviously)

 

I can't see why they'd disable all the processing if it were digitised.

[Bossobass Dave]

So, the Marantz stuff has analog inputs that would yield the following:

 

If you input a left channel and a right channel into the stereo analog inputs, there is no output from the SW out jack?

 

If you input 7 channels into the multichannel analog inputs, there is no output through the SW output jack?

[3ll3d00d]

So, the Marantz stuff has analog inputs that would yield the following:

 

If you input a left channel and a right channel into the stereo analog inputs, there is no output from the SW out jack?

 

If you input 7 channels into the multichannel analog inputs, there is no output through the SW output jack?

No and yes. Generally speaking the stereo inputs are converted, the multichannel inputs are not. At least this is my understanding anyway.

[Shredhead]

Wait a minute...  I was there?  Man that must have been a good trip, I don't even remember going!

 

 

I wish you were there MemX, it would have been great to hang with you. 

[MemX]

I wish you were there MemX, it would have been great to hang with you. 

 

Most kind of you to say so, good sir!

[BeastAudio]

Cool d00d.  I won't have time to read that for at least a couple of days.  That was measuring the RCA.  If I could spend some more time with the unit I think I could figure out what the deal is.  For the time being I'm just happy that there is a work around for passing an unclipped signal for hot re-directed mixes.  I just heard that this unit will definitely not be compatible with DTS X upgrades in the future so that's a bummer. 

 

Do you know for sure that the signal path never hits a dac on it's analog in's?  If so, will you please link me the source because I can't find anything on it specifically for Denon AVRs. 

 

 

The 7702 which I have was the first gen model, The mkii is already out and available and it WILL have the DTS:X upgrade coming to it via software update. Kinda crappy on Marantz to do that, but whatever. I am content until units are rolling off the production line with the update already installed....

[NWCgrad]

I also think it's crappy, it's available for the the 8802. The basic architecture for the two units is the same. If it's free for the 8802 they could at least offer as a paid upgrade for the 7702 (like Auro).

 

But, I will still use and enjoy my 7702. Assuming DTS:X becomes a big thing I will replace with a newer model when I move and have in ceiling coaxial Atmos speakers (based on my DIY eminence speakers which use readily available drivers and have a nice custom XO).

 

Really liked your subwoofer system. It is definitely my weak spot. Will rectify when escape the east coast and buy a house.

[BeastAudio]

Thanks man! Yea it's taken a ton of different sub systems to settle on what I have now. LLT's, FLH's, Ported IB, you name it, I did it. Only took a couple of years to get through all that before I finally transitioned back to sealed....Where it all started....

[Shredhead]

I don't have a definitive statement from the manufacturer that I can reference. It was generally commented as a fact for my model (AV7005).

 

There are a few features that suggest this is the case;

 

- there is no processing of any nature available to the 7.1 multichannel inputs (no surround modes, audyssey, delays etc)

- it has independent channel trims (albeit not accessible via the OSD only the web ui, the OSD is broken in this regard... this was confirmed by marantz support) for the 7.1 MC inputs

- it behaves like a unity gain device (when the trim & MV is zero obviously)

 

I can't see why they'd disable all the processing if it were digitised.

 

Hey d00d, I opened a support ticket with Marantz about the question of whether analog in's stay analog and the MVL is true analog all the way.  I asked this exact question:

 

"My question is for the models: AV7702, AV7702 mark II, and the AV7005.

 

The question is: is the master volume on the above units analog or digital. In other words: if you run an analog signal into the multichannel in's or stereo L&R ins, does the signal get converted by going through an ADAC, or does it stay analog all the way to the AVR's output?"

 

After waiting for a couple of weeks and pushing the query to escalations, the response was:

 

"Response By Email (Darrell Ray) (12/07/2015 10:01 AM)

The signal is converted to digital."

 

Short and to the point with no further explanation.  I guess you are converting your signal through another ADAC after your interface's DAC then for the AVR's volume control.  It seems that a microcontroller routing analog signal through a ladder of voltage dividers takes up too much board area or adds too much cost to the units to keep the signal path analog.  Maybe you will notice an improvement in sound if you cut the AVR's ADAC out of the path and sacrifice a remote volume control.  Or cut your interface out of the equation and only use the digital input of your Marantz.  Or maybe there will be no difference in clarity because the DAC's are transparent.  Worth a try maybe?  Either way, sorry for the bad news, I needed to know this about the Marantz AVR's and I thought you should know. 

[3ll3d00d]

 

Short and to the point with no further explanation.  I guess you are converting your signal through another ADAC after your interface's DAC then for the AVR's volume control.  It seems that a microcontroller routing analog signal through a ladder of voltage dividers takes up too much board area or adds too much cost to the units to keep the signal path analog.  Maybe you will notice an improvement in sound if you cut the AVR's ADAC out of the path and sacrifice a remote volume control.  Or cut your interface out of the equation and only use the digital input of your Marantz.  Or maybe there will be no difference in clarity because the DAC's are transparent.  Worth a try maybe?  Either way, sorry for the bad news, I needed to know this about the Marantz AVR's and I thought you should know. 

 

 

Funnily enough I logged a v similar ticket with marantz but didn't get a response and forgot to chase them, your reply prompted a chaser to which they replied

 

- Master volume is implemented after any signal processing

- Master volume is implemented digitally one step before analogue out

 

I have followed up with a reply specifically on the ADC aspect so we'll see if they reply to that.

 

The first point is also made in a review of the AV8802

 

http://hometheaterhifi.com/reviews/receiver-processor/processors/marantz-av8802-processor-review/

 

The signal at the output of the DAC, which is before the volume control, is doubled in the AV8802 to compensate for the gain reduction at the output.

 

 

 

This goes back to the earlier point about whether the device can deal with WCS and which bit is clipping. Given this confirmation that the MV is after processing & DAC, it's not obvious to me how turning the MV down fixes the problem. Obviously it does fix it but still seems confusing to me.

 

Anyway back to the support response, I think what they really mean is that the MV is implemented *electronically* not digitally. I don't have a schematic of the device to prove it but I'll list the reasons why I am fairly sure they are wrong. Long response coming up!

 

Firstly a disclaimer, I am not a card carrying audiophile so I don't mind if there is an ADC/DAC stage going via the processor. I also don't currently have a practical way to take it out of the system without severely impacting functionality (due to the presence of a cable box that is used fairly heavily) so I'd have to live with it even if I were a card carrying audiophile. Hopefully that means I can be fairly objective about the following, i.e. I'm not just arguing because it's my current setup!

 

Firstly, and most importantly, these devices, to the best of my knowledge, have a single 2 channel ADC chip. If this is correct, it is physically impossible for the device to convert the multichannel analogue inputs and for the MV to be implemented digitally. If you look at the AV8802 as an example, it is listed as using the AKM AK5358B which is a stereo ADC. I don't see anything that says it has 4 of them and this aspect is commented on in http://hometheaterhifi.com/technical/technical-reviews/options-by-supplier-and-price/. This article is based on schematics and service manuals so I think it is trustworthy.

 

My attention centers on the data converters, e.g., DAC, and analog electronics that follow the preamp. Not shown in Figure 1 above are the multiple sets of stereo inputs. In direct mode, the stereo inputs can be connected to the volume control to bypass the digital signal processor (DSP). Alternatively, the inputs can be converted to a digital signal by an analog-to-digital converter (ADC) to drive the DSP. This path is also not shown in the diagram. A direct path for a set of 7.1 analog inputs to electronic volume controls (volume controls that have gain circuits embedded in the volume controls themselves) is also not shown in this diagram.

 

Many older AVRs had eight ADCs instead of the current standard of two. With eight ADCs, the DSP could process 7.1-multichannel analog signals. The additional six ADCs were costly. HDMI obviated them by enabling high-resolution multichannel digital signal transfer.

 

 

 

Secondly, there is a difference between a electronic volume control and a digital volume control. This is covered in http://hometheaterhifi.com/technical/technical-reviews/audio-video-receiver-build-quality-part-ii-design-of-high-performance-avrs-and-pre-pros/

 

Single Chip Analog AVR LSI

 

The AVRs in the table, regardless of price, tend to have a single chip that subsumes almost all of the unit’s analog electronics. This single chip serves a variety of functions:

 

1. Eight channels of electronic volume controls to control the level at the preamp or power amp output.
2. Eight channels of analog buffering for direct connection to the preamp output jacks or internal power amp inputs.
3. A switch at each electronic volume control input to select the DAC output or the 7.1 analog inputs.
4. A selector switch for the two-channel analog inputs (8 – 14) to be sent to the ADC, or in direct mode, sent to the electronic volume controls at the preamps output.
5. The FL and FR volume control inputs have an additional position on the switch to the volume controls. This is for the direct (DSP bypass mode) mode of operation for two channel inputs. All other volume controls are grounded when stereo direct is selected.
6. Two channels of electronic volume controls for the ADC input to adjust levels to prevent overload of the ADC, followed by a pair of opamp buffers.
7. An independent selector switch for the two-channel analog inputs to be sent to the record output. An opamp buffer is placed between the selector switch and the chips output to isolate the selector switch from the load. In addition, switches are in series with the output that open to prevent a tape recorder self-loop fault condition. Some AVRs have no tape output and in that case this selector is for zone 2.
8. Another independent selector switch for the two-channel analog inputs to be sent to an alternate record output. This output can also be used for zone 2 or 3 outputs. The selector switch is again buffered by a pair of opamps

 

 

Each electronic volume control consists of a resistor string to attenuate the incoming signal, and a block of transistor switches. Each switch selects a different volume level at each tap in the resistor string.

 

Each volume control in an AVR must have a large gain adjustment range, for example -96 dB to +32dB. When half dB steps are desired, 256 resistor segments and 512 transistors (2 transistors per switch) are required. The LSI chip has ten volume controls, eight for adjusting the level to the power amp and two, with a smaller range, for adjusting the level to the ADC to prevent overload. In total over 2000 resistors and 4000 MOS transistors are needed. More transistors are on the chip as digital gates to allow an external microcontroller to close the correct switch.

 

The number of pins for these parts runs between 80 and 100. Integrated circuits incorporating this quantity of electrical components are called Large Scale Integrated (LSI) circuit.

 

 

i.e. these are active analogue components.

 

The article goes on to contrast this with higher priced and theoretically better performing options , i.e. opamps or relays. The latter apparently being extremely rare, if not non existent, in multichannel devices.

 

He gives the following as a key takeaway. This is, AIUI, the reason why I should get rid of the AV7005 if I wanted to optimise further (as I could switch to using a digital volume control in jriver).

 

A key takeaway: circuit quality in the direct mode (stereo or 7.1) is almost always invariant to AVR prices in the range of $400 to $2,000. As examples, the $250 Yamaha RX-V367 and Marantz AV8801 ($3000) use the same Renesas LSI chip (R2A15220FP). With the LSI analog chip in these products, the sound of the direct mode is relatively constant, although a more robust power supplies, addition a quality output buffer and enhanced DC blocking capacitor quality can make small differences.

 

 

 

There are then some diagrams in http://hometheaterhifi.com/technical/technical-reviews/avr-audio-video-receiver-build-quality-part-iii-component-choices-for-a-high-performance-design/which provide a block diagram view on how this is implemented. This shows how it is an active circuit that is separate to the ADC/DAC flow.

 

[SME]

This is a very interesting discussion.  I assumed all the D&M MV controls were implemented in the digital domain based on my observations of the  behavior of my Denon 3313CI and the anecdotal evidence that both brands are largely based on the same electronics platform.

 

Is the AV8802 a one-off (or perhaps one of a few) that is the exception to this rule?  I can't think of any good technical reason for implementing MV after the DAC like this unless there is also the capability to pass analog signals through without conversion.  OTOH, it may be a feature in high demand among "audiophile" buyers because I often see it claimed that digital volume controls don't sound good or compromise quality.

 

Well of course, a badly implemented digital volume control can compromise sound quality, but so can a badly implemented analog control.  In a 32-bit floating point DSP like the one provided by Marantz, the SNR is way higher than anything else in the signal chain.  Marantz advertizes 32-bit DACs, which is kind of silly because, as I understand it, practical DAC implementations rarely achieve more than 20ish bits of precision.  Even so, 20-bits provides a quantization noise floor ~120 dB down from digital full scale.  With noise-shaped dithering applied right after the conversion from 32-bit float to 32-bit fixed point (for DAC input), this noise floor can be reduced by several 10s of dB more in terms of A-weighting.  Note that even the best analog electronics advertise SNRs no higher than 120 dB with A-weighting applied, and these figures are likely exaggerated or measured under unrealistically ideal scenarios.

 

But of course, the real elephant in the room is the fact that few listening rooms have a noise floor below 20-30 dB even with A-weighting, yielding an effective SNR of 90-100 dBA SNR even in the best case.  Of course, many systems still suffer from hum and hiss for a variety of reasons, but rest assured, this should never happen within a competently implemented DSP pipeline. 

[3ll3d00d]

 

Is the AV8802 a one-off (or perhaps one of a few) that is the exception to this rule?  I can't think of any good technical reason for implementing MV after the DAC like this unless there is also the capability to pass analog signals through without conversion.  OTOH, it may be a feature in high demand among "audiophile" buyers because I often see it claimed that digital volume controls don't sound good or compromise quality.

 

according to those articles *all* modern mass produced AVRs/prepros implement volume in this way and apparently they nearly all use the same chip, the AV7702 uses 2 of the Reneses R2A15220 for example. Another example is the MDS board that is used in things like the datasat, as far as I can see this block diagram agrees with the other one I posted with the volume control after the DA. 

 

http://www.mds.com/wp-content/uploads/Datasheets/Audio/DAE77_rev1d.pdf

 

 

Hence the summary I posted earlier, the volume control is the limiting factor not the DAC.

[SME]

Hence the summary I posted earlier, the volume control is the limiting factor not the DAC.

 

Thanks for sharing. This is quite fascinating.  Would bypassing the volume control actually help anything?  Presumably the peak DAC output and peak MV input are pretty closely matched.  Anyway, 4V output is still pretty respectable, and I would expect you'd get 8V from the balanced outputs.

[3ll3d00d]

Thanks for sharing. This is quite fascinating.  Would bypassing the volume control actually help anything?  

I think that is the question really, do analogue signal (preamp) paths really sound materially different? Of course there are lots of people who say yes but those people are also the ones who tend to use stuff like cable lifts  It doesn't seem particularly feasible to actually test this either.

 

I'm considering going active with the LCR speakers I'm in the middle of designing/building (a 3way using a pair of TD12Ms under a BMS4550/SEOS) so that would see me move to a purely digital volume control. Of course so much else would change at the same time (would need new DAC with more channels, no prepro in the path, new amps) that a comparison would be impossible.

[Ricci]

I'm considering going active with the LCR speakers I'm in the middle of designing/building (a 3way using a pair of TD12Ms under a BMS4550/SEOS) so that would see me move to a purely digital volume control.

 

 

That sounds like a very nice system. I've been considering swapping my JBL compression drivers for the 4550's but keep putting it off. They are run with vented TD15M-A's.

[Spacebug]

 

 

I'm considering going active with the LCR speakers I'm in the middle of designing/building (a 3way using a pair of TD12Ms under a BMS4550/SEOS) so that would see me move to a purely digital volume control. Of course so much else would change at the same time (would need new DAC with more channels, no prepro in the path, new amps) that a comparison would be impossible.

 

 

Not sure if it is of any help, maybe you have figured out how to do it.

But a few months ago I ditched the analogue multichannel AVR I used solely for master volume duty in favor for digital master volume within the PC, going straight to power amps.

 

I use jriver for audio processing so I'm using it's internal volume control, all well there.

The quirk though is that I don't use jriver as a mediacenter, I prefer other apps, so jriver is running in the background processing sound from other apps, that is fed to jriver via wasapi loopback.

With jriver in the background the real trick was how to monitor the master volume, I was not keen on adjusting volume just by ear after some 10 years of having AVR that displays master volume in the useful -xx dB scale.

 

I tried various volume OSD programs that was supposed to flash the applied volume setting in screen, most did not work seeing as they  usually monitor the default soundcard that the OS sees, but that is a dummy card that is not being used, only recieving audio and patching it forward with wasapi loopback, volume changes to that sound card does nothing...

 

I then stumbled into the Third party plugin dev section of Jriver support forum, and saw to my surprise that there was a plugin for ImonVFD that had the features I wanted, display volume in dB scale.

Jumped on that and ordered a OrigenAE VF310 VFD module, the only ImonVFD compatible VFD I could find around here.

Stuck that behind one of the slots for optical drives in my HTPC case, the height of the slot was just enough to fit both rowes of characters on the VFD module so yay

Put a piece of dark tinted acrylic in front of the VFD, in the slot where the ODD sled front plate would sit, looking very nice and has the same function as the VFD volume display of the previous AVR I had.

 

I had to modify the plugin a bit to get rid of an annoying feature, and get the display to show what I wanted but now I'm pleased.

As it is now it can show these different modes:

"Volume  -Inf" for master volume fully turned down

"Volume  -xx,xdB"  for all intermediate master volume settings

"Volume  0,0dB" for master volume fully turned up

"Volume   Mute" if muted

 

Tricky thing is that the displayed volume is hardcoded in the plugin, following the default volume scale of jriver internal volume control, with 0,0dB corresponding to volume fully up, and not as a reference to THX ref volume.

I'm sure that can be calibrated and the plugin coded to display calibrated THX ref volume and also "+xx dB" as well but for now this will do for me.

Just a matter of making a mental note of what setting corresponds to ref volume...

 

 

 

Oh and the volume control itself, wonderful to have the noisefloor fixed as opposed to changing with MV setting on my (fairly noisy) old AVR I used to have.

Now the noisefloor is dictated by what the power amps can muster, the soundcards noisefloor is way below that of the power amps

 

To avoid having other programs hijacking the MCE remote volume presses and possibly disrupting the operation I disabled remote control in jriver and disabled the MCE volume command from the remote and instead linked the remote to executing various batch scripts firing MCC core commands to jriver with apropriate volume up, down, mute commands.

Some fiddeling with delay between each command and the remote behaved nicely, solid operation and with about the same speed of MV change as the AVR had