OP
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Gene is confused about how the Auto function works. He thinks it is signal sensitive but it is not. As explained above, it only depends on the volume position.
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Denon AVR-X6700H AVR Review (Updated)
- Thread starter amirm
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I think you heard him right, more or less. Regarding the effects of eco on the 8012, I would not call eco auto a work around at all. As I explained before, as soon as you turn the volume high enough eco auto will work the same way as eco off anyway. Off or auto would make no difference at moderate to high volume. If you listen loud enough for the power amps to start clipping, the resulting higher distortion would somehow cause higher distortion (lowering SINAD) in the pre-out as well. The only work around is, don't push the power amp to its clipping point.
The 8015, according to Gene, did not have that issue. Even without using preamp mode, the 8015's pre-out signal doesn't degrade (apparently just slightly) even at 2 V, but you know that already.
Count De Money
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We wouldn’t have to tolerate this pre amp mode / eco mode mumbo jumbo bullshit if denon just gave home theatre enthusiasts what they want
a processor with XLR outs with no garbage underpowered internal amps
a processor with XLR outs with no garbage underpowered internal amps
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To perfectly clear - in my experience on my 3600 if there is nothing coming from the source the amp will kickdown to Eco at higher volume settings, but as soon as there is any signal it kicks out of Eco.
Bello
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I think you heard him right, more or less. Regarding the effects of eco on the 8012, I would not call eco auto a work around at all. As I explained before, as soon as you turn the volume high enough eco auto will work the same way as eco off anyway. Off or auto would make no difference at moderate to high volume. If you listen loud enough for the power amps to start clipping, the resulting higher distortion would somehow cause higher distortion (lowering SINAD) in the pre-out as well. The only work around is, don't push the power amp to its clipping point.
The 8015, according to Gene, did not have that issue. Even without using preamp mode, the 8015's pre-out signal doesn't degrade (apparently just slightly) even at 2 V, but you know that already.
Can we assume (not good to but) from Amirm's graph "clipping" occurs (w/ the good caps) Beyond - Max output 4.4 volts @ 92db SINAD? Or - Just beyond Optimal output 1.5 volts @ 102db SINAD? ............. Plz see attachment.
Thanks!
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Clipping of what part of the device, preamp, power amplifier channel or? Please be more specific.
External preamp performance vs. load on internal power amplifier channels
A preamp output of 1.4V or so will clip a single amplifier channel with no load on the other amplifier channels for 8 ohm loads for the Denon AVR's measured of late. Less than 1.4V is required to drive an amplifier channel to rated output into 8 ohms and less still into 4 ohms. This means that about 1.4V is available from external preamp connections when the preamp channel is connected to an internal, idle, power amplifier channel.
The above assumes that it is clipping of the idle amplifier channel that causes the performance of the associated preamp to the idle channel to drop. This seems likely, but an open mind is suggested on this subject. This question isn't explored in the following.
If clipping, and encountering significant rail voltage ripple before clipping, of an unused amplifier channel directly affects the associated preamp the follow seems true. If other amplifier channels in the AVR are in use, the clipping level for the unused amplifier channel will drop as the load from the other amplifier channels causes the overall amplifier rail voltages to drop.
The DC voltage levels (+/-) from the power supply, that is the rail voltage levels, will drop as current demanded from the power supply increases. The drop in the rail voltages will be more significant when the other power amplifiers channels are driving low impedance loads since more DC current will be required from the power supply. The unused amplifier channel will now clip with a lower input voltage from the preamp because the amplifier's rail voltage is lower.
The amount of DC current drawn from the power supply increases rapidly for multi-channel power amplifiers due to the large number of channels. Even at relatively low output levels the accumulation from multiple channels can be significant.
Examples:
Note: The following uses RMS AC current in the output, DC current from the power supply will not be the same, but it is proportionate to AC current.
A high use amplifier channel: 4 ohms load,100W output, draws 5A
A low use amplifier channel: 4 ohm load, 1W output, draws .5A
10 of the low use channels draw 5A - that's 10W total output, but the current is equal to one 100W channel
A medium use amplifier channel: 4 ohm load, 8W output, draws 1.4A
10 of these channels draw 14A - that's 80W total output, but the current is equal to almost three 100W channels
It's straightforward to use the ASR, and perhaps some Audioholics measurements, of multi-channel performance to determine rail voltages and output currents at high output levels, and with added loaded channels. Some estimates of changes in current and rail voltages with smaller loads and all channels used could likely be made, but there is limited data.
Realistic even average loads per channel for a representative user aren't known, at least to me. The distribution of loads on average between channels and the variations of these distributions overtime seems pure guess work In addition, variations between users are likely large.
It is probable that preamp output performance when driving idle power amplifier channels is affected by the load on power amplifier channels that are in use. Determining the level of this effect from in-use channels and its importance, if any, seems a challenge.
A preamp output of 1.4V or so will clip a single amplifier channel with no load on the other amplifier channels for 8 ohm loads for the Denon AVR's measured of late. Less than 1.4V is required to drive an amplifier channel to rated output into 8 ohms and less still into 4 ohms. This means that about 1.4V is available from external preamp connections when the preamp channel is connected to an internal, idle, power amplifier channel.
The above assumes that it is clipping of the idle amplifier channel that causes the performance of the associated preamp to the idle channel to drop. This seems likely, but an open mind is suggested on this subject. This question isn't explored in the following.
If clipping, and encountering significant rail voltage ripple before clipping, of an unused amplifier channel directly affects the associated preamp the follow seems true. If other amplifier channels in the AVR are in use, the clipping level for the unused amplifier channel will drop as the load from the other amplifier channels causes the overall amplifier rail voltages to drop.
The DC voltage levels (+/-) from the power supply, that is the rail voltage levels, will drop as current demanded from the power supply increases. The drop in the rail voltages will be more significant when the other power amplifiers channels are driving low impedance loads since more DC current will be required from the power supply. The unused amplifier channel will now clip with a lower input voltage from the preamp because the amplifier's rail voltage is lower.
The amount of DC current drawn from the power supply increases rapidly for multi-channel power amplifiers due to the large number of channels. Even at relatively low output levels the accumulation from multiple channels can be significant.
Examples:
Note: The following uses RMS AC current in the output, DC current from the power supply will not be the same, but it is proportionate to AC current.
A high use amplifier channel: 4 ohms load,100W output, draws 5A
A low use amplifier channel: 4 ohm load, 1W output, draws .5A
10 of the low use channels draw 5A - that's 10W total output, but the current is equal to one 100W channel
A medium use amplifier channel: 4 ohm load, 8W output, draws 1.4A
10 of these channels draw 14A - that's 80W total output, but the current is equal to almost three 100W channels
It's straightforward to use the ASR, and perhaps some Audioholics measurements, of multi-channel performance to determine rail voltages and output currents at high output levels, and with added loaded channels. Some estimates of changes in current and rail voltages with smaller loads and all channels used could likely be made, but there is limited data.
Realistic even average loads per channel for a representative user aren't known, at least to me. The distribution of loads on average between channels and the variations of these distributions overtime seems pure guess work In addition, variations between users are likely large.
It is probable that preamp output performance when driving idle power amplifier channels is affected by the load on power amplifier channels that are in use. Determining the level of this effect from in-use channels and its importance, if any, seems a challenge.
The pre-out's distortion at that point started to drop at a rapid rate so I would say it is what some people called " the onset of clipping.." That curve really helps, otherwise if someone just say THD was 0.1%, we wouldn't know if it was at the onset of clipping, or THD increases to that level at some point due to other factors.
Bello
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Attachments
The red and blue curves are representative of the preamp output when the X6700H is driven from a digital source and the volume control is set internally for 0dB gain. The maximum output from a digital source is when the input to the DAC IC of 0dBFS. The output of the AK4458 DAC IC after the filter circuitry with 0dBFS input is 2V. The setting of the volume control inside the X6700H is 0dB, which is 82.5/2.5dB indicated depending on the setup of the X6700H. There is no clipping involved with a correctly recorded digital signal, 0dBFS is simply the maximum level with a digital input and 0dB gain.
The bottom, green curve, is an example of the output when the volume control is set above 82.5/2/5. Setting the external volume control over 82.5/2.5dB allows for output over 2V. The configuration for this test allows the X6700H to reach maximum output, likely clipping, from the volume control IC. The maximum voltage output from the volume control has been reached at 4.4V.
In the bottom curve the input at 2V is still approximately 2V. The bottom curve is lower, that is distortion is worse, because the gain of the volume control internally is set at actually set at +7.5dB. This is 90/10dB indicated externally. This added gain is obtained at the cost of reduced negative feedback around the opamp for the measured channel inside the volume control IC. Reducing feedback by 7.5dB results in increased distortion by a similar amount. The change isn't exact because other small factors are also at work.
Setting the external volume control between 82.5/2.5 and 90/10 likely will result in a curve that is below the red/blue curve, above the green curve, and stops short of 4.4V. The output won't be clipped. The output will represent the 0dBFS output of the DAC circuit plus the added gain between say. .1dB and 7.4dB. The output level won't have reached the output clipping limit of the volume control. The output will be limited by the 0dBFS limit. The higher the gain setting the more the curve will move down on the chart.
Bello
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It's safe to say, I'll be operating way below clipping. W/ my Emotiva - 7 channel (all configured w/ full power amps ~ 300W)
SVS Ultra Towers / Surround @ 8 ohms. @ 2 channel play, I haven't gone much above 74 volume (way below clipping) in Pre-amp mode. 74 volume equates ~ 200 watts? Or under 2 volts?
How do I estimate output power (AVP) based on volume setting using my external amp configuration below.
Emotiva XPA Gen3 Power Amplifier
FTC RATED POWER (2 CHANNELS DRIVEN): 20HZ – 20KHZ, <0.1% THD:
300 watts RMS per channel; THD < 0.1%; into 8 Ω
490 watts RMS per channel; THD < 0.1%; into 4 Ω
POWER OUT PER CHANNEL (ALL CHANNELS DRIVEN): THD <0.1%, INTO 8 Ω:
Two Channels: 300 watts RMS per channel
Three Channels: 275 watts RMS per channel
Four Channels: 260 watts RMS per channel
Five Channels: 250 watts RMS per channel
Six Channels: 225 watts RMS per channel
Seven Channels: 200 watts RMS per channel
Thanks!
No input at all on this question? The audible performance is where the rubber meets the road for me (and doubtless for most users), so it would be great to get input on what (if any) audible effect there would be.
You can only calculate/estimate it if you know the pre-out voltage such as is the case in Amir's measurements.
In that case, at volume 90, the pre-out voltage is 4.4 V, and XPA gen 3's gain is 29 dB, so the output from the XPA gen 3 amp will be:
Output voltage = Input voltage X 10^(29/20) = 124.01 V
Output power = (124.01^2)/8 = 1922 W into an 8 Ohm resistive load.
That's theoretical only, the XPA gen 3 amp would have clipped and tripped well before its output gets that high!
A more realistic example could be based on vol ume at 82.5, again under Amir's test conditions. The pre-out voltage would then be 2 V so the Output power could be calculated as follow:
Output voltage = 2 X 10^(29/20) = 56.37 V
Output power = (56.37^2)/8 = 397 W, 8 Ohm resistor load
The above calculations are based on Amir's test conditions only. For real world applications the actual output from the power amp at a certain volume setting would depend a lot on the source signal level; and it would be different between HDMI inputs and analog inputs too. For example, if you play a source that was recorded in a very high level, your volume could be much lower than 82.5 for the Emo amp to output 397 W. Conversely if the digital source was recorded at a lower level then the volume would have to be higher than 82.5 to output the same 397 W.
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If you have received your new unit, have you run Audyssey? If you have run Audyssey, what the output settings for each channel?
If you haven't received your new unit, then it's hard to know the power output levels. You you need to have the unit setup and running with an Audyssey calibration or other calibration in place.
This uses the example above with 2V providing maximum output from the Emotiva. For a digital recording at a high level the highest possible level is 0dBFS. 0dBFS will result in an output of 2V from the DAC. With the volume control set at a 82.5/2.5 external setting on the volume control, the volume control will be set internally at 0dB gain. 2V into the volume control at 0dB gain will result in 2V output. This means that the volume control must be set at 82.5/2.5 to get the maximum output from the Emotiva amps into 8 ohms.
Setting the volume control at less that 82.5/2.5 will result in less than 2V output and less than maximum output from the Emotiva amp. This assumes that the volume offset for the channel is set at 0dB.
It's easiest to examine the output at a lower level with an example. Let's say that for a lower-level recording the maximum level is -6dBFS. -6dBFS will result in an output of 1V from the DAC. With the volume control set at a 82.5/2.5 external setting on the volume control, the volume control will be set internally at 0dB gain. 1V into the volume control at 0dB gain will result in 1V output.
This means that the volume control will need to be set 6dB higher (2 x 1V = 2V), at 88.5/8.5, to obtain the maximum output from the Emotiva amp into 8 ohms. Setting the volume control at less that 88.5/8.5 will result in less than maximum output from the Emotiva amp. This assumes that the volume offset for the channel is set at 0dB.
I said my example was based on Amir's test conditions,and I believe Amir would have left the level trims at 0 dB.
Bello
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The system I am using is w/ bad cap 6700H. And yes, Audyssey has been run. The new 6700H is still on back order. Due to arrive in the coming weeks. I also failed to add that I I'm streaming a blue tooth signal connection w/ Spotify (high quality) 320 kbps audio music settings. How would I calculate output power? With the volume @ 72.5 (Emotiva loud) great crisp music play. Based on Amirm results as a guideline. Ball park output? I know, if I use the internal amps. At the max power point (2 channel @ 140W) . With the Emotiva, my estimation, volume @ 72.5. I'm at about 150-200w output @ or I'd say under 2 volts pre-amp. Possible?
Fact- As tested w/ streaming music, I am way beyond the max volume of 140W that the 6700H is able to produce. Emotiva output sounds great, @ a much higher output power. Driving my Ultra Towers ( Spec'd 8 ohm rated @ 300w). I understand the unit I have has bad (caps) pre-amp output signal, not up-to-SINAD-PAR. Based on the Emotiva amp chart in 2 channel setup. Full power is rated @ 300 watts per channel. Which I will never reach, unless I'm looking for a quick visit from the NYPD.
Ball park power output? With my volume setting 72.5..............I'm just looking for an estimate, ball park. Not to pull out scientific calculators.
Thanks for all of your responses... + Bigguyca
Sorry if I'm beating a dead horse.
I have already done an numerical example for you in my post#213 so I am only going to be repeating part of it that is applicable here.
On the bench, Amir was getting 2 V, volume 82.5. The power amplifier output would be almost 400 W based on gain = 29 dB. For calculations see post#213.
For volume 72.5, that's a drop of 82.5-72.5 = 10 dB.
To calculate the pre-out voltage:
Vpre-out=2X10^(E5/20) = 2X10^(10/20) = 2X0.31623 = 0.6325 V.
To calculate the power amp output voltage:
https://emotiva.com/products/xpa-2-gen3
From the Emotiva website linked above, we know that the gain is 29 dB, that is, same as the X6700H
Power amp output voltage = Input voltage (that is the X6700H) pre-out voltage X 10^(29/20) = 0.6325 X 28.1838 = 18.826 V
Power amp output =(V^2)/8 = 18.826 X 18.826/8 = 39.72 W
That's of course base on Amir's bench tests that use digital input of 0 dBFS as bigguyca mentioned before.
I took a look of Spotify's website and if I understood right, they use "loudness normalization" and the normalized level is -14 dB LUFS.
https://artists.spotify.com/faq/mas...-is-loudness-normalization-and-why-is-it-used
LUFS is not the same as dBFS, so you really don't know what the pre-out voltage would be if you are streaming from them and have volume at 72.5. From what I can gather though, the pre-out voltage would likely be less than the 0.6325 V that I calculated as shown above, based on Amir's measurements using digital signal at 0 dBFS.
For ball park estimate, I would say use pre-out voltage 0.6325 V and Power amp output 39.72 W and that would be on the high side or reality.
Also, all my calculations were based on trim level settings of "0 dB". What did Audysssey set the level trims to?
For more accurate numbers, you are going to have to take some measurements and make a bunch of assumptions. Even then, you really can only calculate/estimate sort on a worst case scenario basis. That is because the pre-out voltage and power amp output "watts" at volume 72.5 or whatever depends on the input signal level to the AVR, and that various moment by moment with the music. Music is not a test tone at a constant level. So yes, that would be beating a dead horse in a sense.
If you wish to play with more calculations yourself, there are some online calculators. I developed my own in Excel because there aren't any online one that can do everything I want. The one linked below is one of the best site for such calculators.
http://www.sengpielaudio.com/calculator-FactorRatioLevelDecibel.htm
The easiest way to estimate your power need is probably to do it in reverse, that is, find out the spl you listen to with a reliable spl meter such as Radio Shack's 33-2055, use "C" weighting slow, and an online spl calculator such as the one linked below:
https://myhometheater.homestead.com/splcalculator.html
Bello
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Peng- I appreciate your time / attempt to answer my question. I'm certain, if I personally attempt all what you recommended. I'd be left with a far off estimate given all factors, and unknowns. At the end, I think I'll stick with my personal estimate right / left channels (ears) as my power meter SINAD, lol
When I receive my newly, correctly spec'd 6700H. I'll see if I hear a pre-amp difference or not. And later rely on Amirm's random re-test reassurance of a correctly spec'd system.
Thank you!
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